KR20150077712A - Organic light emitting display device and method for driving theteof - Google Patents

Abstract

According to an aspect of the present invention, an organic light emitting display apparatus, which enables to display an equal luminance image by compensating the degradation of an organic light emitting diode, comprises: a display panel including a plurality of unit pixels which are comprised of a plurality of subpixels; a degradation compensation portion for receiving input image data to be supplied to the subpixels, and producing output image data by reflecting a certain gain value on the input image data; a memory for storing the output image data; and a panel driving portion for supplying the output image data, which is produced by the degradation compensation portion, to the corresponding subpixels. The degradation compensation portion stacks and stores sampling data, produced by sampling the output image data to be supplied to one subpixel per unit pixel of each pixel group comprised of neighboring m number of unit pixels, to different storage areas of the memory, and renews the certain gain value into a frame unit based on the sampling data which is stacked and stored in the memory.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display and a driving method thereof, and more particularly, to an organic light emitting display capable of compensating for deterioration of an organic light emitting diode, and a driving method thereof.

Recently, with the development of multimedia, the importance of flat panel display devices is increasing. In response to this, flat panel display devices such as liquid crystal display devices, plasma display devices, and organic light emitting display devices have been commercialized. Among such flat panel display devices, organic light emitting display devices have attracted attention as a next generation flat panel display device because they have a high response speed, low power consumption, and self light emission, so that there is no problem in viewing angle.

A general organic light emitting display includes a display panel including a plurality of pixels and a panel driver for emitting each pixel. Here, each pixel is formed in a pixel region defined by the intersection of a plurality of data lines and a plurality of gate lines.

Each of these pixels includes a switching transistor Tsw, a driving transistor Tdr, a capacitor Cst, and a light emitting element OLED, as shown in Fig.

The switching transistor Tsw is switched in accordance with the gate signal GS supplied to the gate line GL to supply the data voltage Vdata supplied to the data line DL to the driving transistor Tdr.

The driving transistor Tdr is switched according to the data voltage Vdata supplied from the switching transistor Tsw and controls the data current Ioled flowing to the light emitting element OLED by the driving voltage VDD.

The capacitor Cst is connected between the gate terminal and the source terminal of the driving transistor Tdr to store a voltage corresponding to the data voltage Vdata supplied to the gate terminal of the driving transistor Tdr, Tdr).

The light emitting device OLED is electrically connected between the source terminal of the driving transistor Tdr and the cathode electrode CE to which the cathode voltage VSS is applied and is turned on by the data current Ioled supplied from the driving transistor Tdr do.

Each pixel of the general organic light emitting display device controls the size of the data current Ioled flowing to the light emitting element OLED by the driving voltage VDD by switching the driving transistor Tdr according to the data voltage Vdata So that a predetermined image is displayed by causing the light emitting device OLED to emit light.

2 is a graph showing luminance characteristics of a general organic light emitting device.

As can be seen from FIG. 2, in general, as the driving time of the organic light emitting diode increases, the degradation rate is accelerated and the luminance characteristic is gradually decreased.

Therefore, in a general organic light emitting display device, there is a problem that an image of uniform luminance can not be displayed due to deterioration of the organic light emitting device OLED.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide an organic light emitting display device and a method of driving the same, which can display an image with uniform luminance by compensating for deterioration of the organic light emitting device.

According to an aspect of the present invention, there is provided an organic light emitting diode display comprising: a display panel including a plurality of unit pixels including a plurality of sub-pixels; A deterioration compensator configured to receive input image data to be supplied to the plurality of sub-pixels and to generate output image data by reflecting a predetermined gain value to the input image data; A memory for storing the output image data; And a panel driver for supplying the output image data generated by the deterioration compensator to the corresponding subpixel, wherein the deterioration compensator compensates the deterioration compensator for each unit pixel of each pixel group composed of m adjacent unit pixels, And accumulates the sampling data in different storage areas of the memory, and updates the predetermined gain value on a frame-by-frame basis based on the sampling data accumulated and stored in the memory .

According to another aspect of the present invention, there is provided a method of driving an organic light emitting display, the method comprising: receiving input image data to be supplied to a plurality of sub-pixels constituting a unit pixel; Generating output image data by reflecting a predetermined gain value to the input image data; Converting the output image data into a data voltage and supplying the data voltage to the corresponding sub-pixel; And accumulating sampling data obtained by sampling output image data to be supplied to one sub pixel per unit pixel of each pixel group composed of a plurality of unit pixels in different storage areas of the memory, And updating the predetermined gain value on a frame-by-frame basis based on the stored sampling data.

According to the present invention, the output image data of each of a plurality of unit pixels included in each pixel group is sampled and accumulated in different areas of the memory, and based on the accumulated data accumulated in different areas of the memory, The compensation gain value is generated on a frame-by-frame basis, and is reflected on the input image data, thereby compensating for deterioration of the organic light emitting element, thereby displaying an image of uniform luminance.

Further, according to the present invention, there is an effect that the number of memories can be reduced.

In addition, according to the present invention, an effect similar to that of the frame interpolation method can be obtained to minimize image quality deterioration due to data sampling.

1 is a circuit diagram for explaining a pixel structure of a general organic light emitting display device.
2 is a graph showing luminance characteristics of a general organic light emitting device.
FIG. 3 is a block diagram for explaining an organic light emitting display according to an embodiment of the present invention; FIG.
4 is a block diagram schematically showing the structure of the deterioration compensator shown in Fig.
5 is a view for explaining a method of sampling and storing data according to the present invention;
6 is a signal waveform diagram for explaining a read and a write operation of the memory shown in FIG.
FIGS. 7 to 10 are diagrams for explaining a method of generating a compensation gain value by the gain value generator shown in FIG. 4;
11 is a flowchart illustrating a method of driving an OLED display according to an exemplary embodiment of the present invention.
12 is a flowchart showing a method of updating a gain value to be reflected on input image data.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms.

It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one.

Hereinafter, preferred embodiments of the organic light emitting diode display and the driving method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a view for explaining an organic light emitting display according to an embodiment of the present invention.

3, the OLED display includes a display panel 110, a memory 120, a deterioration compensating unit 130, and a panel driver 140. Referring to FIG.

The display panel 110 includes a plurality of sub-pixels SP. The plurality of sub-pixels SP are formed in a pixel region defined by a plurality of gate lines GL and a plurality of data lines DL intersecting with each other. A plurality of driving power lines PL1 are formed on the display panel 110 in parallel with the plurality of data lines DL and supplied with a driving voltage from the panel driving unit 140.

Each of the plurality of sub-pixels SP may be any one of a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel. One unit pixel for displaying one image may include an adjacent red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel, or may include a red pixel, a green pixel, and a blue pixel. Hereinafter, it is assumed that one unit pixel is composed of a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel.

Each of the plurality of sub-pixels SP includes an organic light emitting diode OLED and a pixel circuit PC.

The organic light emitting diode OLED is connected between the pixel circuit PC and the second driving power supply line PL2 and emits a predetermined color light by emitting light in proportion to the amount of data current supplied from the pixel circuit PC do. The organic light emitting diode OLED includes an anode electrode (or a pixel electrode) connected to the pixel circuit PC, a cathode electrode (or a reflective electrode) connected to the second driving power supply line PL2, And a light emitting cell formed between the cathode electrode and the cathode electrode and emitting light of any one of red, green, blue, and white. Here, the light emitting cell may have a structure of a hole transporting layer / an organic light emitting layer / an electron transporting layer or a structure of a hole injecting layer / a hole transporting layer / an organic light emitting layer / an electron transporting layer / an electron injecting layer. Further, the light emitting cell may further include a functional layer for improving the luminous efficiency and / or lifetime of the organic light emitting layer.

The pixel circuit PC responds to the gate signal GS of the gate-on voltage level supplied from the panel driver 140 to the gate line GL and supplies the data voltage Vdd supplied from the panel driver 140 to the data line DL (Vdata) to the organic light emitting diode OLED. To this end, the pixel circuit PC comprises a switching transistor, a driving transistor, and at least one capacitor formed on a substrate by a thin film transistor forming process. In one embodiment, the pixel circuit PC may have the same structure as the pixel shown in FIG. The pixel circuit structure shown in FIG. 1 has already been described with reference to FIG. 1, and a detailed description thereof will be omitted.

The memory 120 has n storage areas allocated to be spatially separated. The memory 120 is compensated by the deterioration compensating unit 130 so that the output image data to be supplied to each sub-pixel SP of the display panel 110 is sampled and accumulated.

In addition, the memory 120 stores the compensation gain value generated based on the sampling data accumulated and stored.

The deterioration compensator 130 groups adjacent m unit pixels into a plurality of pixel groups and outputs sampling image data Odata to be supplied to one sub pixel SP for each unit pixel of each pixel group Accumulates the data in units of frames and stores them in different storage areas of the memory 120 and accumulates the accumulated data in the different storage areas of the memory 120 to the sub pixels SP of each pixel group Generates a gain value to be reflected in the input image data Idata to be supplied, and generates output image data (Odata) by reflecting the generated gain value in the input image data.

The panel driver 140 generates a gate control signal GCS and a data control signal DCS based on the input timing synchronization signal TSS and generates a gate signal GS according to the gate control signal GCS And sequentially converts the output image data Odata supplied from the deterioration compensating unit 130 into a data voltage Vdata according to a data control signal DCS to generate a data line DL, . The panel driver 140 includes a timing controller 142, a gate driving circuit 144, and a data driving circuit 146.

The timing control unit 142 controls the driving timing of each of the gate driving circuit unit 144 and the data driving circuit unit 146 according to a timing synchronization signal TSS input from an external system body (not shown) or a graphic card (not shown) . That is, the timing control unit 142 generates a gate control signal based on a timing synchronization signal TSS such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a dot clock DCLK, (GCS) and a data control signal (DCS), controls the driving timing of the gate driving circuit part 144 through the gate control signal GCS, and controls the driving timing of the data driving circuit part 146 are controlled.

The timing controller 142 may arrange the output image data Odata of red, green, blue, and white supplied from the deterioration compensator 130 so as to be suitable for the pixel arrangement structure of the display panel 110, And supplies the aligned data (DATA) to the data driving circuit portion 146 based on a predetermined interface method.

Meanwhile, the timing controller 142 may include the deterioration compensator 130. In this case, the deterioration compensating unit 130 may be embedded in the timing control unit 142, and in this case, it may be embedded in a program or logic form.

The gate driving circuit 144 generates a gate signal GS corresponding to a display order of an image based on the gate control signal GCS supplied from the timing controller 142 and supplies the generated gate signal GS to the gate line GL . The gate driving circuit 144 may be formed in a form of a plurality of integrated circuits or may be formed directly on the substrate of the display panel 110 together with the transistor forming process of each sub pixel P, (GL), respectively.

The data driving circuit 146 receives the data DATA and the data control signal DCS from the timing controller 142 and receives a plurality of reference gamma voltages from an external reference gamma voltage supply unit. The data driving circuit 146 converts the alignment data DATA to an analog data voltage Vdata using a plurality of reference gamma voltages in accordance with the data control signal DCS, ) To the data line DL of the corresponding sub-pixel. The data driving circuit 146 may be formed in a plurality of integrated circuits (IC), and may be connected to one side and / or both sides of the data line DL.

Hereinafter, the deterioration compensating unit according to the present invention will be described more specifically with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a block diagram schematically showing a configuration of a deterioration compensator according to an embodiment of the present invention. FIG. 5 is a view for explaining a method of sampling and storing data according to the present invention.

First, the deterioration compensating unit 130 according to an embodiment of the present invention receives four-color image data including red image data, green image data, blue image data, and white image data in units of pixel units in series or in parallel . Here, the 4-color image data is converted from red image data, green image data, and blue image data by a data format conversion unit (not shown), and the data format conversion unit converts red image data, , White image data is extracted based on blue image data, and the extracted white image data is reflected on red image data, green image data, and blue image data to generate the 4-color image data.

The deterioration compensation unit 130 according to an exemplary embodiment of the present invention groups adjacent m unit pixels formed on the display panel 110 into a plurality of pixel groups, And compensates for the degradation of the organic light emitting device OLED of each sub-pixel SP by applying different compensation gain values to each pixel group over m frames based on the accumulated sampling data of the sub-pixels SP.

5, the display panel 110 includes first to fourth pixel groups PG1 to PG4 which are adjacent to each other in the upper, lower, right, and left directions, and each of the pixel groups PG1 to PG4, And PG4 includes first to fourth unit pixels arranged in a 2 < 2 > form adjacent to each other in the up, down, left, and right directions.

4 and 5, the deterioration compensation unit 130 according to an embodiment of the present invention includes a data compensation unit 131, a data sampling unit 133, a data accumulation unit 135, an address control unit 137, And a gain value generation unit 139. The gain-

The data compensator 131 receives the input image data Idata to be applied to each sub-pixel constituting the unit pixel, reflects a predetermined gain value to the received input image data Idata, .

In one embodiment, the data compensator 131 may generate output image data (Odata) by multiplying the input image data Idata of each sub-pixel by a predetermined gain value generated for each pixel group.

At this time, the predetermined gain value may be generated by the gain value generation unit 139 and stored in the gain value storage space 123 of the memory 120. [ Accordingly, the data compensator 131 reads a predetermined gain value to be applied to the corresponding sub-pixel in the gain value storage space 123 of the memory 120, and reflects the gain value to the input image data Idata.

In one embodiment, a predetermined gain value is generated for each pixel group PG1 to PG4, and can be updated frame by frame. A predetermined gain value to be initially reflected in the input video data Idata may be preset or may be set to "1 ".

The data compensator 131 provides the generated output image data Odata to the panel driver 140, i.e., the timing controller 142 described above.

The data sampling unit 133 groups the sixteen unit pixels formed on the display panel 110 into first to fourth pixel groups PG1 to PG4 constituted by four unit pixels. The data sampling unit 133 performs a data sampling operation on any one of the output image data Odata of the sub-pixels included in each unit pixel for each unit pixel (first through fourth pixels), for each of the pixel groups PG1 through PG4 The image data (Odata) is sampled with the sampling data (A, B, C, D) of each of the first to fourth unit pixels.

For example, the data sampling unit 133 may output the red output image data, the green output image data, the blue output image data, and the white output image data to be supplied to four sub-pixels included in each of the first to fourth unit pixels, The output image data of any one of the set sub-pixels can be sampled with the sampling data (A, B, C, D) of the corresponding unit pixel.

The data accumulation unit 135 accumulates the sampling data A, B, C, and D of the first to fourth unit pixels for each pixel group PG1 to PG4 sampled by the data sampling unit 133, And stores them in the corresponding first to fourth storage areas S1 to S4 of the memory 120. [ In one embodiment, the data accumulation unit 135 may store the sampling data A, B, C, and D of the first through fourth unit pixels in a sampling data storage space 125).

Hereinafter, a method of accumulating the sampling data in the data accumulation unit 135 and storing it in the sampling data storage space 125 of the memory 120 will be described in more detail.

First, the data accumulation unit 135 accumulates the sampling data (A, B, C, and D) of the first to fourth unit pixels with respect to each pixel group PG1 to PG4 And reads the accumulated sampling data of the unit pixel in the storage areas S1 to S4. The data accumulating unit 135 accumulates the sampled data A, B, C, and D of the first through fourth unit pixels sampled by the data sampling unit 133, And adds it to the accumulated sampling data of four unit pixels. The data accumulation unit 135 accumulates the accumulated sampling data (S1_A, S1_B, S1_C, S1_D), (S2_A, S2_B, S2_C, S2_D), (S3_A, S3_B, S3_C) of the summed first to fourth unit pixels , S3_D), (S4_A, S4_B, S4_C, and S4_D) in the corresponding storage areas S1 to S4 of the memory 120, respectively. In other words, the data accumulation unit 135 accumulates the corresponding units accumulated in the previous frame in the storage areas (S1 to S4) of the memory 120 allocated to each of the plurality of unit pixels included in each of the pixel groups (PG1 to PG4) (A, B, C, D) of each unit pixel sampled by the data sampling unit 133 is added to each of the accumulated sampling data of the corresponding unit pixel, In the storage areas S1 to S4 of the memory 120,

6, the data accumulation unit 135 accumulates the unit pixels in the memory 120 in the active period H in which the data enable signal DE is in a high state, And reads the read data. The data accumulating unit 135 accumulates sampling data of each unit pixel sampled by the data sampling unit 133 in the blank interval L in which the data enable signal DE is in a low state, And accumulates the accumulated sampling data of the pixels in the corresponding storage areas S1 to S4 of the memory 120. [ For example, in the first pixel group PG1, the data accumulating unit 135 accumulates the data of the first to third pixels included in the first pixel group PG1 during the active period H of the data enable signal DE, Sampling data accumulated up to the previous frame is read for each of the four unit pixels. The data accumulation unit 135 accumulates the sampling data A, B, C and D of each of the first to fourth unit pixels and the sampling data accumulated in the previous frame during the blank interval H of the data enable signal DE S1_B, S1_C, and S1_D accumulated to the current frame for each of the first through fourth unit pixels, and stores the sampled data in the first storage area S1 of the memory 120. [

In this manner, the data accumulation unit 135 accumulates the data of the first through fourth unit pixels PG2, PG3, and PG4 to the current frame in accordance with the data enable signal DE S4_B, S4_C, and S4_D) of the corresponding memory 120 to generate the second to eighth accumulation data (S2_A, S2_B, S2_C, S2_D), S3_A, S3_B, S3_C, S3_D, S4_A, 4 storage areas (S2, S3, S4).

The address control unit 137 accumulates the accumulated sampling data S1_A, S1_B, S1_C, S1_D, S2_A of the first to fourth unit pixels of each pixel group PG1 to PG4 generated by the data accumulating unit 135, The storage areas S1 to S4 of the memory 120 in which each of the storage areas S1, S2, S3, S3, S3, S3, S3, and S3 are stored. That is, the address control unit 137 controls the read operation or the write operation of the memory 120 so that the data accumulation unit 135 stores the data in the storage areas S1 to S4 of the memory 120 (S1_A) of the first to fourth unit pixels of each of the pixel groups (PG1 to PG4) newly generated by the data accumulation unit 135 so as to read the stored accumulated sampling data S3_B, S3_C, S3_D), S4_A, S4_B, S4_C, and S4_D) of the memory 120 correspond to the storage areas of the corresponding memory 120 (S1_B, S1_C, S1_D), S2_A, S2_B, S2_C, S2_D, S1 to S4).

The gain value generation unit 139 generates gain values for each pixel group PG1 to PG4 in the first to fourth storage areas S1, S2, S3, and S4 of the sampling data storage space 125 included in the memory 120. [ (S1_A, S2_A, S3_A, S4_A), S1_B, S2_B, S3_B, S4_B, S1_C, S2_C, S3_C, S4_C, S1_D, S2_D, S3_D, S4_D ) For each frame. The gain value generation unit 139 also outputs the accumulated sampling data S1_A, S2_A, S3_A, S4_A, S1_B, S2_B, and S3_B of the first to fourth unit pixels for each of the readout pixel groups PG1 to PG4 (G1_A, G2_A, G3_A, G4_A) for each of the pixel groups (PG1 to PG4) on the basis of each of the pixel groups (PG_P, PG_B, (G1_B, G2_B, G3_B, G4_b), (G1_C, G2_C, G3_C, G4_C), (G1_D, G2_D, G3_D, G4_D)). At this time, the gain value generator 139 may generate a compensation gain value for each pixel group using a lookup table mapped to correspond to the gray level value of the accumulated sampling data.

7, the gain value generating unit 139 generates the gain value of the N frames in the first to fourth storage areas S1 (S1) of the sampling data storage space 125 included in the memory 120, S2_A, S3_A and S4_A of the first unit pixel for each of the pixel groups PG1 to PG4 in each of the pixel groups PG1 to PG4 G2_A, G3_A, and G4_A for each pixel group PG1 to PG4 based on the accumulated sampling data S1_A, S2_A, S3_A, and S4_A of the first unit pixels .

8, the gain value generator 139 of the N + 1 frame stores the first to fourth storage areas S1 and S2 of the sampling data storage space 125 included in the memory 120, S2_B, S3_B and S4_B of the second unit pixel for each of the pixel groups PG1 to PG4 in each of the pixel groups PG1 to PG4 G2_B, G3_B, and G4_B for the respective pixel groups PG1 to PG4 based on the accumulated sampling data S1_B, S2_B, S3_B, and S4_B of the second unit pixel.

9, the gain value generator 139 of the N + 2 frame stores the first to fourth storage areas S1 and S2 of the sampling data storage space 125 included in the memory 120, S2_C, S3_C and S4_C of the third unit pixel for each of the pixel groups PG1 to PG4 in each of the pixel groups PG1 to PG4 (G1_C, G2_C, G3_C, and G4_C) for the respective pixel groups (PG1 to PG4) based on the accumulated sampling data (S1_C, S2_C, S3_C, and S4_C) of the third unit pixel.

10, the gain value generator 139 generates the gain value of the N + 3 frame in the first to fourth storage areas S1 and S2 of the sampling data storage space 125 included in the memory 120, S2_D, S3_D and S4_D of the fourth unit pixel for each of the pixel groups PG1 to PG4 in each of the pixel groups PG1 to PG4 (G1_D, G2_D, G3_D, G4_D) for each pixel group (PG1 to PG4) based on the accumulated sampling data (S1_D, S2_D, S3_D, S4_D) of the fourth unit pixel.

Gain value generator 139 generates compensation gain values (G1_A, G2_A, G3_A, G4_A), (G1_B, G2_B, G3_B, G4_b), (G1_C, G2_C, G3_C, The data accumulation unit 135 accumulates the first to fourth unit pixels of each of the pixel groups PG1 to PG4 for each pixel group PG1 to PG4 during the generation of the first to fourth unit pixels PG1 to PG4 (G1_D, G1_D, G2_D, G3_D and G4_D) The process of generating data is repeatedly performed on a frame-by-frame basis.

Gain value generator 139 generates compensation gain values G1_A, G2_A, G3_A, G4_A, G1_B, G2_B, G3_B, G4_b, G1_C, G2_C, G3_C and G4_C for each pixel group PG1- , G1_D, G2_D, G3_D, and G4_D) in the gain value storage space 123 of the memory 120.

6, when the display panel 110 has a resolution of 1920 (vertical lines) ㅧ 1080 (horizontal lines) ㅧ 4 (R / G / B / W) and the output image data (Odata) The memory 120 is required to have a capacity of 1920 (Vertical lines) ㅧ 1080 (horizontal lines) ㅧ 4 (R / G / B / W) ㅧ 32 bits = 265,420,800 (bits) ) Should be considerably large.

When the display panel 110 having the above resolution is driven according to the vertical synchronizing signal of 120 Hz, the dot clock DCLK has a frequency of 75 MHz, and one active period H of the data enable signal DE, The number of generated dot clocks DCLK is 480. Accordingly, the amount of data to be processed during one horizontal period is 480 (DCLK) ㅧ 4 (Port) ㅧ 4 (R / G / B / W) ㅧ 32 (bits) = 245,760 (bits).

The memory 120 operates at 300 MHz and has a number of input / output pins of 16 (bits), performs a read operation (RP) on the active section H of the data enable signal DE, The number of clocks CLK of the memory 120 used in the read operation RP is equal to the number of clocks CLK of the dot clock DCLK The amount of data that can be processed by the read operation RP of the memory 120 which is a double data rate random access memory (DDRAM) is 1920 (CLK) ㅧ 16 bits, (Dual rate) = 61,440 (bits). Accordingly, when the accumulated sampling data is generated for all the subpixels of the display panel 110, a large number of memories are required. In order to reduce the cost due to the increase in the number of memory, There is a limit to the data bandwidth.

However, the deterioration compensating unit 130 according to the present invention samples the image data of one sub-pixel per unit pixel composed of four sub-pixels, that is, 1/4, and stores the entire space of the memory 120 into a plurality of Data can be processed in the read operation of the memory 120 while reducing the number of the memories 120. Since the sampling data is stored in different storage areas, Since the output image data is generated by compensating the input image data using the accumulated sampling data stored in the other storage area, image degradation due to data sampling can be minimized through an effect similar to the frame interpolation method.

Hereinafter, a driving method of the OLED display according to the present invention will be described with reference to FIGS.

11 is a flowchart illustrating a method of driving an organic light emitting display according to an exemplary embodiment of the present invention.

First, as shown in FIG. 11, input image data to be supplied to a plurality of sub-pixels constituting a unit pixel is received (S1100).

Then, it is determined whether or not the gain value to be reflected in the input image data has been updated (S1110). If the gain value is not updated, output image data is generated by reflecting the gain value generated in the previous frame in the input image data (S1120). If the gain value is updated, the updated gain value is added to the input image data And generates output image data (S1130).

At this time, the gain value initially reflected on the input image data may be preset and stored in the memory.

In one embodiment, the gain value to be reflected in the input image data may include sampling data for sampling output image data to be supplied to one sub-pixel for each unit pixel of each pixel group when grouping a plurality of unit pixels into pixel groups May be accumulated in different storage areas of the memory, and may be updated frame by frame based on the sampling data accumulated in the memory.

Thereafter, the generated output image data is converted into a data voltage and supplied to the corresponding sub-pixel (S1140).

Hereinafter, a method of updating the gain value to be reflected on the input image data will be described in more detail with reference to FIG.

12 is a flowchart showing a method of updating a gain value to be reflected on input image data.

First, in step S1200, one of the input image data of each sub pixel is sampled as sampling data of a unit pixel for each unit pixel of each pixel group composed of a plurality of unit pixels. Since the method of sampling the sampling data of each unit pixel has been described in the data sampling unit 133 shown in FIG. 4, a detailed description thereof will be omitted.

Thereafter, the sampling data of each accumulated unit pixel up to the previous frame stored in the corresponding storage area of the memory in which the sampling data is to be stored is read (S1210), and the sampling data sampled in S1200 and the sampled data read in S1210 The accumulated sampling data is summed and stored in a corresponding storage area of the memory (S1220).

In one embodiment, the read of the accumulated sampling data may be performed in the active period of the data enable signal, and the summing and storing of the sampling data sampled in S1200 and the accumulated sampling data may be performed on the data enable signal Can be performed in the blank section.

Thereafter, the accumulated sampling data of each unit pixel up to the current frame stored in the memory is read (S1230), and applied to each pixel group of the current frame based on the accumulated sampling data of the read unit pixels A gain value is generated (S1240). In one embodiment, the gain value for the accumulated sampling data may be determined using a predetermined look-up table.

A specific method of generating a gain value to be applied to each pixel group has already been described in the description of the gain value generating unit shown in FIG. 4, and a detailed description thereof will be omitted.

Then, it is determined whether the gain value of the current frame generated in S1240 is equal to the gain value of the previous frame (S1250). If not, the generated gain value is written into the memory (S1260) The value is held in the memory (S1270).

As described above, the organic light emitting diode display according to an embodiment of the present invention uses a sampling scheme for sampling only one sub-pixel among a plurality of sub-pixels constituting a unit pixel, One output image data for each unit pixel is sampled and cumulatively stored in different areas of the memory 120. Based on the accumulated sampling data stored in different storage areas of the memory 120, Values are generated on a frame-by-frame basis and reflected on the input image data of the sub-pixels included in each pixel group, thereby compensating for the deterioration of the organic light emitting elements included in each sub-pixel, thereby displaying an image with uniform luminance.

Meanwhile, in the OLED display according to the above-described embodiment of the present invention, each pixel group is composed of four unit pixels adjacent to each other in the up, down, left, and right directions. However, the present invention is not limited thereto, And may be composed of a plurality of adjacent unit pixels. In addition, the memory 120 has a plurality of storage areas spatially separated to correspond to the number of pixel groups.

It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

110: display panel 120: memory
130: deterioration compensating unit 131: data compensating unit
133: Data sampling unit 135: Data accumulation unit
137: address control section 139: gain value generation section
140: panel driver 142: timing controller
144: Gate driving circuit part 146: Data driving circuit part

Claims (10)

A display panel including a plurality of unit pixels composed of a plurality of sub-pixels;
A deterioration compensator configured to receive input image data to be supplied to the plurality of sub-pixels and to generate output image data by reflecting a predetermined gain value to the input image data;
A memory for storing the output image data;
And a panel driver for supplying the output image data generated by the deterioration compensator to the corresponding sub-pixel,
The deterioration compensator accumulates and stores sampling data obtained by sampling output image data to be supplied to one sub-pixel for each unit pixel of each pixel group composed of adjacent unit pixel units in different storage areas of the memory, And updates the predetermined gain value on a frame-by-frame basis based on the sampling data accumulated and stored in the memory. The method according to claim 1,
Wherein the deterioration compensator comprises:
A data sampling unit for sampling output image data of one of the output image data of each sub pixel per sampling pixel of the unit pixel of each pixel group;
A data accumulation unit accumulating sampling data of each of the sampled unit pixels on a frame-by-frame basis and storing the sampled data in different storage areas of the memory;
A gain value generation unit for reading the accumulated sampling data of the unit pixel in the storage area and generating the predetermined gain value to be applied to each pixel group based on the accumulated sampling data of the unit pixel; And
And a data compensator configured to generate the output image data by reflecting the predetermined gain value to be applied to each pixel group to the input image data of each of the sub pixels included in each of the pixel groups. 3. The method of claim 2,
Wherein the data accumulator comprises:
And reading the accumulated sampling data recorded in a corresponding storage area of the memory in which the sampling data is to be stored when the sampling data is sampled by the data sampling unit,
Wherein the sampling data is added to the accumulated sampling data and stored in a corresponding storage area of the memory. 3. The method of claim 2,
Wherein the data accumulator comprises:
And reading the accumulated sampling data recorded in a corresponding storage area of the memory in which the sampling data is to be stored in an active period of the data enable signal when the sampling data is sampled by the data sampling unit,
Wherein the sampling data is added to the cumulative-sampling data in a blank interval of the data enable signal and is stored in a corresponding storage area of the memory. The method according to any one of claims 2 to 4,
Wherein the deterioration compensating unit further comprises an address control unit for designating a storage area of the memory in which sampling data of the unit pixel is accumulated and stored. The method according to claim 1,
The plurality of sub-pixels including an organic light emitting element emitting light by a data current based on a data voltage,
Wherein the panel driving unit converts the output image data generated by the deterioration compensating unit into the data voltage and supplies the data voltage to the corresponding sub pixel. Receiving input image data to be supplied to a plurality of sub-pixels constituting a unit pixel;
Generating output image data by reflecting a predetermined gain value to the input image data;
Converting the output image data into a data voltage and supplying the data voltage to the corresponding sub-pixel; And
Sampling data for sampling output image data to be supplied to one subpixel for each unit pixel of each pixel group composed of a plurality of unit pixels is accumulated and stored in different storage areas of the memory, And updating the predetermined gain value on a frame-by-frame basis based on the sampling data. 8. The method of claim 7,
Wherein the updating comprises:
Sampling one of the input image data of each of the sub-pixels with sampling data of the unit pixel for each unit pixel of each pixel group;
Accumulating sampling data of each of the sampled unit pixels in units of frames and storing the accumulated sampling data in different storage areas of the memory; And
Reading the accumulated sampling data of the unit pixel in the storage area and generating the predetermined gain value to be applied to each pixel group based on the accumulated sampling data of the read unit pixel Wherein the organic light emitting display device comprises: 9. The method of claim 8,
Wherein the storing step comprises:
Wherein when the sampling data is sampled, accumulated sampled data recorded in a corresponding storage area of the memory where the sampling data is to be stored is read,
Wherein the sampling data is added to the accumulated sampling data and stored in a corresponding storage area of the memory. 9. The method of claim 8,
Wherein the storing step comprises:
When the sampling data is sampled, the accumulated sampling data recorded in a corresponding storage area of the memory in which the sampling data is to be stored is read in an active period of the data enable signal,
Wherein the sampling data is added to the cumulative-sampling data in a blank interval of the data enable signal and is stored in a corresponding storage area of the memory.

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