JP2009109819A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of attaining cost reduction of the display device, by reducing the amount of used liquid crystal layer and improving the yield by preventing short-circuiting between wirings. <P>SOLUTION: In the display device 1c which includes a color filter layer 33 provided at a display area 3a of a first substrate 3, a pixel electrode 35 formed and arranged on the color filter layer 33, a second substrate 4 disposed facing a pixel electrode 35 side of the first substrate 3, and a liquid crystal layer LC, held in between the first substrate 3 and the second substrate 4, the color filter layer 33 is extended in a peripheral region 3b, at the periphery of the display area 3a on the first substrate 3. In the peripheral region 3b, filters 33r, 33g, 33b constituting the color filter layer 33 are stacked. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device in which a color filter layer is provided on a substrate provided with a pixel circuit.

  In a display device (liquid crystal display device) having a liquid crystal layer sandwiched between two substrates, a pixel circuit and a color filter for driving a pixel electrode for the purpose of improving the aperture ratio and reducing the manufacturing process Are provided on the same substrate as a COA (color filter on array) or COT (color filter on TFT). FIG. 12 is a cross-sectional view of a main part for explaining such a structure.

  As shown in this figure, on the first substrate 201 on the driving side in the display device, a display area 201a and a peripheral area 201b surrounding it are set, and a mounting area 201c is set on the outer peripheral side in contact with the peripheral area 201b. Has been. In the display area 201a, pixels are arranged in a matrix and a pixel circuit including a thin film transistor Tr is disposed in each pixel. In the outer peripheral area 201b and the mounting area 201c, lead-out wirings 203 connected to the pixel circuits in the display area 201a are wired.

  Further, a color filter layer 205 is provided on the display area 201a by patterning the color filters 205r, 205g, and 205b for each pixel so as to cover the pixel circuit including the thin film transistor Tr. The color filter layer 205 having such a structure also serves as an interlayer insulating film, and is provided with a connection hole reaching the thin film transistor Tr provided in each pixel. On each color filter 205r, 205g, 205b, the pixel electrode 207 connected to the thin film transistor Tr through the connection hole is patterned, and an alignment film (not shown) is provided so as to cover the pixel electrode 207.

  The second substrate 301 is disposed so as to face the pixel electrode 207 forming surface side of the first substrate 201. A common electrode 303 is provided on the surface of the second substrate 301 facing the first substrate 201, and an alignment film (not shown) is provided so as to cover the common electrode 303.

  A liquid crystal layer LC is sandwiched between the substrates 201-301. The liquid crystal layer LC is sealed between the substrates 201-301 by a sealing agent 305 provided between the peripheral edges of the substrates 201-301.

  In the display device configured as described above, a configuration in which an organic insulating layer is provided so as to fill a groove formed between the end portions of the color filters 205r, 205g, and 205b has been proposed. As a result, the electric capacitance between the pixel electrode 207 on the color filter layer 205 and the pixel circuit having the thin film transistor Tr below the color filter layer 205 can be reduced, and crosstalk and display unevenness can be prevented (the following patents). Reference 1).

JP 2006-53419 A

  However, in the display device configured as described above, as shown in FIG. 12, the cell gap g2 in the peripheral region 201b where the color filter layer 205 is not provided is larger than the cell gap g1 in the display region 201a. Although the peripheral area 201b is a so-called frame portion that does not contribute to display, it is a factor that greatly increases the amount of liquid crystal layer LC used.

  In addition, since pixel electrodes are formed with the extraction wiring 203 exposed, a short circuit due to adhesion of conductive foreign matter is likely to occur between the extraction wirings 203.

  Accordingly, an object of the present invention is to provide a display device that can realize cost reduction by reducing the amount of liquid crystal layer used and can improve yield by preventing short-circuiting between wirings. .

  In order to achieve such an object, a display device of the present invention includes a color filter layer provided in a display area of a first substrate, pixel electrodes arrayed on the color filter layer, and a pixel electrode side of the first substrate. In a display device including a second substrate disposed oppositely and a liquid crystal layer sandwiched between the first substrate and the second substrate, the color filter layer is disposed around the display region on the first substrate. Is characterized by being extended.

  In the display device having such a configuration, the cell gap around the display region is narrowed by the color filter layer extending around the display region, and the usage amount of the liquid crystal layer is reduced by the narrowed portion. In addition, since the wiring drawn out around the display area is covered with the color filter layer, a short circuit between the wirings due to foreign matter is prevented.

  As described above, according to the present invention, it is possible to reduce the amount of the liquid crystal layer used, thereby reducing the cost of the display device and preventing the short circuit between the wirings and improving the yield. .

  Hereinafter, embodiments of the display device of the present invention will be described in detail with reference to the drawings.

<Configuration of display device>
FIG. 1A is a plan view showing the configuration of the display device of the embodiment, and FIG. 1B is a schematic cross-sectional view taken along line AA ′ in FIG. In FIG. 1 (1), a part of the constituent elements is cut out for the sake of explanation.

  The display device 1a shown in these drawings is an active matrix type liquid crystal display device, and a liquid crystal layer is interposed between a first substrate 3 and a second substrate 4 formed using a glass substrate or other transparent material. Hold the LC. This display device 1a is different from the conventional display device in the configuration of the color filter layer 33 provided on the first substrate 3, and the other configurations may be the same.

  That is, the first substrate 3 is a display region 3a set at the center, a peripheral region 3b provided around the display region 3a, and a portion extending from the peripheral region 3b, and is an external part such as an IC chip or a circuit board. A mounting area 3c on which the circuit 5 is mounted is provided.

  Among these, in the display area 3a, a plurality of pixels are arranged in a matrix, and a pixel circuit including a thin film transistor Tr is arranged for each pixel. In the outer peripheral region 3b and the mounting region 3c, lead-out wirings 31 connected to the pixel circuits in the display region 3a are wired. The circuit configuration of the pixel circuit and wiring connected thereto will be described later.

  On the display area 3a, a color filter formed by patterning a color filter of each color, that is, a red filter 33r, a green filter 33g, and a blue filter 33b, for each pixel in a state of covering a pixel circuit including the thin film transistor Tr. A layer 33 is provided. Each of such color filters 33r, 33g, and 33b is provided by stacking end portions between pixels, and constitutes a single color filter layer 33. Note that the color filters 33r, 33g, and 33b may be provided in common between adjacent pixels, for example, may be in the form of a stripe common between pixels arranged in the vertical direction.

  The color filter layer 33 composed of the color filters 33r, 33g, and 33b serves as an interlayer insulating film having a flat surface, and is formed with a film thickness that fills the unevenness of the lower pixel circuit. The color filter layer 33 is provided with a connection hole 33a that reaches the thin film transistor Tr in each pixel.

  In particular, the color filter layer 33 is characterized in that it extends not only on the display area 3a but also on the peripheral area 3b around it. In the peripheral region 3b, the color filter layer 33 preferably has a configuration in which the color filters 33r, 33g, and 33b are stacked. This is obtained by stacking the color filters 33r, 33g, and 33b when sequentially forming the patterns in the procedure for manufacturing the color filter layer 33 described below. In such a configuration, it is preferable to set the filter so as to be narrower in the upper layer. As a result, it is possible to prevent the influence of pattern deviation when the color filters 33r, 33g, and 33b are stacked.

  The color filter layer 33 is preferably extended over the entire peripheral area 3b surrounding the display area 3a. Further, the color filter layer 33 does not need to have a laminated structure in the entire peripheral region 3b. For example, the color filter layer 33 has a single layer portion in a part of the peripheral region 3b as an opening for quickly injecting the liquid crystal layer LC into the display region 3a. May be provided. The order in which the color filters 33r, 33g, and 33b are stacked in the peripheral region 3b is not particularly limited, and is the order in which the color filters 33r, 33g, and 33b are manufactured in the manufacturing process described below.

  Further, the cross capacitance and display unevenness can be prevented by suppressing the electric capacity between the pixel electrode 35 on the color filter layer 33 described below and the pixel circuit (having the thin film transistor Tr) below the color filter layer 33. For this purpose, an organic insulating layer may be provided so as to fill a groove between the color filters 33r, 33g, and 33b.

  A pixel electrode 35 made of a transparent conductive material such as ITO (Indium Tin Oxide) is patterned in the display region 3a on the color filter layer 33 having the above configuration. Each pixel electrode 35 is formed in a pattern corresponding to each pixel, and is connected to the thin film transistor Tr through a connection hole 33 a provided in the color filter layer 33.

  In addition, the second substrate 4 is disposed opposite to the surface of the first substrate 3 where the pixel electrode 35 is formed. On the surface of the second substrate 4 facing the first substrate 3, a light shielding film 41 is formed in a pattern corresponding to the peripheral region 3b. That is, the light shielding film 41 is provided in a state of covering the stacked portion of the color filters 33r, 33g, and 33b in the color filter layer 33.

  On the second substrate 4, a common electrode 43 made of a transparent conductive material such as ITO is provided so as to cover the light shielding film 41, and an alignment film (not shown) is provided so as to cover the common electrode 43. It has been.

  The display region 3a is maintained at a predetermined cell gap g1 by sandwiching a spacer (not shown) between these substrates 3-4, and the liquid crystal layer LC is maintained at the interval maintained in the cell gap G1. Is pinched. The liquid crystal layer LC is sealed between the substrates 3-4 by a sealing agent 45 provided between the peripheral edges of the substrates 3-4.

  Here, for example, the cell gap g1 is about 4 μm, and the film thicknesses of the color filters 33r, 33g, 33b are about 2 μm. As a result, the stacked portions of the color filters 33r, 33g, and 33b are substantially the same height as the cell gap g1, the cell gap g2 in the peripheral region 3b is approximately g2 = 0, and the stacked portions of the color filters 33r, 33g, and 33b are It will be used as a spacer.

  The display device 1a having such a configuration is disposed between two polarizing plates, and displays light by taking out light from a backlight provided on the first substrate 3 side from the second substrate 4 side by switching of the liquid crystal layer LC. Done.

<Circuit configuration of display device>
Next, an example of the circuit configuration of the liquid crystal display device of the above-described embodiment will be described with reference to FIG. In addition, the same code | symbol is attached | subjected and demonstrated to the common component in embodiment described using FIG.

  FIG. 2 is a diagram illustrating a circuit configuration of an active matrix liquid crystal display device, which is applied to the display region 1a described with reference to FIG. As described above, the display area 3a and the peripheral area 3b are set on the first substrate 3 side of the display device 1a. In the display area 3a, a plurality of scanning lines 31s and a plurality of signal lines 31d are wired vertically and horizontally, and are configured as a pixel array section in which one pixel is provided corresponding to each intersection. In the display area 3a, a common wiring Vcom is wired in parallel with the scanning line 31s (or the signal line 31d).

  On the other hand, a scanning line driving circuit 36 that scans and drives the scanning line 31s and a signal line driving circuit 37 that supplies a video signal (that is, an input signal) corresponding to luminance information to the signal line 31d are arranged in the peripheral region 3b. ing.

  Each pixel is provided with, for example, a pixel circuit including a thin film transistor Tr as a switching element and a storage capacitor Cs, and further, a pixel electrode 35 connected to the pixel circuit is provided.

  In the above configuration, the pixel electrodes 35 are arranged on the insulating film made of the color filter layer, and other wirings and circuits are provided under the insulating film made of the color filter layer.

  In the thin film transistor Tr constituting each pixel circuit, the gate is connected to the scanning line 31s, one of the source / drain is connected to the signal line 31d, and the other of the source / drain is connected to the storage capacitor Cs and the pixel electrode 35. ing. The other electrode of the capacitive element Cs is connected to the common wiring Vcom. Although not shown here, as described above with reference to FIG. 1, the common electrode connected to the common wiring Vcom is arranged to face the pixel electrode 35 provided in each pixel. The liquid crystal layer is sandwiched between the pixel electrode 35 and the common electrode.

  Then, the video signal written from the signal line 31d via the thin film transistor Tr is held in the holding capacitor Cs, and a voltage corresponding to the held signal amount is supplied to the pixel electrode 35.

  Here, a part of the scanning line 31s and the signal line 31d is wired as an extraction wiring for connecting the pixel circuit provided in the display region 3a and the drive circuits 36 and 37 provided in the peripheral region 3b. Further, from these drive circuits 36 and 37, the lead-out wiring is extended to the mounting region provided adjacent to the peripheral region 3b.

  The configuration of the pixel circuit as described above is merely an example, and a capacitor element may be provided in the pixel circuit as necessary, or a plurality of transistors may be provided to configure the pixel circuit. Further, a necessary drive circuit may be added to the peripheral region 3b according to the change of the pixel circuit.

<Manufacturing method>
3 and 4 are cross-sectional process diagrams illustrating a method of manufacturing the display device 1a described above. As shown in this figure, the display device 1a of the embodiment can be obtained by a manufacturing procedure similar to that of a conventional display device.

  That is, first, as shown in FIG. 3A, a pixel circuit including a thin film transistor Tr and a capacitance element not shown here is formed on the display region 3a of the first substrate 3. The thin film transistor Tr formed here may be either a bottom gate type or a top gate type. In the same process as the formation of the pixel circuit, the lead-out wiring 31 connected to the pixel circuit is formed in the peripheral region 3b to the mounting region 3c of the first substrate 3. In the peripheral region 3b, the above-described scanning line driving circuit, signal line driving circuit, and the like are further formed.

  Next, as shown in FIG. 3B, a negative first resist material 51 is applied on the first substrate 3, and pattern irradiation with exposure light h and subsequent development processing are performed.

  As a result, as shown in FIG. 3C, for example, a blue filter 33b formed by patterning the first resist material 51 is patterned in the display region 3a and the peripheral region 3b. At this time, the blue filter 33b in the display area 3a is provided with a connection hole 33a reaching the thin film transistor Tr.

  Next, as shown in FIG. 3 (4), a negative second resist material 52 is applied on the first substrate 3 so as to cover the blue filter 33b, and pattern irradiation with exposure light h and subsequent development processing are performed. And do.

  As a result, as shown in FIG. 3 (5), for example, a green filter 33g obtained by patterning the second resist material 52 is patterned in the display region 3a and the peripheral region 3b. At this time, in the display area 3a, the green filter 33g is formed in a pixel different from the pixel in which the blue filter 33b is formed, and the connection hole 33a reaching the thin film transistor Tr is provided in the green filter 33g. In the peripheral region 3b, the green filter 33g is formed by being stacked on the blue filter 33b.

  Thereafter, as shown in FIG. 4A, a negative third resist material 53 is applied on the first substrate 3 so as to cover the blue filter 33b and the green filter 33g. Development processing.

  Thereby, as shown in FIG. 4B, for example, a red filter 33r formed by patterning the third resist material 53 is formed in a pattern in the display region 3a and the peripheral region 3b. At this time, in the display area 3a, the red filter 33r is formed in a pixel different from the pixel in which the blue filter 33b and the green filter 33g are formed, and the connection hole 33a reaching the thin film transistor Tr is provided in the red filter 33r. . In the peripheral region 3b, the red filter 33r is formed by being stacked on the green filter 33g.

  As described above, the color filter layer 33 is obtained by arranging the color filters 33r, 33g, and 33b in the display area 3a and laminating the color filters 33r, 33g, and 33b in the peripheral area 3b. Note that the order in which the color filters 33r, 33g, and 33b are manufactured is not particularly limited, and may be different from the order described above.

  Thereafter, as shown in FIG. 4C, the pixel electrode 35 connected to the thin film transistor Tr corresponding to each pixel is formed on the color filter layer 33 in the display region 3a. Further, an alignment film that covers these pixel electrodes 35 is formed.

  Then, as shown in FIG. 1, the second substrate 4 in which the light shielding film 41, the common electrode 43, and the alignment film are provided in this order on the pixel substrate 35 and the alignment film forming surface side of the first substrate 3 is opposed to the second substrate 4. Deploy. At this time, the display region 3a is kept at a predetermined cell gap g1 by sandwiching a spacer not shown here. If the cell gap g1 is about 4 μm and the film thicknesses of the color filters 33r, 33g, and 33b are about 2 μm, the stacked portions of the color filters 33r, 33g, and 33b are also used as spacers.

  In addition, the sealing agent 45 is sandwiched between the peripheral edges of the first substrate 3 and the second substrate 4, and the space between the substrates 3-4 is sealed. In this state, a liquid crystal material is injected between the openings of the sealant 45 between the substrates 3-4, and the openings are sealed to complete the display device 1a.

  According to the display device 1a of the embodiment described above, the cell gap g2 in the peripheral region 3b that does not contribute to display is narrowed and narrowed by the color filter layer 33 extending to the peripheral region 3b around the display region 3a. The use amount of the liquid crystal layer LC is reduced by the amount. In particular, since the color filters 3r, 3g, and 3b are stacked in the peripheral region 3b, the effect of narrowing the cell gap g2 in the peripheral region 3b is high, and the usage amount of the liquid crystal layer LC can be sufficiently reduced. It is.

  In addition, since the lead-out lines 31 drawn from the display area 3a to the peripheral area 3b are covered with the color filter layer 33, a short circuit between the lead-out lines 31 due to foreign matters is prevented. Further, a short circuit due to foreign matter being sandwiched between the lead-out wiring 31 and the common electrode 43 is also prevented.

  As a result, according to the display device 1a of FIG. 1, it is possible to reduce the cost of the display device by reducing the usage amount of the liquid crystal layer, and to prevent the short circuit between the wirings and improve the yield. It becomes possible.

  Even if the cell gap g2> 0 in the peripheral region 3b as shown in FIG. 1 from the value of the cell gap g1 and the film thickness of each of the color filters 33r, 33g, 33b, each color. The stacked portion of the filters 33r, 33g, and 33b functions as a preliminary spacer (so-called sub-pillar) for minimizing the deformation of the cell gap g1 in the display region 3a while maintaining the fluidity of the liquid crystal layer LC. become.

<Modification-1>
FIG. 5 shows a cross-sectional view of the main part of the display device 1b in which the stacked state of the color filters 33r, 33g, 33b in the peripheral region 3b is changed. As shown in FIG. 5, the stacked state of the color filters 33r, 33g, and 33b in the peripheral region 3b is such that only the uppermost color filter (here, the red filter 33r) is narrower than the lower color filters 33g and 33b. It may be formed.

  By adopting such a configuration, the volume of the color filter layer 33 is increased in the peripheral region 3b that does not contribute to the display, and the usage amount of the liquid crystal layer LC is further reduced as compared with the configuration of FIG. Increases effectiveness. If the widths of the color filters 33r, 33g, and 33b in the peripheral region 3b are made the same, the effect of further reducing the usage amount of the liquid crystal layer LC is enhanced.

<Modification-2>
FIG. 6 shows a cross-sectional view of the main part of the display device 1c in which the stacked state of the color filters 33r, 33g, 33b in the peripheral region 3b is changed. As shown in FIG. 6, the laminated state of the color filters 33r, 33g, and 33b in the peripheral region is not limited to the three-layer structure, and may be two layers.

  With such a structure, the liquid crystal layer LC injected between the substrate 3-4 through the opening of the sealant 45 is quickly introduced into the display region 3a. In such a configuration, by increasing the width of the color filter layer 33 extending in the peripheral region 3b as much as possible, the effect of reducing the amount of use of the liquid crystal layer LC is enhanced, and a short circuit between the wirings is prevented. The effect to prevent becomes high.

  In the present invention, if the color filter layer 33 is extended in the peripheral region 3b, the effect of reducing the amount of the liquid crystal layer used and the effect of preventing a short circuit between the wirings can be obtained. For this reason, the color filter layer 33 in the peripheral region 3b may have any single layer structure among the color filters 33r, 33g, and 33b.

  The present invention can also be applied to a reflective liquid crystal display device, and the same effect can be obtained. In this case, a reflective layer is provided at a position outside the color filter layer 33 with respect to the liquid crystal layer LC.

<Application example>
The liquid crystal display device according to the present invention described above is input to various electronic devices shown in FIGS. 7 to 11, such as digital cameras, notebook personal computers, mobile terminal devices such as mobile phones, video cameras, and the like. The video signal generated or the video signal generated in the electronic device can be applied to a display device of an electronic device in any field for displaying as an image or a video. An example of an electronic device to which the present invention is applied will be described below.

  FIG. 7 is a perspective view showing a television to which the present invention is applied. The television according to this application example includes a video display screen unit 101 including a front panel 102, a filter glass 103, and the like, and is created by using the display device according to the present invention as the video display screen unit 101.

  8A and 8B are diagrams showing a digital camera to which the present invention is applied. FIG. 8A is a perspective view seen from the front side, and FIG. 8B is a perspective view seen from the back side. The digital camera according to this application example includes a light emitting unit 111 for flash, a display unit 112, a menu switch 113, a shutter button 114, and the like, and is manufactured by using the display device according to the present invention as the display unit 112.

  FIG. 9 is a perspective view showing a notebook personal computer to which the present invention is applied. A notebook personal computer according to this application example includes a main body 121 including a keyboard 122 that is operated when characters and the like are input, a display unit 123 that displays an image, and the like. It is produced by using.

  FIG. 10 is a perspective view showing a video camera to which the present invention is applied. The video camera according to this application example includes a main body 131, a lens 132 for shooting an object on a side facing forward, a start / stop switch 133 at the time of shooting, a display unit 134, and the like. It is manufactured by using such a display device.

  FIG. 11 is a diagram showing a mobile terminal device to which the present invention is applied, for example, a mobile phone, in which (A) is a front view in an opened state, (B) is a side view thereof, and (C) is in a closed state. (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view. The mobile phone according to this application example includes an upper housing 141, a lower housing 142, a connecting portion (here, a hinge portion) 143, a display 144, a sub display 145, a picture light 146, a camera 147, and the like. And the sub display 145 is manufactured by using the display device according to the present invention.

It is a figure explaining the display apparatus of embodiment. It is a figure which shows an example of the circuit structure in the display apparatus of embodiment. It is a figure (the 1) which shows the manufacturing method of the display apparatus of embodiment. It is FIG. (2) which shows the manufacturing method of the display apparatus of embodiment. It is a figure explaining the modification-1 of the display apparatus of embodiment. It is a figure explaining the modification-2 of the display apparatus of an embodiment. It is a perspective view which shows the television to which this invention is applied. It is a figure which shows the digital camera to which this invention is applied, (A) is the perspective view seen from the front side, (B) is the perspective view seen from the back side. 1 is a perspective view showing a notebook personal computer to which the present invention is applied. It is a perspective view which shows the video camera to which this invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the portable terminal device to which this invention is applied, for example, a mobile telephone, (A) is the front view in the open state, (B) is the side view, (C) is the front view in the closed state , (D) is a left side view, (E) is a right side view, (F) is a top view, and (G) is a bottom view. It is principal part sectional drawing which shows the structure of the conventional display apparatus.

Explanation of symbols

  1a, 1b, 1c ... display device, 3 ... first substrate, 3a ... display region, 3b ... peripheral region, 5 ... second substrate, 31 ... lead wiring, 33 ... color filter layer, 33r ... red filter, 33g ... green Filter 33b Blue filter 35 Pixel electrode LC Liquid crystal layer Tr Thin film transistor (pixel circuit)

Claims (6)

A color filter layer provided in the display area of the first substrate;
Pixel electrodes arranged on the color filter layer;
A second substrate opposed to the pixel electrode side of the first substrate;
In a display device comprising a liquid crystal layer sandwiched between the first substrate and the second substrate,
The display device, wherein the color filter layer extends around the display area on the first substrate. The display device according to claim 1,
The display area of the first substrate is provided with a pixel circuit corresponding to each pixel,
Around the display area of the first substrate, a lead-out line connected to the pixel circuit is provided,
The color filter layer is provided in a state of covering the pixel circuit and the extraction wiring. The display device according to claim 1,
The color filter layer is formed by patterning each color filter corresponding to each pixel of the display region. The display device according to claim 3, wherein
Each of the color filters is stacked around the display area. The display device according to claim 4, wherein
The display device, wherein the stacked portion in which the color filters are stacked around the display area is formed so that the width becomes narrower toward the upper layer. In the display device according to 1 above,
A light-shielding film is provided on the second substrate side corresponding to the periphery of the display area.

Images