Display device

Abstract

An embodiment relates to a display device including a display panel including a plurality of pixels, and a residual image compensation section for generating second image data by reflecting accumulated lifetime data on first image data inputted from outside, the residual image compensation section accumulating degradation data to generate the lifetime data after storing image data of a previous frame, wherein the degradation data is generated by reflecting a frequency weight value corresponding to a frequency of the previous frame, which is judged, to the image data of the previous frame.

Description

Technical Field

[0001] This invention relates to a display device and its driving method. Background Technology

[0002] The light-emitting display device in a display device includes driving transistors, capacitors, light-emitting elements, etc. Due to use, the light-emitting elements or driving transistors of the light-emitting display device may deteriorate (hereinafter referred to as pixel degradation).

[0003] If pixel degradation occurs, the display device may be unable to display an image with the desired brightness, potentially resulting in image retention on the display panel. Therefore, light-emitting display devices utilize image retention compensation methods based on the cumulative lifetime (Age) of each pixel, and compensate for degradation on a per-pixel basis to eliminate image retention. Summary of the Invention

[0004] The purpose of this invention is to provide a display device that compensates for the deterioration of the light-emitting element in order to improve image retention when the operating frequency is changed.

[0005] According to an embodiment of the present invention, a display device includes: a display panel including a plurality of pixels; and a retention compensation unit for generating second image data by reflecting accumulated lifetime data on first image data input from the outside, wherein the retention compensation unit accumulates degradation data to generate the lifetime data after storing image data of a previous frame, wherein the degradation data is generated by reflecting a frequency weight value corresponding to the frequency of the previous frame into the image data of the previous frame.

[0006] It is possible that the image data of the previous frame is the scaled first image data input in the previous frame.

[0007] The display device may further include: a gate driving unit that provides a scanning signal to the display panel; a data driving unit that provides a data signal corresponding to the second image data to the display panel; and a timing control unit that controls the driving of the gate driving unit and the data driving unit, wherein the timing control unit determines the frequency of the previous frame and calculates the frequency weight value based on the determined frequency.

[0008] Alternatively, the image retention compensation unit may include a scaling ratio calculation unit, which calculates the scaling ratio of the display panel.

[0009] Alternatively, the image retention compensation unit may perform calculations on the scaling ratio and the first image data to generate the scaled first image data.

[0010] Alternatively, the image retention compensation unit may further include: a lifetime data generation unit that generates the lifetime data based on the scaled first image data; and a memory that stores the accumulated lifetime data and the image data of the previous frame.

[0011] The memory may include: a first memory for storing the accumulated lifetime data; and a second memory for storing the image data of the previous frame.

[0012] Alternatively, the lifetime data generation unit may multiply the frequency weight value on the image data of the previous frame to generate degradation data, and reflect the accumulated lifetime data on the degradation data to generate lifetime data accumulated up to the previous frame.

[0013] Alternatively, the image retention compensation unit may output the second image data based on the lifetime data accumulated up to the previous frame and the scaled first image data.

[0014] Alternatively, the lifetime data generation unit may update the lifetime data of the previous frame in the first memory.

[0015] One embodiment of the display device includes: a display panel including a plurality of pixels; a scaling ratio calculation unit for calculating a scaling ratio of the display panel; a brightness correction unit for performing calculations on first image data and the scaling ratio to generate scaled first image data; a lifetime data generation unit for generating lifetime data based on the scaled first image data; a memory for storing the lifetime data and the scaled first image data of the previous frame; a compensation unit for outputting second image data based on the scaled first image data and the lifetime data; a gate driving unit for providing a scan signal to the display panel; a data driving unit for providing a data signal corresponding to the second image data to the display panel; and a timing control unit for controlling the driving of the gate driving unit and the data driving unit. The lifetime data generation unit performs calculations on degraded data of a frame in which a frequency weight value has been applied to grayscale data of a frame based on the scaled first image data and the accumulated lifetime data to generate lifetime data accumulated up to the previous frame.

[0016] The memory may include: a first memory for storing the accumulated lifetime data; and a second memory for storing the scaled first image data.

[0017] It is possible that the accumulated lifetime data is the lifetime data accumulated up to the frame before the previous frame.

[0018] Alternatively, the lifetime data generation unit may multiply the frequency weight value on the scaled first image data of the frame to generate degradation data, and reflect the accumulated lifetime data on the degradation data to generate lifetime data accumulated up to the previous frame.

[0019] Alternatively, the compensation unit may output the second image data based on the lifetime data accumulated up to the previous frame and the scaled first image data.

[0020] One embodiment of a driving method for a display device includes: a step of determining a frequency after storing data of a previous frame; a step of calculating a frequency weight value based on the determined frequency; a step of receiving input of first image data; a step of generating scaled first image data by reflecting a scaling ratio on the first image data; a step of generating frame degradation data based on the scaled first image data; and a step of accumulating the degradation data to store lifetime data and storing the scaled first image data of the previous frame separately.

[0021] Alternatively, the driving method may further include the step of generating lifetime data accumulated up to the previous frame based on the frequency weight value, the scaled first image data of the previous frame, and the accumulated lifetime data.

[0022] It is possible that the accumulated lifetime data is the lifetime data accumulated up to the frame before the previous frame.

[0023] Alternatively, the driving method may further include the step of updating the lifetime data of the previous frame for storage.

[0024] Alternatively, the second image data can be output based on the scaled first image data and the lifetime data up to the previous frame.

[0025] (Invention Effects)

[0026] According to one embodiment, image data from the previous frame can be stored separately, and lifetime data can be generated by reflecting a degradation weight value based on the driving frequency of the previous frame. Therefore, a display device that can compensate for the degradation of the light-emitting element and improve image retention can be provided, reflecting the change in the operating frequency of the frame.

[0027] The effects involved in one embodiment are not limited to those illustrated above, and more effects are included in this specification. Attached Figure Description

[0028] Figure 1 This is a block diagram illustrating a display device according to an embodiment.

[0029] Figure 2This is a block diagram illustrating multiple control units of a display device according to an embodiment.

[0030] Figure 3 This is an example signal waveform diagram applied to a display device according to an embodiment.

[0031] Figure 4 This is a block diagram schematically illustrating the timing control unit of a display device according to an embodiment.

[0032] Figure 5 This is a block diagram illustrating the image retention compensation unit of a display device according to an embodiment.

[0033] Figure 6 This is a block diagram illustrating the memory in the image retention compensation section of a display device according to an embodiment.

[0034] Figure 7 This is a conceptual diagram illustrating a calculation method for calculating lifetime data in the image retention compensation unit of a display device according to an embodiment.

[0035] Figure 8a and Figure 8b This generally refers to a method for generating and applying lifetime data when inputting n-1 frames of scaled first image data in a display device according to an embodiment.

[0036] Figure 9a and Figure 9b This generally refers to a method for generating and applying lifetime data when n frames of scaled first image data are input into a display device according to an embodiment.

[0037] Figure 10 This is a schematic diagram illustrating the degradation data accumulated in a frame according to the applied frequency in a display device according to an embodiment.

[0038] Figure 11 This is a sequence diagram illustrating a driving method for a display device according to an embodiment. Detailed Implementation

[0039] Specific details of the other embodiments are included in the detailed description and accompanying drawings.

[0040] References and Appendix Figure 1 As will become clear from the detailed embodiments described below, the advantages, features, and methods of achieving these advantages and features of the present invention will become apparent. However, the present invention is not limited to the embodiments disclosed below, and the present invention may be implemented in different forms. Furthermore, in the following description, the connection between a part and other parts includes not only direct connection but also electrical connection through which other elements are disposed.

[0041] In addition, in order to clearly illustrate the present invention, parts that are not related to the present invention have been omitted, and similar parts are given the same reference numerals throughout the specification.

[0042] Hereinafter, with reference to the accompanying drawings relating to various embodiments of the present invention, a display device and its driving method according to embodiments of the present invention will be described.

[0043] Figure 1 This is a block diagram illustrating a display device according to one embodiment. Figure 2 This is a block diagram illustrating multiple control units of a display device according to one embodiment. Figure 3 This is an example signal waveform diagram applied to a display device according to an embodiment. Figure 4 This is a block diagram schematically illustrating the timing control unit of a display device according to an embodiment.

[0044] First, refer to Figure 1 One embodiment of the display device 1 includes a display panel 100, an image retention compensation unit 200, a gate driving unit 300, a data driving unit 400, and a timing control unit 500.

[0045] Display device 1 may include organic light-emitting display devices, inorganic light-emitting display devices, etc. Additionally, display device 1 may be implemented using flexible display devices, rollable display devices, curved display devices, transparent display devices, mirrored display devices, etc.

[0046] The display panel 100 may include a plurality of pixels PX to display an image. Specifically, the display panel 100 may include pixels PX connected to at least one of a plurality of gate lines SL1 to SLn and at least one of a plurality of data lines DL1 to DLm (here, n and m are natural numbers greater than 1).

[0047] The image retention compensation unit 200 receives input of first image data DATA1 and outputs second image data DATA2 based on lifetime data accumulated up to the previous frame. Here, lifetime data is generated by reflecting (or processing) the degradation data of one frame onto the accumulated lifetime data, wherein the degradation data of one frame is based on the scaled first image data DATA1_SR (refer to...). Figure 5 The grayscale data of a frame is subject to frequency weighting values. A frame can be the frame preceding the current frame, and the accumulated lifetime data can be the lifetime data accumulated up to the frame preceding the previous frame.

[0048] The second image data DATA2 is data provided to the data driving unit 400 (described later), and is based on the scaled first image data DATA1_SR (see reference). Figure 5This reflects the lifetime data accumulated up to the previous frame. Here, the scaled first image data DATA1_SR (refer to...) Figure 5 This can be referred to as the image data of the previous frame.

[0049] Additionally, the image retention compensation unit 200 can adjust the image based on the scaled first image data DATA1_SR (refer to...) based on the first image data DATA1. Figure 5 The accumulated lifetime data is generated by accumulating the grayscale data of each frame of the image. According to an embodiment, the first image data DATA1 may be input image data, which may include input grayscale data.

[0050] For example, when the display panel 100 displays the image of the nth frame, the image retention compensation unit 200 can store the lifetime data accumulated up to the (n-2)th frame, and based on the scaled first image data DATA1_SR of the (n-1)th frame (see reference). Figure 5 This is used to store the degradation data of a frame. The degradation data of a frame can be the scaled first image data DATA1_SR of the (n-1)th frame (refer to...). Figure 5 This reflects the weight value related to the frequency of the (n-1)th frame. Furthermore, the image retention compensation unit 200 can perform calculations on the accumulated lifetime data up to the (n-2)th frame and the degradation data of the (n-1)th frame to generate lifetime data accumulated up to the (n-1)th frame.

[0051] The image retention compensation unit 200 can update the lifetime data of the previous frame for storage. The image retention compensation unit 200 can be based on the scaled first image data DATA1_SR (refer to...). Figure 5 The second image data DATA2 is output, consisting of the lifetime data accumulated up to the previous frame and the data itself.

[0052] On the other hand, Figure 1 The image retention compensation unit 200 is shown as a separate configuration, but according to the embodiment, the image retention compensation unit 200 may be included in the timing control unit 500, and the image retention compensation unit 200 may also be included in the data driving unit 400.

[0053] The accumulated lifetime data can be stored in internal or external memory. The internal memory can be a separate memory included in the image retention compensation unit 200, and the external memory can be flash memory.

[0054] The gate driving unit 300 provides scan signals to each pixel PX of the display panel 100 through multiple gate lines SL1 to SLn. The gate driving unit 300 provides scan signals to the display panel 100 based on a first control signal SCS received from the timing control unit 500.

[0055] The data driving unit 400 provides data signals corresponding to the second image data DATA2 to each pixel PX of the display panel 100 via multiple data lines DL1 to DLm. The data driving unit 400 provides data signals to the display panel 100 based on the second control signal DCS received from the timing control unit 500.

[0056] The data driving unit 400 may include a gamma correction unit (not shown) that converts the second image data DATA2 into a voltage corresponding to the data signal. The gamma correction unit can convert the second image data DATA2 in the grayscale domain into a data voltage (i.e., a data signal) in the voltage domain. The gamma correction unit may be configured to be included in the data driving unit 400 or to be configured separately from the data driving unit 400.

[0057] The timing control unit 500 receives the first image data DATA1 from an external image source, etc., and controls the driving of the gate driving unit 300 and the data driving unit 400. The timing control unit 500 can also control the driving of the image retention compensation unit 200.

[0058] The timing control unit 500 can generate multiple first control signals SCS and second control signals DCS using an externally input synchronization signal Sync (e.g., a clock signal, a data enable signal DE, a horizontal synchronization signal, or a vertical synchronization signal). Furthermore, the generated multiple first control signals SCS and second control signals DCS can be supplied to the gate drive unit 300 and the data drive unit 400 respectively, thereby controlling the gate drive unit 300 and the data drive unit 400.

[0059] Reference Figure 2 The timing control unit 500 may include multiple control units IP0, IP1, IP2, ..., IPn. Each control unit may include an optical compensation unit, a dimming unit, an image retention compensation unit, etc. In this embodiment, the case of the nth control unit being the image retention compensation unit 200 will be described.

[0060] The first image data DATA1 input to the first control unit IP0 can be transformed into the second image data DATA2 through the second control unit IP1, ..., image retention compensation unit 200, etc.

[0061] Reference Figure 3 Before applying the N-frame data strobe signal DE to the first control unit IP0, the timing control unit 500 can determine the operating frequency of the previous frame N-1 and calculate the frequency weight value to be provided to the image retention compensation unit 200. That is, the operating frequency of the previous frame N-1 can be determined before applying the N-frame data strobe signal DE to the image retention compensation unit 200.

[0062] Then, the image retention compensation unit 200 generates degradation data for the previous N-1 frames based on the frequency weight values ​​of the previous frame, and updates the lifetime data based on the degradation data. After the lifetime data is updated, a data strobe signal DE can be applied to the image retention compensation unit 200. Therefore, the image retention compensation unit 200 can compensate for pixel degradation using lifetime data that reflects the operating frequency up to the previous N-1 frames. More details will be described later.

[0063] Below, in Figure 4 The timing control unit 500, which can calculate the frequency weight value, is described in the text.

[0064] Reference Figure 4 The timing control unit 500 includes a frequency determination unit 511 and a weight value calculation unit 512. In one embodiment, this is to compensate for the image data of the current frame by reflecting the variable frequency when the operating frequency of the signal applied to the display device 1 is variable.

[0065] The frequency determination unit 511 receives the synchronization signal Sync to determine the frequency of the frame. Here, the frequency determination unit 511 can determine the frequency of the previous frame (the (n-1)th frame) before the display panel 100 displays n frames of image data. More specifically, the frequency determination unit 511 can determine the frequency of the previous frame after storing the data of the previous frame in the memory. The weight value calculation unit 512 calculates a frequency weight value based on the determined frequency of the previous frame.

[0066] The weight calculation unit 512 can provide the calculated frequency weight values ​​to the image retention compensation unit 200. The image retention compensation unit 200 can use the frequency weight values ​​to generate second image data DATA2. The method for generating the second image data DATA2 will be described below.

[0067] In one embodiment of the display device 1, a signal (and / or data) having the same frequency during multiple frames can be applied, or a signal (and / or data) having different frequencies in multiple frames can be applied. In this case, even if the same grayscale data is input in multiple frames, different degradation data that will be reflected as lifetime data in each of the multiple frames can be set corresponding to the frequency change. The difference in degradation data caused by frequency change will be explained below.

[0068] On the other hand, Figure 4The diagram shows a case where the frequency determination unit 511 and the weight value calculation unit 512 are included in the timing control unit 500. However, according to the embodiment, the frequency determination unit 511 and the weight value calculation unit 512 can be implemented with a configuration different from that of the timing control unit 500. Furthermore, the frequency determination unit 511 and the weight value calculation unit 512 can be included in the image retention compensation unit 200 or the data driving unit 400 respectively, or they can be included together in the image retention compensation unit 200 or the data driving unit 400.

[0069] The following is for reference Figures 5 to 9b Let me explain in detail the image retention compensation unit of the display device.

[0070] Figure 5 This is a block diagram illustrating the image retention compensation unit of a display device according to one embodiment. Figure 6 This is a block diagram illustrating the memory in the image retention compensation unit of a display device according to one embodiment. Figure 7 This is a conceptual diagram illustrating a calculation method for calculating lifetime data in the image retention compensation unit of a display device according to an embodiment. Figure 8a and Figure 8b This generally describes a method for generating and applying lifetime data when inputting n-1 frames of scaled first image data in a display device according to one embodiment. Figure 9a and Figure 9b This generally refers to a method for generating and applying lifetime data when n frames of scaled first image data are input into a display device according to an embodiment.

[0071] First, refer to Figure 5 One embodiment of the image retention compensation unit 200 includes a scaling ratio calculation unit 210, a brightness correction unit 220, a lifetime data generation unit 230, a memory 240, and a compensation unit 250.

[0072] The scaling ratio calculation unit 210 calculates a scaling ratio SR for controlling the brightness of the display panel 100, enabling degradation compensation in the display panel 100. For example, in a display panel 100 divided into a×k pixel blocks (where a and k are natural numbers greater than or equal to 1), the scaling ratio SR for scaling the first image data DATA1 can be calculated by reflecting the maximum lifetime data of the pixel blocks. The scaling ratio calculation unit 210 can receive the maximum value Max AGE from the accumulated lifetime data from the memory 240 (described later) and incorporate it into the calculation of the scaling ratio SR.

[0073] The brightness correction unit 220 performs calculations on the first image data DATA1 and the scaling ratio SR to generate scaled first image data DATA1_SR, and provides it to the lifetime data generation unit 230 and the compensation unit 250.

[0074] In one embodiment, the brightness correction unit 220 can multiply the first image data DATA1 and the scaling ratio SR to generate scaled first image data DATA1_SR. However, according to the embodiment, the calculation method can be changed in various ways. In addition, the brightness correction unit 220 can reduce the first image data DATA1 when the accumulated lifetime data is a large value, thereby providing the optimal scaled first image data DATA1_SR to the entire area of ​​the display panel 100.

[0075] The lifetime data generation unit 230 generates lifetime data for a frame based on the scaled first image data DATA1_SR. The lifetime data can be generated by accumulating degradation data for one frame. Specifically, the lifetime data generation unit 230 can generate degradation data frame by frame based on degradation weight values ​​such as panel conditions in the scaled first image data DATA1_SR, and calculate lifetime data by accumulating the degradation data for each frame. Panel conditions can be at least one of the following: pixel position within the display panel 100, input grayscale value, current display panel temperature, and pixel emission duty cycle.

[0076] In another embodiment, the lifetime data generation unit 230 may further apply a frequency weight value to the grayscale data of a frame based on the scaled first image data DATA1_SR, thereby generating a frame of degraded data. Here, the frequency weight value can be received from the weight value calculation unit 512 of the timing control unit 500.

[0077] The lifetime data generation unit 230 can accumulate lifetime data on a per-pixel or per-pixel-block basis. For example, each per-pixel-block may include 8×8 pixels.

[0078] The lifetime data generation unit 230 stores scaled first image data DATA1_SR per frame unit in the memory 240, and generates degradation data by reflecting frequency weight values ​​and other parameters on the scaled first image data DATA1_SR stored in the memory 240. Furthermore, the lifetime data generation unit 230 stores the generated degradation data in the memory 240, thereby accumulating it into the lifetime data.

[0079] For example, when displaying the image of the nth frame, degradation data up to the (n-2)th frame can be accumulated and stored in memory 240 as lifetime data. (In fact, lifetime data is stored in memory 240 corresponding to the total usage time of each pixel.)

[0080] The lifetime data generation unit 230 can store the scaled first image data DATA1_SR of the (n-1)th frame in another space (or another memory) of the memory 240, and generate degradation data by reflecting the frequency weight value, etc., on the scaled first image data DATA1_SR of the (n-1)th frame when a frequency weight value is input from the weight value calculation unit 512. The lifetime data generation unit 230 can also store lifetime data in the memory 240 that reflects the degradation data into the accumulated lifetime data and accumulates the degradation data up to the (n-1)th frame.

[0081] Reference Figure 6 The memory 240 includes a first memory 241 that stores accumulated lifetime data and a second memory 242 that stores a frame of scaled first image data DATA1_SR.

[0082] The first memory 241 stores lifetime data of each pixel accumulated from the initial use of the display device 1 to the present. The lifetime data stored in the first memory 241 can be updated in real time.

[0083] The scaled first image data DATA1_SR is stored in the second memory 242.

[0084] For example, in order to display an image of n frames, the first memory 241 may store lifetime data accumulated up to the (n-2)th frame, and the second memory 242 may store the scaled first image data DATA1_SR of the (n-1)th frame.

[0085] The lifetime data generation unit 230 can receive accumulated lifetime data from the first memory 241 and a frame of scaled first image data DATA1_SR from the second memory 242, thereby generating accumulated lifetime data. Hereinafter, in Figure 7 The document describes the specific computational methods used to generate cumulative lifetime data.

[0086] The method by which the lifetime data generation unit 230 generates lifetime data accumulated up to the previous frame is as follows.

[0087] Reference Figure 7 The lifetime data generation unit 230 can multiply the scaled first image data DATA1_SR of the previous frame by the frequency weight value of the previous frame and add the accumulated lifetime data to generate lifetime data accumulated up to the previous frame. Here, the scaled first image data DATA1_SR of the previous frame can be provided from the second memory 242, and the accumulated lifetime data can be provided from the first memory 241. Additionally, the frequency weight value can be provided from the weight value calculation unit 512. According to the embodiment, the calculation method of the lifetime data generation unit 230 can be varied in various ways.

[0088] The lifetime data accumulated up to the previous frame generated by the lifetime data generation unit 230 can be stored in the first memory 241. The first memory 241 can update the accumulated lifetime data. In addition, the first memory 241 can provide the scaling ratio calculation unit 210 with the maximum value among the accumulated lifetime data.

[0089] That is, the lifetime data generation unit 230 can update the lifetime data accumulated up to the previous frame in the memory 240. The lifetime data generation unit 230 can update the lifetime data using the first memory 241 and the second memory 242 each time a frame changes. Thus, the first memory 241 can include the updated accumulated lifetime data, and the second memory 242 can include the scaled first image data DATA1_SR of the updated frame.

[0090] The following is for reference Figure 8a , Figure 8b , Figure 9a and Figure 9b This describes a method for updating lifetime data generated by lifetime data generation unit 230 in memory 240.

[0091] First, refer to Figure 8a and Figure 8b Before inputting the scaled first image data DATA1_SR(n-1) of n-1 frames into the lifetime data generation unit 230, the first memory 241 stores lifetime data reflecting up to n-3 frames. Figure 8a (i) step).

[0092] Furthermore, before inputting n-1 frames of scaled first image data DATA1_SR(n-1) to the lifetime data generation unit 230, n-2 frames of scaled first image data DATA1_SR(n-1) are stored in the second memory 242. Figure 8a (ii) step).

[0093] For example, in Figure 8b In the middle, the first memory 241, which is indicated by (1) at the lower end, can store lifetime data up to n-3 frames in units of predetermined pixel blocks, and the second memory 242, which is indicated by (1) at the lower end, can store scaled first image data DATA1_SR of n-2 frames in units of predetermined pixel blocks.

[0094] After storing n-2 frames of scaled first image data DATA1_SR in the second memory 242 ( Figure 8aIn step (ii), the lifetime data generation unit 230 receives the supply of frequency weight values ​​for n-2 frames from the weight value calculation unit 512, and receives the supply of scaled first image data DATA1_SR for n-2 frames from the second memory 242.

[0095] like Figure 8b As shown, the lifetime data generation unit 230, which receives the supply of frequency weight values, reflects the frequency weight values ​​of n-2 frames onto a portion of the scaled first image data DATA1_SR stored in the second memory 242 (for example, the data that has been stored in the second memory 242 for the longest time), thereby generating n-2 frames of degraded data, and accumulating the generated degraded data into the first memory 241, thereby generating lifetime data accumulated up to n-2 frames.

[0096] The lifetime data generation unit 230 can update the degradation data of n-2 frames to the first memory 241. Figure 8a (step (iii)). Therefore, as Figure 8b As shown, the first memory 241, denoted by (2) at the lower end, stores the degraded data of n-2 frames.

[0097] Additionally, the lifetime data generation unit 230 stores scaled first image data DATA1_SR(n-1) of n-1 frames of pixel blocks for which degraded data has been generated in the second memory 242. Figure 8b In the middle, the second memory 242, represented by (3) at the lower end, stores the scaled first image data DATA1_SR of n-1 frames.

[0098] That is, the lifetime data generation unit 230 generates degradation data for n-2 frames by sequentially reflecting the frequency weight values ​​of the scaled first image data DATA1_SR of n-2 frames stored in the second memory 242, and accumulates the generated degradation data into the first memory 241 to generate lifetime data for n-2 frames. Additionally, the lifetime data generation unit 230 sequentially stores the scaled first image data DATA1_SR of n-1 frames into the second memory 242.

[0099] Figure 8b In the middle, the first memory 241, denoted by (n) at the lower end, stores the lifetime data accumulated up to the n-2th frame, and the second memory 242, denoted by (n) at the lower end, stores the scaled first image data DATA1_SR(n-1) of the n-1th frame.

[0100] The compensation unit 250 inputs the scaled first image data DATA1_SR(n-1)(n-1 frames) to the n-1 frame. Figure 8a(iv) step). The compensation unit 250, which receives the supply of scaled first image data DATA1_SR(n-1) of n-1 frames, outputs second image data DATA2 using lifetime data accumulated in the first memory 241 (i.e., lifetime data accumulated up to n-2 frames).

[0101] Reference Figure 9a and Figure 9b Before inputting n frames of scaled first image data DATA1_SR(n) into the lifetime data generation unit 230, lifetime data accumulated up to n-2 frames is stored in the first memory 241. Figure 9a (i) step). Furthermore, before inputting n frames of scaled first image data DATA1_SR(n) to the lifetime data generation unit 230, n-1 frames of scaled first image data DATA1_SR(n-1) are stored in the second memory 242. Figure 9a (ii) step).

[0102] For example, in Figure 9b In the middle, the first memory 241, which is indicated by (1) at the lower end, can store lifetime data accumulated up to n-2 frames in units of predetermined pixel blocks, and the second memory 242, which is indicated by (1) at the lower end, can store scaled first image data DATA1_SR(n-1) of n-1 frames in units of predetermined pixel blocks.

[0103] After storing the scaled first image data DATA1_SR(n-1) of n-1 frames in the second memory 242 ( Figure 9a In step (ii), the lifetime data generation unit 230 receives the frequency weight values ​​of n-1 frames from the weight value calculation unit 512 and receives the scaled first image data DATA1_SR(n-1) of n-1 frames from the second memory 242.

[0104] like Figure 9b As shown, the lifetime data generation unit 230, having received the frequency weight values, generates degraded data for n-1 frames by reflecting the frequency weight values ​​of n-1 frames onto a portion of the scaled first image data DATA1_SR stored in the second memory 242. The generated degraded data is then accumulated in the first memory 241 to generate lifetime data accumulated up to n-1 frames. The lifetime data generation unit 230 updates the first memory 241 with the degraded data of n-1 frames. Figure 9a (step (iii)). Therefore, as Figure 9b As shown, the first memory 241, denoted by (2) at the lower end, stores the degraded data of n-1 frames.

[0105] Additionally, the lifetime data generation unit 230 stores the scaled first image data DATA1_SR(n) of n frames for the pixel blocks in the second memory 242 that have generated degraded data. Figure 9b In the middle, the second memory 242, represented by (3) at the lower end, stores the scaled first image data DATA1_SR(n) of n frames.

[0106] That is, the lifetime data generation unit 230 generates degradation data for n-1 frames by sequentially reflecting frequency weight values ​​onto the scaled first image data DATA1_SR(n-1) of the n-1 frames stored in the second memory 242, and accumulates the generated degradation data into the first memory 241 to generate lifetime data for n-1 frames. Additionally, the lifetime data generation unit 230 sequentially stores the scaled first image data DATA1_SR(n) of n frames into the second memory 242.

[0107] exist Figure 9b In the middle, the first memory 241, denoted by (n) at the lower end, stores the lifetime data accumulated up to the n-1th frame, and the second memory 242, denoted by (n) at the lower end, stores the scaled first image data DATA1_SR(n) of the nth frame.

[0108] The compensation unit 250 receives input from n frames of scaled first image data DATA1_SR(n). Figure 9a (iv) step). The compensation unit 250, which receives the supply of scaled first image data DATA1_SR(n) of n frames, outputs second image data DATA2 using lifetime data accumulated in the first memory 241 (i.e., lifetime data accumulated up to n-1 frames).

[0109] The compensation unit 250 may include multiple lookup tables (LUTs), each LUT containing multiple preset lifetime values ​​corresponding to lifetime data and multiple compensation values ​​corresponding to various display grayscale levels achievable by the display panel. The second image data DATA2 can be determined based on these lookup tables (LUTs).

[0110] The second image data DATA2 can have a digital form defined by a grayscale range. Alternatively, the second image data DATA2 can be transformed into an analog form defined by a separately provided gamma correction unit (not shown) that provides a voltage range to the display panel 100.

[0111] As mentioned above, one embodiment of the display device can store the scaled image data of the previous frame separately and generate lifetime data up to the previous frame by reflecting the frequency weight value based on the driving frequency of the previous frame. Therefore, it can reflect the changes in frame rate in real time to compensate for the degradation of the light-emitting element, thereby providing a display device with improved image retention.

[0112] The following is for reference Figure 10 This describes the degradation data when different frequencies are applied to multiple frames.

[0113] Figure 10 This is a schematic diagram illustrating frame degradation data based on the applied frequency in a display device according to an embodiment.

[0114] Reference Figure 10 The signal shown, in frequency mode (a), applies a 240Hz signal across multiple frames, and degradation data AGE based on the input image data can be generated in each frame. Here, the input image data can be the aforementioned scaled first image data DATA1_SR. For example, if 80 units of degradation data are generated in each frame, the degradation data AGE is accumulated up to the first frame Frame1, the second frame Frame2, the third frame Frame3, and the fourth frame Frame4, thereby generating 320 units of lifetime data. That is, at a driving frequency of 240Hz, after one cycle, 320 units of lifetime data can be reflected in the input image data to generate compensation data. Here, the compensation data can be the aforementioned second image data DATA2.

[0115] Conversely, in frequency mode (b), applying a 60Hz signal across multiple frames allows for the generation of degradation data (AGE) based on the input image data in each frame. For example, if 80% degradation data is generated in each frame, 80% lifetime data can be generated within one frame period (the first to fourth frames at 240Hz). That is, at a drive frequency of 60Hz, 80% lifetime data can be accumulated after one cycle.

[0116] Therefore, in a display device, the lifespan data of the display panel can vary depending on the frequency applied in each frame.

[0117] In one embodiment of the display device, a different frequency can be set for each frame. For example, a 240Hz signal can be applied in the first to fifth frames, and a 60Hz signal can be applied in the sixth to tenth frames. When the basic frequency of the display device is 240Hz, the memory can accumulate degradation data based on the input image data to store lifetime data at the basic frequency. However, in the comparative example of the display device, even if the frequency applied to the display device is changed, the changed frequency is not reflected in the memory, and lifetime data is accumulated based on the input image data. Therefore, the actual lifetime data of the display panel's light emission and the lifetime data stored in the memory may differ. Thus, when the frequency of the display device is variable, the problem of not accurately reflecting lifetime data based on frequency changes may occur.

[0118] One embodiment of the display device can provide a display device that can separately store scaled image data of the previous frame and generate lifetime data reflecting a degradation weight value based on the driving frequency of the previous frame, thereby compensating for the degradation of the light-emitting element by reflecting the change in the operating frequency of the frame, thereby improving image retention.

[0119] The following is for reference Figure 11 This section describes a driving method for a display device according to an embodiment.

[0120] Figure 11 This is a sequence diagram illustrating a driving method for a display device according to an embodiment.

[0121] Figure 11 Referring to the above Figures 1 to 9b It records the relationship with Figures 1 to 9b The symbols shown are the same as those shown.

[0122] In one embodiment of the display device, the frame rate can be varied at least in units of one frame. After storing the data of the previous frame in the memory 240 (S100), the timing control unit 500 calculates a weight value for the frequency of the previous frame (S110). The frequency determination unit 511 of the timing control unit 500 can determine the frequency after storing the data of the previous frame in the second memory 242, and the weight value calculation unit 512 can calculate a frequency weight value based on the determined frequency. The weight value calculation unit 512 can provide the calculated frequency weight value to the lifetime data generation unit 230 for lifetime data calculation.

[0123] Image retention compensation unit 200 receives input of first image data DATA1 from the outside (S200). The brightness correction unit 220 of image retention compensation unit 200 can receive input of first image data DATA1.

[0124] Then, the brightness correction unit 220 can generate scaled first image data DATA1_SR by reflecting the scaling ratio SR used to correct the brightness in the first image data DATA1 (S210). The brightness correction unit 220 can multiply the first image data DATA1 and the scaling ratio SR to generate scaled first image data DATA1_SR.

[0125] Then, the lifetime data generation unit 230 can generate frame degradation data based on the scaled first image data DATA1_SR (S220). The lifetime data generation unit 230 can generate degradation data by reflecting degradation weight values ​​on the scaled first image data DATA1_SR of each frame, and can accumulate degradation data on a frame-by-frame basis to generate lifetime data. The degradation weight values ​​may include frequency weight values, and may also include at least one of the following: pixel position, input grayscale value, current display panel temperature, and pixel emission duty cycle. Here, the frequency weight values ​​can be provided from the weight value calculation unit 512.

[0126] Then, the lifetime data generation unit 230 stores the lifetime data in the memory 240.

[0127] The lifetime data is accumulated and stored in the first memory 241 (S231), and the scaled first image data DATA1_SR of the previous frame is stored in the second memory 242 (S232). For example, if the image of the nth frame is currently displayed, the degradation data up to the (n-2)th frame can be accumulated and stored in the first memory 241, and the scaled first image data DATA1_SR of the (n-1)th frame can be stored in the second memory 242.

[0128] The lifetime data generation unit 230 generates lifetime data accumulated up to the previous frame (S240). The lifetime data generation unit 230 can generate degradation data by reflecting the frequency weight value on the scaled first image data DATA1_SR of the previous frame in the second memory 242, and can generate lifetime data accumulated up to the previous frame by reflecting the degradation data of the previous frame on the accumulated lifetime data in the first memory 241.

[0129] The lifetime data generation unit 230 can update the lifetime data accumulated up to the previous frame in the first memory 241 again (S250). Furthermore, the first memory 241 can provide the lifetime data accumulated up to the previous frame to the compensation unit 250.

[0130] Then, the compensation unit 250 outputs the second image data DATA2 based on the lifetime data accumulated up to the previous frame and the scaled first image data DATA1_SR (S260).

[0131] The above description refers to preferred embodiments of the present invention. However, those skilled in the art or those of ordinary skill in the art should understand that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the invention as set forth in the claims.

[0132] Therefore, the technical scope of this invention should not be limited to the contents described in the detailed specification, but should be determined solely by the claims.

Claims

1. A display device comprising: a display panel including a plurality of pixels; a timing control section for receiving first image data and a data strobe signal of a current frame from outside; and a residual image compensation section for generating second image data by reflecting accumulated life data on the first image data, the residual image compensation section generating the life data by reflecting a frequency weight value corresponding to a frequency of a previous frame into the image data of the previous frame after storing the image data of the previous frame, and generating degradation data of the previous frame by reflecting the frequency weight value of the previous frame, wherein the timing control section judges the frequency of the previous frame before applying the data strobe signal of the current frame to the timing control section, and calculates the frequency weight value of the previous frame by reflecting the frequency of the previous frame.

2. The display device according to claim 1, wherein the image data of the previous frame is scaled first image data input in the previous frame.

3. The display device according to claim 2, further comprising: a gate drive section for supplying a scan signal to the display panel; and a data drive section for supplying a data signal corresponding to the second image data to the display panel, the timing control section controlling driving of the gate drive section and the data drive section.

4. The display device according to claim 3, wherein the residual image compensation section includes a scaling ratio calculation section for calculating a scaling ratio of the display panel.

5. The display device according to claim 4, wherein the residual image compensation section generates the scaled first image data by operating the scaling ratio and the first image data.

6. The display device according to claim 5, wherein the residual image compensation section further includes: a life data generation section for generating the life data based on the scaled first image data; and a memory for storing updated life data and the image data of the previous frame.

7. The display device according to claim 6, wherein the memory includes: a first memory for storing the updated life data; and a second memory for storing the image data of the previous frame.

8. The display device according to claim 7, wherein the life data generation section generates the degradation data by multiplying the frequency weight value on the image data of the previous frame, and generates life data accumulated until the previous frame by reflecting the updated life data on the degradation data.

9. The display device according to claim 8, wherein the residual image compensation section outputs the second image data based on the life data accumulated until the previous frame and the scaled first image data.

10. The display device according to claim 9, wherein the life data generation section updates the life data accumulated until the previous frame in the first memory. ​

Images