JP2008009418A - Liquid crystal display device and electronic apparatus having the liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a level shifter which can simultaneously shift H and L levels of an input signal and can be manufactured at a low cost, and a display device having the level shifter. <P>SOLUTION: Offset of an input signal is performed by using an offset circuit including transistors of the same conductivity type. Then, the input signal after the offset is supplied to a logic circuit including transistors of the same conductivity type as that of the offset circuit, thereby H and L levels of the input signal can be shifted at the same time. Further, since the offset circuit and the logic circuit are formed using the transistors of the same conductivity type, a display device can be manufactured at a low cost. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a semiconductor device and a method for driving the semiconductor device. In addition, the present invention relates to a display device including a semiconductor device, in particular, a liquid crystal display device including a semiconductor device, and an electronic apparatus including the liquid crystal display device.

In recent years, display devices such as liquid crystal display devices and light-emitting devices have been actively developed due to an increase in large display devices such as liquid crystal televisions. In particular, a technology in which a driver circuit including a pixel circuit and a shift register circuit (hereinafter referred to as an internal circuit) is integrally formed using a transistor formed of an amorphous semiconductor over an insulator has low power consumption and low cost. In order to make a significant contribution to the development, development is actively underway. An internal circuit formed on the insulator is connected to a controller IC or the like (hereinafter referred to as an external circuit) disposed outside the insulator via an FPC or the like, and its operation is controlled.

Various level shifters have been devised as internal circuits formed on an insulator (see Patent Documents 1 and 2).
JP 2001-257581 A JP 2002-118458 A

In the level shifters shown in Patent Document 1 and Patent Document 2, the level of the negative power source side and the positive power source side of the input signal cannot be simultaneously shifted. That is, in order to level shift the input signal to the negative power supply side and the positive power supply side, there are a level shifter for level shifting the negative power supply side of the input signal and a level shifter for level shifting the positive power supply side of the input signal. It was necessary.

In view of the above problems, in the present invention, a level shifter capable of simultaneously shifting the level of an input signal to the negative power supply side and the positive power supply side, a semiconductor device including such a level shifter, a display device such as a liquid crystal display device, and the display An object is to provide an electronic apparatus including the device.

One aspect of the present invention includes a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, and a fourth transistor. The first electrode of the capacitor element is electrically connected to the third wiring, the first electrode of the second capacitor element is electrically connected to the fourth wiring, and the gate of the first transistor is The first capacitor is electrically connected to the second electrode, the first terminal of the first transistor is electrically connected to the second wiring, and the second terminal of the first transistor is electrically connected to the second electrode. And the gate of the second transistor is electrically connected to the second electrode of the second capacitor element, and the first terminal of the second transistor is connected to the second electrode of the capacitor element. A second wiring of the second transistor electrically connected to the second wiring; A child is electrically connected to the second electrode of the first capacitor element, a gate of the third transistor is electrically connected to a second electrode of the second capacitor element, and The first terminal is electrically connected to the second wiring, the second terminal of the third transistor is electrically connected to the fifth wiring, and the gate and the first terminal of the fourth transistor are connected to each other. It is electrically connected to a first wiring, and the second terminal of the fourth transistor is electrically connected to a fifth wiring.

Note that the first to fourth transistors may be transistors of the same conductivity type. In the case where the first to fourth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to fourth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

According to one embodiment of the present invention, a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, and a fifth transistor are provided. And a first electrode of the first capacitor is electrically connected to a third wiring, and a first electrode of the second capacitor is electrically connected to a fourth wiring. Connected, a gate of the first transistor is electrically connected to a second electrode of the first capacitor, a first terminal of the first transistor is electrically connected to a second wiring, and The second terminal of the first transistor is electrically connected to the second electrode of the second capacitor element, and the gate of the second transistor is electrically connected to the second electrode of the second capacitor element. , The first terminal of the second transistor is electrically connected to the second wiring. And the second terminal of the second transistor is electrically connected to the second electrode of the first capacitor, and the gate of the third transistor is the second electrode of the second capacitor. The first terminal of the third transistor is electrically connected to the second wiring, the second terminal of the third transistor is electrically connected to the fifth wiring, The gate and first terminal of the fourth transistor are electrically connected to a first wiring, the second terminal of the fourth transistor is electrically connected to the fifth wiring, and the fifth transistor And the second terminal of the fifth transistor is electrically connected to the second electrode of the first capacitor, the first terminal of the fifth transistor is electrically connected to the second wiring, Are electrically connected to the sixth wiring, The gate and first terminal of the sixth transistor are electrically connected to the first wiring, and the second terminal of the sixth transistor is electrically connected to the sixth wiring. The configuration is as follows.

Note that the first to sixth transistors may be transistors of the same conductivity type. In the case where the first to sixth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to sixth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

According to one embodiment of the present invention, a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, and a fifth transistor are provided. And a first electrode of the first capacitor is electrically connected to a third wiring, and a first electrode of the second capacitor is electrically connected to a fourth wiring. Connected, a gate of the first transistor is electrically connected to a second electrode of the first capacitor, a first terminal of the first transistor is electrically connected to a second wiring, and The second terminal of the first transistor is electrically connected to the second electrode of the second capacitor element, and the gate of the second transistor is electrically connected to the second electrode of the second capacitor element. , The first terminal of the second transistor is electrically connected to the second wiring. And the second terminal of the second transistor is electrically connected to the second electrode of the first capacitor, and the gate of the third transistor is the second electrode of the second capacitor. , The first terminal of the third transistor is electrically connected to the second wiring, and the gate and the first terminal of the fourth transistor are electrically connected to the first wiring. And the second terminal of the fourth transistor is electrically connected to the second terminal of the third transistor, and the gate of the fifth transistor is electrically connected to the second electrode of the second capacitor. The first terminal of the fifth transistor is electrically connected to the second wiring, the second terminal of the fifth transistor is electrically connected to a fifth wiring, and the sixth terminal The gate of the transistor is the third transistor And a second terminal of the fourth transistor is electrically connected to the second terminal of the fourth transistor, and a first terminal of the sixth transistor is electrically connected to the first wiring. The second terminal is electrically connected to the fifth wiring.

Note that the first to sixth transistors may be transistors of the same conductivity type. In the case where the first to sixth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to sixth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

  One embodiment of the present invention includes a pixel including a liquid crystal element and a driver circuit, and the driver circuit includes a first capacitor element, a second capacitor element, a first transistor, and a second transistor. A first transistor including a transistor, a third transistor, and a fourth transistor, wherein the first electrode of the first capacitor is electrically connected to a third wiring; Is electrically connected to the fourth wiring, the gate of the first transistor is electrically connected to the second electrode of the first capacitor, and the first terminal of the first transistor is the second electrode. Electrically connected to the wiring, the second terminal of the first transistor is electrically connected to the second electrode of the second capacitor, and the gate of the second transistor is connected to the second capacitor. A first terminal of the second transistor electrically connected to the second electrode; The second wiring is electrically connected to the second wiring, the second terminal of the second transistor is electrically connected to the second electrode of the first capacitor, and the gate of the third transistor is the second wiring. The third transistor is electrically connected to the second electrode, the first terminal of the third transistor is electrically connected to the second wiring, and the second terminal of the third transistor is the fifth wiring. The gate and first terminal of the fourth transistor are electrically connected to a first wiring, and the second terminal of the fourth transistor is electrically connected to a fifth wiring. The liquid crystal display device is connected.

Note that the first to fourth transistors may be transistors of the same conductivity type. In the case where the first to fourth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to fourth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

One embodiment of the present invention includes a pixel including a liquid crystal element and a driver circuit, and the driver circuit includes a first capacitor element, a second capacitor element, a first transistor, and a second transistor. A first transistor including a transistor, a third transistor, a fourth transistor, a fifth transistor, and a sixth transistor, wherein the first electrode of the first capacitor is electrically connected to the third wiring; A first electrode of the second capacitor element is electrically connected to a fourth wiring; a gate of the first transistor is electrically connected to a second electrode of the first capacitor element; The first terminal of the first transistor is electrically connected to the second wiring, the second terminal of the first transistor is electrically connected to the second electrode of the second capacitor, and the second terminal The gate of the transistor is electrically connected to the second electrode of the second capacitor element. Connected, the first terminal of the second transistor is electrically connected to the second wiring, and the second terminal of the second transistor is electrically connected to the second electrode of the first capacitor. The gate of the third transistor is electrically connected to the second electrode of the second capacitor, the first terminal of the third transistor is electrically connected to the second wiring, The second terminal of the third transistor is electrically connected to the fifth wiring, the gate and the first terminal of the fourth transistor are electrically connected to the first wiring, and the fourth terminal of the fourth transistor is electrically connected. Two terminals are electrically connected to the fifth wiring, a gate of the fifth transistor is electrically connected to a second electrode of the first capacitor, and a first terminal of the fifth transistor is Electrically connected to the second wiring; The second terminal of the fifth transistor is electrically connected to the sixth wiring, the gate and the first terminal of the sixth transistor are electrically connected to the first wiring, and the sixth transistor The liquid crystal display device is characterized in that the second terminal is electrically connected to the sixth wiring.

Note that the first to sixth transistors may be transistors of the same conductivity type. In the case where the first to sixth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to sixth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

One embodiment of the present invention includes a pixel including a liquid crystal element and a driver circuit, and the driver circuit includes a first capacitor element, a second capacitor element, a first transistor, and a second transistor. A third transistor, a fourth transistor, a fifth transistor, and a sixth transistor, wherein the first electrode of the first capacitor is electrically connected to the third wiring. The first electrode of the second capacitor element is electrically connected to a fourth wiring, the gate of the first transistor is electrically connected to the second electrode of the first capacitor element, and A first terminal of one transistor is electrically connected to a second wiring, a second terminal of the first transistor is electrically connected to a second electrode of the second capacitor, and the second terminal The gate of the transistor is electrically connected to the second electrode of the second capacitor element. The first terminal of the second transistor is electrically connected to the second wiring, and the second terminal of the second transistor is electrically connected to the second electrode of the first capacitor. The gate of the third transistor is electrically connected to the second electrode of the second capacitor, the first terminal of the third transistor is electrically connected to the second wiring, A gate and a first terminal of a fourth transistor are electrically connected to a first wiring; a second terminal of the fourth transistor is electrically connected to a second terminal of the third transistor; A gate of the fifth transistor is electrically connected to a second electrode of the second capacitor, a first terminal of the fifth transistor is electrically connected to the second wiring, and the fifth transistor The second terminal of the And the gate of the sixth transistor is electrically connected to the second terminal of the third transistor and the second terminal of the fourth transistor, and the first terminal of the sixth transistor is connected to the second terminal of the fourth transistor. The liquid crystal display device is characterized in that it is electrically connected to one wiring and the second terminal of the sixth transistor is electrically connected to the fifth wiring.

Note that the first to sixth transistors may be transistors of the same conductivity type. In the case where the first to sixth transistors are P-channel transistors, the potential of the first wiring may be higher than the potential of the second wiring. In the case where the first to sixth transistors are N-channel transistors, the potential of the first wiring may be lower than the potential of the second wiring.

Note that various types of switches can be used as a switch shown in the present invention, and examples thereof include an electrical switch and a mechanical switch. In other words, any device can be used as long as it can control the flow of current, and it is not limited to a specific device, and various devices can be used. For example, it may be a transistor, a diode (for example, a PN diode, a PIN diode, a Schottky diode, a diode-connected transistor, or the like), a thyristor, or a logic circuit that combines them. Therefore, when a transistor is used as a switch, the transistor operates as a mere switch, and thus the polarity (conductivity type) of the transistor is not particularly limited. However, when it is desirable that the off-state current is small, it is desirable to use a transistor having a polarity with a small off-state current. As a transistor with low off-state current, there are a transistor provided with an LDD region and a transistor having a multi-gate structure. In the case where the transistor operates as a switch when the potential of the source terminal of the transistor is close to a low potential side power supply (Vss, GND, 0V, etc.), the N channel type is used. When operating in a state close to Vdd, etc., it is desirable to use a P-channel type. This is because the absolute value of the gate-source voltage can be increased, so that it can easily function as a switch.

  Note that both N-channel and P-channel switches may be used as CMOS switches. When a CMOS switch is used, a current can flow when either the P-channel switch or the N-channel switch is turned on, so that the switch can easily function as a switch. For example, the voltage can be appropriately output regardless of whether the voltage of the input signal to the switch is high or low. In addition, since the voltage amplitude value of the signal for turning on / off the switch can be reduced, the power consumption can be reduced.

  Note that in the case where a transistor is used as a switch, the transistor has an input terminal (one of a source terminal or a drain terminal), an output terminal (the other of the source terminal or the drain terminal), and a terminal (gate terminal) that controls conduction. Yes. On the other hand, when a diode is used as a switch, it may not have a terminal for controlling conduction. Therefore, the wiring for controlling the terminals can be reduced.

Note that in the present invention, the term “connected” includes the case of being electrically connected, the case of being functionally connected, and the case of being directly connected. Therefore, the configuration disclosed by the present invention includes other than the predetermined connection relationship. For example, one or more elements (for example, a switch, a transistor, a capacitor, an inductor, a resistor, a diode, or the like) that can be electrically connected may be arranged between a certain portion. In addition, a circuit (for example, a logic circuit (an inverter, a NAND circuit, a NOR circuit, etc.), a signal conversion circuit (a DA conversion circuit, an AD conversion circuit, a gamma correction circuit, etc.) or a potential level conversion circuit ( Power supply circuits such as booster circuits and step-down circuits, level shifter circuits that change the potential level of H and L signals, etc., voltage sources, current sources, switching circuits, and amplifier circuits (op amps, differential amplifier circuits, source follower circuits, and buffer circuits) Etc.), or a signal generation circuit, a memory circuit, a control circuit, etc.) may be disposed between them. Alternatively, they may be arranged directly connected without interposing other elements or other circuits therebetween.

  In addition, when only including the case where it is connected without interposing an element or a circuit, it shall be described as being directly connected. In addition, when it is described as being electrically connected, when it is electrically connected (that is, when connected with another element in between) and when it is functionally connected (That is, connected with another circuit in between) and directly connected (that is, connected without another element or circuit in between). .

Note that the display element, the display device, the light-emitting element, and the light-emitting device can have various forms or have various elements. For example, as a display element, a display device, a light emitting element, and a light emitting device, an EL element (an organic EL element, an inorganic EL element, or an EL element containing an organic substance and an inorganic substance), an electron emitting element, a liquid crystal element, electronic ink, a grating light valve ( GLV), plasma display (PDP), digital micromirror device (DMD), piezoelectric ceramic display, carbon nanotube, and other display media whose contrast is changed by an electromagnetic action can be applied. Note that a display device using an EL element is an EL display, and a display device using an electron-emitting device is a liquid crystal display such as a field emission display (FED) or a SED type flat display (SED: Surface-conduction Electron-Emitter Display). A display device using the element includes a liquid crystal display, a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, and a display device using electronic ink includes electronic paper.

Note that in the present invention, various types of transistors can be used as a transistor. Thus, there is no limitation on the type of applicable transistor. Therefore, for example, a thin film transistor (TFT) including a non-single-crystal semiconductor film typified by amorphous silicon or polycrystalline silicon can be used. As a result, they can be manufactured even at a low manufacturing temperature, can be manufactured at low cost, can be manufactured on a large substrate, can be manufactured on a transparent substrate, and light can be transmitted through a transistor. In addition, a transistor formed using a semiconductor substrate or an SOI substrate, a MOS transistor, a junction transistor, a bipolar transistor, or the like can be used. Accordingly, a transistor with little variation can be manufactured, a transistor with high current supply capability can be manufactured, a transistor with a small size can be manufactured, and a circuit with low power consumption can be configured. In addition, a transistor including a compound semiconductor such as ZnO, a-InGaZnO, SiGe, or GaAs, or a thin film transistor obtained by thinning them can be used. Accordingly, the transistor can be manufactured even at a low manufacturing temperature, can be manufactured at room temperature, or a transistor can be directly formed on a substrate having low heat resistance, such as a plastic substrate or a film substrate. In addition, a transistor formed using an inkjet method or a printing method can be used. By these, it can manufacture at room temperature, can manufacture in a state with a low degree of vacuum, or can manufacture with a large sized board | substrate. Further, since the transistor can be manufactured without using a mask (reticle), the layout of the transistor can be easily changed. In addition, a transistor including an organic semiconductor or a carbon nanotube, or another transistor can be used. Thus, a transistor can be formed over a substrate that can be bent. Note that the non-single-crystal semiconductor film may contain hydrogen or halogen. In addition, various types of substrates on which the transistor is arranged can be used, and the substrate is not limited to a specific type. Therefore, for example, it can be disposed on a single crystal substrate, an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a paper substrate, a cellophane substrate, a stone substrate, a stainless steel substrate, a stainless steel substrate, a foil substrate, or the like. Alternatively, a transistor may be formed using a certain substrate, and then the transistor may be moved to another substrate and placed on another substrate. By using these substrates, it is possible to form a transistor with good characteristics, to form a transistor with low power consumption, to make the device hard to break, or to have heat resistance.

The structure of the transistor can take various forms. It is not limited to a specific configuration. For example, a multi-gate structure having two or more gate electrodes may be used. When the multi-gate structure is used, the channel regions are connected in series, so that a plurality of transistors are connected in series. The multi-gate structure reduces the off current, improves the breakdown voltage of the transistor to improve reliability, and even when the drain-source voltage changes when operating in the saturation region. The inter-current does not change so much, and flat characteristics can be achieved. Alternatively, a structure in which gate electrodes are arranged above and below the channel may be employed. By adopting a structure in which the gate electrodes are arranged above and below the channel, the channel region is increased, so that the current value can be increased or a depletion layer can be easily formed and the S value can be decreased. When gate electrodes are provided above and below a channel, a structure in which a plurality of transistors are connected in parallel is obtained. Further, a structure in which a gate electrode is disposed above a channel, a structure in which a gate electrode is disposed below a channel, a normal staggered structure, or an inverted staggered structure may be employed. The channel region may be divided into a plurality of regions, may be connected in parallel, or may be connected in series. In addition, a source electrode or a drain electrode may overlap with the channel (or a part thereof). By using a structure in which a source electrode or a drain electrode overlaps with a channel (or part of it), it is possible to prevent electric charges from being accumulated in part of the channel and unstable operation. There may also be an LDD region. By providing an LDD region, the off-current can be reduced, the breakdown voltage of the transistor can be improved to improve reliability, or the drain-source voltage can be changed even when the drain-source voltage changes when operating in the saturation region. The current does not change so much, and a flat characteristic can be obtained.

Note that various types of transistors can be used in the present invention and can be formed over various substrates. Therefore, the entire circuit may be formed on a glass substrate, may be formed on a plastic substrate, may be formed on a single crystal substrate, or may be formed on an SOI substrate. Alternatively, it may be formed on any substrate. Since all the circuits are formed on the same substrate, the number of parts can be reduced to reduce the cost, and the number of connection points with circuit parts can be reduced to improve the reliability. Alternatively, a part of the circuit may be formed on a certain substrate, and another part of the circuit may be formed on another substrate. That is, all of the circuits may not be formed on the same substrate. For example, part of a circuit is formed using a transistor over a glass substrate, another part of the circuit is formed over a single crystal substrate, and the IC chip is connected with COG (Chip On Glass) to form a glass. You may arrange | position on a board | substrate. Alternatively, the IC chip may be connected to the glass substrate using TAB (Tape Automated Bonding) or a printed board. As described above, since a part of the circuit is formed on the same substrate, the number of parts can be reduced to reduce the cost, and the number of connection points with the circuit parts can be reduced to improve the reliability. In addition, since the power consumption increases in a portion where the drive voltage is high or a portion where the drive frequency is high, an improvement in power consumption can be prevented if such a portion is not formed on the same substrate.

In the present invention, one pixel represents one element whose brightness can be controlled. Therefore, as an example, one pixel represents one color element, and brightness is expressed by one color element. Therefore, at that time, in the case of a color display device composed of R (red), G (green), and B (blue) color elements, the minimum unit of an image is an R pixel, a G pixel, and a B pixel. It is assumed to be composed of three pixels. Note that the color elements are not limited to three colors, and more than that may be used, or colors other than RGB may be used. For example, RGBW (W is white) may be added by adding white. Further, RGB may be obtained by adding one or more colors such as yellow, cyan, magenta, emerald green, vermilion, and the like. Further, for example, a similar color may be added for at least one of RGB. For example, R, G, B1, and B2 may be used. B1 and B2 are both blue, but have slightly different frequencies. By using such a color element, it is possible to perform display closer to the real thing or to reduce power consumption. As another example, in the case where brightness is controlled using a plurality of areas for one color element, one area corresponds to one pixel. Therefore, as an example, when performing area gradation, there are a plurality of areas for controlling the brightness for each color element, and the gradation is expressed as a whole. One portion is defined as one pixel. Therefore, in that case, one color element is composed of a plurality of pixels. In that case, the size of the region contributing to the display may be different depending on the pixel. Further, in a plurality of brightness control areas for one color element, that is, in a plurality of pixels constituting one color element, a signal supplied to each of them is slightly different to widen a viewing angle. You may do it. Note that the description of one pixel (for three colors) is a case where three pixels of R, G, and B are considered as one pixel. In the case of describing one pixel (for one color), it is assumed that when there are a plurality of pixels for one color element, they are collectively considered as one pixel.

In the present invention, the case where the pixels are arranged (arranged) in a matrix is included. Here, the arrangement (arrangement) of pixels in a matrix includes a case where pixels are arranged side by side in a vertical direction or a horizontal direction or a case where they are arranged on a jagged line. Therefore, for example, when full color display is performed with three color elements (for example, RGB), the case where stripes are arranged and the case where dots of three color elements are arranged in a so-called delta are also included. Furthermore, the case where a Bayer is arranged is also included. Note that the color elements are not limited to three colors, and may be more than that, for example, RGBW (W is white) or RGB in which one or more colors of yellow, cyan, magenta, etc. are added. Further, the size of the display area may be different for each dot of the color element. Thereby, power consumption can be reduced and the lifetime of the display element can be extended.

Note that a transistor is an element having at least three terminals including a gate, a drain, and a source, and has a channel region between the drain region and the source region. Current can flow through the source region. Here, since the source and the drain vary depending on the structure and operating conditions of the transistor, it is difficult to limit which is the source or the drain. Therefore, in the present invention, a region functioning as a source and a drain may not be called a source or a drain. In that case, as an example, there are cases where they are referred to as a first terminal and a second terminal, respectively.

  Note that the transistor may be an element having at least three terminals including a base, an emitter, and a collector. Similarly in this case, the emitter and the collector may be referred to as a first terminal and a second terminal.

Note that a gate refers to the whole or part of a gate electrode and a gate wiring (also referred to as a gate line or a gate signal line). A gate electrode refers to a conductive film which overlaps with a semiconductor that forms a channel region, an LDD (Lightly Doped Drain) region, and the like with a gate insulating film interposed therebetween. The gate wiring refers to wiring for connecting between the gate electrodes of each pixel or connecting the gate electrode to another wiring.

However, there is a portion that functions as a gate electrode and also functions as a gate wiring. Such a portion may be called a gate electrode or a gate wiring. That is, there is a region where the gate electrode and the gate wiring cannot be clearly distinguished. For example, when there is a channel region that overlaps with an extended gate wiring, the region functions as a gate wiring, but also functions as a gate electrode. Therefore, such a region may be called a gate electrode or a gate wiring.

A region formed of the same material as the gate electrode and connected to the gate electrode may also be called a gate electrode. Similarly, a region formed of the same material as the gate wiring and connected to the gate wiring may be called a gate wiring. In a strict sense, such a region may not overlap with the channel region or may not have a function of being connected to another gate electrode. However, due to the manufacturing process, there is a region formed of the same material as the gate electrode and the gate wiring and connected to the gate electrode and the gate wiring. Therefore, such a region may also be called a gate electrode or a gate wiring.

For example, in a multi-gate transistor, the gate electrode of one transistor and the gate electrode of another transistor are often connected by a conductive film formed using the same material as the gate electrode. Such a region is a region for connecting the gate electrode and the gate electrode, and may be referred to as a gate wiring. However, a multi-gate transistor can be regarded as a single transistor, and thus the gate electrode You can call it. That is, what is formed of the same material as the gate electrode and the gate wiring and is connected to the gate electrode and the gate wiring may be called a gate electrode and a gate wiring.
For example, a portion of the conductive film where the gate electrode and the gate wiring are connected may be called a gate electrode or a gate wiring.

Note that a gate terminal refers to a part of a region of a gate electrode or a region electrically connected to the gate electrode.

Note that a source refers to the whole or part of a source region, a source electrode, and a source wiring (also referred to as a source line, a source signal line, or the like). The source region refers to a semiconductor region containing a large amount of P-type impurities (such as boron and gallium) and N-type impurities (such as phosphorus and arsenic). Therefore, a region containing a little P-type impurity or N-type impurity, that is, a so-called LDD (Lightly Doped Drain) region is not included in the source region. A source electrode refers to a portion of a conductive layer which is formed using a material different from that of a source region and is electrically connected to the source region. However, the source electrode may be referred to as a source electrode including the source region. The source wiring is a wiring for connecting between the source electrodes of each pixel or connecting the source electrode and another wiring.

However, there is a portion that functions as a source electrode and also functions as a source wiring. Such a portion may be called a source electrode or a source wiring. That is, there is a region where the source electrode and the source wiring cannot be clearly distinguished. For example, when there is a source region that overlaps with an extended source wiring, the region functions as a source wiring, but also functions as a source electrode. Therefore, such a region may be called a source electrode or a source wiring.

A region formed of the same material as the source electrode and connected to the source electrode, or a portion connecting the source electrode and the source electrode may also be referred to as a source electrode. A portion overlapping with the source region may also be called a source electrode. Similarly, a region formed of the same material as the source wiring and connected to the source wiring may be called a source wiring. In a strict sense, such a region may not have a function of connecting to another source electrode. However, due to the manufacturing process, there is a region formed of the same material as the source electrode and the source wiring and connected to the source electrode and the source wiring. Therefore, such a region may also be called a source electrode or a source wiring.

Further, for example, a conductive film in a portion where the source electrode and the source wiring are connected may be called a source electrode or a source wiring.

Note that a source terminal refers to a part of a source region, a source electrode, or a region electrically connected to the source electrode.

The drain is the same as the source.

Note that in the present invention, a semiconductor device refers to a device having a circuit including a semiconductor element (such as a transistor or a diode). In addition, any device that can function by utilizing semiconductor characteristics may be used.

  A display device refers to a device having a display element (such as a liquid crystal element or a light-emitting element). Note that a display panel body in which a plurality of pixels including display elements such as a liquid crystal element and an EL element and peripheral drive circuits for driving these pixels are formed over the same substrate may be used. Further, it may include a peripheral drive circuit, so-called chip on glass (COG), which is disposed on the substrate by wire bonding or bumps. Furthermore, a device to which a flexible printed circuit (FPC) or a printed wiring board (PWB) is attached (such as an IC, a resistor, a capacitor, an inductor, or a transistor) may also be included. Furthermore, an optical sheet such as a polarizing plate or a retardation plate may be included. Furthermore, a backlight unit (which may include a light guide plate, a prism sheet, a diffusion sheet, a reflection sheet, and a light source (such as an LED or a cold cathode tube)) may be included.

  A light-emitting device refers to a display device including a self-luminous display element such as an EL element or an element used in an FED. A liquid crystal display device refers to a display device having a liquid crystal element.

In addition, in the present invention, it is formed on a certain object, or is formed on the top. It is not limited to being in direct contact with. This includes cases where they are not in direct contact, that is, cases where another object is sandwiched between them. Therefore, for example, when the layer B is formed on the layer A (or on the layer A), the case where the layer B is formed in direct contact with the layer A and the case where the layer B is formed In which another layer (for example, layer C or layer D) is formed in direct contact with layer B and layer B is formed in direct contact therewith. The same applies to the description of “above”, and it is not limited to being in direct contact with a certain object, and includes a case where another object is sandwiched therebetween. Therefore, for example, when the layer B is formed above the layer A, the case where the layer B is formed in direct contact with the layer A and the case where another layer is formed in direct contact with the layer A. (For example, the layer C or the layer D) is formed, and the layer B is formed in direct contact therewith. It should be noted that the same applies to the case of below or below, and includes the case of direct contact and the case of no contact.

According to the present invention, it is possible to provide a display device having a level shifter capable of simultaneously shifting the level of an input signal to a negative power source side and a positive power source side. In addition, since all the display devices of the present invention can be formed using transistors having the same conductivity type, a low-cost display device can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes, and those skilled in the art can easily understand that the modes and details can be variously changed without departing from the spirit and scope of the present invention. Is done. Therefore, the present invention is not construed as being limited to the description of this embodiment mode. In addition, in the structure of this invention demonstrated below, regarding the same thing, it shows using a common code | symbol and detailed description of the part which has the same part or the same function is abbreviate | omitted.

(First embodiment)
In the present embodiment, the basic configuration of the level shifter according to the present invention will be described with reference to FIG.

The level shifter illustrated in FIG. 1A includes a circuit 101 and a circuit 102.

As shown in the level shifter of FIG. 1A, the circuit 101 is connected to a wiring 103, a wiring 104, a wiring 105, a wiring 106, a wiring 107, and a wiring 108. The circuit 102 is connected to the wiring 103, the wiring 104, the wiring 107, the wiring 108, and the wiring 109.

Note that a positive power supply VDD and a negative power supply VSS are supplied to the wiring 103 and the wiring 104, respectively. The power supply potential VDD is higher than the power supply potential VSS.

In addition, a signal (hereinafter also referred to as an input signal) is supplied to the wiring 105 and the wiring 106. Note that the circuit 101 is controlled by signals supplied to the wiring 105 and the wiring 106.

A signal from the circuit 101 (hereinafter also referred to as an offset signal) is supplied to the wiring 107 and the wiring 108. Note that the circuit 102 is controlled by signals supplied to the wiring 107 and the wiring 108.

Further, a signal from the circuit 102 (hereinafter also referred to as an output signal) is supplied to the wiring 109.

Note that signals supplied to the wiring 105 and the wiring 106 are digital signals having binary values. The potentials of these digital signals are the potential VH when the signal is an H signal (hereinafter also referred to as H level), and the potential VL when the signal is an L signal (hereinafter also referred to as L level). Note that the potential VH is lower than the power supply potential VDD and higher than the potential VL. Note that the potential VL is higher than the power supply potential VSS and lower than the potential VH. That is, the relationship between each power supply potential and the signal potential is power supply potential VDD> potential VH> potential VL> power supply potential VSS.

Next, the operation of the level shifter shown in FIG. 1A will be described with reference to the timing chart of FIG. Note that the timing chart in FIG. 2A shows a signal of the wiring 105, a signal of the wiring 107, and a signal of the wiring 108. Note that although not illustrated, the signal of the wiring 106 is similar to the signal obtained by inverting the H level and the L level with respect to the signal of the wiring 105.

Here, the circuit 101 has a function of performing an offset operation. Specifically, the circuit 101 offsets an input signal supplied to the wiring 105 and the wiring 106 and supplies an offset signal to the wiring 107 and the wiring 108. This offset signal has substantially the same amplitude voltage at the same timing (or inversion) as the signal supplied to the wiring 105. Then, the potential of the offset signal supplied to the wiring 107 is shifted to the H side with respect to the input signal. In addition, the potential of the offset signal supplied to the wiring 108 is shifted to the L side with respect to the input signal. Note that the circuit 101 is also referred to as an offset circuit.

Therefore, as shown in the timing chart of FIG. 2A, the signal of the wiring 107 is substantially equal in timing and amplitude voltage to the signal of the wiring 105 and the potential is shifted to the H side as compared with the signal of the wiring 105. is doing. Specifically, the signal of the wiring 107 has an L signal potential of VDD and an H signal potential of VDD + (VH−VL). That is, the amplitude voltage of the signal on the wiring 107 is VH−VL, which is almost the same as the amplitude voltage of the signal on the wiring 105.

Similar to the signal of the wiring 107, the signal of the wiring 108 has substantially the same timing and amplitude voltage as the signal of the wiring 105, and the potential is shifted to the L side as compared with the signal of the wiring 105. Specifically, in the signal of the wiring 108, the potential of the L signal is VSS and the potential of the H signal is VSS + (VH−VL). That is, the amplitude voltage of the signal of the wiring 108 is VH−VL, which is almost the same as the amplitude voltage of the signal of the wiring 105.

Note that as described above, the signal of the wiring 107 and the signal of the wiring 108 may be inverted from the H signal and the L signal as compared with the signal of the wiring 105.

2B, the signal of the wiring 107 may be set such that the L signal is VDD− (VH−VL) and the H signal is VDD. In addition, the signal of the wiring 108 may be an L signal VSS- (VH-VL). Even in the case illustrated in FIG. 2B, the amplitude voltage of the signal of the wiring 107 and the amplitude voltage of the signal of the wiring 108 are VH−VL, which is substantially the same as the amplitude voltage of the signal of the wiring 105.

Note that the signal of the wiring 107 and the signal of the wiring 108 illustrated in FIG. 2B may also have the H signal and the L signal inverted compared to the signal of the wiring 105.

Here, the circuit 102 is a logic circuit such as an inverter, a NAND circuit, or a NOR circuit. Specifically, the circuit 102 is controlled by the offset signal and supplies an output signal to the wiring 109. Further, the potential of the output signal is equal to the power supply potential VDD when the signal is an H signal, and is equal to the power supply potential VSS when the signal is an L signal.

Note that since the amplitude voltage of the signal of the wiring 107 and the signal of the wiring 108 is small, the circuit 102 has less through current, so that power saving can be realized. The circuit 102 can reduce noise because the amplitude voltage of the input signal is small.

As described above, the level shifter of the present invention realizes a function as a level shifter by driving a logic circuit with an offset signal. In addition, the level shifter of the present invention is power saving and low noise. The level shifter of the present invention can simultaneously shift the H level and the L level of the input signal with one level shifter.

Note that as illustrated in FIG. 1B, the circuit 102 may be controlled only by a signal of the wiring 105 and a signal obtained by shifting the signal of the wiring 106 to the H side (a signal of the wiring 107). In the case where the circuit 102 is controlled only by a signal from the wiring 107, the circuit 101 does not need to be supplied with the power supply potential VSS.

Similarly, as illustrated in FIG. 1C, the circuit 102 may be controlled only by the signal of the wiring 105 and the signal obtained by shifting the signal of the wiring 106 only to the L side (the signal of the wiring 108). . In the case where the circuit 102 is controlled only by the signal of the wiring 108, the circuit 101 does not need to be supplied with the power supply potential VDD.

Further, when the circuit 102 is controlled only by the signal of the wiring 107 or the signal of the wiring 108, the level shifter of FIGS. 1B and 1C can make the circuit 101 simple.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Second Embodiment)
In this embodiment, a configuration example of the circuit 101 (offset circuit) included in the level shifter shown in the first embodiment will be described. In this embodiment, the signal supplied to the wiring 105 and the wiring 106 is supplied to the wiring 107 by shifting the potential to the H side with the same timing (or inversion) and substantially the same amplitude voltage. An example of the configuration will be described.

Note that components similar to those in Embodiment 1 are denoted by common reference numerals, and detailed description of the same portions or portions having similar functions is omitted.

First, a configuration example of the offset circuit will be described with reference to FIG.

The offset circuit illustrated in FIG. 3A includes a capacitor 301, a capacitor 302, a transistor 303, and a transistor 304.

As shown in the offset circuit in FIG. 3A, the first electrode of the capacitor 301 is connected to the wiring 105. A first electrode of the capacitor 302 is connected to the wiring 106. A gate of the transistor 303 is connected to the second electrode of the capacitor 301, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 302. A gate of the transistor 304 is connected to the second electrode of the capacitor 302, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 301. Note that a connection point of the second electrode of the capacitor 301, the gate of the transistor 303, and the second terminal of the transistor 304 is a node N31. Note that a connection point of the second electrode of the capacitor 302, the second terminal of the transistor 303, and the gate of the transistor 304 is a node N32. One of the node N31 and the node N32 is connected to the wiring 107 (a) shown in FIG.

Next, the operation of the offset circuit shown in FIG. 3A will be described with reference to FIGS. 3B and 3C.

3B shows the operation of the offset circuit in FIG. 3A when the signal of the wiring 105 changes from the H signal to the L signal and the signal of the wiring 106 changes from the L signal to the H signal.

FIG. 3C shows the operation of the offset circuit in FIG. 3A when the signal of the wiring 105 changes from the L signal to the H signal and the signal of the wiring 106 changes from the H signal to the L signal. That is, the offset circuit of FIG. 3A repeats the operation of FIG. 3B and the operation of FIG. 3C at an arbitrary timing. Further, the operation of FIG. 3B is a first operation, and the operation of FIG. 3C is a second operation.

Note that VH−VL is higher than or equal to the threshold voltages of the transistor 303 and the transistor 304.

First, the first operation of the offset circuit of FIG. 3A will be described with reference to FIG. Note that the initial potential of the node N32 is VDD.

As an initial state, the capacitor 302 holds a potential difference VDD−VL between the potential VL (L signal) of the wiring 106 and the potential VDD of the node N32. When the potential of the wiring 106 changes from VL to VH, the potential of the node N32 becomes VDD + (VH−VL) due to capacitive coupling of the capacitor 302. Accordingly, the transistor 304 is turned on.

When the transistor 304 is turned on, the power supply potential VDD is supplied to the node N31, and the potential of the node N31 becomes VDD. Therefore, the capacitor 301 holds a potential difference VDD−VL between the potential VL (L signal) of the wiring 105 and the potential VDD of the node N31. Further, the transistor 303 is turned off.

Further, when the transistor 303 is turned off, the node N32 enters a floating state, and the node N32 maintains the potential at VDD + (VH−VL).

Next, the second operation of the offset circuit of FIG. 3A will be described with reference to FIG.

As already described, VDD-VL is held in the capacitor 301 by the first operation. When the potential of the wiring 105 changes from VL to VH, the potential of the node N31 becomes VDD + (VH−VL) due to capacitive coupling of the capacitor 301. Accordingly, the transistor 303 is turned on.

When the transistor 303 is turned on, the power supply potential VDD is supplied to the node N32, and the potential of the node N32 becomes VDD. Therefore, the capacitor 302 holds a potential difference VDD−VL between the potential VL (L signal) of the wiring 106 and the potential VDD of the node N32. Further, the transistor 304 is turned off.

Further, when the transistor 304 is turned off, the node N31 enters a floating state, and the node N31 maintains the potential at VDD + (VH−VL).

Here, functions of the capacitor 301, the capacitor 302, the transistor 303, and the transistor 304 are described.

First, in the first operation, the capacitor 301 holds a potential difference between the potential VL of the wiring 105 and the potential VDD of the node N31. In the second operation, the capacitor 301 has a function of increasing the potential of the node N31 as the potential of the wiring 105 is increased by capacitive coupling.

Further, in the second operation, the capacitor 302 holds a potential difference between the potential VL of the wiring 106 and the potential VDD of the node N32. In the first operation, the capacitor 302 has a function of increasing the potential of the node N32 as the potential of the wiring 106 increases by capacitive coupling.

The transistor 303 functions as a switch that selects whether to connect the wiring 103 and the node N32 depending on the potential of the node N31. In the first operation, the transistor 303 is turned off, and the node N32 is brought into a floating state. In the second operation, the transistor 303 is turned on and supplies the power supply potential VDD to the node N32.

The transistor 304 functions as a switch that selects whether to connect the wiring 103 and the node N31 according to the potential of the node N32. In the first operation, the transistor 304 is turned on and supplies the power supply potential VDD to the node N31. In the second operation, the transistor 304 is turned off, and the node N31 is brought into a floating state.

By the first operation and the second operation described above, in the first operation, the offset circuit in FIG. 3A supplies the power supply potential VDD to the node N31, sets the node N32 in a floating state, and It operates so as to maintain the potential of N32 at VDD + (VH−VL). Further, in the second operation, the offset circuit of FIG. 3A places the node N31 in a floating state, maintains the potential of the node N31 at VDD + (VH−VL), and supplies the power supply potential VDD to the node N32. To work.

Therefore, in the signal generated by the offset circuit of FIG. 3A, the H signal is VDD + (VH−VL) and the L signal is VDD. That is, the offset circuit in FIG. 3A can generate a signal based on the power supply potential VDD.

Note that the potential of the node N32 in the first operation and the potential of the node N31 in the second operation are maintained at VDD + (VH−VL). However, in reality, the potential of the node N32 in the first operation and the potential of the node N31 in the second operation are lower than VDD + (VH−VL) due to the influence of wiring capacitance and parasitic capacitance. Therefore, in order to reduce the influence of the wiring capacitance and the parasitic capacitance, the capacitance values of the capacitor 301 and the capacitor 302 should be sufficiently larger than the capacitance values of the wiring capacitance and the parasitic capacitance.

Note that if the node N31 is connected to the wiring 107 illustrated in FIG. 1A, a signal having the same H level and L level as the signal supplied to the wiring 105 can be supplied to the wiring 107. Similarly, if the node N32 is connected to the wiring 107 illustrated in FIG. 1, a signal supplied to the wiring 105, a signal obtained by inverting the H signal, and the L signal can be supplied to the wiring 107.

In the case where the node N31 is connected to the wiring 107, the capacitance value of the capacitor 302 is preferably smaller than the capacitance value of the capacitor 301. This is because, as described above, the capacitance value of the capacitor 301 should be sufficiently larger than the capacitance values of the wiring capacitance and the parasitic capacitance. However, if the potential of the node N32 can turn on the transistor 304, This is because the potential of N32 does not have to be VDD + (VH−VL). Therefore, since the capacitance value of the capacitor 302 can be made smaller than the capacitance value of the capacitor 301, the element region of the capacitor 302 can be reduced.

In addition, when the node N32 is connected to the wiring 107, the capacitance value of the capacitor 301 is preferably smaller than the capacitance value of the capacitor 302 for the same reason as when the node N31 is connected to the wiring 107.

Note that the capacitor 301 and the capacitor 302 may have a structure in which an insulating layer is sandwiched between two electrode layers. By using the structure in which the capacitor 301 and the capacitor 302 are sandwiched between two electrode layers, the capacitor 301 and the capacitor 302 can keep the capacitance value constant regardless of the applied voltage. Therefore, the level shifter of the present invention can operate stably.

The insulating layer of the capacitor 301 and the capacitor 302 is preferably a gate insulating film. This is because the thickness of the gate insulating film is generally smaller than that of other insulating films (for example, an interlayer film, a planarization film, and the like), so that the capacitor 301 and the capacitor 302 can efficiently obtain a capacitance value. Because you can.

Note that the capacitor 301 and the capacitor 302 may be a MOS capacitor. FIG. 4A shows a structure in the case where the capacitive element 301 and the capacitive element 302 are MOS capacitive elements. The offset circuit illustrated in FIG. 4A uses an N-channel transistor 401 instead of the capacitor 301 and uses an N-channel transistor 402 instead of the capacitor 302. The transistor 401 is characterized in that the gate is connected to the node N31, and the first terminal and the second terminal are connected to the wiring 105. This is because the potential of the node N31 is higher than the potential of the wiring 105, so that the transistor 401 is turned on and a channel is formed in the channel region of the transistor 401, so that the transistor 401 can operate as a capacitor. Similarly, the transistor 402 is characterized in that the gate is connected to the node N32, and the first terminal and the second terminal are connected to the wiring 106. This is because the potential of the node N32 is higher than the potential of the wiring 106, so that the transistor 402 is turned on and a channel is formed in the channel region of the transistor 402, so that the transistor 402 can operate as a capacitor.

As shown in FIG. 4B, a P-channel transistor can be used as the capacitor as the capacitor. The offset circuit illustrated in FIG. 4B uses a P-channel transistor 403 instead of the capacitor 301 and uses a P-channel transistor 404 instead of the capacitor 302. The transistor 403 is characterized in that the gate is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N31. This is because the potential of the node N31 is higher than the potential of the wiring 105, so that the transistor 403 is turned on and a channel is formed in the channel region of the transistor 403, so that the transistor 403 can operate as a capacitor. Similarly, the transistor 404 is characterized in that the gate is connected to the wiring 106, and the first terminal and the second terminal are connected to the node N32. This is because the potential of the node N32 is higher than the potential of the wiring 106, so that the transistor 404 is turned on and a channel is formed in the channel region of the transistor 404, so that the transistor 404 can operate as a capacitor.

4A, when the node N31 is connected to the wiring 107, the channel of the transistor 402 is more than the channel region (L: channel length × W: channel width) of the transistor 401. The region is preferably smaller. In the case where the node N32 is connected to the wiring 107, the channel region of the transistor 402 is preferably larger than the channel region of the transistor 401.

Similarly, in FIG. 4B, when the node N31 is connected to the wiring 107, the channel region of the transistor 404 is more than the channel region of the transistor 403 (L: channel length × W: channel width). Small is preferable. In the case where the node N32 is connected to the wiring 107, the channel region of the transistor 404 is preferably larger than the channel region of the transistor 403.

Here, the offset circuit illustrated in FIG. 3A is configured with an N-channel transistor and a capacitor, but may be configured with a P-channel transistor and a capacitor. FIG. 5A shows an offset circuit in the case where it is configured by a P-channel transistor and a capacitor.

The offset circuit illustrated in FIG. 5A includes a capacitor 301, a capacitor 302, a transistor 501, and a transistor 502.

Note that the transistor 501 and the transistor 502 correspond to the transistor 303 and the transistor 304 in FIG. 3A, respectively, and have similar functions. Further, the node N51 and the node N52 correspond to the transistor node N31 and the node N32 in FIG.

As shown in the offset circuit of FIG. 5A, the first electrode of the capacitor 301 is connected to the wiring 105. A first electrode of the capacitor 302 is connected to the wiring 106. A gate of the transistor 501 is connected to the second electrode of the capacitor 301, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 302. The gate of the transistor 502 is connected to the second electrode of the capacitor 302, the first terminal is connected to the wiring 103, and the second terminal is connected to the second electrode of the capacitor 301. Note that a connection point of the second electrode of the capacitor 301, the gate of the transistor 501 and the second terminal of the transistor 502 is a node N51. Note that a connection point of the second electrode of the capacitor 302, the second terminal of the transistor 501, and the gate of the transistor 502 is a node N52. Note that one of the node N51 and the node N52 is connected to the wiring 107 shown in FIG.

Next, the operation of the offset circuit shown in FIG. 5A will be described with reference to FIGS. 5B and 5C.

FIG. 5B shows the operation of the offset circuit in FIG. 5A when the signal of the wiring 105 changes from the H signal to the L signal and the signal of the wiring 106 changes from the L signal to the H signal.

5C shows the operation of the offset circuit in FIG. 5A when the signal of the wiring 105 changes from the L signal to the H signal and the signal of the wiring 106 changes from the H signal to the L signal. That is, the offset circuit of FIG. 5A repeats the operation of FIG. 5B and the operation of FIG. 5C at an arbitrary timing. Further, the operation of FIG. 5B is a first operation, and the operation of FIG. 5C is a second operation.

First, the first operation of the offset circuit of FIG. 5A will be described with reference to FIG. Note that the initial potential of the node N51 is VDD.

As an initial state, the capacitor 301 holds a potential difference VDD−VH between the potential VH (H signal) of the wiring 105 and the potential VDD of the node N51. When the potential of the wiring 105 changes from VH to VL, the potential of the node N51 becomes VDD− (VH−VL) due to capacitive coupling of the capacitor 301. Accordingly, the transistor 501 is turned on.

When the transistor 501 is turned on, the power supply potential VDD is supplied to the node N52, and the potential of the node N52 becomes VDD. Therefore, the capacitor 302 holds a potential difference VDD−VH between the potential VH (H signal) of the wiring 106 and the potential VDD of the node N52. Further, the transistor 502 is turned off.

Further, when the transistor 502 is turned off, the node N51 enters a floating state, and the node N51 maintains the potential VDD− (VH−VL).

Next, the second operation of the offset circuit of FIG. 5A will be described with reference to FIG.

As already described, VDD-VH is held in the capacitor 302 by the first operation. When the potential of the wiring 106 changes from VH to VL, the potential of the node N52 becomes VDD− (VH−VL) due to capacitive coupling of the capacitor 302. Accordingly, the transistor 502 is turned on.

When the transistor 502 is turned on, the power supply potential VDD is supplied to the node N51, and the potential of the node N51 becomes VDD. Therefore, the capacitor 301 holds a potential difference VDD−VH between the potential VH (H signal) of the wiring 105 and the potential VDD of the node N51. Further, the transistor 501 is turned off.

Further, when the transistor 501 is turned off, the node N52 enters a floating state, and the node N52 maintains the potential at VDD− (VH−VL).

By the first operation and the second operation described above, the offset circuit in FIG. 5A causes the node N51 to be in a floating state and the potential of the node N51 to be VDD− (VH−VL) in the first operation. And the node N52 operates to supply the power supply potential VDD. In the second operation, the offset circuit in FIG. 5A supplies the power supply potential VDD to the node N51, sets the node N52 in a floating state, and maintains the potential of the node N52 at VDD− (VH−VL). To work.

Therefore, in the signal generated by the offset circuit of FIG. 5A, the H signal is VDD and the L signal is VDD− (VH−VL). That is, the circuit 101 in FIG. 5A can generate a signal based on the power supply potential VDD.

As in the offset circuit of FIG. 3A, the signal generated by the offset circuit of FIG. 5A has the L signal potential VDD− (VH−VL). It is a little higher than (VH-VL).

3A, if the node N51 is connected to the wiring 107 shown in FIG. 1A, a signal having the same H level and L level as the signal supplied to the wiring 105 is connected to the wiring 107. Can be supplied to. Similarly, if the node N52 is connected to the wiring 107 shown in FIG. 1A, a signal supplied to the wiring 105, a signal obtained by inverting the H signal and the L signal can be supplied to the wiring 107.

3A, in the case where the node N51 is connected to the wiring 107, the capacitance value of the capacitor 302 is preferably smaller than the capacitance value of the capacitor 301.

3A, when the node N52 is connected to the wiring 107, the capacitance value of the capacitor 301 is preferably smaller than the capacitance value of the capacitor 302.

Note that as in the offset circuit in FIG. 4, the capacitor 301 and the capacitor 302 may be a MOS capacitor. As illustrated in FIG. 6A, a P-channel transistor 601 may be used instead of the capacitor 301, and a P-channel transistor 602 may be used instead of the capacitor 302. In addition, the gate of the transistor 601 is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N51. Similarly, the gate of the transistor 602 is connected to the wiring 106, and the first terminal and the second terminal are connected to the node N52.

Similarly to the offset circuit in FIG. 4, as shown in FIG. 6B, an N-channel transistor 603 and an N-channel transistor 604 may be used as the capacitor 301 and the capacitor 302, respectively. it can. Further, the gate of the transistor 603 is connected to the node N51, and the first terminal and the second terminal are connected to the wiring 105. Similarly, the gate of the transistor 604 is connected to the node N52, and the first terminal and the second terminal are connected to the wiring 106.

4A, in the case where the node N51 is connected to the wiring 107 in FIG. 6A, the channel region of the transistor 602 is preferably smaller than the channel region of the transistor 601. In the case where the node N52 is connected to the wiring 107, the channel region of the transistor 602 is preferably larger than the channel region of the transistor 601.

Similarly, in FIG. 6B, in the case where the node N51 is connected to the wiring 107, the channel region of the transistor 604 is preferably smaller than the channel region of the transistor 603. In the case where the node N52 is connected to the wiring 107, the channel region of the transistor 604 is preferably larger than the channel region of the transistor 603.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Third embodiment)
In this embodiment, a configuration example of the circuit 101 (offset circuit) included in the level shifter shown in the first embodiment will be described. Note that in this embodiment, the signal supplied to the wiring 105 and the wiring 106 is supplied to the wiring 108 by shifting the potential to the L side with the same timing (or inversion) and substantially the same amplitude voltage. An example of the configuration will be described.

Note that components similar to those in the first embodiment and the second embodiment are denoted by common reference numerals, and detailed description of the same portions or portions having similar functions is omitted.

First, a configuration example of the offset circuit will be described with reference to FIG.

The offset circuit illustrated in FIG. 7A includes a capacitor 701, a capacitor 702, a transistor 703, and a transistor 704.

As shown in the offset circuit in FIG. 7A, the first electrode of the capacitor 701 is connected to the wiring 105. A first electrode of the capacitor 702 is connected to the wiring 106. A gate of the transistor 703 is connected to the second electrode of the capacitor 701, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 702. A gate of the transistor 704 is connected to the second electrode of the capacitor 702, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 701. Note that a connection point of the second electrode of the capacitor 701, the gate of the transistor 703, and the second terminal of the transistor 704 is a node N71. Note that a connection point of the second electrode of the capacitor 702, the second terminal of the transistor 703, and the gate of the transistor 704 is a node N72. One of the node N71 and the node N72 is connected to the wiring 108 shown in FIG.

Next, the operation of the offset circuit shown in FIG. 7A will be described with reference to FIGS. 7B and 7C.

FIG. 7B shows the operation of FIG. 7A when the signal of the wiring 105 changes from the H signal to the L signal and the signal of the wiring 106 changes from the L signal to the H signal.

FIG. 7C shows the operation of the offset circuit in FIG. 7A when the signal of the wiring 105 changes from the L signal to the H signal and the signal of the wiring 106 changes from the H signal to the L signal. That is, the offset circuit of FIG. 7A repeats the operation of FIG. 7B and the operation of FIG. 7C at an arbitrary timing. Further, the operation of FIG. 7B is a first operation, and the operation of FIG. 7C is a third operation.

Note that VH−VL is higher than or equal to the threshold voltage of the transistors 703 and 704.

First, the first operation of the offset circuit of FIG. 7A will be described with reference to FIG. Note that the initial potential of the node N72 is VSS.

As an initial state, the capacitor 702 holds a potential difference VL−VSS between the potential VL (L signal) of the wiring 106 and the potential VSS of the node N72. When the potential of the wiring 106 changes from VL to VH, the potential of the node N72 becomes VSS + (VH−VL) due to capacitive coupling of the capacitor 702. Accordingly, the transistor 704 is turned on.

Further, when the transistor 704 is turned on, the power supply potential VSS is supplied to the node N71, and the potential of the node N71 becomes VSS. Therefore, the capacitor 701 holds a potential difference VL−VSS between the potential VL (L signal) of the wiring 105 and the potential VSS of the node N71. Further, the transistor 703 is turned off.

Further, when the transistor 703 is turned off, the node N72 is in a floating state, and the node N72 maintains the potential at VSS + (VH−VL).

Next, the second operation of the offset circuit of FIG. 7A will be described with reference to FIG.

As already described, VL-VSS is held in the capacitor 701 by the first operation. When the potential of the wiring 105 changes from VL to VH, the potential of the node N71 becomes VSS + (VH−VL) due to capacitive coupling of the capacitor 701. Accordingly, the transistor 703 is turned on.

Further, when the transistor 703 is turned on, the power supply potential VSS is supplied to the node N72, and the potential of the node N72 becomes VSS. Therefore, the capacitor 702 holds a potential difference VL−VSS between the potential VL (L signal) of the wiring 106 and the potential VSS of the node N72. In addition, the transistor 704 is turned off.

Further, when the transistor 704 is turned off, the node N71 enters a floating state, and the node N71 maintains the potential at VSS + (VH−VL).

Here, functions of the capacitor 701, the capacitor 702, the transistor 703, and the transistor 704 are described.

First, in the first operation, the capacitor 701 holds a potential difference between the potential VL of the wiring 105 and the potential VSS of the node N71. In the second operation, the capacitor 701 has a function of increasing the potential of the node N71 as the potential of the wiring 105 is increased by capacitive coupling.

In the second operation, the capacitor 702 holds a potential difference between the potential VL of the wiring 106 and the potential VSS of the node N72. In the first operation, the capacitor 702 has a function of increasing the potential of the node N72 as the potential of the wiring 106 increases by capacitive coupling.

The transistor 703 functions as a switch that selects whether to connect the wiring 104 and the node N72 according to the potential of the node N71. In the first operation, the transistor 703 is turned off, and the node N72 is in a floating state. In the second operation, the transistor 703 is turned on and supplies the power supply potential VSS to the node N72.

The transistor 704 functions as a switch that selects whether to connect the wiring 104 and the node N71 depending on the potential of the node N72. In the first operation, the transistor 704 is turned on and supplies the power supply potential VSS to the node N71. In the second operation, the transistor 704 is turned off, and the node N71 is in a floating state.

By the first operation and the second operation described above, in the first operation, the offset circuit in FIG. 7A supplies the power supply potential VSS to the node N71, sets the node N72 in a floating state, and It operates so as to maintain the potential of N72 at VSS + (VH−VL). In the second operation, the circuit 101 in FIG. 7A places the node N71 in a floating state, maintains the potential of the node N71 at VSS + (VH−VL), and supplies the power supply potential VSS to the node N72. To work.

Therefore, in the signal generated by the offset circuit in FIG. 7A, the H signal is VSS + (VH−VL) and the L signal is VSS. That is, the offset circuit in FIG. 7A can generate a signal based on the power supply potential VSS.

Note that the potential of the node N72 in the first operation and the potential of the node N71 in the second operation are maintained at VSS + (VH−VL). However, in reality, the potential of the node N72 in the first operation and the potential of the node N71 in the second operation are lower than VSS + (VH−VL) due to the influence of wiring capacitance and parasitic capacitance. Therefore, in order to reduce the influence of the wiring capacitance and the parasitic capacitance, the capacitance values of the capacitor 701 and the capacitor 702 should be sufficiently larger than the capacitance values of the wiring capacitance and the parasitic capacitance.

Note that if the node N71 is connected to the wiring 108 illustrated in FIG. 1A, a signal having the same signal as the H signal and the L signal supplied to the wiring 105 can be supplied to the wiring 108. Similarly, when the node N72 is connected to the wiring 108 illustrated in FIG. 1A, a signal supplied to the wiring 105, a signal obtained by inverting the H signal, and the L signal can be supplied to the wiring 108.

In the case where the node N71 is connected to the wiring 108, the capacitance value of the capacitor 702 is preferably smaller than the capacitance value of the capacitor 701. This is because, as described above, the capacitance value of the capacitor 701 should be sufficiently larger than the capacitance values of the wiring capacitance and the parasitic capacitance. However, if the potential of the node N72 can turn on the transistor 704, This is because the potential of N72 does not have to be VSS + (VH−VL). Accordingly, since the capacitance value of the capacitor 702 can be smaller than the capacitance value of the capacitor 701, the element region of the capacitor 702 can be reduced.

In the case where the node N72 is connected to the wiring 108, the capacitance value of the capacitor 701 is preferably smaller than the capacitance value of the capacitor 702 for the same reason as in the case where the node N71 is connected to the wiring 108.

Note that the capacitor 701 and the capacitor 702 may have a structure in which an insulating layer is sandwiched between two electrode layers. When the capacitor 701 and the capacitor 702 have a structure in which an insulating layer is sandwiched between two electrode layers, the capacitor 701 and the capacitor 702 can keep the capacitance value constant regardless of an applied voltage. Therefore, the level shifter of the present invention can operate stably.

The insulating layers of the capacitor 701 and the capacitor 702 are preferably gate insulating films. This is because the thickness of the gate insulating film is generally smaller than that of other insulating films (for example, an interlayer film, a planarization film, and the like), and thus the capacitor element 701 and the capacitor element 702 can efficiently obtain a capacitance value. Because you can.

Note that the capacitor 701 and the capacitor 702 may be a MOS capacitor. FIG. 8A shows a structure in the case where the capacitor 701 and the capacitor 702 are MOS capacitors. The offset circuit illustrated in FIG. 8A uses an N-channel transistor 801 instead of the capacitor 701 and uses an N-channel transistor 802 instead of the capacitor 702. The transistor 801 is characterized in that the gate is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N71. This is because the potential of the wiring 105 is higher than that of the node N71, so that the transistor 801 is turned on and a channel is formed in the channel region of the transistor 901, so that the transistor 801 can operate as a capacitor. Similarly, the transistor 802 is characterized in that the gate is connected to the wiring 106, and the first terminal and the second terminal are connected to the node N72. This is because the potential of the wiring N106 is higher than that of the node N72, so that the transistor 802 is turned on and a channel is formed in the channel region of the transistor 802, so that the transistor 802 can operate as a capacitor.

As shown in FIG. 8B, a P-channel transistor can be used as the capacitor as the capacitor. In the offset circuit illustrated in FIG. 8B, a P-channel transistor 803 is used instead of the capacitor 701, and a P-channel transistor 804 is used instead of the capacitor 702. In addition, the transistor 803 has a gate connected to the node N71 and a first terminal and a second terminal connected to the wiring 105. Because the potential of the node N71 is lower than the potential of the wiring 105, the transistor 803 is turned on and a channel is formed in the channel region of the transistor 803, so that the transistor 803 operates as a capacitor. Similarly, the transistor 804 is characterized in that a gate is connected to the node N72 and a first terminal and a second terminal are connected to the wiring 106. This is because the potential of the node N72 is lower than the potential of the wiring 106, so that the transistor 804 is turned on and a channel is formed in the channel region of the transistor 804, so that the transistor 804 can operate as a capacitor.

Note that as described above, in FIG. 8A, when the node N71 is connected to the wiring 108, the channel of the transistor 802 is more than the channel region (L: channel length × W: channel width) of the transistor 801. The region is preferably smaller. In the case where the node N72 is connected to the wiring 108, the channel region of the transistor 802 is preferably larger than the channel region of the transistor 801.

Similarly, in FIG. 8B, when the node N71 is connected to the wiring 108, the channel region of the transistor 804 is more than the channel region of the transistor 803 (L: channel length × W: channel width). Small is preferable. In the case where the node N72 is connected to the wiring 108, the channel region of the transistor 804 is preferably larger than the channel region of the transistor 803.

Here, the offset circuit illustrated in FIG. 7A is configured with an N-channel transistor and a capacitor, but may be configured with a P-channel transistor and a capacitor. FIG. 9A shows an offset circuit in the case of being constituted by a P-channel transistor and a capacitor.

The offset circuit illustrated in FIG. 9A includes a capacitor 701, a capacitor 702, a transistor 901, and a transistor 902.

Note that the transistor 901 and the transistor 902 correspond to the transistor 703 and the transistor 704 in FIG. 7A, respectively, and have similar functions. Further, the node N91 and the node N92 correspond to the transistor node N71 and the node N72 in FIG. 7A, respectively.

As shown in the offset circuit of FIG. 9A, the first electrode of the capacitor 701 is connected to the wiring 105. A first electrode of the capacitor 702 is connected to the wiring 106. A gate of the transistor 901 is connected to the second electrode of the capacitor 701, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 702. A gate of the transistor 902 is connected to the second electrode of the capacitor 702, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 701. Note that a connection point of the second electrode of the capacitor 701, the gate of the transistor 901, and the second terminal of the transistor 902 is a node N91. Note that a connection point of the second electrode of the capacitor 702, the second terminal of the transistor 901, and the gate of the transistor 902 is a node N92. Note that one of the node N91 and the node N92 is connected to the wiring 108 shown in FIG.

Next, the operation of the offset circuit shown in FIG. 9A will be described with reference to FIGS. 9B and 9C.

Note that FIG. 9B shows the operation of the offset circuit in FIG. 9A when the signal of the wiring 105 changes from the H signal to the L signal and the signal of the wiring 106 changes from the L signal to the H signal.

FIG. 9C shows the operation of the offset circuit in FIG. 9A when the signal of the wiring 105 changes from the L signal to the H signal and the signal of the wiring 106 changes from the H signal to the L signal. That is, the offset circuit of FIG. 9A repeats the operation of FIG. 9B and the operation of FIG. 9C at an arbitrary timing. Further, the operation of FIG. 9B is a first operation, and the operation of FIG. 9C is a second operation.

First, the first operation of the offset circuit of FIG. 9A will be described with reference to FIG. Note that the initial potential of the node N91 is VSS.

As an initial state, the capacitor 701 holds a potential difference VH−VSS between the potential VH (H signal) of the wiring 105 and the potential VSS of the node N91. When the potential of the wiring 105 changes from VH to VL, the potential of the node N91 becomes VSS− (VH−VL) due to capacitive coupling of the capacitor 701. Accordingly, the transistor 901 is turned on.

Further, when the transistor 901 is turned on, the power supply potential VSS is supplied to the node N92, and the potential of the node N92 becomes VSS. Therefore, the capacitor 702 holds a potential difference VH−VSS between the potential VH (H signal) of the wiring 106 and the potential VSS of the node N92. In addition, the transistor 902 is turned off.

Further, when the transistor 902 is turned off, the node N91 enters a floating state, and the node N91 maintains the potential VSS− (VH−VL).

Next, the second operation of the offset circuit of FIG. 9A will be described with reference to FIG.

As already described, VH-VSS is held in the capacitor 702 by the first operation. When the potential of the wiring 106 changes from VH to VL, the potential of the node N92 becomes VSS− (VH−VL) due to capacitive coupling of the capacitor 702. Accordingly, the transistor 902 is turned on.

Further, when the transistor 902 is turned on, the power supply potential VSS is supplied to the node N91, and the potential of the node N91 becomes VSS. Accordingly, the capacitor 701 holds a potential difference VH−VSS between the potential VH (H signal) of the wiring 105 and the potential VSS of the node N91. Further, the transistor 901 is turned off.

Further, when the transistor 901 is turned off, the node N92 enters a floating state, and the node N92 maintains the potential at VSS− (VH−VL).

By the first operation and the second operation described above, the offset circuit of FIG. 9A causes the node N91 to be in a floating state and the potential of the node N91 to be VSS− (VH−VL) in the first operation. And the node N92 operates to supply the power supply potential VSS. In the second operation, the offset circuit in FIG. 9A supplies the power supply potential VSS to the node N91, sets the node N92 in a floating state, and maintains the potential of the node N92 at VSS− (VH−VL). To work.

Therefore, in the signal generated by the offset circuit in FIG. 9A, the H signal is VSS and the L signal is VSS− (VH−VL). That is, the offset circuit in FIG. 9A can generate a signal based on the power supply potential VSS.

As in the offset circuit of FIG. 7A, the signal generated by the offset circuit of FIG. 9A has the potential of the L signal VSS− (VH−VL). It is slightly higher than (VH-VL).

Similarly to the offset circuit of FIG. 7A, if the node N91 is connected to the wiring 108 shown in FIG. 1A, the signal supplied to the wiring 105 is the same as the H signal and the L signal. 108 can be supplied. Similarly, when the node N92 is connected to the wiring 108 illustrated in FIG. 1A, a signal supplied to the wiring 105, a signal obtained by inverting the H signal, and the L signal can be supplied to the wiring 108.

7A, when the node N91 is connected to the wiring 108, the capacitance value of the capacitor 702 is preferably smaller than the capacitance value of the capacitor 701.

7A, when the node N92 is connected to the wiring 108, the capacitance value of the capacitor 701 is preferably smaller than the capacitance value of the capacitor 702.

Note that as in the offset circuit in FIG. 8, the capacitor 701 and the capacitor 702 may be a MOS capacitor. As shown in FIG. 10A, a P-channel transistor 1091 may be used instead of the capacitor 701 and a P-channel transistor 1092 may be used instead of the capacitor 702. In addition, the gate of the transistor 1091 is connected to the node N91, and the first terminal and the second terminal are connected to the wiring 105. Similarly, the gate of the transistor 1092 is connected to the node N92, and the first terminal and the second terminal are connected to the wiring 106.

Similarly to the offset circuit in FIG. 8, as shown in FIG. 10B, an N-channel transistor 1093 and an N-channel transistor 1094 may be used as the capacitor 701 and the capacitor 702, respectively. it can. In addition, the gate of the transistor 1093 is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N91. Similarly, the gate of the transistor 1094 is connected to the wiring 106, and the first terminal and the second terminal are connected to the node N92.

8A, when the node N91 is connected to the wiring 108 in FIG. 10A, the channel region of the transistor 1092 is preferably smaller than the channel region of the transistor 1091. In the case where the node N92 is connected to the wiring 108, the channel region of the transistor 1092 is preferably larger than the channel region of the transistor 1091.

Similarly, in FIG. 10B, when the node N91 is connected to the wiring 108, the channel region of the transistor 1094 is preferably smaller than the channel region of the transistor 1093. In the case where the node N92 is connected to the wiring 108, the channel region of the transistor 1094 is preferably larger than the channel region of the transistor 1093.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Fourth embodiment)
In this embodiment, a configuration example of the circuit 101 (offset circuit) included in the level shifter shown in the first embodiment will be described. Note that in this embodiment, the potential supplied to the wiring 105 and the wiring 106 is shifted to the H side and the L side with the same timing (or inversion) and substantially the same amplitude voltage, so that the wiring 107 A configuration example in the case of supplying the wiring 108 and the wiring 108 will be described.

Note that components similar to those in the first to third embodiments are denoted by common reference numerals, and detailed description of the same portions or portions having similar functions is omitted.

First, a configuration example of the offset circuit will be described with reference to FIG.

The offset circuit illustrated in FIG. 11 includes a capacitor 301, a capacitor 302, a transistor 303, a transistor 304, a capacitor 701, a capacitor 702, a transistor 703, and a transistor 704.

As shown in the offset circuit in FIG. 11, the first electrode of the capacitor 301 is connected to the wiring 105. A first electrode of the capacitor 302 is connected to the wiring 106. A gate of the transistor 303 is connected to the second electrode of the capacitor 301, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 302. A gate of the transistor 304 is connected to the second electrode of the capacitor 302, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 301. A first electrode of the capacitor 702 is connected to the wiring 106. A gate of the transistor 703 is connected to the second electrode of the capacitor 701, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 702. A gate of the transistor 704 is connected to the second electrode of the capacitor 702, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 701.

Note that a connection point of the second electrode of the capacitor 301, the gate of the transistor 303, and the second terminal of the transistor 304 is a node N31. Note that a connection point of the second electrode of the capacitor 302, the second terminal of the transistor 303, and the gate of the transistor 304 is a node N32. Note that a connection point of the second electrode of the capacitor 701, the gate of the transistor 703, and the second terminal of the transistor 704 is a node N71. Note that a connection point of the second electrode of the capacitor 702, the second terminal of the transistor 703, and the gate of the transistor 704 is a node N72.

One of the node N31 and the node N32 is connected to the wiring 107 shown in FIG. One of the node N71 and the node N72 is connected to the wiring 108 shown in FIG.

Note that the capacitor 301, the capacitor 302, the transistor 303, and the transistor 304 constitute the offset circuit illustrated in FIG. In addition, the capacitor 701, the capacitor 702, the transistor 703, and the transistor 704 form the offset circuit illustrated in FIG.

Note that as described above, the power supply potential VDD and the power supply potential VSS are supplied to the wiring 103 and the wiring 104, respectively. In addition, the signal of the wiring 105 is inverted between the H level and the L level with respect to the signal of the wiring 106.

Note that the operation of the offset circuit shown in FIG. 11 is the same as in FIG. 3A and FIG.

Note that as described above, the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 may be a MOS capacitor. A structure in the case where the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 have a MOS structure is illustrated in FIG.

As illustrated in the offset circuit in FIG. 12, the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 can be replaced with a transistor 401, a transistor 402, a transistor 801, and a transistor 802, respectively. Note that each of the transistor 401, the transistor 402, the transistor 801, and the transistor 802 is an N-channel type.

Further, the gate of the transistor 401 is connected to the node N <b> 31, and the first terminal and the second terminal are connected to the wiring 105. The gate of the transistor 402 is connected to the node N <b> 32, and the first terminal and the second terminal are connected to the wiring 106. The gate of the transistor 801 is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N71. A gate of the transistor 802 is connected to the wiring 106, and a first terminal and a second terminal are connected to the node N72.

Here, the offset circuit illustrated in FIG. 11 includes the N-channel transistor and the capacitor, but the P-channel transistor may include the capacitor. FIG. 13 shows an offset circuit in the case where a P-channel transistor and a capacitor are used.

The offset circuit illustrated in FIG. 13 includes a capacitor 301, a capacitor 302, a transistor 501, a transistor 502, a capacitor 701, a capacitor 702, a transistor 901, and a transistor 902.

As shown in the offset circuit in FIG. 13, the first electrode of the capacitor 301 is connected to the wiring 105. A first electrode of the capacitor 302 is connected to the wiring 106. A gate of the transistor 501 is connected to the second electrode of the capacitor 301, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 302. The gate of the transistor 502 is connected to the second electrode of the capacitor 302, the first terminal is connected to the wiring 103, and the second terminal is connected to the second electrode of the capacitor 301. A first electrode of the capacitor 702 is connected to the wiring 106. A gate of the transistor 901 is connected to the second electrode of the capacitor 701, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 702. A gate of the transistor 902 is connected to the second electrode of the capacitor 702, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 701.

Note that a connection point of the second electrode of the capacitor 301, the gate of the transistor 501 and the second terminal of the transistor 502 is a node N51. Note that a connection point of the second electrode of the capacitor 302, the second terminal of the transistor 501, and the gate of the transistor 502 is a node N52. Note that a connection point of the second electrode of the capacitor 701, the gate of the transistor 901, and the second terminal of the transistor 902 is a node N91. Note that a connection point of the second electrode of the capacitor 702, the second terminal of the transistor 901, and the gate of the transistor 902 is a node N92.

Note that one of the node N51 and the node N52 is connected to the wiring 107 shown in FIG. One of the node N91 and the node N92 is connected to the wiring 108 shown in FIG.

Note that the capacitor 301, the capacitor 302, the transistor 501, and the transistor 502 constitute the offset circuit illustrated in FIG. In addition, the capacitor 701, the capacitor 702, the transistor 901, and the transistor 902 constitute the offset circuit illustrated in FIG.

Note that as described above, the power supply potential VDD and the power supply potential VSS are supplied to the wiring 103 and the wiring 104, respectively. In addition, the signal of the wiring 105 is inverted between the H level and the L level with respect to the signal of the wiring 106.

Note that the operation of the offset circuit shown in FIG. 13 is the same as that in FIGS. 5A and 9A, and is omitted.

Note that as described above, the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 may be a MOS capacitor. A structure in the case where the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 have a MOS structure is illustrated in FIG.

As illustrated in the offset circuit in FIG. 14, the capacitor 301, the capacitor 302, the capacitor 701, and the capacitor 702 can be replaced with a transistor 601, a transistor 602, a transistor 1091, and a transistor 1092, respectively. Note that each of the transistor 601, the transistor 602, the transistor 1091, and the transistor 1092 is a P-channel type.

The gate of the transistor 601 is connected to the wiring 105, and the first terminal and the second terminal are connected to the node N51. A gate of the transistor 602 is connected to the wiring 106, and a first terminal and a second terminal are connected to the node N52. A gate of the transistor 1091 is connected to the node N91, and a first terminal and a second terminal are connected to the wiring 105. A gate of the transistor 1092 is connected to the node N92, and a first terminal and a second terminal are connected to the wiring 106.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Fifth embodiment)
In this embodiment, a specific configuration of the level shifter shown in the first embodiment will be described.

In addition, about the thing similar to 1st Embodiment-4th Embodiment, it shows using a common code | symbol and detailed description of the part which has the same part or the same function is abbreviate | omitted.

First, a specific configuration example of the level shifter of the present invention will be described with reference to FIG.

The level shifter illustrated in FIG. 15 includes a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 1501, and a transistor 1502.

As shown in the level shifter of FIG. 15, the first electrode of the capacitor 701 is connected to the wiring 105. A first electrode of the capacitor 702 is connected to the wiring 106. A gate of the transistor 703 is connected to the second electrode of the capacitor 701, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 702. A gate of the transistor 704 is connected to the second electrode of the capacitor 702, a first terminal is connected to the wiring 104, and a second terminal is connected to the second electrode of the capacitor 701. Note that a connection point of the second electrode of the capacitor 701, the gate of the transistor 703, and the second terminal of the transistor 704 is a node N71. Note that a connection point of the second electrode of the capacitor 702, the second terminal of the transistor 703, and the gate of the transistor 704 is a node N72. A gate of the transistor 1502 is connected to the node N 72, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109. A gate of the transistor 1501 is connected to the wiring 103, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109.

Note that the capacitor 701, the capacitor 702, the transistor 703, and the transistor 704 constitute an offset circuit 1503. The offset circuit 1503 is the same as the offset circuit shown in FIG.

Note that a logic circuit 1500 is formed by the transistor 1501 and the transistor 1502. The logic circuit 1500 corresponds to the circuit 102 in FIG.

Note that the transistor 1501 and the transistor 1502 are n-channel transistors. Accordingly, since all of the level shifters shown in FIG. 15 can be formed of N-channel transistors, the level shifter shown in FIG. 15 can use amorphous silicon for the semiconductor layer, thereby simplifying the manufacturing process. . Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

The level shifter shown in FIG. 15 can simplify the manufacturing process even if polysilicon or single crystal silicon is used for the semiconductor layer.

Next, the operation of the level shifter shown in FIG. 15 will be described with reference to the timing chart of FIG. However, the timing of potential change in the timing chart shown in FIG. 16 is arbitrary, and is not limited to the timing chart in FIG.

Note that the timing chart in FIG. 16A shows the signal (potential) supplied to the wiring 105 and the potential of the node N71. The timing chart in FIG. 16B shows the signal (potential) supplied to the wiring 106 and the potential of the node N72. A timing chart in FIG. 16C shows a signal (potential) supplied to the wiring 109.

Note that FIG. 17 shows the operation of the level shifter in FIG. 15 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. The operation of the level shifter in FIG. 15 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106 is shown in FIG. In addition, the operation in FIG. 17 is a first operation, and the operation in FIG. 18 is a second operation.

Since the operation of the offset circuit 1503 is the same as that of the offset circuit of FIG. 7A, detailed description of the operation of the offset circuit 1503 is omitted.

First, the first operation of the level shifter of FIG. 15 will be described with reference to the timing chart of FIG. 16 and FIG.

When the wiring 105 becomes L level, the potential of the node N71 becomes VSS. On the other hand, when the wiring 106 becomes H level, the potential of the node N72 becomes VSS + (VH−VL). Accordingly, the transistor 1502 is turned on, the power supply potential VSS is supplied to the wiring 109, and an L signal is output from the wiring 109. Note that the potential of the wiring 109 is determined by an operating point of the transistor 1501 and the transistor 1502, and is slightly higher than the power supply potential VSS.

Next, the second operation of the level shifter of FIG. 15 will be described with reference to the timing chart of FIG. 16 and FIG.

When the wiring 105 becomes H level, the potential of the node N71 becomes VSS + (VH−VL). On the other hand, when the wiring 106 becomes L level, the potential of the node N72 becomes VSS. Accordingly, the transistor 1502 is turned off, the power supply potential VDD is supplied to the wiring 109, and the potential of the wiring 109 is increased. This rise in the potential of the wiring 109 continues until the potential of the wiring 109 becomes a potential (VDD−Vth1501) obtained by subtracting the threshold voltage Vth1501 of the transistor 1501 from the power supply potential VDD and the transistor 1501 is turned off. Therefore, the potential of the wiring 109 becomes VDD−Vth1501, and an H signal is output from the wiring 109.

Here, functions of the logic circuit 1500 and the offset circuit 1503 are described.

First, the offset circuit 1503 has a function similar to that of the offset circuit shown in FIG. Further, the offset circuit 1503 is an offset signal in which the potential of the H signal is VSS + (VH−VL) and the potential of the L signal is VSS from the control signal in which the potential of the H signal is VH and the potential of the L signal is VL. And the offset signal is supplied to the logic circuit 1500.

In addition, the logic circuit 1500 has an H signal potential of VDD−Vth1501 and an L signal potential of approximately VSS from an offset signal in which the potential of the H signal is VSS + (VH−VL) and the potential of the L signal is VSS. A function of generating an output signal and supplying the output signal to the wiring 109;

Here, functions of the transistor 1501 and the transistor 1502 are described.

First, the transistor 1501 functions as a diode. The input terminal is a gate and a first terminal, and the output terminal is a second terminal. Note that the transistor 1501 may be an element having a resistance component. Note that by using a resistance element instead of the transistor 1501, the logic circuit 1500 can make the potential of the wiring 109 equal to the power supply potential VDD in the second operation.

In addition, the transistor 1502 functions as a switch that selects whether the wiring 104 and the wiring 109 are connected or not depending on the potential of the node N72. In the first operation, the transistor 1502 is turned on and supplies the power supply potential VSS to the wiring 109.

By the first operation and the second operation described above, the level shifter in FIG. 15 changes the control signal supplied to the wiring 105 and the wiring 106 from the VH potential to the VDD and the L signal potential. The signal can be output from the wiring 109 from VL to VSS.

Note that since the gate voltage of the transistor 1502 is VSS + (VH−VL) in the first operation and VSS in the second operation, the through current of the logic circuit 1500 is reduced. This is because the amplitude voltage of the gate of the transistor 1502 is small (VH−VL). Therefore, since the through current of the logic circuit 1500 is small, the power consumption of the semiconductor device having the level shifter of FIG. 15 is reduced.

In addition, since the amplitude voltage of the gate of the transistor 1502 is small, noise generated in the logic circuit 1500 is reduced. This is because noise generated through a parasitic capacitance between the gate of the transistor 1502 and the second terminal (the wiring 109) is reduced.

Note that as described above, the capacitor 701 and the capacitor 702 can have a MOS structure. Note that in the case of the level shifter of FIG. 15, it is preferable to form a capacitor element using an N-channel transistor as in the offset circuit of FIG. This is because by forming the capacitor element with an N-channel transistor, the level shifter shown in FIG. 15 can use amorphous silicon for the semiconductor layer, and the manufacturing process can be simplified. Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

The level shifter shown in FIG. 15 can simplify the manufacturing process by using polysilicon or single crystal silicon for the semiconductor layer.

As shown in FIG. 19, in the level shifter of FIG. 15, the gate of the transistor 1502 may be connected to the node N71. In the case where the gate of the transistor 1502 is connected to the node N71 (FIG. 19), as shown in the timing chart of FIG. 20, the signal (potential) of the wiring 109 is connected to the node N72. Compared to the case (FIG. 15), the H level and the L level are inverted. Further, the operation of the level shifter of FIG. 19 is the same as that of the level shifter of FIG. Accordingly, the connection destination of the gate of the transistor 1502 may be the node N71 or the node N72, as appropriate.

Here, the level shifter illustrated in FIG. 15 includes an N-channel transistor and a capacitor, but may include a P-channel transistor and a capacitor. FIG. 29 shows a level shifter in the case where a P-channel transistor and a capacitor are used.

The level shifter illustrated in FIG. 29 includes a capacitor 301, a capacitor 302, a transistor 501, a transistor 502, a transistor 2901, and a transistor 2902.

Note that the capacitor 301, the capacitor 302, the transistor 501, the transistor 502, the transistor 2901, and the transistor 2902 are respectively the capacitor 701, the capacitor 702, the transistor 703, the transistor 704, the transistor 1501, and the transistor 1502 in FIG. Corresponding and has similar functions. Further, the logic circuit 2900 and the offset circuit 2903 correspond to the logic circuit 1500 and the offset circuit 1503 in FIG. 15, respectively, and have similar functions. Further, the node N51 and the node N52 correspond to the node N71 and the node N72 in FIG.

As shown in the level shifter of FIG. 29, the first electrode of the capacitor 301 is connected to the wiring 105. A first electrode of the capacitor 302 is connected to the wiring 106. A gate of the transistor 501 is connected to the second electrode of the capacitor 301, a first terminal is connected to the wiring 103, and a second terminal is connected to the second electrode of the capacitor 302. The gate of the transistor 502 is connected to the second electrode of the capacitor 302, the first terminal is connected to the wiring 103, and the second terminal is connected to the second electrode of the capacitor 301. Note that a connection point of the second electrode of the capacitor 301, the gate of the transistor 501 and the second terminal of the transistor 502 is a node N51. Note that a connection point of the second electrode of the capacitor 302, the second terminal of the transistor 501, and the gate of the transistor 502 is a node N52. A gate of the transistor 2902 is connected to the node N52, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109. A gate of the transistor 2901 is connected to the wiring 104, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109.

Next, the operation of the level shifter shown in FIG. 29 will be described with reference to the timing chart of FIG. However, the timing of potential change in the timing chart shown in FIG. 30 is arbitrary, and is not limited to the timing chart in FIG.

Note that the timing chart in FIG. 30A shows a signal (potential) supplied to the wiring 105 and the potential of the node N51. The timing chart in FIG. 30B shows a signal (potential) supplied to the wiring 106 and the potential of the node N52. A timing chart in FIG. 30C shows a signal (potential) supplied to the wiring 109.

Note that FIG. 31 shows the operation of the level shifter in FIG. 29 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. FIG. 32 shows the operation of the level shifter in FIG. 29 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106. Further, the operation of FIG. 31 is a first operation, and the operation of FIG. 32 is a second operation.

Since the operation of the offset circuit 2903 is the same as that of the offset circuit of FIG. 5A, the detailed operation of the offset circuit 2903 is omitted.

First, the first operation of the level shifter of FIG. 29 will be described with reference to the timing chart of FIG. 30 and FIG.

When the wiring 105 becomes L level, the potential of the node N51 becomes VDD− (VH−VL). On the other hand, when the wiring 106 becomes H level, the potential of the node N52 becomes VDD. Accordingly, the transistor 2902 is turned off, the power supply potential VSS is supplied to the wiring 109, and the potential of the wiring 109 is decreased. This decrease in the potential of the wiring 109 is until the potential of the wiring 109 becomes a value (VSS + | Vth2901 |) obtained by adding the power supply potential VSS and the absolute value of the threshold voltage Vth2901 of the transistor 2901 until the transistor 2901 is turned off. Continue. Accordingly, the potential of the wiring 109 is VSS + | Vth2901 |, and an L signal is output from the wiring 109.

Next, the second operation of the level shifter of FIG. 29 will be described with reference to the timing chart of FIG. 30 and FIG.

When the wiring 105 becomes H level, the potential of the node N51 becomes VDD. On the other hand, when the wiring 106 becomes L level, the potential of the node N52 becomes VDD− (VH−VL). Accordingly, the transistor 2902 is turned on, the power supply potential VDD is supplied to the wiring 109, and an H signal is output from the wiring 109. Note that the potential of the wiring 109 is determined by an operating point of the transistor 2901 and the transistor 2902 and is slightly lower than the power supply potential VDD.

By the first operation and the second operation described above, the level shifter in FIG. 29 changes the control signal supplied to the wiring 105 and the wiring 106 from VH to VDD and the L signal potential. The signal can be output from the wiring 109 from VL to VSS.

Note that since the gate voltage of the transistor 2902 is VDD in the first operation and VDD− (VH−VL) in the second operation, the through current of the logic circuit 2900 is reduced. This is because the amplitude voltage of the gate of the transistor 2902 is small (VH−VL). Therefore, since the through current of the logic circuit 2900 is small, the power consumption of the semiconductor device having the level shifter in FIG. 29 is reduced.

In addition, since the amplitude voltage of the gate of the transistor 2902 is small, noise generated in the logic circuit 2900 is reduced. This is because noise generated through a parasitic capacitance between the gate of the transistor 2902 and the second terminal (wiring 109) is reduced.

Note that as described above, the capacitor 301 and the capacitor 302 can have a MOS structure. In the case of the level shifter shown in FIG. 29, it is preferable to form a capacitor element using a P-channel transistor as in the offset circuit shown in FIG.

As shown in FIG. 33, in the level shifter of FIG. 29, the gate of the transistor 2902 may be connected to the node N51. A timing chart in the case where the gate of the transistor 2902 is connected to the node N51 is shown in FIG.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Sixth embodiment)
In this embodiment, a specific configuration of the level shifter shown in the first embodiment different from the fifth embodiment will be described.

In addition, about the thing similar to 1st Embodiment-5th Embodiment, it shows using a common code | symbol and detailed description of the part which has the same part or the same function is abbreviate | omitted.

First, a specific configuration example of the level shifter of the present invention will be described with reference to FIG.

The level shifter illustrated in FIG. 21 includes a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 2101, a transistor 2102, a transistor 2103, and a transistor 2104.

As shown in the level shifter of FIG. 21, the gate of the transistor 2101 is connected to the wiring 103, the first terminal is connected to the wiring 103, and the second terminal is connected to the wiring 109-2. A gate of the transistor 2102 is connected to the node N72, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109-2. A gate of the transistor 2103 is connected to the wiring 103, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109-1. A gate of the transistor 2104 is connected to the node N71, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109-1.

Note that the logic circuit 1500 in FIG. 15 includes the transistor 2101 and the transistor 2102. The transistor 2103 and the transistor 2104 also form the logic circuit 1500 in FIG. In addition, a logic circuit 2100 is formed by the transistor 2101, the transistor 2102, the transistor 2103, and the transistor 2104.

Note that the transistor 2101, the transistor 2102, the transistor 2103, and the transistor 2104 are n-channel transistors. Therefore, since all the level shifters shown in FIG. 21 can be formed of N-channel transistors, the level shifter shown in FIG. 21 can use amorphous silicon for the semiconductor layer, and can simplify the manufacturing process. . Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

Further, the level shifter shown in FIG. 21 can simplify the manufacturing process by using polysilicon or single crystal silicon for the semiconductor layer.

Next, the operation of the level shifter shown in FIG. 21 will be described with reference to the timing chart of FIG. Note that the potential change timing in the timing chart illustrated in FIG. 22 is arbitrary and is not limited to the timing chart in FIG.

Note that FIG. 23 shows the operation of the level shifter in FIG. 21 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. FIG. 24 shows the operation of the level shifter in FIG. 21 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106. The operation in FIG. 23 is a first operation, and the operation in FIG. 24 is a second operation.

Since the operation of the offset circuit 1503 is the same as that of the offset circuit of FIG. 7A, detailed description of the operation of the offset circuit 1503 is omitted.

Note that the operation of the circuit configured by the transistor 2101 and the transistor 2102 and the operation of the circuit configured by the transistor 2103 and the transistor 2104 are similar to the operation of the logic circuit 1500 in FIG. 15, and thus detailed description of the operation is omitted. .

First, the first operation of the level shifter of FIG. 21 will be described with reference to the timing chart of FIG. 22 and FIG.

In the first operation, as shown in FIG. 23, the H signal is output from the wiring 109-1, and the L signal is output from the wiring 109-2. Note that the potential of the wiring 109-1 is a potential (VDD−Vth2103) obtained by subtracting the threshold voltage Vth2103 of the transistor 2103 from the power supply potential VDD similarly to the logic circuit 1500 in FIG. The potential of the wiring 109-2 is determined by the operating point of the transistor 2101 and the transistor 2102 as in the logic circuit 1500 in FIG. 15, and is slightly higher than the power supply potential VSS.

Next, the second operation of the level shifter of FIG. 21 will be described with reference to the timing chart of FIG. 22 and FIG.

In the second operation, as shown in FIG. 24, an L signal is output from the wiring 109-1, and an H signal is output from the wiring 109-2. Note that the potential of the wiring 109-1 is determined by the operating point of the transistor 2103 and the transistor 2104 as in the logic circuit 1500 in FIG. 15, and is slightly higher than the power supply potential VSS. The potential of the wiring 109-2 is a potential (VDD−Vth2101) obtained by subtracting the threshold voltage Vth2101 of the transistor 2101 from the power supply potential VDD, similarly to the logic circuit 1500 in FIG.

Here, functions of the logic circuit 2100 will be described.

The logic circuit 2100 includes the two logic circuits 1500 in FIG. 15 and outputs two inverted signals from the wiring 109-1 and the wiring 109-2, respectively.

Here, functions of the transistor 2101, the transistor 2102, the transistor 2103, and the transistor 2104 are described.

First, the transistor 2101 functions as a diode. The input terminal is a gate and a first terminal, and the output terminal is a second terminal. Note that the transistor 2101 may be an element having a resistance component. Note that by using a resistance element instead of the transistor 2101, the logic circuit 2100 can make the potential of the wiring 109-2 equal to the power supply potential VDD in the second operation.

In addition, the transistor 2102 functions as a switch that selects whether the wiring 104 and the wiring 109-2 are connected or not depending on the potential of the node N72. The transistor 2102 is turned on in the first operation to supply the power supply potential VSS to the wiring 109-2.

The transistor 2103 has a function as a diode. The input terminal is a gate and a first terminal, and the output terminal is a second terminal. Note that the transistor 2103 may be an element having a resistance component. Note that by using a resistance element instead of the transistor 2103, the logic circuit 2100 can make the potential of the wiring 109-1 equal to the power supply potential VDD in the first operation.

In addition, the transistor 2104 functions as a switch that selects whether to connect the wiring 104 and the wiring 109-1 depending on the potential of the node N 71. In the first operation, the transistor 2104 is turned on and supplies the power supply potential VSS to the wiring 109-1.

By the first operation and the second operation described above, the level shifter in FIG. 21 changes the control signal supplied to the wiring 105 and the wiring 106 from the VH potential to the VH and the L signal potential. The signal can be output from the wiring 109-1 and the wiring 109-2 from VL to VSS.

Further, the level shifter in FIG. 21 can output two signals in which the H level and the L level are inverted from the wiring 109-1 and the wiring 109-2, respectively.

Note that since the gate voltage of the transistor 2102 is VSS + (VH−VL) in the first operation and VSS in the second operation, the through current of the logic circuit 2100 is reduced. This is because the amplitude voltage of the gate of the transistor 2102 is small (VH−VL). Therefore, since the through current of the logic circuit 2100 is small, the power consumption of the semiconductor device having the level shifter in FIG. 21 is reduced.

Similarly to the transistor 2102, since the gate voltage of the transistor 2104 is VSS in the first operation and VSS + (VH−VL) in the second operation, the through current of the logic circuit 2100 is reduced. This is because the amplitude voltage of the gate of the transistor 2104 is small (VH−VL). Therefore, since the through current of the logic circuit 2100 is small, the power consumption of the semiconductor device having the level shifter in FIG. 21 is reduced.

In addition, since the amplitude voltage of the gate of the transistor 2102 is small, noise generated in the logic circuit 2100 is reduced. This is because noise generated through a parasitic capacitance between the gate of the transistor 2102 and the second terminal (wiring 109-2) is reduced.

Similarly to the transistor 2102, noise generated in the logic circuit 2100 is reduced because the amplitude voltage of the gate of the transistor 2104 is small. This is because noise generated through the parasitic capacitance between the gate of the transistor 2104 and the second terminal (wiring 109-1) is reduced.

Note that the capacitance value of the capacitor 701 and the capacitance value of the capacitor 702 are preferably substantially equal. This is because by making the capacitance value of the capacitor 701 and the capacitance value of the capacitor 702 equal, timing deviations such as delays in output signals of the wiring 109-1 and the wiring 109-2 can be made equal. .

Note that as described above, the capacitor 701 and the capacitor 702 can have a MOS structure. In the case of the level shifter shown in FIG. 21, it is preferable to form a capacitor element using an N-channel transistor as in the offset circuit shown in FIG. This is because by forming the capacitor element with an N-channel transistor, the level shifter shown in FIG. 21 can use amorphous silicon for the semiconductor layer, and the manufacturing process can be simplified. Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

The level shifter shown in FIG. 21 can simplify the manufacturing process even if polysilicon or single crystal silicon is provided in the semiconductor layer.

Here, the level shifter illustrated in FIG. 21 includes an N-channel transistor and a capacitor, but may include a P-channel transistor and a capacitor. FIG. 35 shows a level shifter in the case where a P-channel transistor and a capacitor are used.

The level shifter illustrated in FIG. 35 includes a capacitor 301, a capacitor 302, a transistor 503, a transistor 504, a transistor 3501, a transistor 3502, a transistor 3503, and a transistor 3504.

Note that the capacitor 301, the capacitor 302, the transistor 501, the transistor 502, the transistor 3501, the transistor 3502, the transistor 3503, and the transistor 3504 are the capacitor 701, the capacitor 702, the transistor 703, the transistor 704, and the transistor 2101 in FIG. Each of the transistors 2102, 2103, and 2104 corresponds to each other and has a similar function. An offset circuit 2903 and a logic circuit 3500 correspond to the offset circuit 1503 and the logic circuit 2100 in FIG. 21, respectively, and have similar functions. Further, the node N51 and the node N52 correspond to the node N71 and the node N72 in FIG. 21, respectively.

As shown in the level shifter of FIG. 35, the gate of the transistor 3501 is connected to the wiring 104, the first terminal is connected to the wiring 104, and the second terminal is connected to the wiring 109-2. A gate of the transistor 3502 is connected to the node N52, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109-2. A gate of the transistor 3503 is connected to the wiring 104, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109-1. A gate of the transistor 3504 is connected to the node N51, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109-1.

Next, the operation of the level shifter shown in FIG. 35 will be described with reference to the timing chart of FIG. However, the timing of potential change in the timing chart shown in FIG. 36 is arbitrary and is not limited to the timing chart in FIG.

Note that FIG. 37 shows the operation of the level shifter in FIG. 35 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. The operation of the level shifter of FIG. 35 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106 is shown in FIG. Also, the operation of FIG. 37 is a first operation, and the operation of FIG. 38 is a second operation.

Since the operation of the offset circuit 2903 is the same as that of the offset circuit of FIG. 5A, the detailed operation of the offset circuit 2903 is omitted.

Note that the operation of the circuit formed of the transistor 3501 and the transistor 3502 and the circuit formed of the transistor 3503 and the transistor 3504 are similar to the operation of the logic circuit 2900 in FIG. 29, and thus detailed description of the operation is omitted. .

First, the first operation of the level shifter of FIG. 35 will be described with reference to the timing chart of FIG. 36 and FIG.

In the first operation, as shown in FIG. 37, the H signal is output from the wiring 109-1, and the L signal is output from the wiring 109-2. Note that as in the logic circuit 2900 in FIG. 29, the potential of the wiring 109-1 is determined by the operating point of the transistor 3503 and the transistor 3504, and is slightly lower than the power supply potential VDD. The potential of the wiring 109-2 is a value (VSS + | Vth3501 |) obtained by adding the power supply potential VSS and the absolute value of the threshold voltage Vth3501 of the transistor 3501, as in the logic circuit 2900 in FIG.

Next, the second operation of the level shifter of FIG. 35 will be described with reference to the timing chart of FIG. 36 and FIG.

In the second operation, as shown in FIG. 38, the L signal is output from the wiring 109-1, and the H signal is output from the wiring 109-2. Note that the potential of the wiring 109-1 is a value (VSS + | Vth3503 |) obtained by adding the power supply potential VSS and the absolute value of the threshold voltage Vth3503 of the transistor 3503, similarly to the logic circuit 2900 in FIG. Similarly to the logic circuit 2900 in FIG. 29, the potential of the wiring 109-2 is determined by the operating point of the transistor 3501 and the transistor 3502, and is slightly lower than the power supply potential VDD.

By the first operation and the second operation described above, the level shifter in FIG. 35 changes the control signal supplied to the wiring 105 and the wiring 106 from the VH potential to the VDD and the L signal potential. The signal can be output from the wiring 109-1 and the wiring 109-2 from VL to VSS.

In addition, the level shifter in FIG. 35 can output two signals in which the H level and the L level are inverted from the wiring 109-1 and the wiring 109-2, respectively.

Note that since the gate voltage of the transistor 3502 is VDD in the first operation and VDD− (VH + VL) in the second operation, the through current of the logic circuit 3500 is reduced. This is because the amplitude voltage of the gate of the transistor 3502 is small (VH−VL). Therefore, since the through current of the logic circuit 3500 is small, the power consumption of the semiconductor device having the level shifter in FIG. 35 is reduced.

Similarly to the transistor 3502, since the gate voltage of the transistor 3504 is VDD− (VH−VL) in the first operation and VDD in the second operation, the through current of the logic circuit 350 is reduced. This is because the amplitude voltage of the gate of the transistor 3504 is small (VH−VL). Therefore, since the through current of the logic circuit 3500 is small, the power consumption of the semiconductor device having the level shifter in FIG. 35 is reduced.

In addition, since the amplitude voltage of the gate of the transistor 3502 is small, noise generated in the logic circuit 3500 is reduced. This is because noise generated through a parasitic capacitance between the gate of the transistor 3502 and the second terminal (the wiring 109-2) is reduced.

Similarly to the transistor 3502, when the amplitude voltage of the gate of the transistor 3504 is small, noise generated in the logic circuit 3500 is reduced. This is because noise generated through a parasitic capacitance between the gate of the transistor 3504 and the second terminal (the wiring 109-1) is reduced.

Note that the capacitance value of the capacitor 301 and the capacitance value of the capacitor 302 are preferably substantially equal. This is because by making the capacitance value of the capacitor 301 equal to the capacitance value of the capacitor 302, timing deviations such as delays in output signals of the wiring 109-1 and the wiring 109-2 can be made equal. .

Note that as described above, the capacitor 301 and the capacitor 302 can have a MOS structure. In the case of the level shifter shown in FIG. 35, it is preferable to form a capacitor element using a P-channel transistor as in the offset circuit shown in FIG.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Seventh embodiment)
In this embodiment, a specific configuration of the level shifter shown in the first embodiment different from the fifth embodiment and the sixth embodiment will be described.

In addition, about the thing similar to 1st Embodiment-6th Embodiment, it shows using a common code | symbol and detailed description of the part which has the same part or the same function is abbreviate | omitted.

First, a specific configuration example of the level shifter of the present invention will be described with reference to FIG.

The level shifter illustrated in FIG. 25 includes a capacitor 701, a capacitor 702, a transistor 703, a transistor 703, a transistor 2501, a transistor 2502, a transistor 2503, and a transistor 2504.

As shown in the level shifter in FIG. 25, the first terminal of the transistor 2501 is connected to the wiring 103 and the second terminal is connected to the wiring 109. A gate of the transistor 2502 is connected to the node N 72, a first terminal is connected to the wiring 104, and a second terminal is connected to the wiring 109. A gate of the transistor 2503 is connected to the wiring 103, a first terminal is connected to the wiring 103, and a second terminal is connected to the gate of the transistor 2501. A gate of the transistor 2504 is connected to the node N72, a first terminal is connected to the wiring 104, and a second terminal is connected to the gate of the transistor 2501. Note that a connection point of the gate of the transistor 2501, the second terminal of the transistor 2503, and the second terminal of the transistor 2504 is a node N251.

Note that the logic circuit 2500 includes the transistor 2501, the transistor 2502, the transistor 2503, and the transistor 2504. The logic circuit 2500 corresponds to the circuit 102 in FIG.

Note that the transistors 2501 to 2504 are n-channel transistors. Therefore, since all of the level shifters shown in FIG. 25 can be composed of N-channel transistors, the level shifter shown in FIG. 25 can use amorphous silicon for the semiconductor layer, and the manufacturing process can be simplified. . Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

The level shifter shown in FIG. 25 can simplify the manufacturing process even if polysilicon or single crystal silicon is used for the semiconductor layer.

Next, the operation of the level shifter shown in FIG. 25 will be described with reference to the timing chart of FIG. 16, similarly to FIG. However, the timing of potential change in the timing chart shown in FIG. 16 is arbitrary, and is not limited to the timing chart in FIG.

Note that FIG. 26 shows the operation of the level shifter in FIG. 25 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. FIG. 27 shows the operation of the level shifter in FIG. 25 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106. The operation in FIG. 26 is a first operation, and the operation in FIG. 27 is a second operation.

Since the operation of the offset circuit 1503 is the same as that of the offset circuit of FIG. 7A, detailed description of the operation of the offset circuit 1503 is omitted.

First, the first operation of the level shifter of FIG. 25 will be described with reference to the timing chart of FIG. 16 and FIG.

When the wiring 105 becomes L level, the potential of the node N71 becomes VSS. On the other hand, when the wiring 106 becomes H level, the potential of the node N72 becomes VSS + (VH−VL). Accordingly, the transistor 2502 and the transistor 2504 are turned on. When the transistor 2504 is turned on, the power supply potential VSS is supplied to the node N251, and the potential of the node N251 decreases. Note that the potential of the node N251 is determined by an operating point of the transistor 2503 and the transistor 2504 and is slightly higher than the power supply potential VSS. Since the node N251 is at the L level, the transistor 2501 is turned off. Further, when the transistor 2502 is turned on, the power supply potential VSS is supplied to the wiring 109, so that the potential of the wiring 109 is decreased. Note that the potential of the wiring 109 decreases to the power supply potential VSS, and an L signal is output from the wiring 109.

Next, the second operation of the level shifter of FIG. 25 will be described with reference to the timing chart of FIG. 16 and FIG.

When the wiring 105 becomes H level, the potential of the node N71 becomes VSS + (VH−VL). On the other hand, when the wiring 106 becomes L level, the potential of the node N72 becomes VSS. Accordingly, the transistor 2502 and the transistor 2504 are turned off. When the transistor 2504 is turned off, the power supply potential VDD is supplied to the node N251, and the potential of the node N251 increases. At the same time as the increase in the potential of the node N251, the transistor 2501 is turned on, the power supply potential VDD is supplied to the wiring 109, and the potential of the wiring 109 is also increased. Here, when the potential of the node N251 becomes a value obtained by subtracting the threshold voltage Vth2503 of the transistor 2503 from the power supply potential VDD (VDD−Vth2503), the transistor 2503 is turned off and the node N251 enters a floating state. Note that the potential of the wiring 109 continues to rise even when the potential of the node N251 becomes VDD−Vth2503. Therefore, the potential of the node N251 continues to increase due to capacitive coupling due to parasitic capacitance between the gate (node N251) of the transistor 2501 and the second terminal (wiring 109). Further, the increase in the potential of the node N251 continues until the increase in the potential of the wiring 109 is stopped, and the potential of the node N251 becomes a value equal to or higher than the sum (VDD + Vth2501) of the power supply potential VDD and the threshold voltage Vth2501 of the transistor 2501. Note that the increase in the potential of the wiring 109 stops when the potential of the wiring 109 becomes equal to the power supply potential VDD. This is a bootstrap operation. Accordingly, the potential of the wiring 109 becomes equal to the power supply potential VDD, and an H signal is output from the wiring 109.

Here, functions of the logic circuit 2500 will be described.

The logic circuit 2500 has a function of selecting whether to supply the power supply potential VDD to the wiring 109 or the power supply potential VSS to the wiring 109 depending on the potential of the node N72. In the case where the power supply potential VDD is supplied to the wiring 109, the gate potential of the transistor 2501 is set to VDD + Vth2501 or higher by a bootstrap operation so that the potential of the wiring 109 is equal to the power supply potential VDD.

Here, functions of the transistors 2501 to 2504 are described.

First, the transistor 2501 functions as a switch that selects whether to connect the wiring 103 and the wiring 109 depending on the potential of the node N251. In the second operation, the transistor 2501 is turned on and supplies the power supply potential VDD to the wiring 109.

In addition, the transistor 2502 functions as a switch that selects whether the wiring 104 and the wiring 109 are connected or not depending on the potential of the node N72. The transistor 2502 supplies the power supply potential VSS to the wiring 109 in the first operation.

The transistor 2503 has a function as a diode. The input terminal is a gate and a first terminal, and the output terminal is a second terminal.

The transistor 2504 functions as a switch for selecting whether to connect the wiring 104 and the node N251 depending on the potential of the node N72. The transistor 2504 supplies the power supply potential VSS to the node N251 in the first operation.

With the first operation and the second operation described above, the level shifter in FIG. 25 can make the potential of the wiring 109 equal to the power supply potential VSS in the first operation, and the potential of the wiring 109 in the second operation. Can be made equal to the power supply potential VDD.

Similarly to the logic circuit 1500 in FIG. 15, since the amplitude voltage of the gate of the transistor 2502 and the gate of the transistor 2504 is small, the through current of the logic circuit 2500 can be reduced.

Similarly to the logic circuit 1500 in FIG. 15, since the amplitude voltage of the gate of the transistor 2502 and the gate of the transistor 2504 is small, noise generated in the logic circuit 2500 is reduced.

Note that as described above, the capacitor 701 and the capacitor 702 can have a MOS structure. In the case of the level shifter shown in FIG. 25, it is preferable to form a capacitor element using an N-channel transistor as in the offset circuit shown in FIG. This is because by forming the capacitor element with an N-channel transistor, the level shifter shown in FIG. 25 can use amorphous silicon for the semiconductor layer, and the manufacturing process can be simplified. Therefore, the manufacturing cost can be reduced and the yield can be improved. Furthermore, a large semiconductor device can be manufactured.

The level shifter shown in FIG. 25 can simplify the manufacturing process by using polysilicon or single crystal silicon for the semiconductor layer.

As shown in FIG. 28, in the level shifter of FIG. 25, the gate of the transistor 2502 and the gate of the transistor 2504 may be connected to the node N71. In the case where the gate of the transistor 2502 and the gate of the transistor 2504 are connected to the node N71 (FIG. 28), as illustrated in the timing chart of FIG. 20, the signal (potential) of the wiring 109 is Compared with the case where the gate of the transistor 2504 is connected to the node N72 (FIG. 25), the H level and the L level are inverted. The operation of the level shifter in FIG. 28 is the same as that of the level shifter in FIG. Therefore, the connection destination of the gate of the transistor 2502 and the gate of the transistor 2504 may be the node N71 or the node N72, as appropriate.

Although not shown, two logic circuits may be connected to the node N71 and the node N72, respectively. By using the two logic circuits 2500, two signals in which the H level and the L level are inverted can be output. In the case where the two logic circuits are connected to the node N71 and the node N72, respectively, it is preferable that the capacitance value of the capacitor 701 and the capacitance value of the capacitor 702 be approximately equal as in FIG.

Here, the level shifter illustrated in FIG. 25 includes an N-channel transistor and a capacitor, but may include a P-channel transistor and a capacitor. FIG. 39 shows a level shifter in the case where a P-channel transistor and a capacitor are used.

The level shifter illustrated in FIG. 39 includes a capacitor 301, a capacitor 302, a transistor 501, a transistor 502, a transistor 3901, a transistor 3902, a transistor 3903, and a transistor 3904.

Note that the capacitor 301, the capacitor 302, the transistor 501, the transistor 502, the transistor 3901, the transistor 3902, the transistor 3903, and the transistor 3904 are the capacitor 701, the capacitor 702, the transistor 703, the transistor 703, and the transistor 2501 in FIG. Each of the transistors 2502, 2503, and 2504 corresponds to each other and has a similar function. Further, the logic circuit 3900 and the offset circuit 2903 correspond to the logic circuit 2500 and the offset circuit 1503 in FIG. 25, respectively, and have similar functions. Further, the node N51 and the node N52 correspond to the node N71 and the node N72 in FIG. 25, respectively.

A gate of the transistor 3902 is connected to the node N52, a first terminal is connected to the wiring 103, and a second terminal is connected to the wiring 109. A first terminal of the transistor 3901 is connected to the wiring 104, and a second terminal is connected to the wiring 109. A gate of the transistor 3903 is connected to the wiring 104, a first terminal is connected to the wiring 104, and a second terminal is connected to the gate of the transistor 3901. A gate of the transistor 3904 is connected to the contact N52, a first terminal is connected to the wiring 103, and a second terminal is connected to the gate of the transistor 3901. Note that a connection point of the gate of the transistor 3901, the second terminal of the transistor 3903, and the second terminal of the transistor 3904 is a node N391.

Next, the operation of the level shifter shown in FIG. 39 will be described with reference to the timing chart of FIG. However, the timing of potential change in the timing chart shown in FIG. 30 is arbitrary, and is not limited to the timing chart in FIG.

Note that FIG. 40 shows the operation of the level shifter in FIG. 39 when the L signal is supplied to the wiring 105 and the H signal is supplied to the wiring 106. FIG. 41 shows the operation of the level shifter in FIG. 39 when the H signal is supplied to the wiring 105 and the L signal is supplied to the wiring 106. 40 is a first operation, and the operation of FIG. 41 is a second operation.

Since the operation of the offset circuit 2903 is the same as that of the offset circuit of FIG. 5A, detailed description of the operation of the offset circuit 2903 is omitted.

First, the first operation of the level shifter of FIG. 39 will be described with reference to the timing chart of FIG. 30 and FIG.

When the wiring 105 becomes L level, the potential of the node N51 becomes VDD− (VH−VL). On the other hand, when the wiring 106 becomes H level, the potential of the node N52 becomes VDD. Accordingly, the transistor 3902 and the transistor 3904 are turned off. When the transistor 3904 is turned off, the power supply potential VSS is supplied to the node N391, and the potential of the node N391 decreases. Simultaneously with the decrease in the potential of the node N391, the transistor 3901 is turned on, the power supply potential VSS is supplied to the wiring 109, and the potential of the wiring 109 is also decreased. Here, when the potential of the node N391 becomes a value obtained by adding the power supply potential VSS and the absolute value of the threshold voltage Vth3903 of the transistor 3903 (VSS + | Vth3903 |), the transistor 3903 is turned off and the node N391 enters a floating state. Become. However, even when the potential of the node N391 becomes VSS + | Vth3903 |, the potential of the wiring 109 continues to decrease. Accordingly, the potential of the node N391 continues to decrease due to capacitive coupling due to parasitic capacitance between the gate (node N391) of the transistor 3901 and the second terminal (wiring 109). The decrease in the potential of the node N391 continues until the decrease in the potential of the wiring 109 is stopped, and the potential of the node N391 is a value obtained by adding the power supply potential VSS and the absolute value of the threshold voltage Vth3901 of the transistor 3901 (VSS + | Vth3901). |) The following values are obtained. Note that the decrease in the potential of the wiring 109 is stopped when the potential of the wiring 109 becomes equal to the power supply potential VSS. This is a so-called bootstrap operation. Accordingly, the potential of the wiring 109 becomes equal to the power supply potential VSS, and an L signal is output from the wiring 109.

Next, the second operation of the level shifter of FIG. 39 will be described with reference to the timing chart of FIG. 30 and FIG.

When the wiring 105 becomes H level, the potential of the node N51 becomes VDD. On the other hand, when the wiring 106 becomes L level, the potential of the node N52 becomes VDD− (VH−VL). Accordingly, the transistor 3902 and the transistor 3904 are turned on. When the transistor 3904 is turned on, the power supply potential VDD is supplied to the node N391, and the potential of the node N391 increases. Note that the potential of the node N391 is determined by an operating point of the transistor 3903 and the transistor 3904 and is slightly lower than the power supply potential VDD. Since the node N391 becomes L level, the transistor 3901 is turned off. Further, when the transistor 3902 is turned on, the power supply potential VDD is supplied to the wiring 109, so that the potential of the wiring 109 is increased. Note that the potential of the wiring 109 rises to the power supply potential VDD, and an H signal is output from the wiring 109.

With the first operation and the second operation described above, the level shifter in FIG. 39 can make the potential of the wiring 109 equal to the power supply potential VSS in the first operation, and the potential of the wiring 109 in the second operation. Can be made equal to the power supply potential VDD.

Similarly to the logic circuit 3900 in FIG. 39, since the amplitude voltage of the gate of the transistor 3902 and the gate of the transistor 3904 is small, the through current of the logic circuit 3900 can be reduced.

Similarly to the logic circuit 3900 in FIG. 39, since the amplitude voltage of the gate of the transistor 3902 and the gate of the transistor 3904 is small, noise generated in the logic circuit 3900 is reduced.

Note that as described above, the capacitor 301 and the capacitor 302 can have a MOS structure. Note that in the case of the level shifter in FIG. 39, it is preferable to form a capacitor element using a P-channel transistor as in the offset circuit in FIG.

42, in the level shifter of FIG. 39, the gate of the transistor 3902 and the gate of the transistor 3904 may be connected to the node N51. FIG. 36 shows a timing chart in the case where the gate of the transistor 3902 and the gate of the transistor 3904 are connected to the node N51.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Eighth embodiment)
In the present embodiment, a layout diagram of the level shifter of the present invention will be described.

First, the layout diagram of the level shifter shown in FIG. 15 will be described with reference to FIG.

43 shows the case where the semiconductor layer 4301, the first conductive layer 4302, and the second conductive layer 4303 are formed. Note that the first conductive layer 4302 functions as a gate electrode. The second conductive layer 4303 functions as a wiring layer.

FIG. 43 is a layout diagram in the case where a polycrystalline semiconductor (polysilicon) is used as the semiconductor layer 4301 of each transistor.

In the layout diagram of FIG. 43, a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 1501, and a transistor 1502 are arranged. Further, the wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

In addition, the transistor 703, the transistor 704, the transistor 1501, and the transistor 1502 are n-channel transistors.

Note that the capacitor 702 includes a semiconductor layer 4301 and a first conductive layer 4302 (gate electrode). That is, the capacitor element 702 functions as a MOS capacitor. Further, as described above, since the potential of the first conductive layer 4302 of the capacitor 702 is higher than the potential of the semiconductor layer 4301 of the capacitor 702, a channel is formed in the channel region of the semiconductor layer 4301. Therefore, the capacitor 702 can obtain a large capacitance.

Further, like the capacitor 702, the capacitor 701 includes a semiconductor layer 4301 and a first conductive layer 4302 (gate electrode). That is, the capacitor element 701 also functions as a MOS capacitor. Further, as described above, since the potential of the first conductive layer 4302 of the capacitor 701 is higher than the potential of the semiconductor layer 4301 of the capacitor 702, a channel is formed in the channel region of the semiconductor layer 4301. Therefore, the capacitor 701 can obtain a large capacitance.

Next, a layout diagram of the level shifter shown in FIG. 29 will be described with reference to FIG.

The layout diagram in FIG. 44 illustrates the case where the semiconductor layer 4401, the first conductive layer 4402, and the second conductive layer 4403 are formed. Note that the first conductive layer 4402 functions as a gate electrode. The second conductive layer 4403 functions as a wiring layer.

FIG. 44 is a layout diagram in the case where a polycrystalline semiconductor (polysilicon) is used as the semiconductor layer 4401 of each transistor.

44, a capacitor 301, a capacitor 302, a transistor 501, a transistor 502, a transistor 2901, and a transistor 2902 are arranged. The wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

In addition, the transistor 501, the transistor 502, the transistor 2901, and the transistor 2902 are p-channel transistors.

Note that the capacitor 301 includes a semiconductor layer 4401 and a first conductive layer 4402 (gate electrode). That is, the capacitive element 301 functions as a MOS capacitor. Further, as described above, since the potential of the first conductive layer 4402 of the capacitor 301 is lower than the potential of the semiconductor layer 4401 of the capacitor 301, a channel is formed in the channel region of the semiconductor layer 4401. Therefore, the capacitor 301 can obtain a large capacitance.

Note that as in the capacitor 301, the capacitor 302 includes a semiconductor layer 4401 and a first conductive layer 4402 (gate electrode). That is, the capacitor 302 also functions as a MOS capacitor. Further, as already described, since the potential of the first conductive layer 4402 of the capacitor 302 is lower than the potential of the semiconductor layer 4401 of the capacitor 302, a channel is formed in the channel region of the semiconductor layer 4401. Therefore, the capacitor 302 can obtain a large capacitance.

Next, another example of the layout diagram of the level shifter shown in FIG. 15 different from FIG. 43 will be described with reference to FIG.

The layout diagram of FIG. 45 illustrates the case where the semiconductor layer 4301, the first conductive layer 4302, and the second conductive layer 4303 are formed. Note that the first conductive layer 4302 functions as a gate electrode. The second conductive layer 4303 functions as a wiring layer.

45 is a layout diagram in the case where a polycrystalline semiconductor (polysilicon) is used as the semiconductor layer 4301 of each transistor.

45, a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 1501, and a transistor 1502 are arranged. Further, the wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

In addition, the transistor 703, the transistor 704, the transistor 1501, and the transistor 1502 are n-channel transistors.

Note that the capacitor 702 includes a first conductive layer 4302 and a second conductive layer 4303. This is because the first conductive layer 4302 and the second conductive layer 4303 are formed using a conductive material, and thus the capacitance value of the capacitor 702 is constant regardless of an applied voltage. Therefore, the level shifter shown in FIG. 45 can operate stably.

Note that the capacitor 701 includes a first conductive layer 4302 and a second conductive layer 4303. This is because the first conductive layer 4302 and the second conductive layer 4303 are formed using a conductive material, so that the capacitance value of the capacitor 701 is constant regardless of an applied voltage. Therefore, the level shifter shown in FIG. 45 can operate stably.

In addition, the first electrode of the capacitor 701 and the second electrode of the capacitor 702 are formed by the second conductive layer 4303, and the second electrode of the capacitor 701 and the first electrode of the capacitor 702 are the first conductive layers. It is formed by the layer 4302. This is because the layout area of the level shifter in FIG. 45 is reduced. Specifically, the layout area of the level shifter in FIG. 45 includes the first conductive layer 701 than the second conductive layer 4303 because the second electrode of the capacitor 701 is connected to the gate of the transistor 703. The size formed by the layer 4302 can be reduced. Similarly, the layout area of the level shifter in FIG. 45 is such that the second electrode of the capacitor 702 is connected to the second terminal of the transistor 703, and thus the second conductive layer is formed more than the first conductive layer 4302. The formation with the layer 4303 can be made smaller.

Next, another example of the layout diagram of the level shifter shown in FIG. 29 different from FIG. 44 will be described with reference to FIG.

The layout diagram of FIG. 46 illustrates the case where the semiconductor layer 4401, the first conductive layer 4402, and the second conductive layer 4403 are formed. Note that the first conductive layer 4402 functions as a gate electrode. The second conductive layer 4403 functions as a wiring layer.

46 is a layout diagram in the case where a polycrystalline semiconductor (polysilicon) is used as the semiconductor layer 4401 of each transistor.

In the layout diagram of FIG. 46, a capacitor 301, a capacitor 302, a transistor 501, a transistor 502, a transistor 2901, and a transistor 2902 are arranged. The wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

In addition, the transistor 501, the transistor 502, the transistor 2901, and the transistor 2902 are p-channel transistors.

Note that the capacitor 302 includes a first conductive layer 4402 and a second conductive layer 4403. This is because the first conductive layer 4402 and the second conductive layer 4403 are formed using a conductive material, and thus the capacitance value of the capacitor 302 is constant regardless of the applied voltage. Therefore, the level shifter shown in FIG. 46 can operate stably.

Note that the capacitor 301 includes a first conductive layer 4402 and a second conductive layer 4403. This is because the first conductive layer 4402 and the second conductive layer 4403 are formed using a conductive material, so that the capacitance value of the capacitor 301 is constant regardless of the applied voltage. Therefore, the level shifter shown in FIG. 46 can operate stably.

In addition, the first electrode of the capacitor 301 and the second electrode of the capacitor 302 are formed by the second conductive layer 4403, and the second electrode of the capacitor 301 and the first electrode of the capacitor 302 are formed of the first conductive layer. It is formed by the layer 4402. This is because the layout area of the level shifter in FIG. 46 is reduced. Specifically, the layout area of the level shifter in FIG. 46 is higher than that of the second conductive layer 4403 because the second electrode of the capacitor 301 is connected to the gate of the transistor 501. It can be made smaller if the layer 4402 is formed. Similarly, the layout area of the level shifter in FIG. 46 is such that the second electrode of the capacitor 302 is connected to the second terminal of the transistor 501, so that the second conductivity is higher than that of the first conductive layer 4402. The layer 4403 can be made smaller.

Next, a layout diagram of the level shifter shown in FIG. 15 will be described with reference to FIG.

The layout diagram of FIG. 47A shows the case where a semiconductor layer 4701, a first conductive layer 4702, a second conductive layer 4703, and a third conductive layer 4704 are formed. Note that the first conductive layer 4702 functions as a gate electrode. The second conductive layer 4703 functions as a wiring layer. The third conductive layer 4704 functions as a high resistance wiring layer.

FIG. 47A is a layout diagram in the case where an amorphous semiconductor (amorphous silicon) is used as the semiconductor layer 4701 of each transistor.

In the layout diagram of FIG. 47A, a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 1501, and a transistor 1502 are arranged. Further, the wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

Note that the capacitor 702 includes a semiconductor layer 4701 and a first conductive layer 4302 (gate electrode). That is, the capacitor element 702 functions as a MOS capacitor. Further, as described above, since the potential of the first conductive layer 4702 of the capacitor 702 is higher than the potential of the semiconductor layer 4701 of the capacitor 702, a channel is formed in the channel region of the semiconductor layer 4701. Therefore, the capacitor 702 can obtain a large capacitance.

Further, like the capacitor 702, the capacitor 701 includes a semiconductor layer 4701 and a first conductive layer 4702 (gate electrode). That is, the capacitor element 701 also functions as a MOS capacitor. Further, as described above, since the potential of the first conductive layer 4702 of the capacitor 701 is higher than the potential of the semiconductor layer 4701 of the capacitor 702, a channel is formed in the channel region of the semiconductor layer 4701. Therefore, the capacitor 701 can obtain a large capacitance.

Next, another example of the layout diagram of the level shifter shown in FIG. 15 that is different from FIG. 47A will be described with reference to FIG.

The layout diagram of FIG. 47B shows the case where a semiconductor layer 4701, a first conductive layer 4702, a second conductive layer 4703, and a third conductive layer 4704 are formed. Note that the first conductive layer 4702 functions as a gate electrode. The second conductive layer 4703 functions as a wiring layer. The third conductive layer 4704 functions as a high resistance wiring layer.

Note that FIG. 47B is a layout diagram in the case where an amorphous semiconductor (amorphous silicon) is used as the semiconductor layer 4701 of each transistor.

In the layout diagram of FIG. 47B, a capacitor 701, a capacitor 702, a transistor 703, a transistor 704, a transistor 1501, and a transistor 1502 are arranged. Further, the wiring 103, the wiring 104, the wiring 105, the wiring 106, and the wiring 109 are the same as those described with reference to FIG.

Note that the capacitor 702 includes a first conductive layer 4702 and a second conductive layer 4703. This is because the first conductive layer 4702 and the second conductive layer 4703 are formed using a conductive material, so that the capacitance value of the capacitor 702 is constant regardless of an applied voltage. Therefore, the level shifter shown in FIG. 47B can operate stably.

Note that the capacitor 701 includes a first conductive layer 4702 and a second conductive layer 4703. This is because the first conductive layer 4702 and the second conductive layer 4703 are formed using a conductive material, and thus the capacitance value of the capacitor 701 is constant regardless of the applied voltage. Therefore, the level shifter shown in FIG. 47B can operate stably.

In addition, the first electrode of the capacitor 701 and the second electrode of the capacitor 702 are formed by the second conductive layer 4703, and the second electrode of the capacitor 701 and the first electrode of the capacitor 702 are formed of the first conductive layer. The layer 4702 is formed. This is because the layout area of the level shifter in FIG. Specifically, the layout area of the level shifter in FIG. 47B is higher than that of the second conductive layer 4303 because the second electrode of the capacitor 701 is connected to the gate of the transistor 703. One conductive layer 4302 can be made smaller. Similarly, the layout area of the level shifter in FIG. 47B is higher than that of the first conductive layer 4302 because the second electrode of the capacitor 702 is connected to the second terminal of the transistor 703. Two conductive layers 4403 can be made smaller.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Ninth embodiment)
In the ninth embodiment, an example of a panel in which a plurality of pixels is formed will be described with reference to FIG. 62A, the panel 191 includes a pixel portion 591 including a plurality of pixels 590 arranged in a matrix. The pixel portion 591 can have an active matrix structure in which a switching element such as a thin film transistor is provided for each pixel 590. As a display medium of the pixel 590, a light-emitting element such as an electroluminescence element or a liquid crystal element may be provided.

Note that as illustrated in FIG. 62B, a driver circuit for driving the pixel portion 591 may be provided over the same substrate as the substrate over which the pixel portion 591 is formed. 62B, the same portions as those in FIG. 62A are denoted by the same reference numerals, and description thereof is omitted. FIG. 62B shows a source driver 593 and a gate driver 594 as driver circuits. Note that the present invention is not limited to this, and a driver circuit may be further provided in addition to the source driver 593 and the gate driver 594. The driver circuit may be mounted on a substrate over which another pixel portion 591 is formed. For example, the pixel portion 591 may be formed using a thin film transistor over a glass substrate, the driver circuit may be formed over a single crystal substrate, and the IC chip may be connected to the glass substrate by COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate by TAB (Tape Automated Bonding), or may be connected to the glass substrate using a printed board.

The driver circuit may be formed using a thin film transistor formed in the same process as the thin film transistor included in the pixel 590 over the same substrate as the substrate over which the pixel portion 591 is formed. The channel formation region of the thin film transistor may be formed of a polycrystalline semiconductor or an amorphous semiconductor.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Tenth embodiment)
FIG. 63A shows a configuration example (hereinafter referred to as a first pixel configuration) of the pixel portion 591 shown in FIGS. 62A and 62B. The pixel portion 591 includes a plurality of source signal lines S1 to Sp (p is a natural number), a plurality of scanning lines G1 to Gq (q is a natural number) provided so as to intersect the plurality of source signal lines S1 to Sp, and The pixel 690 is provided at each intersection of the source signal lines S1 to Sp and the scanning lines G1 to Gq.

A structure of the pixel 690 in FIG. 63A is illustrated in FIG. In FIG. 63B, one Sx (x is a natural number less than or equal to p) among the plurality of source signal lines S1 to Sp and one Gy (y is less than or equal to q) among the plurality of scan lines G1 to Gq. A pixel 690 formed at an intersection with (natural number) is shown. The pixel 690 includes a first transistor 691, a second transistor 692, a capacitor 693, and a light-emitting element 694. Note that in this embodiment, an example is described in which a light-emitting element 694 includes a pair of electrodes and emits light when current flows between the pair of electrodes. Further, as the capacitor 693, the parasitic capacitance of the second transistor 692 or the like may be positively used. The first transistor 691 and the second transistor 692 may be n-channel transistors or p-channel transistors. A thin film transistor can be used as a transistor included in the pixel 690.

The gate of the first transistor 691 is connected to the scan line Gy, one of the source and the drain of the first transistor 691 is connected to the source signal line Sx, and the other is one of the gate of the second transistor 692 and the capacitor 693. Connected to the electrode. The other electrode of the capacitor 693 is connected to a terminal 695 to which a potential V3 is applied. One of a source and a drain of the second transistor 692 is connected to one electrode of the light-emitting element 694, and the other is connected to a terminal 696 to which a potential V2 is applied. The other electrode of the light-emitting element 694 is connected to a terminal 697 to which a potential V1 is applied.

A display method of the pixel portion 591 illustrated in FIGS. 63A and 63B is described.

One of the plurality of scanning lines G1 to Gq is selected, and an image signal is input to all of the plurality of source signal lines S1 to Sp while the scanning line is selected. Thus, an image signal is input to one row of pixels in the pixel portion 591. A plurality of scanning lines G1 to Gq are sequentially selected and the same operation is performed, and an image signal is input to all the pixels 690 in the pixel portion 591.

An operation of the pixel 690 in which one Gy of the plurality of scanning lines G1 to Gq is selected and an image signal is input from one of the plurality of source signal lines S1 to Sp will be described. When the scanning line Gy is selected, the first transistor 691 is turned on. The on state of the transistor means that the source and the drain are conductive, and the off state of the transistor means that the source and the drain are nonconductive. When the first transistor 691 is turned on, the image signal input to the source signal line Sx is input to the gate of the second transistor 692 through the first transistor 691. The second transistor 692 is selected to be on or off depending on the input image signal. When the on state of the second transistor 692 is selected, the drain current of the second transistor 692 flows to the light-emitting element 694, and the light-emitting element 694 emits light.

The potential V2 and the potential V3 are kept so that the potential difference is always constant when the second transistor 692 is turned on. The potential V2 and the potential V3 may be the same potential. In the case where the potential V2 and the potential V3 are the same, the terminal 695 and the terminal 696 may be connected to the same wiring. The potential V1 and the potential V2 are set so as to have a predetermined potential difference when the light emitting element 694 is selected to emit light. In this manner, a current is supplied to the light emitting element 694 so that the light emitting element 694 emits light.

  In addition, wiring and an electrode are aluminum (Al), tantalum (Ta), titanium (Ti), molybdenum (Mo), tungsten (W), neodymium (Nd), chromium (Cr), nickel (Ni), platinum (Pt ), Gold (Au), silver (Ag), copper (Cu), magnesium (Mg), scandium (Sc), cobalt (Co), zinc (Zn), niobium (Nb), silicon (Si), phosphorus (P ), Boron (B), arsenic (As), gallium (Ga), indium (In), tin (Sn), oxygen (O), or one or more elements selected from the group consisting of Compounds or alloy materials containing one or more elements selected from the group (for example, indium tin oxide (ITO), indium zinc oxide (IZO, Indium)) Zinc Oxide), indium tin oxide containing silicon oxide (ITSO), zinc oxide (ZnO), aluminum neodymium (Al—Nd), magnesium silver (Mg—Ag), etc.), or a combination of these compounds Formed. Alternatively, a silicon compound (silicide) (for example, aluminum silicon, molybdenum silicon, nickel silicide, or the like) or a nitrogen compound (for example, titanium nitride, tantalum nitride, molybdenum nitride, or the like) is formed. . Note that silicon (Si) may contain a large amount of n-type impurities (such as phosphorus) and p-type impurities (such as boron). By containing these impurities, the conductivity is improved or the same behavior as that of a normal conductor is obtained, so that it can be easily used as a wiring or an electrode. Silicon may be single crystal, polycrystalline (polysilicon), or amorphous (amorphous silicon). The resistance can be reduced by using single crystal silicon or polycrystalline silicon. By using amorphous silicon, it can be manufactured by a simple manufacturing process. Note that since aluminum and silver have high conductivity, signal delay can be reduced and etching is easy, so that patterning is easy and microfabrication can be performed. Note that since copper has high conductivity, signal delay can be reduced. Molybdenum can be manufactured without causing problems such as defective materials even when it comes in contact with oxide semiconductors such as ITO and IZO, and silicon, and is easy to pattern and etch, and has high heat resistance. Desirable because it is expensive. Titanium is desirable because it can be manufactured without causing problems such as failure of the material even when it comes into contact with an oxide semiconductor such as ITO or IZO or silicon, and has high heat resistance. Tungsten is desirable because of its high heat resistance. Neodymium is desirable because of its high heat resistance. In particular, an alloy of neodymium and aluminum is preferable because the heat resistance is improved and aluminum does not easily cause hillocks. Silicon is preferable because it can be formed at the same time as a semiconductor layer included in the transistor and has high heat resistance. Note that indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), zinc oxide (ZnO), and silicon (Si) have translucency. Therefore, it is desirable because it can be used for a portion that transmits light. For example, it can be used as a pixel electrode or a common electrode.

In addition, these may form wiring and an electrode with a single layer, and may have a multilayer structure. By forming with a single layer structure, the manufacturing process can be simplified, the number of process days can be reduced, and the cost can be reduced. In addition, by using a multilayer structure, it is possible to take advantage of each material, reduce demerits, and form wiring and electrodes with good performance. For example, by including a low-resistance material (such as aluminum) in the multilayer structure, the resistance of the wiring can be reduced. In addition, if a material having high heat resistance is included, for example, a wiring or electrode as a whole can be obtained by forming a laminated structure in which a material having low merit is sandwiched between materials having another merit. As a result, the heat resistance can be increased. For example, it is preferable to form a layered structure in which a layer containing aluminum is sandwiched between layers containing molybdenum or titanium. In addition, if there is a portion that is in direct contact with a wiring or electrode of another material, it may adversely affect each other. For example, one material may be contained in the other material, changing its properties and failing to fulfill its original purpose, or producing a problem and making it impossible to manufacture normally. is there. In such a case, the problem can be solved by sandwiching or covering one layer with another layer. For example, when indium tin oxide (ITO) and aluminum are in contact with each other, it is desirable to sandwich titanium or molybdenum between them. In addition, when silicon and aluminum are to be brought into contact with each other, it is desirable to sandwich titanium or molybdenum between them.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Eleventh embodiment)
FIG. 64A illustrates a configuration example of the pixel portion 591 illustrated in FIGS. 62A and 62B. FIG. 64A shows an example (hereinafter referred to as a second pixel configuration) different from the first pixel configuration shown in the eleventh embodiment. The pixel portion 591 includes a plurality of source signal lines S1 to Sp (p is a natural number), a plurality of scanning lines G1 to Gq (q is a natural number) and a plurality of scanning lines G1 to Gq provided so as to intersect the plurality of source signal lines S1 to Sp. Scanning lines R1 to Rq, and pixel 790 provided at each intersection of the source signal lines S1 to Sp and the scanning lines G1 to Gq.

A structure of the pixel 790 in FIG. 64A is illustrated in FIG. In FIG. 64B, one Sx (x is a natural number less than or equal to p) among the plurality of source signal lines S1 to Sp and one Gy (y is less than or equal to q) among the plurality of scan lines G1 to Gq. A natural number) and a pixel 790 formed at the intersection with one Ry of the plurality of scanning lines R1 to Rq are shown. Note that in the pixel having the structure illustrated in FIG. 64B, the same portions as those in FIG. 63B are denoted by the same reference numerals, and description thereof is omitted. FIG. 64B is different in that the pixel 690 illustrated in FIG. 63B includes the third transistor 791. The third transistor 791 may be an n-channel transistor or a p-channel transistor. A thin film transistor can be used as a transistor included in the pixel 790.

The gate of the third transistor 791 is connected to the scan line Ry, one of the source and the drain of the third transistor 791 is connected to the gate of the second transistor 692 and one electrode of the capacitor 693, and the other is connected to the potential V4. Is connected to a terminal 792.

A display method of the pixel portion 591 illustrated in FIGS. 64A and 64B will be described.

The method for causing the light emitting element 694 to emit light is the same as the method described in the tenth embodiment. 64A and 64B includes the scan line Ry and the third transistor 791, so that the pixel 790 emits light regardless of the image signal input from the source signal line Sx. A feature is that the element 694 can emit no light. The time during which the light emitting element 694 of the pixel 790 emits light can be set by a signal input to the scanning line Ry. In this way, it is possible to set a light emission period shorter than a period in which the scanning lines G1 to Gq are sequentially selected and all the scanning lines G1 to Gq are selected. Thus, when display is performed in a time division gray scale method, a short subframe period can be set, so that high gray scale can be expressed.

The potential V4 may be set so that the second transistor 692 is turned off when the third transistor 791 is turned on. For example, the potential V4 can be set to be the same potential as the potential V3 when the third transistor 791 is turned on. By making the potential V3 and the potential V4 the same, the charge held in the capacitor 693 is discharged, the voltage between the source and the gate of the second transistor 692 is set to zero, and the second transistor 692 is turned off. can do. Note that in the case where the potential V3 and the potential V4 are the same, the terminal 695 and the terminal 792 may be connected to the same wiring.

Note that the third transistor 791 is not limited to the arrangement shown in FIG. For example, the third transistor 791 may be arranged in series with the second transistor 692. In this structure, the third transistor 791 is turned off by a signal input to the scan line Ry, whereby the current flowing through the light-emitting element 694 can be cut off and the light-emitting element 694 can be made non-light-emitting.

A diode can be used instead of the third transistor 791 shown in FIG. A structure of a pixel in which a diode is used instead of the third transistor 791 is illustrated in FIG. Note that in FIG. 64C, the same portions as those in FIG. 64B are denoted by the same reference numerals, and description thereof is omitted. One electrode of the diode 781 is connected to the scan line Ry, and the other electrode is connected to the gate of the second transistor 692 and one electrode of the capacitor 693.

The diode 781 allows a current to flow from one electrode to the other electrode. The second transistor 692 is a p-channel transistor. By increasing the potential of one electrode of the diode 781, the potential of the gate of the second transistor 692 can be increased, so that the second transistor 692 can be turned off.

In FIG. 64C, the diode 781 flows current from one electrode connected to the scan line Ry to the other electrode connected to the gate of the second transistor 692, and the second transistor 692 is connected to the p-channel. Although a configuration of a type transistor is shown, the present invention is not limited to this. The diode 781 has a configuration in which current flows from the other electrode connected to the gate of the second transistor 692 to one electrode connected to the scanning line Ry, and the second transistor 692 is an n-channel transistor. Also good. When the second transistor 692 is an n-channel transistor, the potential of one electrode of the diode 781 is decreased to decrease the potential of the gate of the second transistor 692 so that the second transistor 692 is turned off. It can be.

As the diode 781, a diode-connected transistor may be used. A diode-connected transistor refers to a transistor having a drain and a gate connected to each other. As the diode-connected transistor, a p-channel transistor or an n-channel transistor may be used.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Twelfth embodiment)
FIG. 65A shows an example of a structure of the pixel portion 591 shown in FIGS. 62A and 62B (hereinafter referred to as a third pixel structure). The pixel portion 591 includes a plurality of source signal lines S1 to Sp (p is a natural number), a plurality of scanning lines G1 to Gq (q is a natural number) provided so as to intersect the plurality of source signal lines S1 to Sp, and The pixel 690 is provided at each intersection of the source signal lines S1 to Sp and the scanning lines G1 to Gq.

A structure of the pixel 690 in FIG. 65A is illustrated in FIG. In FIG. 65B, one Sx (x is a natural number less than or equal to p) of the plurality of source signal lines S1 to Sp and one Gy (y is less than or equal to q) among the plurality of scan lines G1 to Gq. A pixel 690 formed at an intersection with (natural number) is shown. A capacitor line C0 is provided corresponding to each row. The pixel 690 includes a transistor 4691, a liquid crystal element 4692, and a capacitor 4693. The transistor 4691 may be an n-channel transistor or a p-channel transistor. A thin film transistor can be used as a transistor included in the pixel 690.

A gate of the transistor 4691 is connected to the scan line Gy, one of a source and a drain of the transistor 4691 is connected to the source signal line Sx, and the other is connected to one electrode of the liquid crystal element 4692 and one electrode of the capacitor element 4893. . The other electrode of the liquid crystal element 4692 is connected to a terminal 4694 to which a potential V0 is applied. The other electrode of the capacitor 4663 is connected to the capacitor line C0. The same potential as the potential V0 applied to the terminal 4694 is applied to the capacitor line C0.

A display method of the pixel portion 591 illustrated in FIGS. 65A and 65B is described.

One of the plurality of scanning lines G1 to Gq is selected, and an image signal is input to all of the plurality of source signal lines S1 to Sp while the scanning line is selected. Thus, an image signal is input to one row of pixels in the pixel portion 591. A plurality of scanning lines G1 to Gq are sequentially selected and the same operation is performed, and an image signal is input to all the pixels 690 in the pixel portion 591.

An operation of the pixel 690 in which one Gy of the plurality of scanning lines G1 to Gq is selected and an image signal is input from one of the plurality of source signal lines S1 to Sp will be described. When the scanning line Gy is selected, the transistor 4691 is turned on. The on state of the transistor means that the source and the drain are conductive, and the off state of the transistor means that the source and the drain are nonconductive. When the transistor 4691 is turned on, the image signal input to the source signal line Sx is input to one electrode of the liquid crystal element 4692 and one electrode of the capacitor element 4693 through the transistor 4691. Thus, a voltage (corresponding to a potential difference between the potential of the input image signal and the potential V0 of the terminal 4694) is applied between the pair of electrodes of the liquid crystal element 4692, and the transmittance of the liquid crystal element 4692 changes.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(13th Embodiment)
In this embodiment, an example in which a pixel is actually manufactured will be described. 48A and 48B are cross-sectional views of the pixels of the panel described in the eleventh to twelfth embodiments. An example of a light-emitting device using a TFT as a switching element arranged in a pixel and using a light-emitting element as a display medium arranged in the pixel will be described.

48A and 48B, 1000 is a substrate, 1001 is a base film, 1002 is a semiconductor layer, 1102 is a semiconductor layer, 1003 is a first insulating film, 1004 is a gate electrode, 1104 is an electrode, 1005 Is a second insulating film, 1006 is an electrode, 1007 is a first electrode, 1008 is a third insulating film, 1009 is a light emitting layer, and 1010 is a second electrode. Reference numeral 1100 denotes a TFT, 1011 denotes a light emitting element, and 1101 denotes a capacitor element. In FIG. 48, the TFT 1100 and the capacitor 1101 are shown as representatives as elements constituting the pixel. The structure of FIG. 48A is described.

As the substrate 1000, for example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, a ceramic substrate, or the like can be used. Alternatively, a metal substrate containing stainless steel or a semiconductor substrate with an insulating film formed on the surface thereof may be used. A substrate made of a synthetic resin having flexibility such as plastic may be used. The surface of the substrate 1000 may be planarized by polishing such as a CMP method.

As the base film 1001, an insulating film such as silicon oxide, silicon nitride, or silicon nitride oxide can be used. The base film 1001 can prevent alkali metal such as Na or alkaline earth metal contained in the substrate 1000 from diffusing into the semiconductor layer 1002 and adversely affecting the characteristics of the TFT 1100. In FIG. 48, the base film 1001 has a single-layer structure, but it may be formed of two or more layers. Note that the base film 1001 is not necessarily provided when diffusion of impurities such as a quartz substrate does not cause any problem.

As the semiconductor layer 1002 and the semiconductor layer 1102, a crystalline semiconductor film or an amorphous semiconductor film processed into a predetermined shape can be used. The crystalline semiconductor film can be obtained by crystallizing an amorphous semiconductor film. As a crystallization method, a laser crystallization method, a thermal crystallization method using an RTA or a furnace annealing furnace, a thermal crystallization method using a metal element that promotes crystallization, or the like can be used. The semiconductor layer 1002 includes a channel formation region and a pair of impurity regions to which an impurity element imparting a conductivity type is added. Note that an impurity region (LDD region) to which the impurity element is added at a low concentration may be provided between the channel formation region and the pair of impurity regions. The semiconductor layer 1102 can have a structure in which an impurity element imparting conductivity is added to the whole.

As the first insulating film 1003, silicon oxide, silicon nitride, silicon nitride oxide, or the like can be used, and a single layer or a plurality of films can be stacked.

Note that a film containing hydrogen may be used as the first insulating film 1003 and the semiconductor layer 1002 may be hydrogenated.

As the gate electrode 1004 and the electrode 1104, one kind of element selected from Ta, W, Ti, Mo, Al, Cu, Cr, and Nd, or an alloy or compound containing a plurality of such elements can be used. Furthermore, these single layers or laminated structures can be used.

The TFT 1100 includes a semiconductor layer 1002, a gate electrode 1004, and a first insulating film 1003 between the semiconductor layer 1002 and the gate electrode 1004. In FIG. 48, only the TFT 1100 connected to the first electrode 1007 of the light-emitting element 1011 is illustrated as a TFT included in the pixel; however, a structure including a plurality of TFTs may be used. In this embodiment, the TFT 1100 is shown as a top gate type transistor. However, a bottom gate type transistor having a gate electrode below the semiconductor layer may be used, or a dual gate having gate electrodes above and below the semiconductor layer. It may be a gate type transistor.

The capacitor 1101 includes a first insulating film 1003 as a dielectric, and a semiconductor layer 1102 and an electrode 1104 that face each other with the first insulating film 1003 interposed therebetween as a pair of electrodes. Note that in FIG. 48, as a capacitor element included in a pixel, one of a pair of electrodes is a semiconductor layer 1102 formed at the same time as the semiconductor layer 1002 of the TFT 1100 and the other electrode is an electrode 1104 formed at the same time as the gate electrode 1004 of the TFT 1100. However, the present invention is not limited to this configuration.

As the second insulating film 1005, a single layer or a stacked layer of an inorganic insulating film or an organic insulating film can be used. As the inorganic insulating film, a silicon oxide film formed by a CVD method, a silicon oxide film formed by a SOG (Spin On Glass) method, or the like can be used. As an organic insulating film, polyimide, polyamide, BCB (benzocyclobutene) can be used. ), A film of acrylic or positive photosensitive organic resin, negative photosensitive organic resin, or the like can be used.

For the second insulating film 1005, a material in which a skeleton structure is formed by a bond of silicon (Si) and oxygen (O) can be used. As a substituent of this material, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen as a substituent and a fluoro group may be used.

Note that the surface of the second insulating film 1005 may be nitrided by treatment with high-density plasma. The high density plasma is generated by using a high frequency microwave, for example 2.45 GHz. Note that as the high-density plasma, one having an electron density of 10 ¹¹ cm ⁻³ or more and an electron temperature of 0.2 eV or more and 2.0 eV or less (more preferably 0.5 eV or more and 1.5 eV or less) is used. As described above, high-density plasma characterized by low electron temperature has low kinetic energy of active species, and thus can form a film with less plasma damage and fewer defects than conventional plasma treatment. In the high density plasma treatment, the substrate 1000 is set to a temperature of 350 ° C. to 450 ° C. In the apparatus for generating high-density plasma, the distance from the antenna that generates microwaves to the substrate 1000 is 20 mm to 80 mm (preferably 20 mm to 60 mm).

In an atmosphere of nitrogen (N) and a rare gas (including at least one of He, Ne, Ar, Kr, and Xe), nitrogen and hydrogen (H) and a rare gas atmosphere, or NH ₃ and a rare gas atmosphere The surface of the second insulating film 1005 is nitrided by performing the high density plasma treatment. H, He, Ne, Ar, Kr, and Xe elements are mixed in the surface of the second insulating film 1005 formed by nitriding treatment with high-density plasma. For example, a silicon oxide film or a silicon oxynitride film is used as the second insulating film 1005, and a silicon nitride film is formed by processing the surface of the film with high-density plasma. Hydrogen contained in the silicon nitride film formed in this manner may be used to hydrogenate the semiconductor layer 1002 of the TFT 1100. Note that this hydrogenation treatment may be combined with the hydrogenation treatment using hydrogen in the first insulating film 1003 described above.

Note that an insulating film may be further formed over the nitride film formed by the high-density plasma treatment to form the second insulating film 1005.

As the electrode 1006, a kind of element selected from Al, W, Mo, Ti, Pt, Cu, Ta, Au, Mn, or Al, Ni, C, W, Mo, Ti, Pt, Cu, Ta, Au An alloy selected from Mn and containing two or more elements can be used. Furthermore, these single layers or laminated structures can be used.

One or both of the first electrode 1007 and the second electrode 1010 can be a transparent electrode. As the transparent electrode, indium oxide containing tungsten oxide (IWO), indium oxide containing tungsten oxide and zinc oxide (IWZO), indium oxide containing titanium oxide (ITO), indium tin oxide containing titanium oxide (ITTiO) ) Etc. can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

The light emitting element is divided into a light emitting element that emits light when a DC voltage is applied (hereinafter referred to as a DC driving light emitting element) and a light emitting element that emits light when an AC voltage is applied (hereinafter referred to as an AC driven light emitting element). It is done.

In the direct current drive light emitting device, the light emitting layer is preferably configured using a plurality of layers having different functions such as a hole injection transport layer, a light emission layer, and an electron injection transport layer.

The hole injecting and transporting layer is preferably formed of a composite material including a hole transporting organic compound material and an inorganic compound material that exhibits an electron accepting property with respect to the organic compound material. By adopting such a configuration, many hole carriers are generated in an organic compound that has essentially no intrinsic carrier, and extremely excellent hole injecting and transporting properties can be obtained. Due to this effect, the drive voltage can be made lower than in the prior art. In addition, since the hole injecting and transporting layer can be thickened without causing an increase in driving voltage, a short circuit of the light emitting element due to dust or the like can be suppressed.

As a hole-transporting organic compound material, 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 1,3,5- Tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m-MTDAB), N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl- 4,4′-diamine (abbreviation: TPD), 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), and the like, but are not limited thereto. There is no.

Examples of the inorganic compound material that exhibits electron acceptability include titanium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, and zinc oxide. Vanadium oxide, molybdenum oxide, tungsten oxide, and rhenium oxide are particularly preferable because they can be vacuum-deposited and are easy to handle.

The electron injecting and transporting layer is formed using an organic compound material having an electron transporting property. Specific examples include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), and the like, but are not limited thereto. .

In the direct current drive light emitting element, the light emitting layer has 9,10-di (2-naphthyl) anthracene (abbreviation: DNA), 9,10-di (2-naphthyl) -2-tert-butylanthracene (abbreviation: t-BuDNA). ), 4,4′-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), coumarin 30, coumarin 6, coumarin 545, coumarin 545T, perylene, rubrene, periflanthene, 2,5,8,11-tetra (Tert-butyl) perylene (abbreviation: TBP), 9,10-diphenylanthracene (abbreviation: DPA), 5,12-diphenyltetracene, 4- (dicyanomethylene) -2-methyl- [p- (dimethylamino) styryl ] -4H-pyran (abbreviation: DCM1), 4- (dicyanomethylene) -2-methyl-6- [2- (julolidine) -9-yl) ethenyl] -4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) styryl] -4H-pyran (abbreviation: BisDCM), and the like. It is done. In addition, bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (picolinate) (abbreviation: FIrpic), bis {2- [3 ′, 5′-bis (trifluoromethyl) ) Phenyl] pyridinato-N, C ^{2 ′} } iridium (picolinate) (abbreviation: Ir (CF ₃ ppy) ₂ (pic)), tris (2-phenylpyridinato-N, C ^{2 ′} ) iridium (abbreviation: Ir (Ppy) ₃ ), bis (2-phenylpyridinato-N, C ^{2 ′} ) iridium (acetylacetonate) (abbreviation: Ir (ppy) ₂ (acac)), bis [2- (2′-thienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) _{(abbreviation: Ir (thp) 2 (acac} )), bis (2-phenylquinolinato--N, C ^2') iridium (Asechirua Tonato) _{(abbreviation: Ir (pq) 2 (acac} )), bis [2- (2'-benzothienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) (abbreviation: Ir _(btp) 2 (acac A compound capable of emitting phosphorescence such as)) can also be used.

In addition, examples of the polymer electroluminescent material that can be used for forming the light emitting layer include polyparaphenylene vinylene, polyparaphenylene, polythiophene, and polyfluorene.

The other of the first electrode 1007 and the second electrode 1010 may be formed using a material that does not transmit light. For example, alkali metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr, alloys containing these (Mg: Ag, Al: Li, Mg: In, etc.), and compounds thereof (CaF ₂ , In addition to calcium nitride), rare earth metals such as Yb and Er can be used.

The third insulating film 1008 can be formed using a material similar to that of the second insulating film 1005. The third insulating film 1008 is formed around the first electrode 1007 so as to cover the end portion of the first electrode 1007, and has a function of separating the light emitting layer 1009 in adjacent pixels.

The light emitting layer 1009 is composed of one or more layers. When composed of a plurality of layers, these layers can be classified into a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like from the viewpoint of carrier transport characteristics. Note that the boundaries between the layers are not necessarily clear, and there are cases where the materials constituting the layers are partially mixed and the interface is unclear. For each layer, an organic material or an inorganic material can be used. As the organic material, any of a high molecular weight material and a low molecular weight material can be used.

The light-emitting element 1011 includes a light-emitting layer 1009 and a first electrode 1007 and a second electrode 1010 that overlap with each other with the light-emitting layer 1009 interposed therebetween. One of the first electrode 1007 and the second electrode 1010 corresponds to an anode, and the other corresponds to a cathode. When a voltage larger than the threshold voltage is applied between the anode and the cathode with a forward bias, the light-emitting element 1011 emits light by current flowing from the anode to the cathode.

On the other hand, an AC drive light emitting element has an insulating double structure having a light emitting layer sandwiched between two insulating films between a pair of electrodes, and emits light when an AC voltage is applied between the pair of electrodes. can get. In the AC drive light-emitting element, ZnS, SrS, BaAl ₂ S ₄ or the like can be used for the light-emitting layer. As the insulating film sandwiching the light emitting layer, Ta ₂ O ₅ , SiO ₂ , Y ₂ O ₃ , BaTiO ₃ , SrTiO ₃ , silicon nitride, or the like can be used.

The structure in FIG. 48B will be described. Note that the same portions as those in FIG. 48A are denoted by the same reference numerals, and description thereof is omitted.

FIG. 48B illustrates a structure in which the insulating film 1108 is provided between the second insulating film 1005 and the third insulating film 1008 in FIG. The electrode 1006 and the first electrode 1007 are connected to each other through the electrode 1106 in a contact hole provided in the insulating film 1108.

Note that the electrode 1106 is not necessarily required. That is, the first electrode 1007 may be directly connected to the electrode 1006 without the electrode 1106 interposed therebetween. Thus, the number of steps for forming the electrode 1106 can be reduced, and cost can be reduced.

Further, in the case where the first electrode 1007 is directly connected to the electrode 1006 without using the electrode 1106, the covering property of the first electrode 1007 may be deteriorated depending on the material and the manufacturing method of the first electrode 1007, which may cause disconnection. . In such a case, as shown in FIG. 48B, it is advantageous to connect the electrode 1006 and the first electrode 1007 with the electrode 1106 in the contact hole provided in the insulating film 1108.

The insulating film 1108 can have a structure similar to that of the second insulating film 1005. The electrode 1106 can have a structure similar to that of the electrode 1006.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Fourteenth embodiment)
In this embodiment, an example in which a pixel is actually manufactured will be described. FIG. 49 is a cross-sectional view of a pixel of the panel described in the ninth to eleventh embodiments. An example of a light-emitting device using a TFT as a switching element arranged in a pixel and using a light-emitting element as a display medium arranged in the pixel will be described. In addition, the same part as FIG. 48 shown in 13th Embodiment is shown using the same code | symbol, and description is abbreviate | omitted.

The pixel shown in FIG. 49 differs from the configuration shown in FIG. 48A in the thirteenth embodiment in the configuration of the TFT 1100 and the capacitor 1101. This is an example in which a bottom-gate TFT is used as the TFT 1100. The TFT 1100 includes a gate electrode 2703, a semiconductor layer having a channel formation region 2706, an LDD region 2707, and an impurity region 2708, a gate electrode 2703, and a first insulating film 2705 between the semiconductor layer. The first insulating film 2705 functions as a gate insulating film of the TFT 1100. The impurity region 2708 becomes a source region and a drain region of the TFT 1100.

The capacitor 1101 includes a first insulating film 2705 as a dielectric, and a semiconductor layer and an electrode 2704 facing each other with the first insulating film 2705 interposed therebetween as a pair of electrodes. The semiconductor layer includes a channel formation region 2709, an LDD region 2710, and an impurity region 2711. Note that in FIG. 49, as a capacitor element included in a pixel, one of a pair of electrodes is a semiconductor layer formed at the same time as a semiconductor layer serving as an active layer of the TFT 1100 and the other electrode is formed at the same time as a gate electrode 2703 of the TFT 1100 Although an example in which the electrode 2704 is used is shown, the present invention is not limited to this configuration.

A semiconductor layer including the channel formation region 2706, the LDD region 2707, and the impurity region 2708, and a semiconductor layer including the channel formation region 2709, the LDD region 2710, and the impurity region 2711 are similar to the semiconductor layer 1002 and the semiconductor layer 1102 in FIG. Materials can be used. As the first insulating film 2705, a material similar to that of the first insulating film 1003 in FIG. 48 can be used. As the gate electrode 2703 and the electrode 2704, a material similar to that of the gate electrode 1004 in FIG. 48 can be used.

An impurity element imparting a conductivity type may be added to the channel formation region 2706 and the channel formation region 2709.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Fifteenth embodiment)
In this embodiment, an example in which a pixel is actually manufactured will be described. FIG. 50 is a cross-sectional view of a pixel of the panel described in the eleventh embodiment. An example of a light-emitting device using a TFT as a switching element arranged in a pixel and using a light-emitting element as a display medium arranged in the pixel will be described. In addition, the same part as FIG. 48 shown in 13th Embodiment is shown using the same code | symbol, and description is abbreviate | omitted.

The pixels shown in FIGS. 50A and 50B are different in the configuration of the TFT 1100 and the capacitor 1101 from the configuration shown in FIG. 48A in the thirteenth embodiment. FIG. 50A illustrates an example in which a bottom-gate TFT with a channel etch structure is used as the TFT 1100. FIG. 50B illustrates an example in which a bottom-gate TFT with a channel protection structure is used as the TFT 1100. A TFT 1100 having a channel protection structure illustrated in FIG. 50B includes an insulator 3001 serving as an etching mask over a region where a channel of the semiconductor layer 2906 is formed in the TFT 1100 having a channel etching structure illustrated in FIG. Different points are provided.

50A and 50B, the TFT 1100 includes a gate electrode 2993, a first insulating film 2905 over the gate electrode 2993, a semiconductor layer 2906 over the first insulating film 2905, and a semiconductor layer 2906. The upper N-type semiconductor layer 2908 and the N-type semiconductor layer 2909 are included. The first insulating film 2905 functions as a gate insulating film of the TFT 1100. The N-type semiconductor layer 2908 and the N-type semiconductor layer 2909 serve as the source and drain of the TFT 1100. An electrode 2911 and an electrode 2912 are formed over the N-type semiconductor layer 2908 and the N-type semiconductor layer 2909, respectively. One end of the electrode 2911 extends to a region where the semiconductor layer 2906 is not present, and an electrode 1006 is formed in contact with the upper portion of the electrode 2911 in a region where the semiconductor layer 2906 is not present.

The capacitor 1101 uses the first insulating film 2905 as a dielectric, the electrode 2904 as one electrode, the semiconductor layer 2907 opposed to the electrode 2904 across the first insulating film 2905, and an N-type semiconductor over the semiconductor layer 2907. The layer 2910 and the electrode 2913 over the N-type semiconductor layer 2910 are formed as the other electrode. The electrode 2904 can be formed at the same time as the gate electrode 2993. The semiconductor layer 2907 can be formed at the same time as the semiconductor layer 2906. The N-type semiconductor layer 2910 can be formed at the same time as the N-type semiconductor layer 2908 and the N-type semiconductor layer 2909. The electrode 2913 can be formed at the same time as the electrode 2911 and the electrode 2912.

As the gate electrode 2993 and the electrode 2904, a material similar to that of the gate electrode 1004 in FIG. 48 can be used. As the semiconductor layer 2906 and the semiconductor layer 2907, an amorphous semiconductor film can be used. As the first insulating film 2905, a material similar to that of the first insulating film 1003 in FIG. 48 can be used. As the electrode 2911, the electrode 2912, and the electrode 2913, the same material as the electrode 1006 can be used. As the N-type semiconductor layer 2910, the N-type semiconductor layer 2908, and the N-type semiconductor layer 2909, a semiconductor film containing an N-type impurity element can be used.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Sixteenth embodiment)
In this embodiment, an example in which a pixel is actually manufactured will be described. FIG. 51 is a cross-sectional view of a pixel of the panel described in the eleventh embodiment. An example in which a TFT is used as a switching element arranged in a pixel and a liquid crystal element is used as a display medium arranged in the pixel is shown.

The pixels shown in FIGS. 51A, 51B, and 51C are the same as those shown in FIGS. 48A and 48B in the thirteenth embodiment, and the fourteenth embodiment. 49 is an example in which a liquid crystal element is provided instead of the light emitting element 1011 in the structure shown in FIG. The same parts as those in FIGS. 48 and 49 are denoted by the same reference numerals, and description thereof is omitted.

The liquid crystal element includes a first electrode 4000, an alignment film 4001 formed over the first electrode 4000, a liquid crystal 4002, an alignment film 4003, and a second electrode 4004. When a voltage is applied between the first electrode 4000 and the second electrode 4004, the alignment state of the liquid crystal changes, and the transmittance of the liquid crystal element changes. The second electrode 4004 and the alignment film 4003 are formed on the counter substrate 4005.

One or both of the first electrode 4000 and the second electrode 4004 can be a transparent electrode. As the transparent electrode, indium oxide containing tungsten oxide (IWO), indium oxide containing tungsten oxide and zinc oxide (IWZO), indium oxide containing titanium oxide (ITO), indium tin oxide containing titanium oxide (ITTiO) ) Etc. can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used. The other of the first electrode 4000 and the second electrode 4004 may be formed using a material that does not transmit light. For example, alkali metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr, alloys containing these (Mg: Ag, Al: Li, Mg: In, etc.), and compounds thereof (CaF ₂ , In addition to calcium nitride), rare earth metals such as Yb and Er can be used.

As the liquid crystal 4002, a known liquid crystal can be used freely. For example, a ferroelectric liquid crystal or an antiferroelectric liquid crystal may be used as the liquid crystal 4002. In addition, a liquid crystal drive system can be a TN (Twisted Nematic) mode, an MVA (Multi-domain Vertical Alignment) mode, an ASM (Axial Symmetrical Microcell) mode, an OCB (Optically Full Bend), or the like.

In this embodiment mode, an example in which a pair of electrodes (a first electrode 4000 and a second electrode 4004) for applying a voltage to the liquid crystal 4002 is formed over different substrates is described, but the present invention is not limited to this. The second electrode 4004 may be provided over the substrate 1000. Thus, an IPS (In-Plane-Switching) mode may be used as a liquid crystal driving method. Further, depending on the liquid crystal 4002, one or both of the alignment film 4001 and the alignment film 4003 may not be provided.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Seventeenth embodiment)
In this embodiment, an example in which a pixel is actually manufactured will be described. FIG. 52 is a cross-sectional view of a pixel of the panel described in the thirteenth embodiment. An example in which a TFT is used as a switching element arranged in a pixel and a liquid crystal element is used as a display medium arranged in the pixel is shown.

The pixel shown in FIGS. 52A and 52B is provided with a liquid crystal element instead of the light emitting element 1011 in the structure shown in FIGS. 50A and 50B in the fifteenth embodiment. This is an example. The same parts as those in FIG. 50 are denoted by the same reference numerals, and description thereof is omitted. The configuration of the liquid crystal element is the same as that shown in FIG. 51 in the sixteenth embodiment, and a description thereof will be omitted.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Eighteenth embodiment)
In this embodiment, a structure in which a substrate on which pixels are formed is sealed will be described with reference to FIG. FIG. 53A is a top view of a panel formed by sealing a substrate on which pixels are formed. FIGS. 53B and 53C are cross-sectional views of FIGS. It is sectional drawing in A '. FIG. 53B and FIG. 53C are examples in which sealing is performed by different methods.

53A to 53C, a pixel portion 1302 including a plurality of pixels is provided over a substrate 1301, a sealant 1306 is provided so as to surround the pixel portion 1302, and a sealing material 1307 is attached. ing. For the pixel structure, the configurations shown in the best mode for carrying out the invention, the fourteenth embodiment, the fifteenth embodiment, and the sixteenth embodiment can be used.

In the display panel in FIG. 53B, the sealing material 1307 in FIG. 53A corresponds to the counter substrate 1321. A transparent counter substrate 1321 is attached using the sealant 1306 as an adhesive layer, and a sealed space 1322 is formed by the substrate 1301, the counter substrate 1321, and the sealant 1306. The counter substrate 1321 is provided with a color filter 1320 and a protective film 1323 for protecting the color filter. Light emitted from the light emitting elements arranged in the pixel portion 1302 is emitted to the outside through the color filter 1320. The sealed space 1322 is filled with an inert resin or liquid. Note that a light-transmitting resin in which a hygroscopic material is dispersed may be used as the resin filled in the sealed space 1322. Alternatively, the sealing material 1306 and the material filled in the sealed space 1322 may be the same material, and the counter substrate 1321 may be bonded and the pixel portion 1302 may be sealed at the same time.

In the display panel shown in FIG. 53C, the sealing material 1307 in FIG. 53A corresponds to the sealing material 1324. A sealing material 1324 is attached using the sealing material 1306 as an adhesive layer, and a sealed space 1308 is formed by the substrate 1301, the sealing material 1306, and the sealing material 1324. The sealing material 1324 is provided with a hygroscopic agent 1309 in the concave portion in advance, and plays a role in adsorbing moisture, oxygen, and the like in the sealed space 1308 to keep a clean atmosphere and suppressing deterioration of the light emitting element. This concave portion is covered with a fine mesh-shaped cover material 1310. The cover member 1310 allows air and moisture to pass through, but does not allow the moisture absorbent 1309 to pass. Note that the sealed space 1308 may be filled with a rare gas such as nitrogen or argon, and may be filled with a resin or a liquid if inactive.

An input terminal portion 1311 for transmitting a signal to the pixel portion 1302 and the like is provided on the substrate 1301, and a signal such as a video signal is transmitted to the input terminal portion 1311 via an FPC (flexible printed circuit) 1312. The In the input terminal portion 1311, the wiring formed over the substrate 1301 and the wiring provided in the FPC 1312 are electrically connected using a resin in which a conductor is dispersed (anisotropic conductive resin: ACF). .

A driver circuit that inputs a signal to the pixel portion 1302 may be formed over the substrate 1301 over which the pixel portion 1302 is formed. A driver circuit for inputting a signal to the pixel portion 1302 may be formed using an IC chip and connected to the substrate 1301 by COG (Chip On Glass). Alternatively, the IC chip may be connected to the substrate 1301 using a TAB (Tape Automated Bonding) or a printed circuit board. It may be placed on top.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(Nineteenth embodiment)
The present invention can be applied to a display module in which a circuit for inputting a signal to the panel is mounted on the panel.

FIG. 54 shows a display module in which a panel 1900 and a circuit board 1904 are combined. FIG. 54 shows an example in which a controller 1905, a signal dividing circuit 1906, and the like are formed on a circuit board 1904. The circuit formed on the circuit board 1904 is not limited to this. Any circuit may be formed as long as it generates a signal for controlling the panel.

Signals output from these circuits formed on the circuit board 1904 are input to the panel 1900 through the connection wiring 1907.

The panel 1900 includes a pixel portion 1901, a source driver 1902, and a gate driver 1903. The configuration of the panel 1900 can be the same as the configuration shown in the ninth to twelfth embodiments. FIG. 54 shows an example in which the source driver 1902 and the gate driver 1903 are formed over the same substrate as the substrate over which the pixel portion 1901 is formed. However, the display module of the present invention is not limited to this. Only the gate driver 1903 may be formed over the same substrate as the substrate over which the pixel portion 1901 is formed, and the source driver may be formed over the circuit substrate. Both the source driver and the gate driver may be formed on the circuit board.

By incorporating such a display module, display portions of various electronic devices can be formed.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(20th embodiment)
The present invention can be applied to various electronic devices. Electronic devices include cameras (video cameras, digital cameras, etc.), projectors, head-mounted displays (goggles-type displays), navigation systems, car stereos, personal computers, game machines, personal digital assistants (mobile computers, mobile phones or electronic books) Etc.), and an image reproducing apparatus provided with a recording medium. Specific examples of the image reproducing apparatus provided with the recording medium include an apparatus provided with a display capable of reproducing a recording medium such as Digital Versatile Disc (DVD) and displaying the image. An example of the electronic device is illustrated in FIG.

FIG. 55A illustrates a laptop personal computer, which includes a main body 911, a housing 912, a display portion 913, a keyboard 914, an external connection port 915, a pointing device 916, and the like. The present invention is applied to the display unit 913. By using the present invention, power consumption of the display portion can be reduced.

FIG. 55B shows an image reproducing device (specifically, a DVD reproducing device) provided with a recording medium, which includes a main body 921, a housing 922, a first display portion 923, a second display portion 924, a recording medium ( DVD, etc.) includes a reading unit 925, operation keys 926, a speaker unit 927, and the like. The first display unit 923 mainly displays image information, and the second display unit 924 mainly displays character information. The present invention is applied to the first display portion 923 and the second display portion 924. By using the present invention, power consumption of the display portion can be reduced.

FIG. 55C illustrates a cellular phone, which includes a main body 931, an audio output portion 932, an audio input portion 933, a display portion 934, operation switches 935, an antenna 936, and the like. The present invention is applied to the display unit 934. By using the present invention, power consumption of the display portion can be reduced.

FIG. 55D shows a camera, which includes a main body 941, a display portion 942, a housing 943, an external connection port 944, a remote control receiving portion 945, an image receiving portion 946, a battery 947, an audio input portion 948, operation keys 949, and the like. The present invention is applied to the display portion 942. By using the present invention, power consumption of the display portion can be reduced.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

(21st Embodiment)
In this embodiment mode, an application mode is shown and described for an application example using a display panel in which a display device using the pixel configuration of the present invention is used as a display portion. A display panel in which a display device using the pixel configuration of the present invention is used as a display portion can be configured to be provided integrally with a moving body, a building, or the like.

An example of a display panel having a display device using the pixel structure of the present invention in a display portion is shown in FIG. FIG. 56A shows an example in which the display panel 9702 is used as the glass of the door glass door of the train car main body 9701 as an example of the display device-integrated moving body. A display panel 9702 having a display device using the pixel configuration of the present invention shown in FIG. 56A in the display portion can easily switch an image displayed on the display portion by an external signal. Therefore, it is possible to expect a more effective advertising effect by switching the image on the display panel every time when the customer base of the passengers on the train changes.

In addition, the display panel having the display device using the pixel configuration of the present invention in the display unit is not limited to being applicable only to the door glass in the train car body shown in FIG. By changing the shape, it can be applied to any place. An example thereof will be described with reference to FIG.

FIG. 56 (b) illustrates the interior of the train car body. FIG. 56B shows a display panel 9703 provided on the glass window and a display panel 9704 suspended from the ceiling in addition to the glass door display panel 9702 shown in FIG. 56A. Since the display panel 9703 including the pixel structure of the present invention includes a self-luminous display element, the display panel 9703 displays an advertisement image when crowded and does not display other than when crowded. You can also see In addition, the display panel 9704 including the pixel structure of the present invention is provided with a switching element such as an organic transistor on a film-like substrate and drives the self-luminous display element to display the display panel by curving the display panel itself. It is also possible.

Another application example of a display device-integrated moving body using a display panel having a display device using the pixel structure of the present invention in a display portion will be described with reference to FIG.

As an example of a display panel having a display device using the pixel structure of the present invention in a display portion, a moving body integrated with a display device is shown in FIG. FIG. 57 shows an example of a display panel 9902 attached to a car body 9901 of an automobile as an example of a display unit-integrated moving body. A display panel 9902 having a display device using the pixel configuration of the present invention shown in FIG. 57 in a display portion is attached integrally with the body of an automobile, and information input from inside and outside the body is on demand. It also has a display function and a navigation function to the destination of the car.

Note that the display panel having the display device using the pixel configuration of the present invention in the display portion is not limited to being applicable only to the front portion of the vehicle body shown in FIG. Therefore, it can be applied to any place such as a glass window and a door.

Another application example of an application example of a display device-integrated moving body using a display panel having a display device using the pixel structure of the present invention in a display portion will be described with reference to FIG.

An example of a display panel having a display device using the pixel configuration of the present invention in a display portion is shown in FIG. FIG. 58A shows an example of a display panel 10102 that is integrally attached to a passenger seat ceiling in an airplane body 10101 as an example of a display unit-integrated moving body. A display panel 10102 having a display device using the pixel configuration of the present invention shown in FIG. 58A in a display portion is integrally attached via an aircraft body 10101 and a hinge portion 10103, and is expanded and contracted by the hinge portion 10103. The passenger can view the display panel 10102. The display panel 10102 has a function of displaying information by being operated by a passenger or being used as an advertisement or an entertainment means. Further, as shown in FIG. 58 (b), safety at the time of takeoff and landing can be taken into consideration by folding the hinge portion and storing it in the airplane body 10101. Note that it can also be used as a guide light for the airplane body 10101 by turning on the display element of the display panel in an emergency.

Note that the display panel having the display device using the pixel structure of the present invention in the display portion is not limited to being applicable only to the ceiling portion of the airplane body 10101 shown in FIG. It can be applied to any place such as a seat or a door. For example, a configuration may be employed in which a display panel is provided behind the seat in front of the seat for operation / viewing.

In this embodiment, examples of the moving body include a train car body, an automobile body, and an airplane body. However, the present invention is not limited to this, but a motorcycle, an automobile (including an automobile, a bus, etc.), a train (monorail) , Including railways), ships, etc. By applying a display panel having a display portion using the pixel structure of the present invention, a moving body including a display medium that achieves miniaturization and low power consumption of the display panel and has good operation is provided. be able to. In particular, it is easy to switch the display of the display panel in the moving body at the same time by an external signal, so it can be used as an advertising display board for an unspecified number of customers, or as an information display board in an emergency disaster. It can be said that it is extremely useful.

An application example using a display panel having a display device using the pixel structure of the present invention in a display portion will be described with reference to FIG.

FIG. 59 shows a display panel having a display device using the pixel structure of the present invention in a display portion. The display panel itself is formed by providing a switching element such as an organic transistor on a film substrate and driving a self-luminous display element. A display panel that can be displayed by curving is described, and an application example thereof will be described. FIG. 59 illustrates a structure in which a display panel is provided on a curved surface of a columnar body provided outdoors such as a utility pole as a building, and here, a structure in which the display panel 9802 is provided on a utility pole 9801 as a columnar body is illustrated.

The display panel 9802 shown in FIG. 59 is positioned at the middle of the height of the utility pole and is provided at a position higher than the human viewpoint. By visually recognizing the display panel from the moving body 9803, an image on the display panel 9802 can be recognized. The viewer can visually recognize the information display and the advertisement display by repeatedly foresting outdoors like a utility pole and displaying the same image on the display panel 9802 provided on the established utility pole. In FIG. 59, since the display panel 9802 provided on the utility pole 9801 can easily display the same image from the outside, extremely efficient information display and advertising effect can be expected. In addition, it can be said that the display panel of the present invention is useful as a display medium with high visibility even at night by providing a self-luminous display element as a display element.

In addition, an application example of a building different from that in FIG. 59 will be described with reference to FIGS.

FIG. 60 shows an application example of a display panel having a display device using the pixel structure of the present invention in a display portion. FIG. 60 shows an example of a display panel 10002 integrally attached to a side wall in the unit bus 10001 as an example of a display device integrated type. A display panel 10002 having a display device using the pixel structure of the present invention shown in FIG. 60 as a display portion is attached to a unit bath 10001 so that a bather can view the display panel 10002. The display panel 10002 has a function of displaying information by being operated by a bather or being used as an advertisement or an entertainment means.

Note that the display panel having the display device using the pixel structure of the present invention in the display portion is not limited to being applicable only to the side wall of the unit bus 10001 shown in FIG. Therefore, the present invention can be applied to various places such as a part of a mirror surface or a bathtub.

FIG. 61 shows an example in which a television device having a large display portion is provided in a building. FIG. 61 includes a housing 8010, a display portion 8011, a remote control device 8012 which is an operation portion, a speaker portion 8013, and the like. A display panel including a display device using the pixel structure of the present invention for a display portion is applied to manufacture of the display portion 8011. The television device in FIG. 61 is integrated with a building as a wall-hanging type, and can be installed without requiring a large installation space.

Note that in this embodiment, as a building, a utility pole, a unit bus, or the like is used as a columnar body, but this embodiment is not particularly limited as long as the building can include a display panel. By applying a display device having a display portion using the pixel structure of the present invention, a building having a display medium that achieves miniaturization and low power consumption of the display device and operates well is provided. be able to.

Note that this embodiment mode can be freely combined with any description in other embodiment modes in this specification. In addition, any description in the present embodiment can be implemented in any combination.

The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the offset circuit which the level shifter of this invention has. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the timing chart of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the structure of the level shifter of this invention. The figure which shows the layout figure of the level shifter of this invention. The figure which shows the layout figure of the level shifter of this invention. The figure which shows the layout figure of the level shifter of this invention. The figure which shows the layout figure of the level shifter of this invention. The figure which shows the layout figure of the level shifter of this invention. FIG. 3 is a cross-sectional view of a pixel according to the present invention. FIG. 3 is a cross-sectional view of a pixel according to the present invention. FIG. 3 is a cross-sectional view of a pixel according to the present invention. FIG. 3 is a cross-sectional view of a pixel according to the present invention. FIG. 3 is a cross-sectional view of a pixel according to the present invention. The figure which shows the display module which concerns on this invention. The figure which shows the display module which concerns on this invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 14 illustrates a method for using an electronic device of the invention. FIG. 11 illustrates a structure of a display panel of the present invention. 4A and 4B illustrate a structure of a display panel and a structure of an EL pixel of the present invention. 4A and 4B illustrate a structure of a display panel and a structure of an EL pixel of the present invention. 2A and 2B illustrate a structure of a display panel and a structure of a liquid crystal pixel of the present invention.

Explanation of symbols

101 circuit 102 circuit 103 wiring 104 wiring 105 wiring 106 wiring 107 wiring 108 wiring 109 wiring 191 panel 301 capacitive element 302 capacitive element 303 transistor 304 transistor 350 logic circuit 401 transistor 402 transistor 403 transistor 404 transistor 501 transistor 502 transistor 590 pixel 591 pixel portion 593 Source driver 594 Gate driver 601 Transistor 602 Transistor 603 Transistor 604 Transistor 690 Pixel 691 Transistor 692 Transistor 693 Capacitance element 694 Light-emitting element 695 Terminal 696 Terminal 697 Terminal 701 Capacitance element 702 Capacitance element 703 Transistor 704 Transistor 781 Diode 790 Pixel 791 Transistor 7 2 terminal 801 transistor 802 transistor 803 transistor 804 transistor 901 transistor 902 transistor 911 body 912 housing 913 display unit 914 keyboard 915 external connection port 916 pointing mouse 921 body 922 housing 923 display unit 924 display unit 925 unit 926 operation key 927 speaker unit 931 Main unit 932 Audio output unit 933 Audio input unit 934 Display unit 935 Operation switch 936 Antenna 941 Main unit 942 Display unit 943 Case 944 External connection port 945 Remote control receiver 946 Image receiver 947 Battery 948 Audio input unit 949 Operation key 1000 Substrate 1001 Bottom Base film 1002 Semiconductor layer 1003 Insulating film 1004 Gate electrode 1005 Insulating film 1006 Electrode 1007 Electrode 1008 Insulating film 1 09 light-emitting layer 1010 electrodes 1011 light emitting element 1091 transistor 1092 transistors 1093 transistors 1094 transistor 1100 TFT
1101 Capacitance element 1102 Semiconductor layer 1104 Electrode 1106 Electrode 1108 Insulating film 1301 Substrate 1302 Pixel portion 1306 Sealing material 1307 Sealing material 1308 Sealed space 1309 Hygroscopic agent 1310 Cover material 1311 Input terminal portion 1312 FPC (flexible printed circuit)
1320 Color filter 1321 Counter substrate 1322 Sealed space 1323 Protective film 1324 Sealing material 1500 Logic circuit 1501 Transistor 1502 Transistor 1503 Offset circuit 1900 Panel 1901 Pixel portion 1902 Source driver 1903 Gate driver 1904 Circuit board 1905 Controller 1906 Signal division circuit 1907 Connection wiring 2100 Logic Circuit 2101 Transistor 2102 Transistor 2103 Transistor 2104 Transistor 2500 Logic circuit 2501 Transistor 2502 Transistor 2503 Transistor 2504 Transistor 2703 Gate electrode 2704 Electrode 2705 Insulating film 2706 Channel formation region 2707 LDD region 2708 Impurity region 2709 Channel formation region 2710 LD Region 2711 Impurity region 2900 Logic circuit 2901 Transistor 2902 Transistor 2903 Offset circuit 2904 Electrode 2905 Insulating film 2906 Semiconductor layer 2907 Semiconductor layer 2908 N-type semiconductor layer 2909 N-type semiconductor layer 2910 N-type semiconductor layer 2911 Electrode 2912 Electrode 2913 Electrode 2993 Gate electrode 3001 Insulator 3500 logic circuit 3501 transistor 3502 transistor 3503 transistor 3504 transistor 3900 logic circuit 3901 transistor 3902 transistor 3903 transistor 3904 transistor 4000 electrode 4001 alignment film 4002 liquid crystal 4003 alignment film 4004 electrode 4005 counter substrate 4301 semiconductor layer 4302 conductive layer 4303 conductive layer 4401 semiconductor Layer 4402 Conductive layer 4403 Conductive layer 4691 Transistor 4692 Liquid crystal element 4693 Capacitance element 4694 Terminal 4701 Semiconductor layer 4702 Conductive layer 4703 Conductive layer 4704 Conductive layer 8010 Housing 8011 Display unit 8012 Remote control device 8013 Speaker unit 9701 Train vehicle body 9702 Display panel 9703 Display panel 9704 Display panel 9801 Telephone pole 9802 Display panel 9803 Moving body 9901 Car body 9902 Display panel 10001 Unit bus 10002 Display panel 10101 Aircraft body 10102 Display panel 10103 Hinge portion

Claims (13)

A pixel having a liquid crystal element and a driving circuit;
The drive circuit includes a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, and a fourth transistor,
A first electrode of the first capacitive element is electrically connected to a third wiring; a first electrode of the second capacitive element is electrically connected to a fourth wiring;
A gate of the first transistor is electrically connected to a second electrode of the first capacitor; a first terminal of the first transistor is electrically connected to a second wiring; and A second terminal of the transistor is electrically connected to the second electrode of the second capacitor;
A gate of the second transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the second transistor is electrically connected to the second wiring; A second terminal of the transistor is electrically connected to the second electrode of the first capacitor,
A gate of the third transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the third transistor is electrically connected to the second wiring; and The second terminal of the transistor is electrically connected to the fifth wiring;
A gate and a first terminal of the fourth transistor are electrically connected to a first wiring, and a second terminal of the fourth transistor is electrically connected to a fifth wiring. A liquid crystal display device. In claim 1,
The liquid crystal display device, wherein the first to fourth transistors are transistors of the same conductivity type. In claim 1 or claim 2,
The first to fourth transistors are P-channel transistors,
The liquid crystal display device, wherein a potential of the first wiring is higher than a potential of the second wiring. In claim 1 or claim 2,
The first to fourth transistors are N-channel transistors,
The liquid crystal display device, wherein a potential of the first wiring is lower than a potential of the second wiring. A pixel having a liquid crystal element and a driving circuit;
The driving circuit includes a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, 6 transistors,
A first electrode of the first capacitive element is electrically connected to a third wiring; a first electrode of the second capacitive element is electrically connected to a fourth wiring;
A gate of the first transistor is electrically connected to a second electrode of the first capacitor; a first terminal of the first transistor is electrically connected to a second wiring; and A second terminal of the transistor is electrically connected to the second electrode of the second capacitor;
A gate of the second transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the second transistor is electrically connected to the second wiring; A second terminal of the transistor is electrically connected to the second electrode of the first capacitor,
A gate of the third transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the third transistor is electrically connected to the second wiring; and The second terminal of the transistor is electrically connected to the fifth wiring;
A gate and a first terminal of the fourth transistor are electrically connected to a first wiring; a second terminal of the fourth transistor is electrically connected to the fifth wiring;
A gate of the fifth transistor is electrically connected to a second electrode of the first capacitor; a first terminal of the fifth transistor is electrically connected to the second wiring; The second terminal of the transistor is electrically connected to the sixth wiring;
A gate and a first terminal of the sixth transistor are electrically connected to the first wiring, and a second terminal of the sixth transistor is electrically connected to the sixth wiring. A liquid crystal display device. In claim 5,
The liquid crystal display device, wherein the first to sixth transistors are transistors of the same conductivity type. In claim 5 or claim 6,
The first to sixth transistors are P-channel transistors,
A liquid crystal display device, wherein the potential of the first wiring is higher than the potential of the second wiring. In claim 5 or claim 6,
The first to sixth transistors are N-channel transistors,
A liquid crystal display device, wherein the potential of the first wiring is lower than the potential of the second wiring. A pixel having a liquid crystal element and a driving circuit;
The driving circuit includes a first capacitor, a second capacitor, a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, 6 transistors,
A first electrode of the first capacitive element is electrically connected to a third wiring; a first electrode of the second capacitive element is electrically connected to a fourth wiring;
A gate of the first transistor is electrically connected to a second electrode of the first capacitor; a first terminal of the first transistor is electrically connected to a second wiring; and A second terminal of the transistor is electrically connected to the second electrode of the second capacitor;
A gate of the second transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the second transistor is electrically connected to the second wiring; A second terminal of the transistor is electrically connected to the second electrode of the first capacitor,
A gate of the third transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the third transistor is electrically connected to the second wiring;
A gate and a first terminal of the fourth transistor are electrically connected to a first wiring; a second terminal of the fourth transistor is electrically connected to a second terminal of the third transistor;
A gate of the fifth transistor is electrically connected to a second electrode of the second capacitor; a first terminal of the fifth transistor is electrically connected to the second wiring; The second terminal of the transistor is electrically connected to the fifth wiring;
The gate of the sixth transistor is electrically connected to the second terminal of the third transistor and the second terminal of the fourth transistor, and the first terminal of the sixth transistor is connected to the first wiring. A liquid crystal display device, wherein the liquid crystal display device is electrically connected, and the second terminal of the sixth transistor is electrically connected to the fifth wiring. In claim 9,
The liquid crystal display device, wherein the first to sixth transistors are transistors of the same conductivity type. In claim 9 or claim 10,
The first to sixth transistors are P-channel transistors,
A liquid crystal display device, wherein the potential of the first wiring is higher than the potential of the second wiring. In claim 9 or claim 10,
The first to sixth transistors are N-channel transistors,
A liquid crystal display device, wherein the potential of the first wiring is lower than the potential of the second wiring. An electronic apparatus comprising the liquid crystal display device according to any one of claims 1 to 12.

Images