KR20200076993A - Electroluminescence display and methode of driving the same - Google Patents

Abstract

The present invention relates to an electroluminescent display device and to a driving method thereof. By sensing the deterioration of each of sub-pixels, the driving amount of the sub-pixels in each of the pixels is adjusted based on the deterioration level of each of the sub-pixels. The electroluminescent display device includes: a display panel; a data driving unit; a sensing unit; and a timing controller.

Description

Electroluminescent display device and its driving method{ELECTROLUMINESCENCE DISPLAY AND METHODE OF DRIVING THE SAME}

The present invention relates to an electroluminescent display device that disperses deterioration of sub-pixels based on a result of deterioration sensing for each sub-pixel.

The electroluminescent display device is roughly classified into an inorganic light emitting display device and an organic light emitting display device according to the material of the light emitting layer. The active matrix type organic light emitting display device includes a light emitting device that emits light by itself, and has a fast response speed, high light emission efficiency, high brightness, and a large viewing angle. The light emitting device may be an organic light emitting diode (hereinafter, referred to as "OLED"). Since the organic light emitting diode display can express black gradation in full black, it is possible to reproduce an image at a level superior to that of contrast ratio and color reproduction.

The pixels of the organic light emitting display device include an OLED and a driving element that supplies the current to the OLED according to the voltage between the gate and the source to drive the OLED. The OLED of the organic light emitting display device includes an anode and a cathode, and an organic compound layer formed between the electrodes. The organic compound layer includes a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (Electron Injection layer, EIL). When a current flows through the OLED, holes passing through the hole transport layer (HTL) and electrons passing through the electron transport layer (ETL) are moved to the emission layer (EML) to form excitons, and as a result, the emission layer (EML) generates visible light. .

When high grayscale pixel data is continuously written to specific pixels, such as subtitles or logos, in an organic light emitting display device, the cumulative stress of these pixels increases compared to other pixels. Pixels with high cumulative stress are accelerated to deteriorate faster than other pixels, thereby reducing luminance. Due to the deteriorated pixels, non-restored afterimages or stains may remain on the screen. In order to prevent such afterimages, various methods are known. However, in the conventional method, since image information is arbitrarily changed when stress is distributed between sub-pixels, image quality may deteriorate, such as color distortion occurring in the reproduced image.

In the conventional method, since the cumulative usage of sub-pixels for each color varies depending on an input image, it is impossible to accurately determine the actual level of deterioration of each of the sub-pixels. If the deterioration level of the sub-pixels is not detected to be purified, the afterimage improvement effect may be insignificant or an afterimage may be caused.

If the stress of pixels is predicted based on the frame of the input image, the level of deterioration of pixels for each location on the screen is not known, so the stress cannot be distributed considering the deterioration level of different pixels for each location on the screen.

Accordingly, the present invention senses the deterioration level of each sub-pixel in real time to distribute stress between pixels having different positions on the screen, and an electroluminescence display capable of dispersing the stress of pixels accumulated over time and its driving Provides a method.

The electroluminescent display device of the present invention includes a display panel in which pixels including data lines, sensing lines, and a plurality of sub-pixels having different colors are disposed; A data driver that converts pixel data of an input image into a data voltage and supplies the data lines to the data lines; A sensing unit configured to sense deterioration of each of the sub-pixels; And a timing controller adjusting the driving amount of the sub-pixels in each of the pixels based on the deterioration level of each of the sub-pixels.

The driving method of the electroluminescent display device includes sensing the deterioration of each of the sub-pixels using the sensing unit, and based on the deterioration level of each of the sub-pixels sensed by the sensing unit in each of the pixels. And adjusting the driving amount of the sub-pixels.

According to the present invention, the deterioration of the light emitting device in each of the sub-pixels is sensed in real time to accurately determine the accumulated luminance stress for each sub-pixel in real time. The present invention determines the deterioration level of each sub-pixel and adjusts the driving amount for each color in each pixel to distribute stress between pixels at different locations on the screen without color distortion and effectively reduce the stress of pixels accumulated over time. Can be dispersed.

The present invention can improve the lifetime and image quality of pixels by preventing the under-compensation or over-compensation of pixels by properly dispersing the cumulative stress for each color in each pixel based on the deterioration sensing result for each sub-pixel sensed in real time.

1 is a block diagram showing an electroluminescent display device according to an exemplary embodiment of the present invention.
2 is a view showing a sensing line connected to a pixel.
3 is a circuit diagram showing a deterioration sensing unit connected to a pixel circuit.
4 is a view showing an example in which the deterioration sensing unit is built in the source driver IC.
5 is a diagram illustrating a deterioration sensing method for a sub-pixel to be sensed.
6 is a waveform diagram showing sensing operation of a pixel circuit before and after deterioration.
7 is a view showing a sensing mode.
8 is a diagram illustrating an example in which stains and afterimages are seen on a screen after a use time has elapsed due to a stress variation between pixels.
9 is a view showing luminance differences between pixels as the use time increases due to a stress difference between pixels.
10 is a diagram illustrating an example of driving a pixel in a combination of a WRGB method and an RGB method.
11 is a diagram illustrating an example of using luminance of sub-pixels for each color in the WRGB method and the RGB method.
12 is a diagram illustrating an example in which one pixel is driven by the WRGB method and the RGB method.
13 is an image showing an example in which an afterimage is seen when a red image is displayed on the screen and then is changed to a white image.
14 is an image showing an example in which white and red pixels are coexisting on one screen.
15 is a flowchart illustrating a method of driving an electroluminescence display according to an embodiment of the present invention.
16 is a view showing an example of adjusting the driving ratio in the WRGB method and the RGB method to reduce cumulative stress for each color.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. The present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the scope of the invention, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing the embodiments of the present invention are exemplary, and the present invention is not limited to the details shown in the drawings. Throughout the specification, the same reference numerals refer to substantially the same components. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

When "equipped", "included", "have", "consisting of" and the like referred to herein are used, other parts may be added unless'~ only' is used. When a component is expressed in singular, it may be interpreted in plural unless otherwise specified.

In interpreting the components, it is interpreted as including the error range even if there is no explicit description.

In the case of the description of the positional relationship, for example, when the positional relationship between the two components is described as'on the top','on the top','on the bottom','on the side', ' One or more other components may be interposed between those components for which no'direct' or'direct' is used.

The first, second, etc. may be used to classify the components, but the functions or structures of these components are not limited by the ordinal number or the name of the component before the component.

The following embodiments may be partially or totally combined or combined with each other, and technically various interlocking and driving are possible. Each of the embodiments may be implemented independently of each other or may be implemented together in an association relationship.

The pixel circuit and gate driver of the present invention may include transistors formed on a substrate of a display panel. Transistors may be implemented as an oxide TFT (Thin Film Transistor) including an oxide semiconductor, an LTPS TFT including Low Temperature Poly Silicon (LTPS). Further, each of the transistors can be implemented with a p-type TFT or an n-type TFT.

Transistors are three-electrode devices, including gates, sources, and drains. The source of the transistor is an electrode that supplies a carrier to the transistor. In the transistor, carriers begin to flow from the source. The drain is an electrode through which a carrier is driven out of the transistor. In the transistor, the carrier flows from source to drain. In the case of an n-type transistor, since the carrier is electron, the source voltage has a voltage lower than the drain voltage so that electrons can flow from the source to the drain. In n-type transistors, the direction of current flows from drain to source. In the case of a p-type transistor, the source voltage is higher than the drain voltage so that holes can flow from the source to the drain because the carrier is a hole. In the p-type transistor, current flows from the source to the drain because holes flow from the source to the drain. It should be noted that the source and drain of the transistor are not fixed. For example, the source and drain of the transistor can be changed according to the applied voltage. Therefore, the invention is not limited due to the source and drain of the transistor. In the following description, the source and drain of the transistor will be referred to as first and second electrodes.

The gate signal output from the gate driver swings between a gate on voltage and a gate off voltage. The gate-on voltage is set to a voltage higher than the threshold voltage of the transistor, and the gate-off voltage is set to a voltage lower than the threshold voltage of the transistor. The transistor is turned on in response to the gate on voltage, while it is turned off in response to the gate off voltage. In the case of the n-type transistor, the gate-on voltage may be a gate high voltage (VGH), and the gate-off voltage may be a gate low voltage (VGL). In the case of a p-type transistor, the gate-on voltage may be a gate low voltage (VGL), and the gate-off voltage may be a gate high voltage (VGH).

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the electroluminescent display device of the present invention will be mainly described with an example in which an external compensation circuit is applied.

1 to 4, an electroluminescent display device according to an exemplary embodiment of the present invention includes a display panel 100 and a display panel driver.

The electroluminescent display device of the present invention operates in a display driving mode for displaying an input image on a screen and a sensing mode for sensing the electrical characteristics of pixels.

In the display driving mode, the display panel driver writes pixel data of an input image to pixels during a vertical active time (AT) every frame period under the control of the timing controller 130. In the sensing mode, the display panel driver senses each sub-pixel under the control of the timing controller 130 to sense deterioration of the sub-pixels in real time.

The screen of the display panel 100 includes the active area AA. The active area AA includes a pixel array in which an input image is reproduced. The pixel array includes a plurality of data lines 102, a plurality of gate lines 104 intersecting the data lines 102, and pixels arranged in a matrix form.

When the resolution of the pixel array is m*n, the pixel array includes m (m is a positive integer greater than or equal to 2) pixel columns and n (n is a positive integer greater than or equal to 2) pixel lines intersecting Fields (L1 to Ln) are included. The pixel column includes pixels arranged along the y-axis direction. The pixel line includes pixels PIX arranged along the x-axis direction. One vertical period is one frame period required to write one frame of pixel data to all pixels PIX on the screen. This is the time required to write one line of pixel data sharing the gate line to pixels of one pixel line. One horizontal period is a period obtained by dividing one frame period by the number of m pixel lines L1 to Lm, that is, the vertical resolution of the display panel 100.

Each of the pixels PIX has a red sub-pixel (hereinafter referred to as “R sub-pixel”), a green sub-pixel (hereinafter referred to as “G sub-pixel”), and a blue sub as shown in FIG. 2 for color realization. It includes a pixel (hereinafter referred to as “B sub-pixel”) and a white sub-pixel (hereinafter referred to as “W sub-pixel”). Each of the sub-pixels includes a pixel circuit 101 as shown in FIG. 3. Hereinafter, red, green, and blue sub-pixels disposed in one pixel PIX will be referred to as “R, G, and B sub-pixels”.

Touch sensors may be disposed on the display panel 100. The touch input may be sensed using separate touch sensors or may be sensed through pixels. The touch sensors may be implemented as in-cell type or in-cell type touch sensors disposed on a screen of a display panel or embedded in a pixel array in an on-cell type or an add-on type. Can.

The display panel driver includes a data driver 110, a gate driver 120, a timing controller 130, and a power supply unit 150. A demultiplexer 140 disposed between the data driver 110 and the data lines 102 may be disposed.

The display panel driver displays the input image on the screen by writing the pixel data of the input image to the pixels of the display panel 100 under the control of the timing controller 130 in the display driving mode. In a mobile device or a wearable device, the data driving unit 110, the timing controller 130, and the power supply unit 150 may be integrated in one drive integrated circuit (IC).

The data driver 110 receives pixel data RGBW received from the timing controller 130. The data driving unit 110 divides the gamma reference voltage (GMA) to generate gamma compensation voltage for each gray level of pixel data and supplies it to a digital to analog converter (hereinafter referred to as “DAC”) 112. The data driver 110 converts the pixel data RGBW to a gamma compensation voltage using a DAC to generate a data voltage Vdata. The data voltage Vdata is divided into a sensing data voltage supplied to sub-pixels in a sensing mode and a pixel data voltage written into sub-pixels in a display driving mode and reproduced as an image. The data voltage Vdata output from the data driver 110 is supplied to the data lines 102. The data driver 110 may be implemented with one or more source drive integrated circuits (SDICs) as shown in FIG. 4.

The data driver 110 includes a sensing unit 111 that senses deterioration of each of the sub-pixels by using a sampling switch element connected to the sensing lines 103.

The demultiplexer 140 distributes the data voltage Vdata output from the data driver 110 to a plurality of data lines 102 using switch elements disposed between the data driver 110 and the data lines 102. do. Since the data voltage Vdata output from one channel of the data driver 110 by the demultiplexer 140 is time-divided and distributed to a plurality of data lines, the number of channels of the data driver 110 may be reduced.

The gate driver 120 may be implemented as a gate in panel (GIP) circuit formed directly on the display panel 100 together with the pixel array of the active area AA. The GIP circuit may be disposed on a bezel area of the display panel 100 outside the pixel array. The gate driver 120 outputs a gate signal to the gate lines 104 under the control of the timing controller 130. The gate driver 120 may sequentially supply the signals to the gate lines 104 by shifting the gate signal using a shift register. The gate signal may include the scan signal SCAN illustrated in FIG. 3. The scan signal SCAN is synchronized with the data voltage Vdata.

The timing controller 130 receives input zero pixel data RGB and a timing signal synchronized therewith from the host system 200. The timing signal received by the timing controller 130 may include a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a main clock (MCLK), and a data enable signal (DE).

The timing controller 130 controls the operation timing of the display panel driver in the display driving mode and the sensing mode based on the timing signal received from the host system 200. One period of the vertical synchronization signal Vsync is one frame period. One cycle of the horizontal synchronization signal Hsync and the data enable signal DE is one horizontal period (1H). The pulse of the data enable signal DE is synchronized with the pixel data of one pixel line to be displayed on the pixels of the active area AA to define an effective data section. Since the frame period and the horizontal period are known by the method of counting the data enable signal DE, the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync may be omitted.

Since the vertical period and the horizontal period can be known by counting the data enable signal DE, the vertical synchronization signal Vsync and the horizontal synchronization signal Hsync may be omitted from the input signal of the timing controller 130. The voltage level of the gate timing control signal output from the timing controller 130 is converted into a gate high voltage VGH and a gate low voltage VGL through a level shifter and supplied to the gate driver 120.

The timing controller 130 may adjust the frame rate to a frequency greater than or equal to the input frame frequency. For example, the timing controller 130 may multiply the input frame frequency by i times to control the operation timing of the display panel driver at a frame frequency x i (i is a positive integer greater than 0) Hz. The frame frequency is 60 Hz in the NTSC (National Television Standards Committee) method and 50 Hz in the PAL (Phase-Alternating Line) method.

The timing controller 130 includes a stress distribution processing unit 132. The stress distribution processing unit 132 inputs red, green, blue, and white data (hereinafter referred to as “RGBW data”) as input pixel data (RGB) including red, green, and blue data (hereinafter referred to as “RGB data”). Convert to pixel data (RGBW) including. The stress distribution processing unit 132 generates white data from the RGB data using a preset white gain calculation algorithm. As the white gain calculation algorithm, a known method such as Korean Patent 10-1857809 can be used.

The stress distribution processing unit 132 accumulates the real-time sensing results of each of the sub-pixels received through the deterioration sensing unit illustrated in FIG. 3, stores the accumulated stress for each sub-pixel in memory, and updates each frame period. The stress dispersion processing unit 132 compares the cumulative stress of each of the W sub-pixels and the R, G, and B sub-pixels in each of the pixels PIX based on the cumulative stress for each sub-pixel, and determines whether the degradation of the W sub-pixel is large. It is determined whether the deterioration of the, G, and B subpixels is large. The stress dispersion processing unit 132 decreases the driving intensity of the W subpixel when the degradation of the W subpixel is greater than that of each of the R, G, and B subpixels, and the degradation of the R, G, and B subpixels is the W subpixel In order to prevent color distortion when the deterioration of is large, the driving amount of the R, G, and B sub-pixels is maintained, and the driving amount of the R, G, and B sub-pixels is relatively low in surrounding pixels with little deterioration Increases.

The stress dispersion processing unit 132 may compare the deterioration amount of the sub-pixels by color or compare the deterioration amount of each sub-pixel by comparing the deterioration amount of the sub-pixels for each color based on the real-time sensing result of the sub-pixel deterioration amount. .

For each of W, R, G, and B, the threshold of the deterioration amount for each color is set, and when the deterioration amount is greater than the threshold value, the accumulated amount of sub-pixels can be distributed by adjusting the driving amount for each color. have. In other words, the stress dispersion processing unit 132 adjusts the driving amount for each color from the time when the amount of degradation among sub-pixels is greater than a threshold value.

In an actual driving environment, a residual image on the screen may be generated in two or more colors. When the amount of deterioration is reduced for a sub-pixel of a color having the largest amount of deterioration in each of the pixels, an afterimage in the corresponding color may be reduced. Subsequently, if a sub-pixel of a different color has a higher heat capacity than other sub-pixels in a pixel, reducing the amount of deterioration of the same sub-pixel reduces the afterimage even in other colors.

The stress distribution processing unit 132 may compare the amount of deterioration for each sub-pixel sensed in real time through the sensing unit 111 with a predetermined reference value to determine the deterioration level for each sub-pixel. In addition, the stress dispersion processing unit 132 may compare the amount of deterioration sensed for each sub-pixel between neighboring pixels (or sub-pixels) to determine the deterioration level of each pixel (or sub-pixels).

The stress dispersion processing unit 132 may adjust the driving amount of sub-pixels for each color in order to distribute stress between pixels and between sub-pixels. The stress dispersion processing unit 132 may add or subtract a preset fixed value to the pixel data according to the driving amount for each color, or the compensation value to the pixel data according to the deterioration level.

When reproducing pixel data in which two or more colors are mixed in a pixel, W subpixel, R subpixel and B subpixels (W+R+B) or W subpixel, G subpixel and B subpixels (W The pixel data written in +R+B) expresses the color of the corresponding pixel data (WRGB method), or the pixel data (RGB) written in R subpixel, G subpixel and B subpixels (R+G+B) Method) to express the color of the corresponding pixel data.

In the stress distribution processing unit 132, the compensation value is determined by a combination of the WRGB method and the RGB method, and the deterioration variation between pixels between sub-pixels can be reduced by appropriately determining the combination ratio. Adding or subtracting a fixed value means that the luminance ratio of the RGB method can be fixed. For example, as illustrated in FIG. 16, the luminance ratio of the RGB method may be fixed at 5%. When the deterioration level of the W sub-pixel increases, adjusting the luminance ratio of the RGB method to 10% decreases the driving amount of the W sub-pixel and increases the driving amount of the R, G, and B sub-pixels, thereby quickly distributing the stress of the sub-pixels. I can adjust it. When the deterioration level is small, the luminance ratio of the RGB method can be reduced to about 2%. The combination ratio of the WRGB method and the RGB method can be appropriately selected in consideration of the stress dispersion effect and image quality.

The stress dispersion processing unit 132 distributes stress between the W sub-pixels and R, G, and B sub-pixels shown in FIG. 5 by modulating the gradation value of data written to the sub-pixels to compensate for deterioration deviation between the sub-pixels. Decrease. To this end, the stress distribution processing unit 132 may lower the gradation values of white data written in the W sub-pixels and increase the gradation values of red, green, and blue data written in the R, G, and B sub-pixels. Therefore, the stress dispersion processing unit 132 may lower the driving intensity of the W sub-pixel without distortion of the white and color of the pixel, and reduce the variation in deterioration of the W sub-pixel and the R, G, and B sub-pixels. The timing controller 130 transmits the pixel data RGBW modulated by the stress distribution processing unit 132 to the data driver 110.

The power supply unit 150 uses a DC-DC converter to generate power required for driving the pixel array of the display panel 100 and the display panel driver. The DC-DC converter may include a charge pump, a regulator, a buck converter, and a boost converter. The DC-DC converter adjusts the DC input voltage (Vin) from the host system 200 to determine a gamma reference voltage (GMA) and a gate high voltage (VGH). A DC power source such as a pixel driving voltage ELVDD, a low potential power voltage ELVSS, and a reference voltage Vref may be generated. The gamma reference voltage GMA is supplied to the data driver 110. The gate-off voltage VGH and the gate-on voltage VGL are supplied to the gate driver 120. The reference voltage Vref is a reference voltage commonly supplied to the sub-pixels in order to uniformly initialize the voltage of the sensing node, that is, the second node n2 in each of the sub-pixels. The power supply unit 150 may be implemented as a power management integrated circuit (PMIC).

The host system 200 may be any one of a TV (Television) system, a set top box, a navigation system, a personal computer (PC), a home theater system, a mobile device, and a wearable device.

The deterioration sensing unit converts the result of sensing the deterioration of the light emitting element OLED into digital data while controlling the transistor (driving element) driving the light emitting element OLED in each of the sub-pixels to the off state, thereby converting the timing controller 130 into digital data. ). The deterioration sensing unit may use a known method for sensing deterioration of each of the sub-pixels. For example, the deterioration sensing unit may use the sensing method disclosed in published patent 10-2017-0021406 (2017. 02. 28.) previously filed by the applicant. The deterioration sensing unit will be described with reference to FIGS. 3 to 6.

The deterioration sensing unit includes a sensing line 103 and a sensing unit 111 connected to the pixel circuit 101 in each of the sub-pixels, as shown in FIG. 3. The sensing line 103 may be arranged on the screen of the display panel 100 in parallel with the data lines 102. The sensing unit 111 senses deterioration of each of the sub-pixels through the sensing line 103. The sensing unit 111 may be integrated in a source drive IC (SDIC) in which the data driver 110 is integrated together with the DAC 112.

The deterioration sensing unit senses the current or voltage of the second node n2 after initializing the source voltage of the sensing line 103 and the driving element DT, that is, the voltage of the second node n2 with the reference voltage Vref. The electrical characteristics of the light emitting device OLED and the driving device DT may be sensed. The electrical characteristics of the light emitting element OLED and the driving element DT include a threshold voltage Vth, mobility Vth, μ, and the like.

The sensing unit 111 includes a reference voltage control switch SW1, a sampling switch SW2, and a sample and hold unit 116. The reference voltage control switch SW1 switches the current path between the input terminal of the reference voltage Vref and the sensing line 103 according to the reference voltage control signal PRE. The sampling switch SW2 switches the current path between the sensing line 1103 and the sample and hold unit 116 according to the sampling control signal SAM.

The reference voltage control switch SW1 is turned on during the first and second periods to apply the reference voltage Vref to the sensing line 103 and then turn-off in the third period. off). The sampling switch SW2 is turned on at a specific time in the third period and electrically connects the sensing line 103 to the sample and hold unit 116.

The sample and hold unit 116 samples the current or voltage on the sensing line 103 connected to the pixel circuit 101 in the sensing mode with an integrator. The output voltage of the integrator is input to an analog-to-digital converter (hereinafter referred to as “ADC”) 115 and converted to digital data (ADC DATA). The digital data (ADC DATA) output from the ADC 115 includes electrical characteristics of each of the sub-pixels, for example, threshold voltage (Vth) and mobility (Vth, μ) information of the light emitting device (OLED). The digital data (ADC DATA) output from the ADC 115 is transmitted to the timing controller 130.

The pixel circuit 101 includes a light emitting element OLED, a driving element DT connected to the light emitting element OLED, a plurality of switch TFTs M1 and M2, and a capacitor Cst, as shown in the example of FIG. 3. do. The driving element DT and the switch TFTs M1 and M2 may be implemented as an n-channel transistor NMOS, but are not limited thereto.

The light emitting device OLED emits light with a current generated according to the gate-source voltage Vgs of the driving device DT that changes according to the data voltage Vdata. The light emitting device (OLED) includes an organic compound layer formed between the anode and the cathode. The organic compound layer may include, but is not limited to, a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL). The anode of the light emitting element OLED is connected to the driving element DT through the second node n2, and the cathode of the light emitting element OLED is connected to the ELVSS electrode to which the low potential power voltage ELVSS is applied.

The first switch TFT M1 is turned on according to the gate-on voltage of the scan signal SCAN to connect the data line 102 to the first node n1 to connect the data voltage Vdata to the first node n1. To supply. The first switch TFT M1 includes a gate electrode connected to the gate line 104 to which the scan signal SCAN is applied, a first electrode connected to the data line 102, and a second electrode connected to the first node n1. Includes. The gate electrode of the driving element DT, the first electrode of the capacitor Cst, and the second electrode of the first switch TFT M1 are connected to the first node n1.

The second switch TFT M2 is turned on according to the scan signal SCAN to supply the reference voltage Vref to the second node n2. The second switch TFT M2 includes a gate electrode connected to the gate line 104 to which the scan signal SCAN is applied, a first electrode connected to the second node n2, and a sensing line to which the reference voltage Vref is applied ( 103). The second electrode of the driving element DT, the second electrode of the capacitor Cst, and the first electrode of the second switch TFT M2 are connected to the second node n2.

The driving device DT drives the light emitting device OLED by supplying a current to the light emitting device OLED according to the gate-source voltage Vgs. The driving element DT includes a gate connected to the first node n1, a first electrode connected to the ELVDD line to which the pixel driving voltage ELVDD is supplied, and a second electrode connected to the second node n2.

The capacitor Cst is connected between the first node n1 and the second node n2 to maintain the gate-source voltage Vgs of the driving element DT between frames.

The sensing line 103 may be shared by a plurality of sub-pixels 101 as shown in FIG. 2. For example, one sensing line 103 may be connected to four sub pixels. Meanwhile, although the sensing line 104 may be connected to each of the sub-pixels 1:1, the aperture ratio of the pixel may be lowered because the number of sensing lines 103 disposed on the pixel array is large. As the aperture ratio of the pixel is low, the brightness of the light emitting device OLED can be increased, but in this case, the current density of the light emitting device OLED is increased, so that the deterioration rate of the light emitting device OLED may be increased and the life may be reduced.

The source drive IC (SDIC) may include a deterioration sensing unit as illustrated in FIGS. 3 and 4. For example, the data driver 110 includes a sensing unit 111, a multiplexer (113), a shift register 114, and an ADC 115. The multiplexer 113 sequentially supplies the output voltages of the sensing units 111 to one ADC 115 through switch elements SS1 and SS2 connected between the sensing units 111 and the ADC 115.

The shift register 114 shifts the pulse of the input signal according to the ADC clock signal ACLK. The switch elements SS1 and SS2 of the multiplexer 113 are sequentially turned on according to the signal from the shift register 114. The shift register 114 and the ADC 115 are synchronized by sharing the ADC clock signal ACLK.

The sensing data voltage Vdata is applied to the gate electrode of the driving element DT in the sensing mode, and the first sensing data voltage Vdata and the non-sensing subpixels applied to the sensing subpixels 101 are applied. It is divided by the second sensing data voltage applied to (101). The non-sensing sub-pixels 101 mean a sub-pixel that is not sensed when it is sensed by the sensing target sub-pixel 101. Since the electrical characteristics of all sub-pixels are sensed, the non-sensing sub-pixels 101 are sequentially selected as sensing sub-pixels and sensed.

When the driving element DT is deteriorated, it is difficult to determine the degradation of the light emitting element OLED because the electrical characteristics (mobility, threshold voltage, etc.) of the driving element change and the current of the light emitting element OLED changes. This is because the current change of the light emitting element OLED due to the deterioration of the driving element DT decreases accuracy when sensing the deterioration of the light emitting element OLED.

In order to block the influence of the driving element DT when sensing the deterioration of the light emitting element OLED, the first sensing data voltage for sensing the deterioration of the light emitting element OLED turns off the driving element DT. It can be set to a voltage lower than the reference voltage enough to turn-off. The data voltage for the second sensing may be set higher than the reference voltage so that the driving element DT is turned on. The first sensing data voltage may be set as a black gray level voltage, and the second sensing data voltage may be set as a white gray level voltage. The sensing unit 111 senses the current or voltage from the second node n2 of the sensing target sub-pixel to which the first sensing data voltage is applied. As the first sensing data voltage is sequentially applied to all the sub-pixels 101 and the sub-pixels 101 are sensed in synchronization with this, as illustrated in FIGS. 3 and 4, the sensing line includes a plurality of sub-pixels. The light emitting device OLED may be sensed in each of the sub pixels 101 even though it is shared with the 101.

5 is a diagram illustrating a deterioration sensing method for a sub-pixel to be sensed. 6 is a waveform diagram showing the sensing operation of the pixel circuit 101 before and after the deterioration. In FIG. 6, Ng is a voltage of the first node n1 equal to the gate node voltage of the driving element DT. Ns is the voltage of the second node n2 equal to the source node voltage of the driving element DT.

5 and 6, the sub-pixel deterioration sensing method includes an initialization step (S10) performed in a first period (Tint), an operation point setting step (S20) performed in a second period (Tbst), and a third period. It includes a sensing step (S30) made in (Tsen). During the sensing driving, the data driving circuit 12 supplies the first sensing data voltage (eg, black gradation data voltage, 0.5V), which can turn off the driving element DT, to the data lines 102.

In the first period Tint, the first and second switch TFTs M1 and M2 included in the sub-pixel to be sensed according to the scan signal SCAN having the first gate-on voltage VGH1 of the first level 24V ) Is turned on. Then, in the first period Tint, the reference voltage control switch SW1 is turned on, and the sampling switch SW2 is turned off.

Accordingly, the first sensing data voltage (black gradation data voltage, 0.5 V) at which the driving device DT is turned off is a gate node of the sensing device DT of the sub-pixel to be sensed, that is, the first node n1. Is applied to. In addition, the reference voltage Vref of the first level LV1 and 9V higher than the operating point voltage of the light emitting element OLED is the source node of the driving element DT through the sensing line 17, that is, the second node n2 ).

In the first period Tint, the driving element DT is turned off, and the light emitting element OLED of the sensing target sub-pixel is turned on.

In the second period Tbst, the first and second switch TFTs M1 and M2 are turned off according to the scan signal SCAN having the gate-off voltage VGL of the second level (-6V). At this time, the reference voltage control switch SW1 maintains a turn-on state, and the sampling switch SW2 maintains a turn-off state.

In the second period Tbst, the anode of the light emitting device OLED is floated. In addition, a current flows to the light emitting device OLED by the reference voltage Vref of the first level LV1 and 9V charged in the anode of the light emitting device OLED, and the light emitting device OLED emits light. The anode voltage of the light emitting device OLED is lowered from the reference voltage Vref of the first level LV1 and 9V to the operating point voltage of the light emitting device OLED by the current flowing through the light emitting device OLED. At this time, the operating point voltage of the light emitting device OLED varies according to the deterioration level of the light emitting device OLED. For example, the operating point voltage of the light emitting device OLED may be 8.5 after the deterioration of the light emitting device OLED, whereas the voltage of the operating point of the light emitting device OLED is 8V before the light emitting device OLED deterioration.

In the second period Tbst, the second node n2 connected to the gate node of the driving element DT is also floated. Since the gate node of the driving element DT is coupled to the anode of the light emitting element OLED through the storage capacitor Cst, its potential is also lowered in proportion to the change in the anode potential of the light emitting element OLED. For example, when the anode potential of the light emitting device OLED changes from 9V to 8V, the gate node potential of the driving device DT may also change from 0.5V to -0.5V, and also, the anode potential of the light emitting device OLED When is changed from 9V to 8.5V, the gate node potential of the driving element DT may also change from 0.5V to 0V.

Meanwhile, in the second period Tbst, the reference voltage Vref of the second levels LV2 and 14V higher than the first levels LV1 and 9V is charged in the sensing line 103.

In the third period Tsen, the first and second switch TFTs M1 and M2 are turned on according to the scan signal SCAN having the second gate-on voltage VGH2 of the third level 11V. Then, the reference voltage control switch SW1 is turned off, and the sampling switch SW2 is turned on at a specific time point (sampling time point).

The second gate-on voltage VGH2 of the third level 11V is higher than the operating point voltage of the light emitting element OLED and lower than the reference voltage Vref of the second level LV2, 14V so that a smooth discharge operation is achieved. . In the third period Tsen, the gate node potential of the driving element DT is maintained at the first sensing data voltage (black gradation data voltage, for example, 0.5V), so that the driving element DT is turned off. Therefore, when the anode voltage of the light emitting element OLED is sensed, the driving element DT does not affect.

In the third period Tsen, the electrical connection with the input terminal of the reference voltage Vref is released, and the sensing line 103 is electrically connected to the anode of the light emitting device OLED through the second switch TFT M2. As a result, the threshold voltage of the light emitting device OLED is sensed while the reference voltages Vref of the second levels LV2 and 14V charged in the sensing line 103 are discharged through the light emitting device OLED. The anode of the light emitting element OLED rises from the operating point voltage of the light emitting element OLED. In the case of deterioration before the operation point voltage of the light emitting element OLED is low, the second switch TFT (M2) is used because the voltage (Vgs, 11V-8V=3V) between the gate and the source of the second switch TFT (M2) is relatively large. The amount of current discharged through it becomes large. In other words, the discharge rate is relatively fast. On the other hand, the second switch TFT (M2) because the voltage between the gate-source (Vgs, 11V-8.5V=2.5V) of the second switch TFT (M2) is relatively small after the high operating point voltage of the light emitting device (OLED) is deteriorated. ), the amount of current discharged is smaller than before deterioration, so the discharge rate is relatively slow. The voltage remaining in the sensing line 103 is changed due to the difference in the discharge rate of the second node n2 according to the deterioration level of the sub-pixel. Therefore, when the sampling switch SW2 is turned on at a specific point in time (sampling point), after sensing the residual voltage of the sensing line 103 and comparing the sensed value with the initial value before deterioration, the level of degradation of the light emitting element OLED Can be seen.

As shown in FIG. 7, the sensing mode is an ON RF mode performed in a power ON sequence, an RT MODE performed in a vertical blank (VB) during a display driving period, and a power off sequence (Power) OFF sequence).

In the ON RF mode, deterioration of each of the sub-pixels is sensed when the field emission display is powered on. In the RT mode, deterioration of each of the sub-pixels is sensed in a vertical blank interval (VB) every frame period in a display driving period in which an image is displayed. In the OFF RS mode, degradation of each of the sub-pixels is sensed when the display device is turned off.

8 is a diagram illustrating an example in which stains and afterimages are seen on a screen after a use time has elapsed due to a stress variation between pixels. 9 is a view showing luminance differences between pixels as the use time increases due to a stress difference between pixels.

8 and 9, the initial luminance of the screen is uniform at the time of product shipment. As the use time of the organic light emitting display increases, the stress of the pixels accumulates and progresses. However, the cumulative stress of the pixels varies according to the image input to the pixels, and thus the acceleration of deterioration may vary.

Due to the deterioration of the pixels, the luminance retention ratio of the pixels is lowered. In particular, the luminance retention rate of pixels having a lot of cumulative stress (hereinafter referred to as “first degraded pixel”) has a higher luminance retention rate compared to pixels having less cumulative stress (hereinafter referred to as “second deterioration pixel”). It falls quickly. The first deteriorated pixel may be a pixel having the greatest cumulative stress, for example, a pixel at which a subtitle or logo is displayed. The second deteriorated pixel may be a pixel under a cumulative stress of an average stress level, for example, a pixel on which a background image around a subtitle or logo is displayed.

Due to the deterioration variation due to the difference in cumulative stress between the first and second pixels, as shown in FIG. 8, when the deterioration of the pixels proceeds significantly as the usage time elapses, even when pixel data of the same white gradation is applied to all pixels As shown in Fig. 8, spots and afterimages are seen due to the difference in luminance (ΔL) at positions P1 and P2 on the screen AA. Further, the luminance at the P3 position is lower than the background luminance around it.

The present invention distributes the accumulated stress of the first and second pixels based on the deterioration sensing result of each of the sub-pixels. The present invention increases the usage of the W sub-pixel or increases the usage of the R, G, and B sub-pixels according to the deterioration level of the W sub-pixel and the R, G, and B sub-pixels when writing the pixel data to the pixels. The pixel data has a gradation value of 0 or more in each of R, G, and B.

Each of the pixels PIX of the present invention includes a W sub-pixel and R, G, and B sub-pixels. As shown in FIG. 10, white in the pixel PIX has a WRGB method in which the driving amount of the W sub-pixel is higher than the R, G, and B sub-pixels, and the driving amount of the R, G, and B sub-pixels compared to the W sub-pixel. It can be expressed in an RGB way to increase. Here, the driving amount of the sub-pixel is proportional to the current flowing through the light emitting element (OLED). The driving amount of the sub-pixels can be adjusted to the gradation value of the pixel data.

The stress distribution processing unit 132 may modulate the pixel data written in the sub-pixels to adjust the driving amount for each sub-pixel. The higher the data voltage Vdata applied to the pixel circuit 101, the higher the current intensity of the light emitting element OLED, the more stress the light emitting element OLED has, and the longer the driving time for the current to flow through the light emitting element OLED becomes. The more the stress of the light emitting element (OLED) increases.

The WRGB method increases the driving amount of the W sub-pixel compared to the R, G, and B sub-pixels to match the color temperature. In order to optimize the color temperature, the WRGB method can drive R and B subpixels with W subpixels (W+R+B) or G and B subpixels with W subpixels (W+G+B). . The RGB method increases the driving amount of the three primary color sub-pixels, that is, the R, G, and B sub-pixels than the W sub-pixel.

FIG. 11 shows an example of using luminance for each color when pixels are driven by the WRGB method (A) and the RGB method (B) to reproduce pixel data.

Referring to FIG. 11, in the first pixel PIX1 driven by the WRGB method (A), the W sub-pixel has the highest luminance use ratio, so the W sub-pixel is under a lot of stress, and relatively R, G, and B sub-pixels Their stress is less. In the second pixel PIX2 driven by the WRGB method A, the luminance use ratio of the W sub-pixel is the highest, but the stress intensity received by the sub-pixels of all colors is less than the first pixel PIX1. The higher the driving amount of the sub-pixel, the higher the luminance use ratio of the sub-pixel.

Since the W sub-pixel is not driven in the first pixel PIX1 driven by the RGB method B, only the R, G, and B sub-pixels are stressed. In the second pixel PIX2 driven by the RGB method (A), there is no stress of the W sub-pixel and the stress intensity received by the R, G, and B sub-pixels is less than that of the first pixel PIX1.

In the example of FIG. 11, when the accumulated stress of the W sub-pixel in the first pixel PIX1 is large as a result of real-time deterioration sensing, the stress of the W sub-pixel is reduced by driving the first pixel PIX1 in an RGB manner. On the other hand, by increasing the stress of the R, G and B sub-pixels, the cumulative stress variation of sub-pixels for each color in each of the pixels PIX1 and PIX2 can be reduced, and the cumulative stress variation between pixels can be reduced. Accordingly, the present invention adaptively switches the WRGB method and the RGB method according to the cumulative stress variation between sub-pixels, as shown in FIG. 12 for the driving method of each pixel.

13 is an image showing an example in which an afterimage is seen when a red image is displayed on the screen AA and then is changed to a white image.

Referring to FIG. 13, there may be a first deterioration pixel P01 and a second deterioration pixel P02 on the screen AA. The first deterioration pixel P01 is a pixel in which the R subpixel is deteriorated due to a high driving amount of the R subpixel. The first deterioration pixel PO1 may be a pixel of a maximum cumulative stress area in which a red logo is displayed. The second deterioration pixel PO2 is a pixel having less cumulative stress than the first deterioration pixel PO1. The second degradation pixel PO2 may be a pixel on which a background image around the red logo is displayed.

After displaying red screen by writing red data to all pixels of the screen AA, white data may be written to pixels to display a white screen. On the red screen, the luminance of the R sub-pixel is lowered in the first deterioration pixel P01, and a residual image is seen. On the white screen, an afterimage in which the first deterioration pixel P01 is dark is seen. The stress dispersion processing unit 132 drives the second deterioration pixel P02 having relatively little deterioration of the R subpixel in an RGB manner when reproducing the pixel data by modulating the pixel data based on the deterioration sensing result of each subpixel. Thus, the driving amount of the W sub-pixels is reduced, and the driving amount of the R, G, and B sub-pixels is increased. On the other hand, the stress distribution processing unit 132 increases the driving amount of the W sub-pixels in the WRGB manner to the driving amount of the R, G, and B sub-pixels in order to slow the deterioration progress rate of the R sub-pixels in the first deterioration pixel P01. . Therefore, the present invention can reduce the deterioration deviation between pixels by increasing the driving amount in pixels with relatively little degradation. When the deterioration variation between pixels is small, the deterioration compensation spread across the screen is reduced, so that the deterioration compensation effect can be further improved.

When the green and blue screens are displayed, even when an afterimage is seen for each screen position, deterioration deviation between pixels may be reduced in the same manner as above.

14 is an image showing an example in which a white degradation pixel and a red degradation pixel coexist on one screen AA.

Referring to FIG. 14, there may be first to fourth deteriorated pixels P11 to P14 on the screen AA. The first deteriorated pixel P11 is a pixel in which the W sub-pixel is deteriorated due to a high driving amount. The second deteriorated pixel P12 is a pixel having a relatively small driving amount of the W sub-pixel. The stress dispersion processing unit 132 may determine the deterioration level for each color of the first and second deterioration pixels P11 and P12 based on the deterioration sensing result of each subpixel. When reproducing the pixel data, the stress dispersion processing unit 132 drives the first deteriorated pixel P11 in an RGB manner, thereby reducing the driving amount of the W sub-pixels and increasing the driving amount of the R, G, and B sub-pixels. On the other hand, when reproducing pixel data, the stress distribution processing unit 132 drives the second deteriorated pixel P12 in a WRGB manner, thereby increasing the driving amount of the W sub-pixels than the driving amount of the R, G, and B sub-pixels. Therefore, the present invention can reduce the deterioration deviation between pixels by increasing the driving amount in pixels with relatively little degradation.

The third deterioration pixel P13 is a pixel in which the R subpixel is deteriorated due to a high driving amount of the R subpixel. The fourth deterioration pixel P14 is a pixel having a relatively small driving amount of the R subpixel. The stress dispersion processing unit 132 may determine the level of deterioration for each color of the third and fourth degraded pixels P13 and P14 based on the deterioration sensing result of each of the sub-pixels. The stress dispersion processing unit 132 maintains the driving amount of the R sub-pixel in the third degradation pixel P13 in order to prevent color distortion when reproducing red data. On the other hand, the stress distribution processing unit 132 increases the driving amount of the R sub-pixel in the fourth deterioration pixel P14, thereby deteriorating between the R, G, and B sub-pixels between the third and fourth deterioration pixels P13 and P14. In order to reduce the deviation, when reproducing the pixel data, the fourth deteriorated pixel P14 is driven by the RGB method to reduce the driving amount of the W sub-pixel and increase the driving amount of the R, G, and B sub-pixels. Therefore, the present invention can reduce the deterioration deviation between pixels by increasing the driving amount in pixels with relatively little degradation.

15 is a flowchart illustrating a method of driving an electroluminescent display device according to an embodiment of the present invention. This driving method is implemented by the sensing unit 111 and the stress distribution processing unit 132.

Referring to FIG. 15, the sensing unit 111 senses deterioration of the light emitting element OLED in each of the sub pixels in real time (S01).

In the case of the first pixel in which the W sub-pixel is deteriorated, the stress dispersion processing unit 132 drives the first pixel in an RGB manner to reduce the driving amount of the W sub-pixel and increases the driving amount of the R, G, and B sub-pixels. (S20 and S21). In the case of the second pixel in which the W sub-pixel is not deteriorated, the stress dispersion processing unit 132 maintains the driving amount of the W sub-pixel by driving the second pixel in the WRGB method or increases the driving amount of the R, G, and B sub-pixels. Decrease (S20 and S21). The second pixel is a pixel having a lower level of deterioration of the W sub-pixel than the first pixel.

In the case of a third pixel in which deterioration is greatly performed in one or more of the R, G, and B sub-pixels, the stress dispersion processing unit 132 drives the third pixel in an RGB manner to prevent color distortion, thereby causing R, G, The driving amount of the B sub-pixels is maintained (S30 and S31). When the R, G, and B subpixels are deteriorated, the driving amount of the R, G, and B subpixels must be reduced to improve the deterioration of these subpixels, but the color may be distorted when reproducing the image, so the R, G, and B subpixels It is desirable to maintain the amount of RGB driving in the case of deterioration, and to increase the deterioration level of pixels in which R, G, and B sub-pixels are relatively less deteriorated.

In the case of the fourth pixel in which the R, G, and B sub-pixels are relatively less deteriorated, the stress dispersion processing unit 132 drives the fourth pixel in an RGB manner to increase the driving amount of the R, G, and B sub-pixels to increase the R, The deterioration deviation from the third pixel in which the G and B sub-pixels are greatly deteriorated is reduced (S30 and S32). The fourth pixel is a pixel having a lower level of deterioration of R, G, and B sub-pixels than the third pixel.

16 is a view showing an example of adjusting the driving ratio in the WRGB method and the RGB method to reduce cumulative stress for each color.

Referring to FIG. 16, the stress dispersion processing unit 32 may reduce the stress of the W sub-pixel than when the W sub-pixel emits 90 nit by adjusting the luminance ratio of the RGB sub-pixels to 10% or 5%. When the luminance ratio of the RGB method is 10%, the luminance of the W sub-pixel is reduced to 81 nit, and when the luminance ratio of the RGB method is 5%, the luminance of the W sub-pixel is reduced to 85.5 nit.

Through the above description, those skilled in the art will appreciate that various changes and modifications are possible without departing from the technical idea of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the scope of the claims.

100: display panel 110: data driver
111: sensing unit 120: gate driver
130: timing controller 132: stress distribution processing unit

Claims (12)

A display panel in which pixels including data lines, sensing lines, and a plurality of sub-pixels having different colors are disposed;
A data driver that converts pixel data of an input image into a data voltage and supplies the data lines to the data lines;
A sensing unit configured to sense deterioration of each of the sub-pixels; And
And a timing controller that adjusts a driving amount of the sub-pixels in each of the pixels based on the deterioration level of each of the sub-pixels. According to claim 1,
Each of the sub-pixels,
An electroluminescent display device comprising a white sub-pixel, a red sub-pixel, a green sub-pixel, and a blue sub-pixel. According to claim 2,
The timing controller,
Lowering the driving amount of the white pixel in the first pixel in which the white sub-pixel is deteriorated,
An electroluminescence display that maintains the driving amount of the white pixel in the second pixel having a lower level of deterioration of the white sub-pixel than the first pixel. The method of claim 3,
The timing controller,
The driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixel is increased in the first pixel,
An electroluminescent display device for reducing the driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixel in the second pixel. The method of claim 4,
The timing controller,
Maintaining the driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixels in the third pixel in which the red sub-pixel, the green sub-pixel, and the blue sub-pixels are deteriorated,
The driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixels in the fourth pixel having a lower level of deterioration of the red sub-pixel, the green sub-pixel, and the blue sub-pixels compared to the third pixel Height is an electroluminescent display. The method of claim 5,
The timing controller,
An electroluminescent display device that lowers the driving amount of the white sub-pixel in the fourth pixel. According to claim 2,
The timing controller,
An electroluminescent display device that increases the driving amount of the white subpixel when white data is reproduced from the first pixel in which the color subpixel of any one of the red subpixel, the green subpixel, and the blue subpixel is deteriorated. The method of claim 6,
The timing controller,
The red sub-pixel, the green sub-pixel, and the blue sub when reproducing white data in the red sub-pixel, the green sub-pixel, and the second pixel having a low deterioration level of the blue sub-pixels compared to the first pixel An electroluminescent display device that increases the driving amount of pixels higher than the white sub-pixel. According to claim 2,
The timing controller,
When driving the first pixel in which the white sub-pixel is deteriorated, the driving amount of the white sub-pixel is lowered and the driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixels is increased,
When driving the second pixel having a lower level of deterioration of the white sub-pixel than the first pixel, the driving amount of the white sub-pixel is increased and the driving amount of the red sub-pixel, the green sub-pixel, and the blue sub-pixels is increased. Lowered electroluminescent display. The method of claim 9,
The timing controller,
When data of the same color as the color of the color subpixel is reproduced in the third pixel in which the color subpixel of any one of the red subpixel, the green subpixel, and the blue subpixel is deteriorated, Maintain the driving amount,
When the white data is reproduced in the fourth pixel having a lower level of deterioration of the color sub-pixel than the third sub-pixel, the driving amount of the white sub-pixel is reduced and the red sub-pixel, the green sub-pixel, and the blue sub-pixel are reduced. An electroluminescent display device that increases the driving amount of them. The method of claim 9,
The sensing unit,
An electroluminescent display device that converts the result of sensing the deterioration of the light emitting element into digital data and transmits the result of sensing the deterioration of the light emitting element to the timing controller while controlling the transistor driving the light emitting element in each of the sub-pixels. A display panel in which pixels including data lines, sensing lines, and a plurality of sub-pixels having different colors are disposed, a data driver that converts pixel data of an input image into a data voltage and supplies the data lines to the data lines, and the sub In the driving method of the electroluminescent display device including a sensing unit for sensing the degradation of each of the pixels,
Sensing deterioration of each of the sub-pixels using the sensing unit; And
And adjusting the driving amount of the sub-pixels in each of the pixels based on the deterioration level of each of the sub-pixels sensed by the sensing unit.

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