KR102138592B1 - Organic light emitting display device and method for driving theteof - Google Patents

Abstract

An organic light emitting display device according to an aspect of the present invention to compensate for deterioration of an organic light emitting device and to display an image of uniform luminance includes 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 generate output image data by reflecting a predetermined gain value in the input image data; A memory in which the output image data is stored; And a panel driver supplying the output image data generated by the degradation compensation unit to a corresponding sub-pixel, and the degradation compensation unit includes one sub-pixel for each unit pixel of each pixel group consisting of adjacent m unit pixels. Sampling data sampling the output image data to be supplied to the memory is accumulated and stored in different storage areas, and the predetermined gain value is updated in units of frames based on the sampling data accumulated and stored in the memory. It is characterized by.

Description

Organic light emitting display device and driving method of organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD FOR DRIVING THETEOF}

The present invention relates to an organic light emitting display device and a driving method thereof, and more particularly, to an organic light emitting display device and a driving method thereof to compensate for deterioration of an organic light emitting device.

Recently, with the development of multimedia, the importance of a flat panel display device has increased. 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 these flat panel display devices, the organic light emitting display device has attracted attention as a next-generation flat panel display device because it has a high-speed response speed, low power consumption, and has no problem in viewing angle because of its own light emission.

A typical organic light emitting display device includes a display panel including a plurality of pixels and a panel driver that emits 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 pixel includes a switching transistor Tsw, a driving transistor Tdr, a capacitor Cst, and a light emitting device OLED, as shown in FIG. 1.

The switching transistor Tsw is switched according to 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 to control the data current Ioled flowing to the light emitting device 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, and the driving transistor ( Tdr) is turned on.

The light emitting element 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 to emit light by the data current Ioled supplied from the driving transistor Tdr. do.

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

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

As can be seen in FIG. 2, it can be seen that, in general, the organic light emitting device gradually decreases in luminance characteristic due to an accelerated deterioration rate as the driving time increases.

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

The present invention has been devised to solve the above-mentioned problems, and it is a technical problem to provide an organic light emitting display device and a driving method thereof to compensate for deterioration of an organic light emitting device to display an image of uniform luminance.

An organic light emitting display device according to an aspect of the present invention for achieving the above technical problem is 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 generate output image data by reflecting a predetermined gain value in the input image data; A memory in which the output image data is stored; And a panel driver supplying the output image data generated by the degradation compensation unit to a corresponding sub-pixel, and the degradation compensation unit includes one sub-pixel for each unit pixel of each pixel group consisting of adjacent m unit pixels. Sampling data sampling the output image data to be supplied to the memory is accumulated and stored in different storage areas, and the predetermined gain value is updated in units of frames based on the sampling data accumulated and stored in the memory. It is characterized by.

A method of driving an organic light emitting diode display according to another aspect of the present invention for achieving the above-described technical problem includes 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 in the input image data; Converting the output image data into a data voltage and supplying it to a corresponding sub-pixel; And sampling data obtained by sampling output image data to be supplied to one sub-pixel for each unit pixel of each pixel group consisting of a plurality of unit pixels, is accumulated and stored in different storage areas of the memory, and is accumulated in 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 stored in different areas of the memory, and based on data accumulated and stored in different areas of the memory, The compensation gain value is generated in units of frames and reflected in the input image data, thereby compensating for deterioration of the organic light emitting device and displaying an image of uniform luminance.

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

In addition, according to the present invention, there is an effect that the degradation of image quality due to data sampling can be minimized through an effect similar to the frame interpolation method.

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 typical organic light emitting device.
3 is a block diagram illustrating an organic light emitting display device according to an exemplary embodiment of the present invention.
4 is a block diagram schematically showing the structure of the deterioration compensation unit shown in FIG. 3.
5 is a view for explaining a method of sampling and storing data according to the present invention.
FIG. 6 is a signal waveform diagram for explaining the read and write operations of the memory shown in FIG. 4.
7 to 10 are views 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 organic light emitting diode 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 in input image data.

The meaning of the terms described in this specification should be understood as follows.

It should be understood that a singular expression includes a plurality of expressions unless the context clearly defines otherwise, and the terms "first", "second", etc. are intended to distinguish one component from another component, The scope of rights should not be limited by these terms.

It should be understood that terms such as "include" or "have" do not preclude the presence or addition possibility of one or more other features or numbers, steps, actions, components, parts 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 2 of the first item, the second item, or the third item, as well as the first item, the second item, and the third item, respectively. Any combination of items that can be presented from more than one dog.

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

3 is a diagram for describing an organic light emitting diode display according to an exemplary embodiment of the present invention.

Referring to FIG. 3, an organic light emitting diode display according to an exemplary embodiment of the present invention includes a display panel 110, a memory 120, a deterioration compensation unit 130, and a panel driver 140.

The display panel 110 includes a plurality of sub-pixels SP. The plurality of sub-pixels SP are formed in a pixel area defined by a plurality of gate lines GL and a plurality of data lines DL intersecting each other. In addition, a plurality of driving power lines PL1 to which driving voltages are supplied from the panel driving unit 140 are formed on the display panel 110 in parallel with each of the plurality of data lines DL.

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 displaying one image may include adjacent red sub-pixels, green sub-pixels, blue sub-pixels, and white sub-pixels, or may include red, green, and blue pixels. Hereinafter, it is assumed that the single 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 line PL2 to emit a predetermined color light by emitting light in proportion to the amount of data current supplied from the pixel circuit PC. do. To this end, the organic light emitting diode OLED includes an anode electrode (or pixel electrode) connected to the pixel circuit PC, a cathode electrode (or reflective electrode) connected to the second driving power line PL2, and an anode electrode. And a light emitting cell that is formed between the cathode electrode and emits light of any one of red, green, blue, and white colors. Here, the light emitting cell may be formed to have a structure of a hole transport layer / organic light emitting layer / electron transport layer or a hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer. Furthermore, a functional layer for improving luminous efficiency and/or lifespan of the organic light emitting layer may be further formed in the light emitting cell.

The pixel circuit PC is a data voltage supplied from the panel driver 140 to the data line DL in response to a gate signal GS having a gate-on voltage level supplied from the panel driver 140 to the gate line GL. The data current corresponding to (Vdata) is supplied to the organic light emitting diode (OLED). To this end, the pixel circuit PC includes 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 be formed in the same structure as the pixel illustrated in FIG. 1. Since the pixel circuit structure shown in FIG. 1 has already been described in the description of FIG. 1, a detailed description is omitted.

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

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

The deterioration compensation unit 130 groups adjacent m unit pixels into a plurality of pixel groups, and samples the output image data Odata to be supplied to one sub-pixel SP for each unit pixel of each pixel group. Data is accumulated in frame units and stored in different storage areas of the memory 120, and is stored in sub-pixels SP of each pixel group based on the sampling data accumulated and stored in different storage areas of the memory 120. The gain value to be reflected in the input image data (Idata) to be supplied is generated, and the generated gain value is reflected in the input image data to generate the output image data (Odata).

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. The data line DL by sequentially supplying it to the gate line GL and converting the output image data Odata supplied from the deterioration compensator 130 into a data voltage Vdata according to the data control signal DCS. To supply. To this end, the panel driving unit 140 includes a timing control unit 142, a gate driving circuit unit 144, and a data driving circuit unit 146.

The timing control unit 142 drives the 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 main body (not shown) or a graphics card (not shown). Control. That is, the timing control unit 142 is 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 generates a data control signal (DCS), and controls the driving timing of the gate driving circuit unit 144 through the gate control signal (GCS), the data driving circuit unit through the data control signal (DCS) to synchronize with this 146) is controlled.

In addition, the timing control unit 142 arranges red, green, blue, and white output image data Odata supplied from the degradation compensation unit 130 to suit the pixel arrangement structure of the display panel 110, The aligned data DATA is supplied to the data driving circuit unit 146 based on a predetermined interface method.

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

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

The data driving circuit unit 146 receives data DATA and a data control signal DCS from the timing control unit 142 and receives a plurality of reference gamma voltages from an external reference gamma voltage supply unit (not shown). The data driving circuit unit 146 converts the alignment data DATA into an analog data voltage Vdata using a plurality of reference gamma voltages according to the data control signal DCS, and converts the converted data voltage Vdata. ) Is supplied to the data line DL of the corresponding sub-pixel. As such, the data driving circuit unit 146 may be formed in a plurality of integrated circuit (IC) shapes and connected to one side and/or both sides of the data line DL.

Hereinafter, the deterioration compensator according to the present invention will be described in more detail with reference to FIGS. 4 and 5.

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

First, the deterioration compensator 130 according to an embodiment of the present invention receives four-color image data consisting of red image data, green image data, blue image data, and white image data in units of unit pixels in series or in parallel. Can be. Here, the four-color image data is converted from red image data, green image data, and blue image data by a data format conversion unit (not shown), wherein the data format conversion unit includes red image data and green image data for each unit pixel. , By extracting white image data based on blue image data, and reflecting the extracted white image data on red image data, green image data, and blue image data, the four-color image data is generated.

In addition, the deterioration compensator 130 according to an embodiment of the present invention groups adjacent m unit pixels formed on the display panel 110 into a plurality of pixel groups, and different unit pixels during m frames in each pixel group Deterioration compensation for the organic light emitting diode OLED of each sub-pixel SP is performed by applying different compensation gain values to each pixel group over m frames based on the accumulated sampling data of.

For convenience of description, in the following description, as illustrated in FIG. 5, the display panel 110 includes first to fourth pixel groups PG1 to PG4 adjacent vertically and horizontally, and each pixel group PG1 to PG4) will be described as an example that includes first to fourth unit pixels arranged in a 2'2 form adjacent to each other vertically and horizontally.

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, and an address control unit 137. , And a gain value generator 139.

The data compensation unit 131 receives input image data Idata to be applied to each sub-pixel constituting the unit pixel, and reflects a predetermined gain value in the received input image data Idata to output image data Odata. Produces

In one embodiment, the data compensation unit 131 may multiply the input image data Idata of each sub-pixel by a predetermined gain value generated for each pixel group to generate output image data Odata.

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

In one embodiment, a predetermined gain value is generated for each pixel group PG1 to PG4, and may be updated in units of frames. The predetermined gain value to be reflected in the input image data Idata for the first time may be specified in advance or may be set to "1".

In addition, the data compensation unit 131 provides the generated output image data Odata to the above-described panel driving unit 140, that is, the timing control unit 142.

The data sampling unit 133 groups 16 unit pixels formed on the display panel 110 into first to fourth pixel groups PG1 to PG4 including four unit pixels. The data sampling unit 133 may select any one of output image data Odata of sub-pixels included in each unit pixel for each unit pixel (first to fourth pixels) for each pixel group PG1 to PG4. The image data Odata is sampled with the sampling data A, B, C, and D of each of the first to fourth unit pixels.

For example, the data sampling unit 133 among red output image data, green output image data, blue output image data, and 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 one of the set sub-pixels can be sampled with the sampling data (A, B, C, D) of the corresponding unit pixel.

The data accumulator 135 accumulates the sampling data (A, B, C, D) of the first to fourth unit pixels for each pixel group PG1 to PG4 sampled by the data sampling unit 133 in units of frames. To the first to fourth storage areas S1 to S4 of the memory 120. In one embodiment, the data accumulator 135 stores the sampling data (A, B, C, D) of each of the first to fourth unit pixels in the memory 120, where the sampling data is stored ( 125).

Hereinafter, a method in which the data accumulator 135 accumulates the sampling data and stores it in the sampling data storage space 125 of the memory 120 will be described in more detail.

First, the data accumulation unit 135 corresponds to the memory 120 allocated to each of the sampling data A, B, C, and D of the first to fourth unit pixels for each pixel group PG1 to PG4. The accumulated sampling data of the corresponding unit pixel is read in the storage areas S1 to S4. Thereafter, the data accumulator 135 reads the first to fourth sampling data A, B, C, and D of the first to fourth unit pixels sampled by the data sampling unit 133, respectively. It is added to the accumulated sampling data of 4 unit pixels. Thereafter, the data accumulator 135 accumulates the accumulated sampling data of the first to fourth unit pixels ((S1_A, S1_B, S1_C, S1_D), (S2_A, S2_B, S2_C, S2_D), (S3_A, S3_B, S3_C , S3_D), (S4_A, S4_B, S4_C, S4_D)) in the respective storage areas S1 to S4 of the memory 120. That is, the data accumulation unit 135 is a corresponding unit accumulated from 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 to the previous frame. The sampling data of the pixel is read, and the sampling data (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 to be applied. To be stored in the storage areas S1 to S4 of the memory 120.

In one embodiment, the data accumulator 135 accumulates unit pixels in the memory 120 in the active section H in which the data enable signal DE is in a high state, as shown in FIG. 6. Read the read data. In addition, the data accumulator 135 reads the sampling data of each unit pixel sampled by the data sampling unit 133 in the blank section L in which the data enable signal DE is in a low state and each unit read. The accumulated sampling data of the pixels are summed and stored in the corresponding storage areas S1 to S4 of the memory 120. For example, in the first pixel group PG1, the data accumulator 135 during the active period H of the data enable signal DE includes the first to the first pixels included in the first pixel group PG1. For each of the 4 unit pixels, the sampling data accumulated up to the previous frame are read. Also, the data accumulator 135 samples the accumulated data up to the previous frame and the sampling data (A, B, C, D) of each of the first to fourth unit pixels during the blank period H of the data enable signal DE. Data is summed to generate sampling data S1_A, S1_B, S1_C, and S1_D accumulated up to the current frame for each of the first to fourth unit pixels and stored in the first storage area S1 of the memory 120.

In this way, the data accumulator 135 is configured to the current frame for the first to fourth unit pixels according to the data enable signal DE for each of the second to fourth pixel groups PG2, PG3, and PG4. Generated sampling data ((S2_A, S2_B, S2_C, S2_D), (S3_A, S3_B, S3_C, S3_D), (S4_A, S4_B, S4_C, S4_D), respectively, generating the second to second of the corresponding memory 120 4 Save in the storage area (S2, S3, S4).

The address control unit 137 accumulates 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 accumulation unit 135. , S2_B, S2_C, S2_D), (S3_A, S3_B, S3_C, S3_D), (S4_A, S4_B, S4_C, S4_D)) designate storage areas S1 to S4 of the memory 120 in which each is stored. That is, the address control unit 137 controls a read operation or a write operation of the memory 120, and the data accumulation unit 135 is stored in each of the storage areas S1 to S4 of the memory 120. The stored accumulated sampling data is read, and the accumulated sampling data (S1_A) of the first to fourth unit pixels of each pixel group PG1 to PG4 newly generated by the data accumulation unit 135 is read. , S1_B, S1_C, S1_D), (S2_A, S2_B, S2_C, S2_D), (S3_A, S3_B, S3_C, S3_D), (S4_A, S4_B, S4_C, S4_D)) storage areas of the corresponding memory 120 ( S1 to S4).

The gain value generation unit 139 is configured 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. Cumulative sampling data of the 1 to 4th unit pixels ((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, S4D )) is read for each frame. In addition, the gain value generation unit 139 may accumulate sampling data ((S1_A, S2_A, S3_A, S4_A), (S1_B, S2_B, S3_B) of the first to fourth unit pixels for each of the read pixel groups PG1 to PG4. , S4_B), (S1_C, S2_C, S3_C, S4_C), (S1_D, S2_D, S3_D, S4_D)) compensation gain values for each pixel group PG1 to PG4 ((G1_A, G2_A, G3_A, G4_A) , (G1_B, G2_B, G3_B, G4_b), (G1_C, G2_C, G3_C, G4_C), (G1_D, G2_D, G3_D, G4_D)) for each frame. At this time, the gain value generator 139 may generate a compensation gain value for each pixel group using a look-up table mapped to correspond to the gradation value of the accumulated sampling data.

For example, in the N frame, the gain value generating unit 139, as shown in FIG. 7, the first to fourth storage areas S1 of the sampling data storage space 125 included in the memory 120 , S2, S3, S4 reads each of the accumulated sampling data S1_A, S2_A, S3_A, S4_A of the first unit pixel for each pixel group PG1 to PG4, and reads each read pixel group PG1 To PG4) Compensation gain values (G1_A, G2_A, G3_A, G4_A) for each pixel group (PG1 to PG4) are generated based on the accumulated sampling data (S1_A, S2_A, S3_A, S4_A) of the first unit pixel for each PG4). .

In the N+1 frame, the gain value generation unit 139, as shown in Figure 8, the first to fourth storage areas (S1, S2) of the sampling data storage space 125 included in the memory 120 , S3, S4) reads each of the accumulated sampling data S1_B, S2_B, S3_B, S4_B of the second unit pixel for each pixel group PG1 to PG4, and reads each read pixel group PG1 to PG4 Compensation gain values (G1_B, G2_B, G3_B, G4_B) for each pixel group (PG1 to PG4) are generated based on the accumulated sampling data (S1_B, S2_B, S3_B, S4_B) of the second unit pixel per ).

In the N+2 frame, the gain value generation unit 139, as shown in FIG. 9, the first to fourth storage areas S1 and S2 of the sampling data storage space 125 included in the memory 120 , S3, S4) reads each of the accumulated sampling data (S1_C, S2_C, S3_C, S4_C) of the third unit pixel for each pixel group (PG1 to PG4), and reads each read pixel group (PG1 to PG4) Compensation gain values (G1_C, G2_C, G3_C, G4_C) for each pixel group (PG1 to PG4) are generated based on the accumulated sampling data (S1_C, S2_C, S3_C, S4_C) of the third unit pixel per ).

In the N+3 frame, the gain value generation unit 139, as shown in FIG. 10, the first to fourth storage areas S1 and S2 of the sampling data storage space 125 included in the memory 120 , S3, S4) reads each of the accumulated sampling data S1_D, S2_D, S3_D, S4_D of the fourth unit pixel for each pixel group PG1 to PG4, and reads each read pixel group PG1 to PG4 Compensation gain values (G1_D, G2_D, G3_D, G4_D) for each pixel group (PG1 to PG4) are generated based on the accumulated sampling data (S1_D, S2_D, S3_D, S4_D) of the fourth unit pixel per ).

On the other hand, the gain value generating unit 139 is a compensation gain value ((G1_A, G2_A, G3_A, G4_A), (G1_B, G2_B, G3_B, G4_b), (G1_C, G2_C, G3_C, G3_C, for each pixel group PG1 to PG4) G4_C), while generating (G1_D, G2_D, G3_D, G4_D)), the data accumulation unit 135, as described above, cumulative sampling of the first to fourth unit pixels for each pixel group PG1 to PG4 The process of generating data is repeatedly performed on a frame-by-frame basis.

The gain value generator 139 includes compensation gain values for each pixel group PG1 to PG4 ((G1_A, G2_A, G3_A, G4_A), (G1_B, G2_B, G3_B, G4_b), (G1_C, G2_C, G3_C, G4_C) , (G1_D, G2_D, G3_D, G4_D)) in the gain value storage space 123 of the memory 120.

6, the display panel 110 has a resolution of 1920 (Vertical lines) x 1080 (horizontal lines) x 4 (R/G/B/W), and the output image data (Odata) consists of 32 bits. In this case, the above-described memory 120 should have a capacity of 1920 (Vertical lines) x 1080 (horizontal lines) x 4 (R/G/B/W) x 32 (bits) = 265,420,800 (bits). ) Must have a fairly large capacity.

In addition, when the display panel 110 having the above resolution is driven according to a vertical synchronization 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 dot clocks (DCLK) generated at is 480. Accordingly, in one horizontal period, the amount of data to be processed is 480 (DCLK) ㅧ 4 (Port) ㅧ 4 (R/G/B/W) ㅧ 32 (bits) = 245,760 (bits).

Then, the memory 120 operates at 300 MHz, has 16 (bits) input/output pin counts, reads (RPs) the active section H of the data enable signal DE, and performs data (RP). Since the write operation WP is performed on the blank section L of the enable signal DE, the number of clocks CLK of the memory 120 used in the read operation RP is the dot clock DCLK ), which is four times as fast as 1920. Accordingly, the amount of data that the memory 120, which is a double data rate random access memory (DDRRAM), can process in a read operation (RP) is 1920 (CLK) ㅧ 16 (bits). ㅧ2(Dual rate)=61,440(bits). Accordingly, when generating accumulated sampling data for all sub-pixels of the display panel 110, a large number of memories are required, and when reducing the number of memories to reduce the cost burden due to an increase in the number of memories, the memory 120 There is a limit to the data bandwidth (Data Bandwidth).

However, the deterioration compensator 130 according to the present invention samples the image data of one sub-pixel for each unit pixel composed of four sub-pixels, that is, samples in 1/4, and stores the entire space of the memory 120 in a plurality Since the data is divided into regions and stored in different storage regions, data can be processed during the read operation of the memory 120 while reducing the number of the memory 120, and each of the memory 120 is frame-by-frame. Since the output image data is generated by compensating the input image data by using the accumulated sampling data stored in another storage area, it is possible to minimize the deterioration of image quality due to data sampling through an effect similar to the frame interpolation method.

Hereinafter, a driving method of the organic light emitting display device according to the present invention will be described with reference to FIGS. 11 and 12.

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

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

Thereafter, it is determined whether there is an update of the gain value to be reflected in the input image data (S1110). As a result of determination, if there is no update of the gain value, output image data is generated by reflecting the gain value generated in the previous frame to the input image data (S1120), and if there is an update of the gain value, the updated gain value is input to the input image data. Reflect to generate the output image data (S1130).

At this time, the gain value first reflected in 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 is sampling data obtained by sampling output image data to be supplied to one sub-pixel for each unit pixel of each pixel group when a plurality of unit pixels are grouped into a pixel group. May be accumulated and stored in different storage areas of the memory, and may be updated frame by frame based on the sampling data accumulated and stored 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 in the input image data will be described in more detail with reference to FIG. 12.

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

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

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

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

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 each unit pixel read. A gain value to be generated is generated (S1240). In one embodiment, the gain value for the accumulated sampling data may be determined using a predetermined lookup table.

Since a detailed method of generating a gain value to be applied to each pixel group has already been described in the description of the gain value generator illustrated in FIG. 4, a detailed description is omitted.

Thereafter, it is determined whether the gain value of the current frame generated in S1240 is the same as the gain value of the previous frame (S1250), and if not, the generated gain value is recorded in the memory (S1260), and if equal, the gain of the previous frame The value is kept in the memory (S1270).

As described above, the organic light emitting diode display according to an exemplary embodiment of the present invention uses a sampling method of sampling only one sub-pixel among a plurality of sub-pixels constituting a unit pixel, and the plurality of pixels included in the plurality of pixel groups Compensation gain of each pixel group based on the accumulated sampling data stored in different storage areas of the memory 120 by sampling one output image data for each unit pixel and accumulating and storing them in different areas of the memory 120 By generating values in units of frames and reflecting them in the input image data of sub-pixels included in each pixel group, deterioration of the organic light-emitting device included in each sub-pixel can be compensated to display an image of uniform luminance.

On the other hand, in the organic light emitting diode display according to the exemplary embodiment of the present invention described above, each pixel group is described as consisting of four unit pixels vertically and horizontally, but is not limited thereto, and each pixel group is horizontal or vertical. It may be formed of a plurality of adjacent unit pixels. In addition, the above-described memory 120 has a plurality of spatially separated storage areas to correspond to the number of pixel groups.

Those skilled in the art to which the present invention pertains will understand that the above-described present invention can be implemented in other specific forms without changing its technical spirit or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. do.

110: display panel 120: memory
130: deterioration compensation unit 131: data compensation unit
133: data sampling unit 135: data accumulation unit
137: address control unit 139: gain value generating unit
140: panel driving unit 142: timing control unit
144: gate driving circuit section 146: data driving circuit section

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 generate output image data by reflecting a predetermined gain value in the input image data;
A memory in which the output image data is stored;
And a panel driver supplying the output image data generated by the degradation compensation unit to a corresponding sub-pixel,
The deterioration compensator accumulates and stores sampling data, which samples output image data to be supplied to one sub-pixel for each unit pixel of each pixel group composed of adjacent m unit pixels, in different storage areas of the memory, And updating the predetermined gain value in units of frames based on the sampling data accumulated and stored in the memory. According to claim 1,
The deterioration compensation unit,
A data sampling unit sampling one output image data among output image data of each sub-pixel for each unit pixel of each pixel group with sampling data of the unit pixel;
A data accumulator configured to accumulate sampling data of each sampled unit pixel in frame units and store them in different storage areas of the memory;
A gain value generating unit which reads the accumulated sampling data of the unit pixels from the storage area and generates the predetermined gain value to be applied to each pixel group based on the accumulated sampling data of the unit pixels; 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 input image data of each sub-pixel included in each pixel group. . According to claim 2,
The data accumulation unit,
When the sampling data is sampled by the data sampling unit, the accumulated sampling data recorded in a corresponding storage area of the memory in which the sampling data is to be stored is read,
And adding the sampling data to the accumulated sampling data and storing the data in a corresponding storage area of the memory. According to claim 2,
The data accumulation unit,
When the sampling data is sampled by the data sampling unit, 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 section of the data enable signal.
And summing the sampled data to the accumulated sampling data in a blank section of the data enable signal and storing the sampled data in a corresponding storage area of the memory. The method according to any one of claims 2 to 4,
The deterioration compensation unit further includes an address control unit that designates a storage area of the memory in which the sampling data of the unit pixel is accumulated and stored. According to claim 1,
The plurality of sub-pixels include an organic light emitting element that emits light by a data current based on the data voltage,
The panel driving unit converts the output image data generated by the deterioration compensation unit into the data voltage and supplies it 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 in the input image data;
Converting the output image data into a data voltage and supplying it to a corresponding sub-pixel; And
The sampling data sampling the output image data to be supplied to one sub-pixel 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 is accumulated and stored in the memory. And updating the predetermined gain value in units of frames based on the sampled data. The method of claim 7,
The updating step,
Sampling the image data of any one of the input image data of each sub-pixel for each unit pixel of each pixel group with sampling data of the unit pixel;
Accumulating sampling data of each sampled unit pixel in frame units and storing them in different storage areas of the memory; And
Reading the accumulated sampling data of the unit pixels 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 pixels. Method of driving an organic light emitting display device, characterized in that. The method of claim 8,
The storing step,
When the sampling data is sampled, the accumulated sampling data recorded in a corresponding storage area of the memory in which the sampling data will be stored is read,
A method of driving an organic light emitting display device, characterized in that the sampling data is added to the accumulated sampling data and stored in a corresponding storage area of the memory. The method of claim 8,
The storing step,
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 section of the data enable signal.
A method of driving an organic light emitting display device, characterized in that the sampling data is added to the accumulated sampling data in a blank section of the data enable signal and stored in a corresponding storage area of the memory.

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