KR20120063049A - Organic light emitting diode display device and driving method thereof - Google Patents

Abstract

PURPOSE: An organic light emitting diode display device and a driving method thereof are provided to compensate degradation of an organic light emitting diode device by outputting RGB data in which the degradation is compensated. CONSTITUTION: A degradation compensation unit(10) compensates degradation of an organic light emitting diode device. A brightness calculation unit(11) outputs brightness and color difference information from RGB data. A brightness sampling unit(12) samples brightness with a time interval of an N-th frame period. A look-up table(13) outputs a brightness compensation value to a brightness compensation unit. The brightness compensation unit(14) compensates degradation using the brightness compensation value.

Description

Organic light emitting diode display and its driving method {ORGANIC LIGHT EMITTING DIODE DISPLAY DEVICE AND DRIVING METHOD THEREOF}

The present invention relates to an organic light emitting diode display device and a driving method thereof for compensating deterioration of an organic light emitting diode device.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms. Recently, a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode are being developed. Various flat panel display devices such as organic light emitting diodes (OLEDs) are utilized. Among these flat panel display devices, organic light emitting diode display devices are capable of low voltage driving, are thin, have excellent viewing angles, and have fast response speeds. As the organic light emitting diode display, an active matrix type organic light emitting diode (Organic Light Emitting Diode) display device in which a plurality of pixels are positioned in a matrix and displaying an image is widely used.

The organic light emitting diode device of the organic light emitting diode display has a problem of deterioration when continuously emitting light for a predetermined time or more. When the organic light emitting diode element deteriorates, the luminance of emitted light is different from the target luminance, and the lifespan of the organic light emitting diode element is reduced. As one of methods for compensating degradation of an organic light emitting diode device, a method of compensating in a timing controller by receiving feedback of a voltage value of an organic light emitting diode device of each pixel is known.

However, a method of compensating in the timing controller by receiving feedback of the voltage value of the organic light emitting diode device of each pixel has the following problem. First, since a voltage value fed back from an organic light emitting diode element of each pixel has a small value of 10 mV or less, noise of a sensing line fed back the voltage of the organic light emitting diode element of each pixel is fed back. Reacts sensitively For this reason, when the feedback data includes a noise value, there is a problem in that degradation of the organic light emitting diode device is compensated with an incorrect value. Second, since the voltage value of the organic light emitting diode element of each pixel is analog data, the source drive IC must convert the analog data into digital data and input it to the timing controller. For this reason, since the source drive IC must have an analog-to-digital converter, component cost increases. Third, since a sensing line receiving feedback of the voltage value of the organic light emitting diode device of each pixel is required, the number of lines connected to the display panel from the source driver IC increases. Fourth, since the timing controller needs to receive feedback data, the number of pins increases. Fifth, since there is a need for a memory for storing the feedback data, there is a problem that parts cost increases. Hereinafter, an organic light emitting diode display and a driving method thereof for compensating deterioration of an organic light emitting diode device which solve the above problems will be described.

The present invention provides an organic light emitting diode display device and a driving method thereof capable of compensating for degradation of an organic light emitting diode device.

An organic light emitting diode display according to an embodiment of the present invention comprises: a display panel including a pixel array in which data lines and scan lines intersect, each pixel of the pixel array including an organic light emitting diode element; A timing controller including a degradation compensator for sampling luminance of input RGB data and outputting RGB data compensated for degradation of the organic light emitting diode element of each pixel based on the sampled luminance; A data driving circuit converting RGB data deteriorated by the timing controller into data voltages and outputting the data voltages to the data lines; And a scan driving circuit sequentially outputting scan pulses synchronized with the data voltages to the scan lines, wherein the deterioration compensator comprises: a luminance calculator configured to calculate luminance of the input RGB data; A luminance sampling unit for sampling the luminance calculated by the luminance calculating unit at time intervals of an Nth frame (N is a natural number of 10 or more); A look-up table that receives the luminance sampled by the luminance sampling unit as an input address and outputs a preset luminance compensation value; A luminance compensator for compensating and outputting the luminance compensation value to the luminance calculated by the luminance calculator during an N frame period; And an RGB converter configured to convert the luminance compensated by the luminance compensator into the degradation compensated RGB data.

A method of driving an organic light emitting diode display according to the present invention includes a pixel array in which data lines and scan lines intersect, and each pixel of the pixel array includes an organic light emitting diode having a display panel including an organic light emitting diode element. A display device comprising the steps of: sampling luminance of input RGB data, and outputting RGB data compensated for degradation of an organic light emitting diode element of each pixel based on the sampled luminance; Converting degradation-compensated RGB data into a data voltage and outputting the data voltage to the data lines; And sequentially outputting scan pulses synchronized with the data voltage to the scan lines, sampling luminance of the input RGB data, and compensating for degradation of the organic light emitting diode element based on the sampled luminance. The outputting of the RGB data may include calculating a luminance of the input RGB data; Sampling the calculated luminance at time intervals of an Nth frame (N is a natural number of 10 or more); Receiving a sampled luminance as an input address and outputting a preset luminance compensation value; Compensating and outputting the luminance compensation value to the calculated luminance for N frame periods; And converting the compensated luminance into the degradation compensated RGB data.

The present invention samples the luminance of the input RGB data, predicts the degree of degradation based on the sampled luminance, and outputs the compensated RGB data. As a result, the present invention can compensate for deterioration of the organic light emitting diode device.

In addition, the present invention does not receive a feedback value of the voltage of the organic light emitting diode device of each pixel. As a result, the present invention does not need to include an analog-to-digital converter, and does not require a large amount of memory for storing the feedback data, thereby reducing component cost.

Furthermore, the present invention does not require a sensing line for feeding back the voltage value of the organic light emitting diode element of each pixel, and does not increase the number of pins of the timing controller because there is no feedback data input to the timing controller. As a result, the present invention can simplify the organic light emitting diode display.

1 is a block diagram schematically illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention.
FIG. 2 is a detailed block diagram illustrating a degradation compensation unit of the timing controller of FIG. 1.
3 is a diagram schematically illustrating timing of a degradation compensation unit according to an exemplary embodiment of the present invention.
4A to 4C are simulation result diagrams showing output results of the luminance sampling unit.
5 is a graph showing a look-up table according to an embodiment of the present invention.
6A and 6B are diagrams of simulation results showing output results of the luminance compensator.
7A and 7B are diagrams illustrating RGB data and output RGB data input to the degradation compensation unit of the timing controller of FIG. 2.
8 is a flowchart illustrating a method of driving an organic light emitting diode display according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like numbers refer to like elements throughout. In the following description, when it is determined that a detailed description of known functions or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The names of the components used in the following description are selected in consideration of the ease of preparation of the specification, and may be different from the names of the actual products.

1 is a block diagram schematically illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention. Referring to FIG. 1, an organic light emitting diode display according to an exemplary embodiment of the present invention may include a display panel 200, a timing controller 100, a scan driving circuit 110, a data driving circuit 102, and a host system 130. It is provided.

The display panel 200 includes a pixel array in which the data lines D and the scan lines G cross each other and are formed in a matrix form. The pixel array of the display panel 200 displays an image by controlling a current flowing through an organic light emitting diode (OLED) device using a thin film transistor (hereinafter, referred to as a TFT). Each pixel of the pixel array includes a red pixel including a red organic light emitting diode (OLED) device, a green pixel including a green organic light emitting diode (OLED) device, and a blue pixel including a blue organic light emitting diode (OLED) device. It includes. Each of the pixels includes a driving TFT, at least one switch TFT, a storage capacitor, and the like. The pixel may be implemented in any known structure. Each of the pixels is connected to the data line D and the scan line G through the switch TFT. Each of the pixels receives a data voltage from the data driver circuit 120 through the data line D and a scan pulse from the scan driver circuit 110 through the scan line G.

The timing controller 100 receives timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal Data Enable (DE), and a dot clock CLK from the host system 130. Control signals for controlling the operation timing of the driving circuit 120 and the scan driving circuit 110 are generated. The control signals include a gate timing control signal for controlling the operation timing of the scan driving circuit 110 and a data timing control signal for controlling the operation timing of the data driving circuit 120.

The timing controller 100 includes a degradation compensator 10 for compensating for degradation of the organic light emitting diode device as shown in FIG. 2. The degradation compensator 10 receives RGB data RGB from the host system 130, and supplies the RGB data RGB ′ compensated for degradation of the organic light emitting diode element of each pixel to the data driving circuit 120. do. The deterioration compensator 10 of the timing controller 100 will be described later with reference to FIG. 2.

The data driver circuit 120 includes a plurality of source drive ICs. The data driving circuit 120 converts the RGB data RGB into a data voltage according to the data timing control signal output from the timing controller 100 and outputs the RGB data to the data lines D.

The data timing control signal includes a source start pulse (SSP), a source sampling clock (SSC), a polarity control signal (Polarity, POL), a source output enable signal (Source Output Enable, SOE), and the like. It includes. The source start pulse SSP controls the shift start timing of the source drive ICs. The source sampling clock SSC is a clock signal that controls sampling timing of data in the source drive ICs based on a rising or falling edge. The polarity control signal POL controls the polarity of the data voltages output from the source drive ICs. If the data transfer interface between the timing controller 100 and the source drive ICs is a mini LVDS interface, the source start pulse SSP and the source sampling clock SSC may be omitted.

The scan driving circuit 110 sequentially supplies the scan pulses synchronized with the data voltage to the scan lines G according to the gate timing control signal output from the timing controller 100. The scan driving circuit 110 is formed directly on the lower substrate of the display panel 200 by a gate drive-IC in panel (GIP) method, or the scan lines (G) and the timing controller of the display panel 200 by a TAB method. It may be connected between the (100). In the GIP method, the level shifter is mounted on a printed circuit board (PCB).

The gate timing control signal includes a gate start pulse, gate shift clocks, a gate output enable signal, and the like. The gate start pulse is input to the scan driving circuit 110 to control the shift start timing. The gate shift clocks are input to the level shifter and level shifted, and then the scan shift circuit 110 is used as a clock signal for shifting the gate start pulse GSP. The gate output enable signal controls the output timing of the scan driving circuit 110.

The host system 130 supplies the RGB data RGB to the timing controller 100 through an interface such as a low voltage differential signaling (LVDS) interface and a transition minimized differential signaling (TMDS) interface. In addition, the host system 130 may include timing signals such as a horizontal synchronization signal Hsync, a vertical synchronization signal Vsync, a dot clock CLK, and a data enable signal DE, and RGB data RGB. 100).

The user may select a normal mode and a compensation mode through the user input device 140. The user input device 140 may be formed of a touch screen, an on screen display (OSD), a keyboard, a mouse, a remote controller, or the like attached or embedded on the display panel 200. The user input device 140 outputs a mode signal MODE generated according to the normal mode and the compensation mode to the timing controller 100. The mode signal MODE may occur at a low logic level in a normal mode and may occur at a high logic level in a compensation mode.

The timing controller 100 operates in one of a normal mode and a compensation mode according to the input mode signal MODE. The degradation compensator 10 of the timing controller 100 bypasses the RGB data RGB input in the normal mode and converts the RGB data RGB input in the compensation mode into the degradation compensated RGB data RGB '. To print.

FIG. 2 is a detailed block diagram illustrating a degradation compensation unit of the timing controller of FIG. 1. Referring to FIG. 2, the degradation compensation unit 10 of the timing controller 100 of the present invention may include a luminance calculator 11, a luminance sampling unit 12, a look-up table 13, and a luminance compensation unit 14. And an RGB converter 15.

The luminance calculator 11 receives 8-bit RGB data RGB and calculates a luminance Y and color difference information CbCr from the received RGB data RGB. The luminance calculator 11 calculates the luminance Y and the color difference information CbCr of the RGB data RGB as shown in Equations 1 to 3.

In Equations 1 to 3, Y is luminance of RGB data RGB, Cb and Cr are color difference information of RGB data RGB, R is gray scale of R data, and G is gray scale of G data ( Gray Scale), B means Gray Scale of the B data.

The luminance calculator 11 outputs the luminance Y of the RGB data RGB calculated through Equation 1 to the luminance sampler 12. The luminance calculator 11 outputs the luminance Y to the luminance compensator 14 through Equation 1. The luminance calculator 11 outputs the color difference information CbCr of the RGB data RGB calculated through Equations 2 and 3 to the RGB converter 15.

The luminance sampling unit 12 receives the luminance Y from the luminance calculating unit 11. The luminance sampling unit 12 samples the luminance Y (N) at a time interval of a predetermined Nth (N is a natural number of 10 or more) frame period. The luminance sampling unit 12 outputs the luminance Y (N) sampled in the Nth frame to the look-up table 13. The luminance sampling unit 12 may include a frame counter that counts the Nth frame and starts counting the Nth frame from the next frame after the Nth frame. The luminance Y sampled from the luminance sampling unit 12 will be described in detail with reference to the simulation results of FIGS. 4A to 4C.

The look-up table 13 receives a luminance Y (N) sampled in the Nth frame from the luminance sampling unit 12. The look-up table 13 receives the sampled luminance Y (N) as an input address and outputs a preset luminance compensation value α to the luminance compensator 14. The luminance compensation value α stored in the look-up table 13 will be described in detail with reference to FIG. 5.

The luminance compensator 14 receives the luminance compensation value α from the look-up table 13. In addition, the luminance compensator 14 receives the luminance Y of the RGB data RGB from the luminance calculator 11. The luminance compensator 14 receives the luminance compensation value α from the look-up table 13 at the time interval of the Nth frame period and compensates using the luminance compensation value α input during the N frame period. . The luminance compensator 14 may include a frame counter that counts the Nth frame and starts counting the Nth frame from the next frame after the Nth frame. This will be described later with reference to FIG. 4.

The luminance compensator 14 compensates as shown in equation (4).

Y 'denotes the luminance compensated by the luminance compensator 14, Y denotes the luminance of the RGB data RGB in the Nth frame, and α denotes the luminance compensation value. The luminance compensator 14 may include a memory for storing the luminance compensation value α input from the look-up table 13.

The luminance compensator 14 outputs the compensated luminance Y 'to the RGB converter 15. The compensated luminance Y 'output from the luminance compensator 14 will be described in detail with reference to the simulation results of FIGS. 6A and 6B.

The RGB converter 15 receives the luminance Y 'compensated by the luminance compensator 14, and receives the color difference information CbCr from the luminance calculator 11. The RGB converter 15 converts the compensated luminance Y 'and the color difference information CbCr into 8-bit RGB data, and extends the 8-bit RGB data into 10-bit RGB data. The RGB converter 15 accurately compensates the expanded 10-bit RGB data with the compensated luminance Y 'by comparing it with the compensated luminance Y', and then outputs the degraded compensated RGB data RGB '.

The RGB converter 15 converts the compensated luminance Y 'and the color difference information CbCr into 8-bit RGB data as shown in Equations 5 to 7. In Equations 5 to 7, R 'is gray scale of R' data, G 'is gray scale of G' data, B 'is gray scale of B' data, Y 'Is the compensated luminance, Cb and Cr is the color difference information.

The RGB converter 15 expands the 8-bit RGB data converted through Equations 5 to 7 into 10-bit RGB data RGB '. Since the 10-bit RGB data RGB 'is 4 times larger in size than the 8-bit RGB data, the compensated luminance Y' can be represented more accurately. Therefore, the RGB converter 15 accurately compensates the expanded 10-bit RGB data with the compensated luminance Y 'by comparing the compensated luminance Y', and then outputs the deteriorated compensated RGB data RGB '. do. The 10-bit RGB data RGB 'conversion of the RGB converter 15 will be described in detail with reference to the simulation results of FIGS. 7A and 7B.

3 is a diagram schematically illustrating a compensation timing of a degradation compensation unit according to an exemplary embodiment of the present invention. Referring to FIG. 3, the vertical synchronization signal Vsync, the data enable signal DE, the RGB data RGB input to the deterioration compensator 10, the luminance Y calculated from the RGB data RGB, and the vertical The synchronization signal start signal Vsync_Start, the frame counter, the sampled luminance Y (N), the luminance compensation value α output from the look-up table 13, and the output from the degradation compensation unit 10. RGB data RGB 'is shown.

The vertical synchronization signal Vsync occurs at the start of the frame and occurs at one frame period. The data enable signal DE is a signal indicating the presence or absence of RGB data RGB. One pulse period of the data enable signal DE is substantially equal to a value obtained by dividing one frame period by a vertical line of the display panel 200. In addition, one pulse period of the data enable signal DE is set to approximately one horizontal period. During one horizontal period, RGB data RGB is written to pixels present in one display line. The luminance Y is calculated from the RGB data RGB as shown in equations (1) to (3). The vertical synchronization signal start signal Vsync_Start occurs at the start of every frame. The frame counter counts the Nth frame, and starts counting the Nth frame from the next frame after the Nth frame. The sampled luminance Y (N) means the luminance Y sampled in the Nth frame. The luminance compensation value α is calculated using the look-up table 13 from the luminance Y (N) sampled in the Nth frame. The luminance compensation value α calculated in the Nth frame is a value compensated for the luminance Y as in Equation 4 during the N frame period thereafter. RGB data RGB 'outputted from the deterioration compensator 10 is calculated from the compensated luminance Y'.

4A to 4C are simulation result diagrams illustrating input and output of a luminance calculator and a luminance sampling unit. 4a to 4c, vsy_in is a vertical synchronization signal (Vsync), clk is a clock (CLK), de_in is a data enable signal (DE), r_in, g_in, b_in is RGB data (RGB), y_out is RGB The luminance Y calculated from the data RGB, frame_st is a vertical sync signal (Vsync) reference frame start signal, monitoring_time is a sampling time, FRM_CNT is a frame counter, and y_pre is sampled at a time interval of an Nth frame period. Mean luminance Y (N).

FIG. 4B is an enlarged view of portion A of FIG. 4A. 4C is an enlarged view of a portion B of FIG. 4B. In this simulation, the luminance sampling unit 12 samples the luminance y_out calculated from the luminance calculating unit 11 at time intervals of the tenth frame period.

4A to 4C, RGB data r_in, g_in, and b_in are input to the luminance calculator 11 in a section in which the data enable signal de_in is at a high logic level. The luminance calculator 11 calculates the luminance y_out from the input RGB data r_in, g_in, and b_in. At this time, a delay occurs for approximately three horizontal periods. The luminance sampling unit 12 samples the luminance y_out calculated by the luminance calculator 11, and outputs the sampled luminance y_pre to the look-up table 13. At this time, a delay occurs for approximately one horizontal period.

5 is a graph showing a look-up table according to an embodiment of the present invention. Referring to FIG. 5, the x-axis represents luminance Y (N) sampled at time intervals of the N-th frame period, and the y-axis represents the luminance compensation value α.

The look-up table 13 outputs the luminance compensation value α to the luminance compensator 14 according to the sampled luminance Y (N). It is assumed that the look-up table 13 has a maximum luminance of 200 nit, and the sampled luminance Y (N) of the x-axis is divided into 8 nit or 16 nit units, and the luminance compensation value α according to the divided range. ) Is set.

The look-up table 13 sets the luminance compensation value α higher than when the sampled luminance Y (N) is low when the sampled luminance Y (N) is high. In addition, the look-up table 13 does not compensate for luminance at luminance corresponding to 0 to 16 nit. This is because the organic light emitting diode device deteriorates when it emits light for a long time with high luminance. The look-up table 13 outputs a luminance compensation value α corresponding to the sampled luminance Y (N) to the luminance compensator 14.

6A and 6B are diagrams of simulation results showing input and output results of the luminance compensator and the RGB converter. 6A and 6B, clk is a clock CLK, CP_EN is a degradation compensation enable signal, vsy_in is a vertical synchronization signal Vsync, hs_in is a horizontal synchronization signal Hsync, and de_in is a data enable signal DE r_in, g_in, and b_in denote RGB data (RGB), frm_cnt denotes a frame counter, and y_pre denotes luminance Y (N) sampled at time intervals of an Nth frame period. In addition, y_csc is luminance Y calculated from RGB data RGB, u_csc, v_csc is color difference information CbCr calculated from RGB data RGB, y_cmp is compensated luminance Y ', u_cmp, and v_cmp is RGB. The color difference information CbCr, vs_cmp input to the converter 15 is a vertical synchronization signal Vsync synchronized to the compensated luminance Y ', and hs_cmp is a horizontal synchronization signal Hsync synchronized to the compensated luminance Y'. ), de_cmp is the data enable signal DE synchronized with the compensated luminance Y ', r-out, g-out, b-out are degradation compensated RGB data (RGB'), vs_out is degradation compensated RGB The vertical synchronization signal Vsync synchronized to the data RGB ', hs_out is the horizontal synchronization signal Hsync synchronized to the degradation compensated RGB data RGB', and the de_out is synchronized to the degradation compensated RGB data RGB '. It means the data enable signal DE.

FIG. 6B is an enlarged view of portion C of FIG. 6A. 6A and 6B, the output of compensated luminance y_cmp and degradation compensated RGB data r_out, g_out, and b_out are shown in detail. The luminance compensator 14 converts the sampled luminance y_pre into the compensated luminance y_cmp. In the conversion of the luminance compensator 14, no delay occurs. The RGB converter 15 outputs degradation-compensated RGB data r_out, g_out, and b_out from the compensated luminance y_cmp and the color difference information u_cmp and v_cmp. At this time, a delay occurs for approximately three horizontal periods.

7A and 7B are diagrams illustrating RGB data and output RGB data input to the degradation compensation unit of the timing controller of FIG. 2. 7A and 7B, 8-bit RGB data RGB is input to the deterioration compensator 10 of the timing controller 100, and 10-bit RGB data RGB is output. 8-bit RGB data (RGB) may represent a gray scale of 0 to 255, whereas 10-bit RGB data (RGB) may represent a gray scale of 0 to 1023. That is, the 10-bit RGB data RGB may represent four times more gray scales than the 8-bit RGB data RGB.

Referring to FIG. 7A, 8-bit RGB data RGB input to the deterioration compensator 10 has 200 gray scales. 8-bit RGB data of 200 gray scale may be represented by 10-bit RGB data of 800 gray scale to 803 gray scale.

Referring to FIG. 7B, 8-bit RGB data RGB of 200 gray scale input to the degradation compensator 10 has a luminance of 170 nit. The luminance-compensated 10-bit RGB data RGB output from the degradation compensator 10 has a luminance of 172 nit. The RGB converter 15 of the deterioration compensator 10 converts the 8-bit RGB data of 200 gray scales corresponding to 172 nits by using Equations 5 to 7 below. Next, 8-bit RGB data of 200 gray scales is extended to 10-bit RGB data of 800 gray scales. In this case, in the 8-bit gray scale, both 170 nit and 172 nit may be represented by 200 gray scales. However, 10-bit RGB data with 800 gray scales is only 170 nit. Since the 10-bit RGB data can represent four times more gray scales than the 8-bit RGB data, the RGB converter 15 converts the 800-bit gray scale 10-bit RGB data to 172, which is a luminance that is compensated for. Compare with nit Since the luminance of the 10-bit RGB data of the 800 gray scale is only 170 nits, the RGB converter 15 compensates for the luminance of the 10-bit RGB data of the 800 gray scale again and finally 172. 10-bit RGB data RGB 'of 802 gray scale having nit brightness is output.

8 is a flowchart illustrating a method of driving an organic light emitting diode display according to an exemplary embodiment of the present invention. A method of driving an organic light emitting diode display according to an exemplary embodiment of the present invention will be described with reference to FIG. 2.

First, RGB data RGB is input to the deterioration compensator 10 of the timing controller 100. The luminance calculator 11 of the deterioration compensator 10 calculates the luminance Y and the color difference information CbCr from the RGB data RGB. The luminance calculating unit 11 calculates the luminance Y and the color difference information CbCr as shown in Equations 1 to 3, and outputs the luminance to the luminance sampling unit 12. (S101)

Secondly, the luminance sampling unit 12 samples the luminance Y input from the luminance calculating unit 11 at time intervals of the Nth frame period. The luminance Y (N) sampled in the Nth frame is output to the look-up table 13. (S102, S103)

Third, the look-up table 13 receives the sampled luminance Y (N) as an input address and outputs a preset luminance compensation value α to the luminance compensator 14. (S104)

Fourth, the luminance compensator 14 receives the luminance Y from the luminance calculator 11 and a luminance compensation value α from the look-up table 13. The luminance compensator 14 receives the luminance compensation value α from the look-up table 13 at the time interval of the Nth frame period and compensates using the luminance compensation value α input during the N frame period. . The luminance compensator 14 compensates as shown in equation (4). The luminance compensator 14 outputs the compensated luminance Y 'to the RGB converter 15. (S105)

Fifth, the RGB converter 15 outputs the compensated luminance Y 'as degradation-compensated 10-bit RGB data RGB'. The RGB converter 15 converts the compensated luminance Y 'into 8-bit RGB data as shown in Equations 5 to 7 and extends the 8-bit RGB data into 10-bit RGB data. The RGB converter 15 accurately compensates the expanded 10-bit RGB data with the compensated luminance Y 'by comparing it with the compensated luminance Y', and then outputs the degraded compensated RGB data RGB '. (S106)

The present invention can compensate for degradation of the organic light emitting diode device by sampling luminance of input RGB data, predicting the degree of degradation based on the sampled luminance, and outputting compensated degradation RGB data. In addition, since the present invention does not receive the voltage value of the organic light emitting diode element of each pixel, it is not necessary to include an analog-to-digital converter, and does not require a large amount of memory for storing the feedback data. Thus, component cost is reduced. Furthermore, the present invention does not require a sensing line for feeding back the voltage value of the organic light emitting diode element of each pixel, and there is no feedback data input to the timing controller, so that the number of pins of the timing controller does not increase. Therefore, the organic light emitting diode display can be simplified.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit 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 defined by the claims.

10: deterioration compensator 11: luminance calculator
12: luminance sampling unit 13: look-up table
14: luminance compensator 15: RGB converter
100: timing controller 110: scan driving circuit
120: data driving circuit 130: host system
200: display panel

Claims (14)

A display panel including a pixel array in which data lines and scan lines intersect, each pixel of the pixel array including an organic light emitting diode element;
A timing controller including a degradation compensator for sampling luminance of input RGB data and outputting RGB data compensated for degradation of the organic light emitting diode element of each pixel based on the sampled luminance;
A data driving circuit converting RGB data deteriorated by the timing controller into data voltages and outputting the data voltages to the data lines; And
A scan driving circuit sequentially outputting scan pulses synchronized with the data voltage to the scan lines;
The deterioration compensation unit,
A luminance calculator for calculating luminance of the input RGB data;
A luminance sampling unit for sampling the luminance calculated by the luminance calculating unit at time intervals of an Nth frame (N is a natural number of 10 or more);
A look-up table that receives the luminance sampled by the luminance sampling unit as an input address and outputs a preset luminance compensation value;
A luminance compensator for compensating and outputting the luminance compensation value to the luminance calculated by the luminance calculator during an N frame period; And
And an RGB converter converting the luminance compensated by the luminance compensator into the degradation compensated RGB data. The method of claim 1,
The luminance sampling unit,
And a frame counter counting the Nth frame and starting counting the Nth frame from the next frame following the Nth frame. The method of claim 1,
The look-up table is,
And the higher the luminance sampled by the luminance sampling unit, the higher the luminance compensation value is. The method of claim 1,
The luminance compensator,
A frame counter counting the Nth frame and starting counting the Nth frame from the next frame following the Nth frame; And
And a memory for storing the luminance compensation value. The method of claim 1,
And the luminance compensator receives a luminance compensation value from the look-up table at time intervals of the N-th frame period. The method of claim 1,
The input RGB data is 8 bits,
And the degradation-compensated RGB data output from the RGB converter is 10 bits. The method according to claim 6,
The RGB converter,
Converts the luminance compensated by the luminance compensator into 8-bit RGB data, extends the converted 8-bit RGB data into 10-bit RGB data, and converts the expanded 10-bit RGB data into the luminance compensated by the luminance compensator. And comparing the deteriorated compensated RGB data after accurately compensating with the luminance compensated by the luminance compensating unit. An organic light emitting diode display device comprising: a pixel array in which data lines and scan lines intersect, each pixel of the pixel array including a display panel including an organic light emitting diode element;
Sampling luminance of the input RGB data and outputting RGB data compensated for degradation of the organic light emitting diode element of each pixel based on the sampled luminance;
Converting degradation-compensated RGB data into a data voltage and outputting the data voltage to the data lines; And
Sequentially outputting scan pulses synchronized with the data voltage to the scan lines,
Sampling the luminance of the input RGB data, and outputting the RGB data compensated for degradation of the organic light emitting diode device based on the sampled luminance,
Calculating a luminance of the input RGB data;
Sampling the calculated luminance at time intervals of an Nth frame (N is a natural number of 10 or more);
Receiving a sampled luminance as an input address and outputting a preset luminance compensation value;
Compensating and outputting the luminance compensation value to the calculated luminance for N frame periods; And
And converting the compensated luminance into the deteriorated compensated RGB data. The method of claim 8,
Sampling the calculated luminance at a time interval of an Nth frame period,
And counting a frame until the Nth frame, and starting the frame count again from the next frame after the Nth frame. The method of claim 8,
The step of receiving the sampled luminance as an input address and outputting a preset luminance compensation value,
And the luminance compensation value is set to be higher as the sampled luminance is higher. The method of claim 8,
Compensating and outputting the luminance compensation value to the calculated luminance during the N frame period,
Counting a frame until an Nth frame and starting the frame count from the next frame following the Nth frame; And
And storing the luminance compensation value. The method of claim 8,
Compensating and outputting the luminance compensation value to the calculated luminance during the N frame period,
And the luminance compensation value is input at a time interval of the Nth frame period. The method of claim 8,
And the input RGB data is 8 bits, and the deterioration compensated RGB data is 10 bits. The method of claim 13,
Converting the compensated luminance into the degradation compensated RGB data,
Converting the compensated luminance into 8-bit RGB data, extending the converted 8-bit RGB data into 10-bit RGB data, and comparing the expanded 10-bit RGB data with the compensated luminance to accurately compensate for the compensated luminance. And afterwards, outputting the deteriorated compensated RGB data.

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