KR101671514B1 - Organic Light Emitting Display Device - Google Patents

Abstract

The present invention relates to a display panel, A data driver for supplying a data signal to the display panel; A scan driver for supplying a scan signal to the display panel; An arithmetic unit for calculating luminance information and duty cycle information of the data signal supplied from the outside; And a light emitting control section for controlling the light emitting section duty of the display panel based on the light emitting duty information supplied from the calculating section.

Organic electroluminescent display device, luminescence, luminance

Description

[0001] The present invention relates to an organic light emitting display device,

The present invention relates to an organic light emitting display.

An organic electroluminescent device used in an organic electroluminescent display device is a self-luminous device in which a light emitting layer is formed between two electrodes. The organic electroluminescent device injects electrons and holes from the electron injecting electrode and the hole injecting electrode into the light emitting layer, and excites the excited electrons and holes, And emits light when it is dropped to the ground state.

The organic light emitting display device using the organic electroluminescent device has a top emission mode, a bottom emission mode, and a dual emission mode depending on a direction in which light is emitted, Passive matrix type and active matrix type according to the following.

In the organic light emitting display, when a scan signal, a data signal, a power supply, and the like are supplied to the subpixels arranged in a matrix form, the selected subpixel emits light, thereby displaying an image.

However, when a moving picture (moving picture) is implemented on a display panel, the conventional organic light emitting display device exhibits a phenomenon of display quality degradation due to motion blur, and improvement thereof is required.

SUMMARY OF THE INVENTION The present invention for solving the problems of the background art described above is to provide an organic electroluminescent display device capable of reducing motion blur and improving display quality.

According to the present invention, there is provided a display panel comprising: a display panel; A data driver for supplying a data signal to the display panel; A scan driver for supplying a scan signal to the display panel; An arithmetic unit for calculating luminance information and duty cycle information of the data signal supplied from the outside; And a light emission control unit for controlling a light emission section duty of the display panel based on the light emission section duty information supplied from the operation unit.

And a luminance controller that varies a gamma voltage supplied to the data driver based on the luminance information.

The scan driver can control the duty cycle of the light emitting section of the display panel using the light emission control signal supplied from the light emission control section.

The calculation unit can calculate the luminance information and the light emitting interval duty information based on the average image level.

The light emitting section duty information can be determined by the gain of the maximum luminance contained in the luminance information.

The operation unit can generate the luminance information and the light emission section duty information differently according to the motion speed of the data signal.

The light emission control unit may generate a light emission control signal for controlling the duty cycle of the light emitting section of the display panel based on the gate timing control signal supplied from the timing driver for controlling the data driver and the scan driver.

The display panel includes subpixels arranged in a matrix, the subpixel includes a capacitor for storing a data signal as a data voltage, a driving transistor for generating a driving current corresponding to the data voltage, And a control transistor for controlling the supply of the driving current according to the emission control signal supplied from the emission control unit.

The display panel includes subpixels arranged in a matrix form, and the subpixel converts the data signal supplied through the data line to the at least one capacitor in response to the first scan signal supplied through the first scan line to a data voltage A driving transistor for supplying a driving current to the organic light emitting diode corresponding to the data voltage, and a second transistor for compensating a threshold voltage of the driving transistor in response to a second scan signal supplied through the second scan line And a control transistor which is located between the driving transistor and the organic light emitting diode and regulates the supply of the driving current in response to the emission control signal supplied through the control wiring.

At least one of the capacitors includes a first capacitor having one end connected to the first terminal of the first transistor and the other end connected to the gate electrode of the driving transistor and one end connected to the first power supply line to which a high- And the other end connected to the gate electrode of the storage capacitor.

The present invention provides an organic electroluminescent display device capable of varying the duty cycle of an emission region of an organic light emitting diode through image analysis and varying luminance corresponding to the duty cycle of an emission region to improve motion blur and display quality. .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of an organic light emitting display according to an embodiment of the present invention.

1, an organic light emitting display according to an exemplary embodiment of the present invention includes an operation unit 110, a timing driver 120, a data driver 130, a scan driver 140, a display panel 150, A luminance controller 170, a light emission controller 180, and a gamma generator 190.

The operation unit 110 receives a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, a clock signal CLK, and a data signal DATA from the outside. The operation unit 110 analyzes the data signal DATA supplied from the outside and calculates an average picture level (APL) of the highest values among red, green, and blue (R, G, B) values And calculates luminance information (PLG) and light emitting section duty information (ED) on the basis thereof. The arithmetic operation unit 110 may generate the luminance information PLG and the light emitting interval duty information ED in accordance with the motion speed by analyzing the data signal input from the outside. Here, the maximum luminance gain value (Peak Luminance Gain) is included in the luminance information (PLG).

The timing driver 120 receives a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, a clock signal CLK and a data signal DATA from the operation unit 110 . The timing driver 120 may be connected to the data driver 130 and the scan driver 130 using timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a clock signal CLK. And controls the operation timing of the driving unit 140. The timing driver 120 can determine the frame period by counting the data enable signal DE in one horizontal period so that the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync supplied from the outside can be omitted. The control signals generated by the timing driver 120 include a gate timing control signal GDC for controlling the operation timing of the scan driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130. [ ) May be included. The gate timing control signal GDC includes a gate start pulse GSP, a gate shift clock GSC and a gate output enable signal GOE. The gate start pulse (GSP) is supplied to a gate drive IC (Integrated Circuit) generating the first scan signal. The gate shift clock GSC is a clock signal commonly input to the gate drive ICs, and is a clock signal for shifting the gate start pulse GSP. The gate output enable signal GOE controls the output of the gate drive ICs. The data timing control signal (DDC) includes Source Start Pulse (SSP), Source Sampling Clock (SSC), and Source Output Enable (SOE). The source start pulse SSP controls the data sampling start timing of the data driver 130. The source sampling clock SSC is a clock signal for controlling the sampling operation of data in the data driver 130 based on the rising or falling edge. The source output enable signal SOE controls the output of the data driver 130. Meanwhile, the source start pulse SSP supplied to the data driver 130 may be omitted depending on the data transfer mode.

The data driver 130 samples and latches the data signal DATA supplied from the timing driver 120 in response to the data timing control signal DDC supplied from the timing driver 120 and converts the sampled data signal into data of a parallel data system . The data driver 130 converts the data signal DATA into a gamma reference voltage when converting into data of a parallel data system. The data driver 130 supplies the data signal DATA converted through the data lines DL1 to DLn to the sub-pixels SP included in the display panel 150. [

The scan driver 140 generates a gate drive voltage for driving the transistors of the subpixels SP included in the display panel 150 in response to a gate timing control signal GDC supplied from the timing driver 120 And sequentially generates a scan signal while shifting the level of the signal. The scan driver 140 supplies the scan signals generated through the scan lines SL1 to SLm to the subpixels SP included in the display panel 150. [

The display panel 150 is formed of an organic electroluminescence display panel including sub-pixels SP arranged in a matrix form. The subpixels SP are constituted by a 2T (Capacitor) structure including a switching transistor, a driving transistor, a capacitor and an organic light emitting diode, or a structure in which transistors and capacitors are further added such as 3T1C, 4T2C, 5T2C, . The subpixels SP having the above structure may be formed by a top emission method, a bottom emission method, or a dual emission method depending on the structure.

The luminance controller 170 generates a luminance control signal PLC based on the luminance information PLG supplied from the calculator 110 and supplies the generated luminance control signal to the gamma power unit 190 to change the gamma power.

The emission control unit 180 generates the emission control signal EM based on at least one of the emission period duty information ED and the gate timing control signal GDC supplied from the calculation unit 110 and supplies the emission control signal EM to the scan driving unit 140 Emitting period of the organic light emitting diode included in the sub-pixels SP, that is, the emission time and the non-emission time. The emission control signal EM generated from the emission control unit 180 is transmitted to the scan driver 140 and is supplied to the sub pixels SP included in the display panel 150 through the scan lines SL1 to SLm But are not limited thereto. In the following description, it is assumed that the emission control signal EM is supplied to the scan driver 140 and supplied to the sub-pixels SP included in the display panel 150 through the scan lines SL1 to SLm. .

The gamma power supply 190 generates a gamma reference power VGM based on the brightness control signal PLC supplied from the brightness controller 170 and supplies the gamma reference power VGM to the data driver 130, Change the voltage.

Hereinafter, an organic light emitting display according to an embodiment will be described in more detail with reference to a circuit configuration diagram of subpixels.

FIG. 2 is a circuit diagram of a subpixel according to an embodiment of the present invention, FIG. 3 is a drive waveform of the subpixel shown in FIG. 2, and FIG. 4 is a circuit diagram of a subpixel FIG. 5 is a driving waveform diagram of the subpixel shown in FIG. 4, and FIG. 6 is a waveform diagram for explaining a light emission period and a non-light emission period according to a light emission control signal.

2 and 3, the subpixel SP according to an exemplary embodiment of the present invention includes a first transistor S1, a storage capacitor Cst, a driving transistor DR, a control transistor T1, And a diode (D). Although the first transistor S1, the driving transistor DR and the control transistor T1 are P-type in this embodiment, the N-type transistor may be driven by inverting the driving waveform of FIG. 3 .

The first transistor S1 has a gate electrode connected to the first scan line SL1A, a first electrode connected to the data line DL1, and a second electrode connected to the first node n1. The storage capacitor Cst is connected at one end to a second node n2 connected to a first power supply line VDD to which a high potential power is supplied and at the other end to the first node n1. In the driving transistor DR, a gate electrode is connected to the first node n1, a first electrode is connected to the second node n2, and a second electrode is connected to the third node n3. The control transistor T1 has a gate electrode connected to the control line SL1C and a first electrode connected to the third node n3 and a second electrode connected to the anode electrode of the organic light emitting diode D. In the organic light emitting diode D, a cathode electrode is connected to a second power supply line GND to which an anode electrode is connected to the second electrode of the control transistor Tl and a low potential power is supplied.

The first transistor S1 transfers the data signal Vdata supplied through the data line DL1 to the storage capacitor Cst in response to the first scan signal SCAN. The storage capacitor Cst stores the data signal Vdata as a data voltage. The driving transistor DR generates a driving current corresponding to the data voltage stored in the storage capacitor Cst. The control transistor Tl regulates the supply of the driving current according to the emission control signal EM.

The sub-pixel SP described above operates as follows. The first transistor S1 supplies the data signal Vdata supplied to the data line DL1 to the capacitor Cst in response to the first scan signal SCAN supplied through the first scan line SL1A as a data voltage To be stored. The control transistor Tl is driven so that the driving current generated from the driving transistor DR is supplied to the organic light emitting diode D in response to the light emission control signal EM supplied through the control line SL1C.

4 and 5, a subpixel SP according to another embodiment of the present invention includes a first transistor S1, a second transistor S2, a first capacitor C1, a storage capacitor Cst, A driving transistor DR, a control transistor Tl and an organic light emitting diode D. [ The subpixel according to another embodiment includes a second transistor S2 and a first capacitor C1 that compensate the threshold voltage of the driving transistor DR and drive the data voltage to be stored. Although the first transistor S1, the second transistor S2, the driving transistor DR and the control transistor Tl are of the P-type in this embodiment, they may be of the N-type, May be reversed.

In the first transistor S1, a gate electrode is connected to the first scan line SL1A, a first electrode is connected to the data line DL1, and a second electrode is connected to one end of the first capacitor C1. The first capacitor C1 has one end connected to the second electrode of the first transistor S1 and the other end connected to the first node n1. The storage capacitor Cst is connected at one end to a second node n2 connected to a first power supply line VDD to which a high potential power is supplied and at the other end to the first node n1. In the driving transistor DR, a gate electrode is connected to the first node n1, a first electrode is connected to the second node n2, and a second electrode is connected to the third node n3. The second transistor S2 has a gate electrode connected to the second scan line SL1B, a first electrode connected to the first node n1, and a second electrode connected to the third node n3. The control transistor T1 has a gate electrode connected to the control line SL1C and a first electrode connected to the third node n3 and a second electrode connected to the anode electrode of the organic light emitting diode D. In the organic light emitting diode D, a cathode electrode is connected to a second power supply line GND to which an anode electrode is connected to the second electrode of the control transistor Tl and a low potential power is supplied.

The sub-pixel SP described above operates as follows. The second transistor S2 responds to the second scan signal SEN so that the driving transistor DR is formed as a diode connection and the threshold voltage of the driving transistor DR is stored in the first capacitor C1. The first transistor S1 is turned on in response to the first scan signal SCAN and the data signal Vdata supplied through the data line DL1 and the threshold voltage value stored in the first capacitor C1 And transfers the data voltage to the storage capacitor Cst. The storage capacitor Cst stores a voltage corresponding to a difference value of the threshold voltage value stored in the first capacitor C1 as a data voltage. The driving transistor DR generates a driving current corresponding to the data voltage stored in the storage capacitor Cst. The control transistor Tl regulates the supply of the driving current according to the emission control signal EM.

1 to 6, in the organic light emitting display according to the embodiment, the luminance information PLG and the light emitting interval duty information ED for the data signal DATA are calculated by the arithmetic unit 110 , The luminance is controlled in addition to the duty ratio of the light emitting section of the display panel 150 based on the luminance information PLG and the light emitting section duty information ED. According to the emission control signal EM supplied from the emission control unit 180, the non-emission period and the emission period duty of the control transistor T1 of the subpixel shown in FIG. 2 and FIG. 4 are different. As described above, the light emitting section duty can be expressed as "turn-on time of control transistor T1 / one frame ". The light emitting section duty varies depending on the light emitting section duty information (ED) calculated by the calculating section 110. Since the non-emission period increases as the duty ratio of the light emitting section becomes smaller, it becomes closer to the impulsive driving. Therefore, the motion blur effect due to eye tracking is reduced. Here, the meaning of increasing the non-emission period will be described in other words, meaning that the amount of black data insertion (BDI) is increased.

Meanwhile, the embodiment reduces the motion blur by reducing the duty cycle of the light emitting section and adjusts the luminance so as to satisfy the average emission time of the organic light emitting diode (D). To this end, in the embodiment, a method of increasing the driving current generated by the driving transistor DR by adjusting the gamma voltage VGM of the gamma power supply 190 based on the maximum luminance gain value included in the luminance information PLG Increase or decrease the brightness. For example, if the gain for increasing the driving current is referred to as "maximum luminance gain (G) ", it can be defined as the following equation (1).

In order for the luminance due to the light emitting section duty (D) and the maximum luminance gain value (G) to be canceled, the two values should be as shown in the following Equation (2).

In order to maintain the luminance increasing effect according to the maximum luminance gain G, the duty cycle D of the light emitting section must have a value larger than that of Equation (2), and the Equation (3) .

As described above, in the organic light emitting display according to the embodiment of the present invention, the duty cycle of the light emitting period and the non-light emitting period is varied according to the data signal. To compensate for the variation of the duty ratio, To compensate the driving current.

FIGS. 7 and 8 are diagrams for explaining the luminance and the duty ratio adjustment according to the fixed maximum luminance gain.

As shown in FIG. 7, the maximum luminance gain G can be variously adjusted according to the analysis of the data signal, using a fixed value (G = static) regardless of the data signal.

FIGS. 9 and 10 are diagrams for explaining a luminance and luminous interval duty adjusting method according to an average image level.

As shown in FIG. 9, the maximum luminance gain G can be variously applied not only in a linear shape but also in a curved shape. Therefore, the light emitting section duty graph can also be in the form of a straight line or a curve.

FIG. 11 is a view for explaining a luminance and a duty ratio of a light emitting section according to a motion speed.

As shown in FIG. 11, when the motion speed is used, the maximum luminance gain G and the light emitting section duty D can be different.

The organic light emitting display according to an embodiment of the present invention may be implemented in a complex form by applying one or more of the methods described above.

FIG. 12 is a diagram illustrating an output image in the case where the light emitting section duty is 0.75.

As shown in FIG. 12, when the maximum luminance gain G is 1 / 0.75 or more, it can be seen that the image can be displayed without loss of the average luminance. In the image which is perceived on the average in the display panel, the brightness reduction due to the black data writing and the luminance increase due to the maximum brightness cancel each other out. According to the above description, the present invention can display a higher maximum luminance than the original image according to the method of setting the light emitting interval duty.

As described above, the present invention provides an organic light emitting display device capable of varying the duty cycle of the light emitting section of the organic light emitting diode through image analysis and varying the luminance corresponding to the duty cycle of the light emitting section to improve motion blur and display quality. .

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

1 is a block diagram of an organic light emitting display according to an embodiment of the present invention.

2 is a circuit configuration diagram of a subpixel according to an embodiment of the present invention.

FIG. 3 is a drive waveform diagram of the subpixel shown in FIG. 2; FIG.

4 is a circuit configuration diagram of a subpixel according to another embodiment of the present invention.

5 is a drive waveform of the sub-pixel shown in FIG.

6 is a waveform diagram for explaining a light emission period and a non-light emission period according to a light emission control signal;

FIG. 7 and FIG. 8 are diagrams for explaining a luminance and a duty ratio adjustment according to a fixed maximum luminance gain; FIG.

FIGS. 9 and 10 are diagrams for explaining a luminance and a light emitting interval duty according to an average image level; FIG.

11 is a view for explaining a luminance and a duty ratio of a light emitting section according to a motion speed;

12 is an exemplary output image when the light emitting section duty is 0.75;

DESCRIPTION OF THE REFERENCE NUMERALS

110: Operation unit 120: Timing driver

130: Data driver 140:

150: display panel 170: luminance controller

180: emission control unit 190: gamma-

Claims (12)

Display panel; An arithmetic unit operable to calculate luminance information and duty cycle information based on an average picture level (APL) of a data signal supplied from outside; A light emission control unit for controlling a light emission duty by supplying a signal to a transistor included in subpixels of the display panel based on the light emitting interval duty information supplied from the operation unit; A data driver for supplying the data signal to the display panel; A scan driver for supplying a scan signal to the display panel; And And a luminance controller for varying a gamma voltage supplied to the data driver based on the luminance information, Wherein the operation unit determines the light emitting interval duty based on a gain value of a maximum luminance included in the luminance information and sets a gain value of the maximum luminance to compensate for luminance depending on the increase / And controls the brightness controller to adjust the gamma voltage corresponding to the gamma voltage. delete delete delete delete The method according to claim 1, The operation unit, Wherein the luminance information and the light emitting interval duty information are generated differently according to a motion speed of the data signal. The method according to claim 1, The light- And generates a light emission control signal for controlling a light emitting section duty of the display panel based on a gate timing control signal supplied from a timing driver for controlling the data driver and the scan driver. The method according to claim 1, The sub- A capacitor for storing the data signal as a data voltage, A driving transistor for generating a driving current corresponding to the data voltage, An organic light emitting diode which emits light by the driving current generated from the driving transistor, And a control transistor for controlling the supply of the driving current according to a light emission control signal supplied from the light emission control unit. The method according to claim 1, The sub- A first transistor for driving a data signal supplied through a data line in response to a first scan signal supplied through a first scan line to store the data signal in at least one capacitor as a data voltage, A driving transistor for supplying a driving current to the organic light emitting diode corresponding to the data voltage, A second transistor for driving to compensate a threshold voltage of the driving transistor in response to a second scan signal supplied through a second scan line, And a control transistor located between the driving transistor and the organic light emitting diode and controlling the supply of the driving current in response to a light emission control signal supplied through the control wiring. 10. The method of claim 9, Wherein the at least one capacitor comprises: A first capacitor having one end connected to a first terminal of the first transistor and the other end connected to a gate electrode of the driving transistor; And a second capacitor having one end connected to a first power supply line to which a high potential power is supplied and the other end connected to a gate electrode of the driving transistor. delete The method according to claim 1, The maximum luminance gain Wherein the data signal is set to a fixed value irrespective of the data signal or is varied according to the analysis of the data signal.

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