Display device and method of compensating for image sticking in a display device

Abstract

A display device and a method of compensating for image sticking in the display device are provided. The display device includes a display panel including a plurality of pixels, a data driver configured to provide a data signal to the plurality of pixels, a scan driver configured to provide a scan signal to the plurality of pixels, and a controller configured to control the data driver and the scan driver. The controller includes a volatile life memory configured to store a cumulative degradation amount of the plurality of pixels and an internal life memory configured to store a backup cumulative degradation amount generated based on the cumulative degradation amount. The controller is further configured to compensate for input image data by selectively using the cumulative degradation amount stored in the volatile life memory or the backup cumulative degradation amount stored in the internal life memory.

Description

Technical Field

[0001] Embodiments of the present invention relate to a display device, and more specifically, to a display device for performing image retention compensation operations and a method for compensating for image retention in the display device. Background Technology

[0002] As a display device (such as an organic light-emitting diode (OLED) display device) operates over time, the driving transistors and / or OLEDs, including the pixels within the display device, may degrade. If a pixel degrades, it will not emit light with the desired brightness, and image retention will be perceived in the display device. To reduce or eliminate image retention caused by pixel degradation, the display device may perform an image retention compensation operation that calculates the cumulative degradation amount of the pixels and compensates the image data based on the cumulative degradation amount.

[0003] However, if the write or read operations of the lifetime memory, which stores the accumulated degradation amount, are not performed normally due to electrostatic discharge (ESD), memory access failure, hardware failure, etc., the image retention compensation operation cannot be performed accurately, and the image data cannot be compensated accurately. Therefore, the image quality of the display device will deteriorate. Summary of the Invention

[0004] According to an embodiment of the present invention, a display device includes: a display panel including a plurality of pixels; a data driver configured to provide data signals to the plurality of pixels; a scan driver configured to provide scan signals to the plurality of pixels; and a controller configured to control the data driver and the scan driver. The controller includes a volatile lifetime memory and an internal lifetime memory, the volatile lifetime memory being configured to store cumulative degradation amounts of the plurality of pixels, and the internal lifetime memory being configured to store backup cumulative degradation amounts generated based on the cumulative degradation amounts. The controller is further configured to compensate input image data by selectively using either the cumulative degradation amounts stored in the volatile lifetime memory or the backup cumulative degradation amounts stored in the internal lifetime memory.

[0005] In embodiments of the present invention, the controller may further include an image persistence compensation circuit, a volatile lifetime memory located outside the image persistence compensation circuit, and an internal lifetime memory located inside the image persistence compensation circuit. In the first frame, the image persistence compensation circuit can calculate the current degradation amount based on the input image data, calculate a first cumulative degradation amount by accumulating the current degradation amount, write the first cumulative degradation amount to the volatile lifetime memory, generate a backup cumulative degradation amount based on the first cumulative degradation amount, and write the backup cumulative degradation amount to the internal lifetime memory. In the second frame, the image persistence compensation circuit can read a second cumulative degradation amount from the volatile lifetime memory. The second cumulative degradation amount read from the volatile lifetime memory can be compared with the first cumulative degradation amount calculated in the first frame. In the first case where the second cumulative degradation amount read from the volatile lifetime memory is substantially equal to the first cumulative degradation amount calculated in the first frame, the input image data can be compensated in the second frame by using the second cumulative degradation amount read from the volatile lifetime memory. In the second case where the second cumulative degradation amount read from the volatile lifetime memory is different from the first cumulative degradation amount calculated in the first frame, the input image data can be compensated in the second frame by using a backup cumulative degradation amount stored in the internal lifetime memory.

[0006] In an embodiment of the present invention, the image persistence compensation circuit can calculate a first checksum of the second cumulative degradation amount read from the volatile lifetime memory, calculate a second checksum of the first cumulative degradation amount calculated by accumulating the current degradation amount, and determine whether the second cumulative degradation amount read from the volatile lifetime memory is substantially equal to the first cumulative degradation amount calculated by accumulating the current degradation amount by comparing the first checksum with the second checksum.

[0007] In an embodiment of the present invention, the first cumulative degradation amount can be calculated on a first pixel block as a unit, and the backup cumulative degradation amount can be calculated on a second pixel block as a unit, and the size of the second pixel block can be larger than the size of the first pixel block.

[0008] In embodiments of the present invention, the image persistence compensation circuit may include: an internal lifetime memory; a current lifetime calculator circuit configured to divide the input image data into multiple block image data corresponding to multiple first pixel blocks in a first frame, and calculate the current degradation amount of the multiple first pixel blocks based on the multiple block image data; and a cumulative lifetime calculator circuit configured to calculate a first cumulative degradation amount of the multiple first pixel blocks by accumulating the current degradation amount of the multiple first pixel blocks, write the first cumulative degradation amount of the multiple first pixel blocks to a volatile lifetime memory, generate a backup cumulative degradation amount of the multiple second pixel blocks by merging the first cumulative degradation amounts of the multiple first pixel blocks, and store the backup cumulative degradation amount of the multiple second pixel blocks. The data is written to an internal lifetime memory; a data compensator circuit is configured to read a second cumulative degradation amount of a plurality of first pixel blocks from the volatile lifetime memory; and a lifetime comparator circuit is configured to compare the second cumulative degradation amount read by the data compensator circuit with a first cumulative degradation amount calculated by the cumulative lifetime calculator circuit, generating a fault flag signal with a first level in a first case where the second cumulative degradation amount read by the data compensator circuit is substantially equal to the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit, and generating a fault flag signal with a second level in a second case where the second cumulative degradation amount read by the data compensator circuit is different from the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit. In response to the fault flag signal with the first level, the data compensator circuit can compensate for the input image data by using the second cumulative degradation amount of the plurality of first pixel blocks. In response to the fault flag signal with the second level, the data compensator circuit can read a backup cumulative degradation amount of the plurality of second pixel blocks from the internal lifetime memory and can compensate for the input image data by using the backup cumulative degradation amount of the plurality of second pixel blocks.

[0009] In embodiments of the present invention, the size of each of the plurality of second pixel blocks can be larger than the size of each of the plurality of first pixel blocks.

[0010] In an embodiment of the present invention, the lifetime comparator circuit can calculate a first checksum of the second cumulative degradation amount read by the data compensator circuit, calculate a second checksum of the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit, and generate a fault flag signal by comparing the first checksum with the second checksum.

[0011] In an embodiment of the present invention, the image persistence compensation circuit may further include: a weight determiner circuit configured to determine the block degradation weight of the plurality of first pixel blocks based on at least one of the driving frequency of the display panel, the temperature of the display panel, and the position of the plurality of first pixel blocks.

[0012] In an embodiment of the present invention, the current lifetime calculator circuit can calculate the current degradation of multiple first pixel blocks by applying block degradation weights to multiple block image data.

[0013] In embodiments of the present invention, the controller may further include: a prescaling circuit configured to receive a cumulative degradation amount from an image retention compensation circuit, determine a prescaling factor based on the maximum cumulative degradation amount among the received cumulative degradation amounts, generate prescaled input image data by applying the prescaling factor to the input image data, and provide the prescaled input image data to the image retention compensation circuit.

[0014] In embodiments of the present invention, the display device may further include a non-volatile lifetime memory configured to store accumulated degradation when the display device is powered off.

[0015] In an embodiment of the present invention, the controller can periodically write the accumulated degradation stored in the volatile lifetime memory to the non-volatile lifetime memory.

[0016] According to an embodiment of the present invention, in a method for compensating for image retention in a display device, a current degradation amount is calculated based on input image data in a first frame, a first cumulative degradation amount is calculated by accumulating the current degradation amount, the first cumulative degradation amount is written to a volatile lifetime memory located outside the image retention compensation circuit, a backup cumulative degradation amount is generated based on the first cumulative degradation amount, the backup cumulative degradation amount is written to an internal lifetime memory of the image retention compensation circuit, a second cumulative degradation amount is read from the volatile lifetime memory in a second frame, the second cumulative degradation amount read from the volatile lifetime memory is compared with the first cumulative degradation amount calculated by accumulating the current degradation amount, and the input image data is compensated in the second frame by selectively using the second cumulative degradation amount read from the volatile lifetime memory or the backup cumulative degradation amount stored in the internal lifetime memory based on the comparison result.

[0017] In an embodiment of the present invention, input image data can be compensated in a second frame by using the second cumulative degradation amount read from the volatile lifetime memory if, in a first case, the second cumulative degradation amount read from the volatile lifetime memory is substantially equal to the first cumulative degradation amount calculated by accumulating the current degradation amount; and input image data can be compensated in a second frame by using a backup cumulative degradation amount stored in the internal lifetime memory if, in a second case, the second cumulative degradation amount read from the volatile lifetime memory is different from the first cumulative degradation amount calculated by accumulating the current degradation amount.

[0018] In embodiments of the present invention, a first checksum of the second cumulative degradation amount read from the volatile lifetime memory can be calculated, a second checksum of the first cumulative degradation amount calculated by accumulating the current degradation amount can be calculated, and it can be determined whether the second cumulative degradation amount read from the volatile lifetime memory is substantially equal to the first cumulative degradation amount calculated by accumulating the current degradation amount by comparing the first checksum with the second checksum.

[0019] In an embodiment of the present invention, the first cumulative degradation amount can be calculated on a first pixel block as a unit, and the backup cumulative degradation amount can be calculated on a second pixel block as a unit, and the size of the second pixel block can be larger than the size of the first pixel block.

[0020] In embodiments of the present invention, the input image data can be divided into multiple block image data corresponding to multiple first pixel blocks in the first frame. The block degradation weight of the multiple first pixel blocks can be determined based on at least one of the driving frequency of the display panel included in the display device, the temperature of the display panel, and the position of the multiple first pixel blocks. The current degradation amount of the multiple first pixel blocks can be calculated by applying the block degradation weight to the multiple block image data.

[0021] In an embodiment of the present invention, backup cumulative degradation amounts of multiple second pixel blocks can be generated by merging the first cumulative degradation amounts of multiple first pixel blocks.

[0022] In an embodiment of the present invention, a first cumulative degradation amount stored in a volatile lifetime memory can be periodically written to a non-volatile lifetime memory.

[0023] In embodiments of the present invention, a prescaling factor can be determined based on the maximum cumulative degradation amount, and the prescaling factor can be applied to the input image data.

[0024] According to an embodiment of the present invention, a method for compensating for image retention in a display device includes: generating prescaled input image data by applying a prescale factor to input image data; calculating a current degradation amount based on the prescaled input image data in a first frame; calculating a first cumulative degradation amount by accumulating the current degradation amount; writing the first cumulative degradation amount to a first memory; generating a backup cumulative degradation amount based on the first cumulative degradation amount; writing the backup cumulative degradation amount to a second memory; reading a second cumulative degradation amount from the first memory in a second frame; comparing the second cumulative degradation amount with the first cumulative degradation amount; and compensating the prescaled input image data in a second frame by selectively using the second cumulative degradation amount or the backup cumulative degradation amount according to the comparison result. Attached Figure Description

[0025] The above and other features of the inventive concept will be more clearly understood by describing embodiments of the inventive concept in detail with reference to the accompanying drawings.

[0026] Figure 1 This is a block diagram illustrating a display device according to an embodiment of the concept of the present invention.

[0027] Figure 2 The embodiments shown are included in the present invention. Figure 1 The circuit diagram of the pixels in the display device.

[0028] Figure 3 The embodiments shown are included in the present invention. Figure 1 A diagram of image retention compensation blocks in a display device.

[0029] Figure 4 It is used to describe embodiments of the concept according to the present invention. Figure 3 Timing diagram of the operation of the image residue compensation block.

[0030] Figure 5 It is a diagram used to describe a plurality of first pixel blocks for calculating the current degradation amount and the cumulative degradation amount according to an embodiment of the present invention.

[0031] Figure 6 It is a diagram used to describe the calculation of the cumulative degradation amount of backup for a plurality of second pixel blocks according to an embodiment of the present invention.

[0032] Figure 7 This is a compensation illustrating an embodiment of the concept according to the present invention. Figure 1 A flowchart of a method for handling image retention in a display device.

[0033] Figure 8 This is a block diagram illustrating a display device according to an embodiment of the concept of the present invention.

[0034] Figure 9 This is a compensation illustrating an embodiment of the concept according to the present invention. Figure 8 A flowchart of a method for handling image retention in a display device.

[0035] Figure 10 This is a block diagram illustrating an electronic device including a display device according to an embodiment of the concept of the present invention. Detailed Implementation

[0036] An embodiment of the present invention provides a display device capable of accurately performing image retention compensation operations.

[0037] Embodiments of the present invention also provide a method for compensating for image retention in a display device, which can accurately perform image retention compensation operations.

[0038] In the following, embodiments of the inventive concept will be explained in detail with reference to the accompanying drawings. Throughout this application, the same reference numerals may denote the same elements.

[0039] Figure 1 This is a block diagram illustrating a display device according to an embodiment of the concept of the present invention. Figure 2 The embodiments shown are included in the present invention. Figure 1 The circuit diagram of the pixels in the display device. Figure 3 The embodiments shown are included in the present invention. Figure 1 A diagram of image retention compensation blocks in a display device. Figure 4 It is used to describe embodiments of the concept according to the present invention. Figure 3 Timing diagram of the operation of the image residue compensation block. Figure 5 It is a diagram used to describe a plurality of first pixel blocks for calculating the current degradation amount and the cumulative degradation amount according to an embodiment of the present invention. Figure 6 It is a diagram used to describe the calculation of the cumulative degradation amount of backup for a plurality of second pixel blocks according to an embodiment of the present invention.

[0040] Reference Figure 1 A display device 100 according to an embodiment of the present invention may include a display panel 110, a data driver 120, a scan driver 130, and a controller 150. The display panel 110 includes a plurality of pixels PX. The data driver 120 provides data signals DS to the plurality of pixels PX. The scan driver 130 provides scan signals SS to the plurality of pixels PX. The controller 150 controls the data driver 120 and the scan driver 130. In an embodiment of the present invention, the display device 100 may further include a non-volatile lifetime memory 140.

[0041] The display panel 110 may include multiple data lines, multiple scan lines, and multiple pixels PX combined with the multiple data lines and multiple scan lines. In embodiments of the present invention, the display panel 110 may be an organic light-emitting diode (OLED) display panel, wherein each pixel PX includes an OLED.

[0042] For example, such as Figure 2As shown, each pixel PX may include a switching transistor TSW, a storage capacitor CST, a driving transistor TDR, and an organic light-emitting diode EL. The switching transistor TSW transmits the data signal DS of the data line to the storage capacitor CST in response to the scan signal SS of the scan line. The storage capacitor CST stores the data signal DS transmitted by the switching transistor TSW. The driving transistor TDR generates a driving current based on the data signal DS stored in the storage capacitor CST. The organic light-emitting diode EL emits light based on the driving current generated by the driving transistor TDR. The driving transistor TDR and the organic light-emitting diode EL may be connected between a high power supply voltage ELVDD and a low power supply voltage ELVSS. In embodiments of the inventive concept, as... Figure 2 As shown, the switching transistor TSW and the driving transistor TDR can be implemented using NMOS transistors, but are not limited to this.

[0043] The construction of the pixel PX according to embodiments of the present invention is not limited to Figure 2 Examples of this invention are provided, and the pixel PX in embodiments of the present invention can have various configurations. In embodiments of the present invention, the display panel 110 can be an inorganic light-emitting diode display panel, a quantum dot light-emitting diode display panel, a liquid crystal display (LCD) panel, or any other suitable display panel.

[0044] Return to reference Figure 1 The data driver 120 can generate a data signal DS based on the output image data ODAT and the data control signal DCTRL received from the controller 150, and can provide the data signal DS to multiple pixels PX via multiple data lines. In embodiments of the present invention, the data control signal DCTRL may include, but is not limited to, an output data enable signal, a level start signal, and a load signal. In embodiments of the present invention, the data driver 120 can be implemented using one or more integrated circuits separate from the integrated circuit of the controller 150. In embodiments of the present invention, the data driver 120 and the controller 150 can be implemented using a single integrated circuit, and this single integrated circuit may be referred to as a timing controller embedded data driver (TED) integrated circuit.

[0045] The scan driver 130 can generate a scan signal SS based on the scan control signal SCTRL received from the controller 150, and can sequentially provide the scan signal SS to multiple pixels PX line by line based on the scan control signal SCTRL. In embodiments of the present invention, the scan control signal SCTRL may include, but is not limited to, a scan start signal and a scan clock signal. In embodiments of the present invention, the scan driver 130 may be integrated or formed in the peripheral portion of the display panel 110. In embodiments of the present invention, the scan driver 130 may be implemented using one or more integrated circuits.

[0046] The non-volatile lifetime memory 140 can store the cumulative degradation of a plurality of pixels PX of the display panel 110, and can retain or maintain the stored cumulative degradation even when the display device 100 is powered off. In embodiments of the inventive concept, such as Figure 5 As shown, the display panel 110 can be divided into a plurality of first pixel blocks BL1, each including a plurality of pixels PX, and the non-volatile lifetime memory 140 can store the cumulative degradation amount corresponding to the plurality of first pixel blocks BL1 respectively.

[0047] Furthermore, in embodiments of the present invention, when the display device 100 is powered on, the controller 150 can read the accumulated degradation amount from the non-volatile lifetime memory 140 and can write or store the accumulated degradation amount to the volatile lifetime memory 170. The volatile lifetime memory 170 may be referred to as the first memory. The image retention compensation block 200 of the controller 150 can read the accumulated degradation amount from the volatile lifetime memory 170, update the accumulated degradation amount for each frame during operation of the display device 100, and write the updated accumulated degradation amount to the volatile lifetime memory 170 for each frame. In embodiments of the present invention, the image retention compensation block 200 may be a circuit.

[0048] Furthermore, the controller 150 can periodically write the accumulated degradation amount stored in the volatile lifetime memory 170 to the non-volatile lifetime memory 140. For example, the accumulated degradation amount stored in the volatile lifetime memory 170 can be written to the non-volatile lifetime memory 140 every approximately five to ten minutes, but the period of the write operation to the non-volatile lifetime memory 140 is not limited to this. In this way, the display device 100 can calculate and store the accumulated degradation amount corresponding to a plurality of first pixel blocks BL1, wherein the accumulated degradation amount is accumulated over a period of time from the time when the display device 100 was manufactured to the present time. In embodiments of the inventive concept, the non-volatile lifetime memory 140 can be implemented using, but is not limited to, flash memory.

[0049] Controller 150 (e.g., a timing controller (TCON)) can receive input image data IDAT and control signal CTRL from an external host processor (e.g., a graphics processing unit (GPU), application processor (AP), or graphics card). In embodiments of the present invention, the input image data IDAT may be RGB image data including red image data, green image data, and blue image data. In embodiments of the present invention, the control signal CTRL may include, but is not limited to, a vertical synchronization signal, a horizontal synchronization signal, an input data enable signal, a master clock signal, etc. Furthermore, controller 150 can generate output image data ODAT by compensating for the input image data IDAT based on the cumulative degradation. Controller 150 can control the operation of data driver 120 by providing the output image data ODAT and data control signal DCTRL to data driver 120, and can control the operation of scan driver 130 by providing scan control signal SCTRL to scan driver 130.

[0050] In a display device 100 according to an embodiment of the present invention, in order to perform an image retention compensation operation, a controller 150 may include a volatile lifetime memory 170 and an image retention compensation block 200.

[0051] The volatile lifetime memory 170 can store the accumulated degradation amount read from the non-volatile lifetime memory 140 when the display device 100 is powered on, and can provide the read accumulated degradation amount to the image retention compensation block 200. Furthermore, when the display device 100 is operating, the volatile lifetime memory 170 can receive and store the accumulated degradation amount updated in each frame from the image retention compensation block 200, and can provide the stored accumulated degradation amount to the image retention compensation block 200 in each frame. In embodiments of the present invention, the accumulated degradation amount of the volatile lifetime memory 170 can be periodically written to the non-volatile lifetime memory 140. In embodiments of the present invention, the volatile lifetime memory 170 can be implemented using, but is not limited to, static random access memory (SRAM), dynamic random access memory (DRAM), etc.

[0052] Image persistence compensation block 200 may include internal lifetime memory 210. Internal lifetime memory 210 may be referred to as a second memory. In a first frame (e.g., the current frame), image persistence compensation block 200 may calculate the current degradation amount based on input image data IDAT, calculate the cumulative degradation amount by accumulating the current degradation amount (and the cumulative degradation amount read from non-volatile lifetime memory 140 via volatile lifetime memory 170), write the cumulative degradation amount to volatile lifetime memory 170, generate a backup cumulative degradation amount based on the cumulative degradation amount, and write the backup cumulative degradation amount to internal lifetime memory 210.

[0053] Furthermore, in the second frame (e.g., the next frame), the image persistence compensation block 200 can read the cumulative degradation amount from the volatile lifetime memory 170, compare the cumulative degradation amount read from the volatile lifetime memory 170 with the cumulative degradation amount calculated in the first frame by accumulating the current degradation amount, and compensate the input image data IDAT in the second frame by selectively using either the cumulative degradation amount read from the volatile lifetime memory 170 or the backup cumulative degradation amount stored in the internal lifetime memory 210 based on the comparison result (e.g., the input image data IDAT can be compensated in the second frame by selectively using either the cumulative degradation amount read from the volatile lifetime memory 170 or the backup cumulative degradation amount stored in the internal lifetime memory 210 based on the comparison result).

[0054] In embodiments of the present invention, in order to perform these operations, such as Figure 3 As shown, the image persistence compensation block 200 may include an internal lifetime memory 210, a current lifetime calculator 220, a cumulative lifetime calculator 230, a data compensator 240, and a lifetime comparator 250. In an embodiment of the present invention, the image persistence compensation block 200 may further include a weight determiner 260. In an embodiment of the present invention, the current lifetime calculator 220, the cumulative lifetime calculator 230, the data compensator 240, the lifetime comparator 250, and the weight determiner 260 may be circuits.

[0055] The current lifespan calculator 220 can divide the input image data IDAT into corresponding values ​​in the first frame (e.g., the current frame). Figure 5 The diagram shows multiple block image data of multiple first pixel blocks BL1, and the current degradation amount (CDA) of the multiple first pixel blocks BL1 can be calculated based on the multiple block image data. For example, each first pixel block BL1 may have a size of, but is not limited to, four pixels by four pixels, eight pixels by eight pixels, etc. In embodiments of the present invention, the current degradation amount (CDA) of the first pixel block BL1 can increase as the block image data of each first pixel block BL1 increases. For example, the current lifetime calculator 220 can calculate the current degradation amount (CDA) of the first pixel block BL1 by summing the pixel image data (e.g., sixteen, sixty-four pixel image data, etc.) included in the block image data of the first pixel block BL1, but the calculation of the current lifetime calculator 220 is not limited to this.

[0056] In an embodiment of the present invention, the current lifetime calculator 220 can receive block degradation weights (BDWs) of a plurality of first pixel blocks BL1 from the weight determiner 260, and can calculate the current degradation amount (CDA) of the plurality of first pixel blocks BL1 by applying the block degradation weights (BDWs) to the multiple block image data. In an embodiment of the present invention, the weight determiner 260 can determine the block degradation weights (BDWs) of the plurality of first pixel blocks BL1 based on at least one of the driving frequency of the display panel 110, the temperature of the display panel 110, and the position of the plurality of first pixel blocks BL1. For example, the current lifetime calculator 220 can increase the block degradation weights (BDWs) as the driving frequency of the display panel 110 increases.

[0057] Furthermore, for example, the weight determiner 260 may include a weight lookup table storing block degradation weights (BDWs) based on the temperature of the display panel 110 and the positions of a plurality of first pixel blocks BL1, and the block degradation weights (BDWs) of the plurality of first pixel blocks BL1 may be determined by using the weight lookup table. In an embodiment of the present invention, the current lifetime calculator 220 may calculate the intermediate current degradation amount of each first pixel block BL1 by summing the pixel image data of the first pixel blocks BL1, calculate the final current degradation amount of the first pixel block BL1 by multiplying the intermediate current degradation amount by the block degradation weight (BDW) of the first pixel block BL1, and output the final current degradation amount as the current degradation amount (CDA) of the first pixel block BL1.

[0058] The cumulative lifetime calculator 230 can calculate the cumulative degradation amount CDA of multiple first pixel blocks BL1 by accumulating the current degradation amount CDA of multiple first pixel blocks BL1. In an embodiment of the present invention, the cumulative lifetime calculator 230 can read the previous cumulative degradation amount from the previous driving period through the volatile lifetime memory 170 when the display device 100 is powered on, and can add the current degradation amount CDA in the corresponding frame to the previous cumulative degradation amount to calculate the cumulative degradation amount CDA of the corresponding frame from when the display device was manufactured until the current driving period.

[0059] The cumulative lifetime calculator 230 can write the cumulative degradation amount CDA of multiple first pixel blocks BL1 to the volatile lifetime memory 170. In embodiments of the present invention, the cumulative degradation amount CDA stored in the volatile lifetime memory 170 can be read by the data compensator 240 to compensate the input image data IDAT in a second frame (e.g., the following frame), and / or can be read again by the cumulative lifetime calculator 230 to calculate the cumulative degradation amount CDA in a second frame (e.g., the following frame).

[0060] Furthermore, the cumulative lifetime calculator 230 can generate, based on the cumulative degradation amount of multiple first pixel blocks BL1 (CADA), such as... Figure 6 The backup cumulative degradation amount BADA of multiple second pixel blocks BL2 shown can be written to the internal lifetime memory 210. In embodiments of the present invention, such as Figure 5 and Figure 6 As shown, the size of each second pixel block BL2 can be larger than the size of each first pixel block BL1.

[0061] For example, each first pixel block BL1 may have a size of, but is not limited to, four pixels by four pixels, eight pixels by eight pixels, etc. Furthermore, for example, the display panel 110 may be divided into, but is not limited to, 18×16 second pixel blocks BL2, and each second pixel block BL2 may have a size of, but is not limited to, 240 pixels by 120 pixels. Therefore, since the cumulative degradation amount CADA is calculated on a per-first pixel block BL1 basis and the backup cumulative degradation amount BADA is calculated on a per-secondary pixel block BL2 basis, which has a larger size than the first pixel block BL1, the data size of the backup cumulative degradation amount BADA can be smaller than the data size of the cumulative degradation amount CADA. Therefore, the internal lifetime memory 210 of the image retention compensation block 200 can have a smaller size than the volatile lifetime memory 170, and thus can be suitable for formation within the image retention compensation block 200.

[0062] In an embodiment of the present invention, in order to generate a backup cumulative degradation amount BADA with a data size smaller than the cumulative degradation amount CADA, the cumulative lifetime calculator 230 can generate a backup cumulative degradation amount BADA for multiple second pixel blocks BL2 by merging the cumulative degradation amounts CADA of multiple first pixel blocks BL1.

[0063] Data compensator 240 can read the cumulative degradation amount RADA of multiple first pixel blocks BL1 from volatile lifetime memory 170 during the initial period of the second frame (e.g., the following frame). Furthermore, during the initial period of the second frame, lifetime comparator 250 can compare the cumulative degradation amount RADA read by data compensator 240 from volatile lifetime memory 170 (which was written to volatile lifetime memory 170 in the first frame) with the cumulative degradation amount CADA calculated by cumulative lifetime calculator 230 in the first frame.

[0064] In an embodiment of the present invention, the lifetime comparator 250 can calculate a first checksum of the cumulative degradation amount RADA read from the volatile lifetime memory 170, calculate a second checksum of the cumulative degradation amount CADA calculated by the cumulative lifetime calculator 230, and determine whether the cumulative degradation amount RADA read from the volatile lifetime memory 170 is substantially equal to the cumulative degradation amount CADA calculated by the cumulative lifetime calculator 230 by comparing the first checksum with the second checksum.

[0065] Furthermore, the lifetime comparator 250 can generate a fault flag signal FFS by comparing a first checksum with a second checksum. For example, the lifetime comparator 250 can generate a fault flag signal FFS with a first level (e.g., high level) when the first checksum is substantially equal to the second checksum or when the read cumulative degradation amount RADA is substantially equal to the calculated cumulative degradation amount CADA, and can generate a fault flag signal FFS with a second level (e.g., low level) when the first checksum is different from the second checksum or when the read cumulative degradation amount RADA is different from the calculated cumulative degradation amount CADA.

[0066] When the read cumulative degradation amount RADA is substantially equal to the calculated cumulative degradation amount CADA, the data compensator 240 can compensate the input image data IDAT by using the cumulative degradation amounts RADA of multiple first pixel blocks BL1 read from the volatile lifetime memory 170. In embodiments of the present invention, the data compensator 240 may include a lifetime compensation lookup table storing compensation coefficients according to gray levels and degradation amounts. The compensation coefficients of multiple first pixel blocks BL1 corresponding to the gray levels represented by the input image data IDAT and the read cumulative degradation amount RADA can be obtained from the lifetime compensation lookup table, and the output image data ODAT can be generated by applying the compensation coefficients of the multiple first pixel blocks BL1 to the input image data IDAT.

[0067] Furthermore, if the read cumulative degradation amount RADA differs from the calculated cumulative degradation amount CADA, the data compensator 240 can compensate the input image data IDAT by using the backup cumulative degradation amount BADA stored in the internal lifetime memory 210. For example, the data compensator 240 can obtain compensation coefficients for multiple second pixel blocks BL2 corresponding to the gray levels represented by the input image data IDAT and the backup cumulative degradation amount BADA from the lifetime compensation lookup table, and can generate the output image data ODAT by applying the compensation coefficients of the multiple second pixel blocks BL2 to the input image data IDAT.

[0068] In an embodiment of the present invention, the data compensator 240 can receive a fault flag signal FFS from the lifetime comparator 250 and can compensate for the input image data IDAT by using the cumulative degradation amount RADA of a plurality of first pixel blocks BL1 in response to the fault flag signal FFS having a first level. Furthermore, in response to the fault flag signal FFS having a second level, the data compensator 240 can read the backup cumulative degradation amount BADA of a plurality of second pixel blocks BL2 from the internal lifetime memory 210 and can compensate for the input image data IDAT by using the backup cumulative degradation amount BADA of the plurality of second pixel blocks BL2.

[0069] Since the size of each second pixel block BL2 is larger than the size of each first pixel block BL1, the image retention compensation operation using backup cumulative degradation amount BADA can be less precise or coarser than the image retention compensation operation using cumulative degradation amount RADA. However, since the image retention compensation operation using backup cumulative degradation amount BADA is only performed during the period when the fault flag signal FFS has a first level, or only during the period when write or read operations of non-volatile lifetime memory 140 and / or volatile lifetime memory 170 cannot be performed normally due to electrostatic discharge (ESD), memory access failure, hardware failure, etc., the image quality of the display device will not be excessively degraded.

[0070] In the following text, it will be referred to below. Figures 1 to 6 An example describing the operation of image persistence compensation block 200.

[0071] Reference Figures 1 to 6 In the Nth frame FN (where N is an integer greater than 1), the current lifetime calculator 220 can calculate the current degradation amount CDAN of multiple first pixel blocks BL1 in the Nth frame FN based on the input image data IDAT in the Nth frame FN, and the cumulative lifetime calculator 230 can calculate the cumulative degradation amount ADAN of multiple first pixel blocks BL1 in the Nth frame FN by adding the current degradation amount CDAN in the Nth frame FN to the cumulative degradation amount ADAN-1 in the (N-1)th frame FN-1.

[0072] In one example, the cumulative lifetime calculator 230 can store the cumulative degradation amount ADAN-1 in frame N-1 (FN-1), and can calculate the cumulative degradation amount ADAN in frame N (FN) by adding the current degradation amount CDAN in frame N (FN) to the stored cumulative degradation amount ADAN-1. In another example, the cumulative lifetime calculator 230 can read the cumulative degradation amount ADAN-1 in frame N-1 (FN-1) from the volatile lifetime memory 170 at the start time of frame N (FN), and can calculate the cumulative degradation amount ADAN in frame N (FN) by adding the current degradation amount CDAN in frame N (FN) to the read cumulative degradation amount ADAN-1. The cumulative lifetime calculator 230 can write the cumulative degradation amount ADAN of multiple first pixel blocks BL1 in frame N (FN) to the volatile lifetime memory 170. Furthermore, the cumulative lifetime calculator 230 can generate a backup cumulative degradation amount BADAN of multiple second pixel blocks BL2 in the Nth frame FN based on the cumulative degradation amount ADAN of multiple first pixel blocks BL1, and can write the backup cumulative degradation amount BADAN of multiple second pixel blocks BL2 in the Nth frame FN to the internal lifetime memory 210.

[0073] During the initial period of frame N+1 FN+1, the data compensator 240 can read the cumulative degradation amount ADAN in frame NF from the volatile lifetime memory 170, and the lifetime comparator 250 can compare the cumulative degradation amount ADAN in frame NF read by the data compensator 240 with the cumulative degradation amount ADAN in frame NF calculated by the cumulative lifetime calculator 230.

[0074] If the cumulative degradation amount ADAN in the Nth frame FN read by the data compensator 240 is substantially the same as the cumulative degradation amount ADAN in the Nth frame FN calculated by the cumulative lifetime calculator 230, the data compensator 240 can compensate for the input image data IDAT in the N+1th frame FN+1 by using the cumulative degradation amount ADAN of the multiple first pixel blocks BL1 read from the volatile lifetime memory 170 in the Nth frame FN.

[0075] If the cumulative degradation amount ADAN read by the data compensator 240 in the Nth frame FN is different from the cumulative degradation amount ADAN calculated by the cumulative lifetime calculator 230, the data compensator 240 can read the backup cumulative degradation amount BADAN of multiple second pixel blocks BL2 in the Nth frame FN from the internal lifetime memory 210, and can compensate the input image data IDAT in the N+1th frame FN+1 by using the backup cumulative degradation amount BADAN of multiple second pixel blocks BL2 in the Nth frame FN.

[0076] Furthermore, in frame N+1 FN+1, the current lifetime calculator 220 can calculate the current degradation amount CDAN+1 in frame N+1 FN+1. Additionally, the cumulative lifetime calculator 230 can calculate the cumulative degradation amount ADAN+1 in frame N+1 FN+1 by adding the current degradation amount CDAN+1 in frame N+1 FN+1 to the cumulative degradation amount ADAN in frame N FN. The cumulative degradation amount ADAN+1 in frame N+1 FN+1 can be written to the volatile lifetime memory 170, a backup cumulative degradation amount BADAN+1 in frame N+1 FN+1 can be generated, and the backup cumulative degradation amount BADAN+1 in frame N+1 FN+1 can be written to the internal lifetime memory 210.

[0077] In conventional display devices that perform image retention compensation operations, if write or read operations on non-volatile memory and / or volatile memory cannot be performed normally due to electrostatic discharge (ESD), memory access failure, hardware failure, etc., the input image data will be compensated based on inaccurate cumulative degradation, and the image quality of the conventional display device will degrade.

[0078] However, in the display device 100 according to an embodiment of the present invention, the image retention compensation block 200 may have an internal lifetime memory 210, which can calculate the cumulative degradation amount CADA by accumulating the current degradation amount CDA, and can read the cumulative degradation amount RADA from the volatile lifetime memory 170 located outside the image retention compensation block 200. The calculated cumulative degradation amount CADA can be compared with the read cumulative degradation amount RADA, and the read cumulative degradation amount RADA or the backup cumulative degradation amount BADA stored in the internal lifetime memory 210 can be selectively used to compensate the input image data IDAT based on the comparison result. Therefore, even if the write or read operations of the volatile lifetime memory 170 and / or the non-volatile lifetime memory 140 located outside the image retention compensation block 200 cannot be performed normally due to ESD, memory access failure, hardware failure, etc., the image retention compensation operation can be accurately performed by using the backup cumulative degradation amount BADA in the internal lifetime memory 210.

[0079] Figure 7 This is a compensation illustrating an embodiment of the concept according to the present invention. Figure 1 A flowchart of a method for handling image retention in a display device.

[0080] Reference Figure 1 , Figure 3 and Figure 7In the first frame (e.g., the current frame), the current lifetime calculator 220 of the image persistence compensation block 200 can calculate the current degradation amount CDA based on the input image data IDAT (S310). In an embodiment of the present invention, the current lifetime calculator 220 can divide the input image data IDAT into multiple block image data corresponding to multiple first pixel blocks BL1 in the first frame. The weight determiner 260 of the image persistence compensation block 200 can determine the block degradation weight BDW of the multiple first pixel blocks BL1 based on at least one of the driving frequency of the display panel 110, the temperature of the display panel 110, and the position of the multiple first pixel blocks BL1. The current lifetime calculator 220 can calculate the current degradation amount CDA of the multiple first pixel blocks BL1 by applying the block degradation weight BDW to the multiple block image data.

[0081] The cumulative lifetime calculator 230 of the image persistence compensation block 200 can calculate the cumulative degradation amount CDA by accumulating the current degradation amount CDA (S320). The cumulative lifetime calculator 230 can write the cumulative degradation amount CDA to the volatile lifetime memory 170 located outside the image persistence compensation block 200 (S330). In an embodiment of the present invention, the cumulative degradation amount CDA stored in the volatile lifetime memory 170 can be periodically written to the non-volatile lifetime memory 140.

[0082] The cumulative lifetime calculator 230 can generate a backup cumulative degradation amount BADA based on the cumulative degradation amount CDA (S340), and can write the backup cumulative degradation amount BADA to the internal lifetime memory 210 of the image residual compensation block 200 (S350). In an embodiment of the present invention, the cumulative lifetime calculator 230 can generate backup cumulative degradation amount BADA for multiple second pixel blocks BL2 by merging the cumulative degradation amount CDAs of multiple first pixel blocks BL1. Furthermore, in an embodiment of the present invention, the cumulative degradation amount CDA can be calculated on a per-first-pixel-block-BL1 basis, and the backup cumulative degradation amount BADA can be calculated on a per-secondary-pixel-block-BL2 basis, and the size of the second-pixel-block-BL2 can be larger than the size of the first-pixel-block-BL1. Therefore, the data size of the backup cumulative degradation amount BADA can be smaller than the data size of the cumulative degradation amount CDA, and the internal lifetime memory 210 of the image residual compensation block 200 can have a smaller size than the size of the volatile lifetime memory 170.

[0083] In the second frame (e.g., the next frame), the data compensator 240 of the image persistence compensation block 200 can read the cumulative degradation amount RADA from the volatile lifetime memory 170 (S360), and the lifetime comparator 250 of the image persistence compensation block 200 can compare the cumulative degradation amount RADA read from the volatile lifetime memory 170 with the cumulative degradation amount CADA calculated by accumulating the current degradation amount CDA (S370). In an embodiment of the inventive concept, the lifetime comparator 250 can calculate a first checksum of the cumulative degradation amount RADA read from the volatile lifetime memory 170, can calculate a second checksum of the cumulative degradation amount CADA calculated by accumulating the current degradation amount CDA, and can determine whether the cumulative degradation amount RADA read from the volatile lifetime memory 170 is substantially equal to the cumulative degradation amount CADA calculated by accumulating the current degradation amount CDA by comparing the first checksum with the second checksum.

[0084] Data compensator 240 can selectively use the cumulative degradation amount RADA read from volatile lifetime memory 170 or the backup cumulative degradation amount BADA stored in internal lifetime memory 210 to compensate for the input image data IDAT in the second frame (S370, S380, and S390) based on the comparison result. For example, if the cumulative degradation amount RADA read from volatile lifetime memory 170 is substantially equal to the cumulative degradation amount CADA calculated by accumulating the current degradation amount CDA (S370: Yes), data compensator 240 can compensate for the input image data IDAT in the second frame by using the cumulative degradation amount RADA read from volatile lifetime memory 170 (S380). Furthermore, if the cumulative degradation amount RADA read from the volatile lifetime memory 170 is different from the cumulative degradation amount CADA calculated by accumulating the current degradation amount CDA (S370: No), the data compensator 240 can compensate the input image data IDAT in the second frame by using the backup cumulative degradation amount BADA stored in the internal lifetime memory 210 (S390).

[0085] As described above, in the method for compensating for image retention in the display device 100 according to an embodiment of the present invention, the image retention compensation block 200 may have an internal lifetime memory 210, which can calculate the cumulative degradation amount CADA by accumulating the current degradation amount CDA, and can read the cumulative degradation amount RADA from the volatile lifetime memory 170 located outside the image retention compensation block 200. The calculated cumulative degradation amount CADA can be compared with the read cumulative degradation amount RADA, and the input image data IDAT can be compensated by selectively using the read cumulative degradation amount RADA or the backup cumulative degradation amount BADA stored in the internal lifetime memory 210 based on the comparison result. Therefore, even if write or read operations to the volatile lifetime memory 170 and / or non-volatile lifetime memory 140 located outside the image retention compensation block 200 cannot be performed normally due to ESD, memory access failure, hardware failure, etc., the image retention compensation operation can be accurately performed by using the backup cumulative degradation amount BADA in the internal lifetime memory 210.

[0086] Figure 8 This is a block diagram illustrating a display device according to an embodiment of the concept of the present invention.

[0087] Reference Figure 8 The display device 400 according to an embodiment of the present invention may include a display panel 410, a data driver 420, a scan driver 430, a non-volatile lifetime memory 440, and a controller 450. The controller 450 may include a volatile lifetime memory 470, a pre-scaling block 490, and an image retention compensation block 500. The image retention compensation block 500 may include an internal lifetime memory 510. In addition to the controller 450, it may also include a pre-scaling block 490. Figure 8 The display device 400 can have the same as Figure 1 The display device 100 has a similar configuration and similar operation. In an embodiment of the present invention, the pre-scaling block 490 can be a circuit.

[0088] The prescaling block 490 can receive the accumulated degradation amount from the image lingering compensation block 500, determine the prescaling factor based on the maximum accumulated degradation amount, generate prescaled input image data PSIDAT by applying the prescaling factor to the input image data IDAT, and provide the prescaled input image data PSIDAT to the image lingering compensation block 500. In embodiments of the inventive concept, the prescaling block 490 can generate prescaled input image data PSIDAT reduced from the input image data IDAT based on the maximum accumulated degradation amount, and the image lingering compensation block 500 can generate output image data ODAT by increasing the prescaled input image data PSIDAT based on the accumulated degradation amount. Therefore, even if the input image data IDAT represents the maximum gray level (e.g., 255 gray levels), since the input image data IDAT is prescaled to a prescaled input image data PSIDAT reduced from the input image data IDAT, the image lingering compensation operation of increasing the prescaled input image data PSIDAT based on the accumulated degradation amount can still be performed normally.

[0089] Figure 9 This is a compensation illustrating an embodiment of the concept according to the present invention. Figure 8 A flowchart of a method for handling image retention in a display device.

[0090] Reference Figure 8 and Figure 9 In the first frame (e.g., the current frame), the prescaling block 490 can receive the accumulated degradation amount from the image retention compensation block 500, determine the prescaling factor based on the maximum accumulated degradation amount, and generate prescaled input image data PSIDAT by applying the prescaling factor to the input image data IDAT (S605). The image retention compensation block 500 can calculate the current degradation amount based on the prescaled input image data PSIDAT in the first frame (S610), calculate the accumulated degradation amount by accumulating the current degradation amount (S620), and write the accumulated degradation amount to a volatile lifetime memory 470 located outside the image retention compensation block 500 (S630). Furthermore, the image retention compensation block 500 can generate a backup accumulated degradation amount based on the accumulated degradation amount (S640), and write the backup accumulated degradation amount to the internal lifetime memory 510 of the image retention compensation block 500 (S650).

[0091] In the second frame (e.g., the next frame), the image persistence compensation block 500 can read the cumulative degradation amount from the volatile lifetime memory 470 (S660). If the cumulative degradation amount read from the volatile lifetime memory 470 is substantially equal to the cumulative degradation amount calculated by accumulating the current degradation amount (S670: Yes), the image persistence compensation block 500 can compensate for the prescaled input image data PSIDAT in the second frame by using the cumulative degradation amount read from the volatile lifetime memory 470 (S680). On the other hand, if the cumulative degradation amount read from the volatile lifetime memory 470 is different from the cumulative degradation amount calculated by accumulating the current degradation amount (S670: No), the image persistence compensation block 500 can compensate for the prescaled input image data PSIDAT in the second frame by using the backup cumulative degradation amount stored in the internal lifetime memory 510 (S690).

[0092] Figure 10 This is a block diagram illustrating an electronic device including a display device according to an embodiment of the concept of the present invention.

[0093] Reference Figure 10 Electronic device 1100 may include processor 1110, memory device 1120, storage device 1130, input / output (I / O) device 1140, power supply 1150, and display device 1160. Electronic device 1100 may also include multiple ports for communicating with video cards, sound cards, memory cards, universal serial bus (USB) devices, other electronic devices, etc.

[0094] Processor 1110 can perform various computing functions or tasks. Processor 1110 can be an application processor (AP), a microprocessor, a central processing unit (CPU), etc. Processor 1110 can be integrated with other components via address buses, control buses, data buses, etc. Furthermore, in embodiments of the present invention, processor 1110 can also be integrated with an expansion bus (such as a peripheral component interconnect (PCI) bus).

[0095] The memory device 1120 can store data for the operation of the electronic device 1100. For example, the memory device 1120 may include at least one non-volatile memory device (such as an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase-change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano-floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, a ferroelectric random access memory (FRAM) device, etc.) and / or at least one volatile memory device (such as a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, a mobile DRAM device, etc.).

[0096] Storage device 1130 may be a solid-state drive (SSD), hard disk drive (HDD), CD-ROM, etc. I / O device 1140 may be input devices (such as a keyboard, keypad, mouse, touchscreen, etc.) and output devices (such as a printer, speaker, etc.). Power supply 1150 provides power for the operation of electronic device 1100. Display device 1160 can be connected to other components via a bus or other communication link.

[0097] In the display device 1160, the image retention compensation block may have an internal lifetime memory. It can calculate the cumulative degradation amount by accumulating the current degradation amount, and can read the cumulative degradation amount from a volatile lifetime memory located outside the image retention compensation block. It can compare the calculated cumulative degradation amount with the read cumulative degradation amount, and selectively use either the read cumulative degradation amount or a backup cumulative degradation amount stored in the internal lifetime memory to compensate the input image data based on the comparison result. Therefore, even if write or read operations to the volatile and / or non-volatile lifetime memory located outside the image retention compensation block cannot be performed normally due to electrostatic discharge (ESD), memory access failure, hardware malfunction, etc., the image retention compensation operation can be accurately performed using the backup cumulative degradation amount in the internal lifetime memory.

[0098] This invention concept can be applied to any electronic device, including display devices. For example, it can be applied to televisions (TV), digital TVs, 3D TVs, smartphones, wearable electronic devices, tablet computers, mobile phones, personal computers (PCs), home appliances, laptop computers, personal digital assistants (PDAs), portable multimedia players (PMPs), digital cameras, music players, portable game consoles, navigation devices, etc.

[0099] As described above, in the display device and the method for compensating for image retention in the display device according to embodiments of the present invention, the image retention compensation block may have an internal lifetime memory, which can calculate the cumulative degradation amount by accumulating the current degradation amount, read the cumulative degradation amount from a volatile lifetime memory located outside the image retention compensation block, compare the calculated cumulative degradation amount with the read cumulative degradation amount, and selectively use the read cumulative degradation amount or a backup cumulative degradation amount stored in the internal lifetime memory to compensate for the input image data based on the comparison result. Therefore, even if the write or read operations of the volatile and / or non-volatile lifetime memory located outside the image retention compensation block cannot be performed normally due to electrostatic discharge (ESD), memory access failure, hardware failure, etc., the image retention compensation operation can be accurately performed by using the backup cumulative degradation amount in the internal lifetime memory.

[0100] Although embodiments of the inventive concept have been shown and described with reference to them, it will be apparent to those skilled in the art that various modifications in form and detail may be made to the inventive concept without departing from the spirit and scope of the inventive concept as set forth in the appended claims.

Claims

1. A display device, the display device comprising: The display panel includes multiple pixels; A data driver is configured to provide data signals to the plurality of pixels; A scan driver is configured to provide scan signals to the plurality of pixels; as well as A controller, configured to control the data driver and the scan driver, and including a volatile lifetime memory and an internal lifetime memory, wherein the controller is configured to: in a first frame, calculate a current degradation amount based on input image data, calculate a first cumulative degradation amount by accumulating the current degradation amount, and write the first cumulative degradation amount to the volatile lifetime memory to form a second cumulative degradation amount, wherein the volatile lifetime memory is configured to store the second cumulative degradation amount of the plurality of pixels, and the internal lifetime memory is configured to store a backup cumulative degradation amount generated based on the first cumulative degradation amount. The controller is further configured to: compare the second cumulative degradation amount read from the volatile lifetime memory with the first cumulative degradation amount calculated in the first frame; and compensate the input image data in the second frame by selectively using the second cumulative degradation amount stored in the volatile lifetime memory or the backup cumulative degradation amount stored in the internal lifetime memory based on the comparison result.

2. The display device according to claim 1, wherein, The controller also includes an image persistence compensation circuit. The volatile lifetime memory is located outside the image persistence compensation circuit. The internal lifetime memory is located inside the image persistence compensation circuit. In the first frame, the image persistence compensation circuit calculates the current degradation amount based on the input image data, calculates the first cumulative degradation amount by accumulating the current degradation amount, writes the first cumulative degradation amount to the volatile lifetime memory, generates the backup cumulative degradation amount based on the first cumulative degradation amount, and writes the backup cumulative degradation amount to the internal lifetime memory. In the second frame, the image persistence compensation circuit reads the second cumulative degradation amount from the volatile lifetime memory and compares the second cumulative degradation amount read from the volatile lifetime memory with the first cumulative degradation amount calculated in the first frame. In a first case where the second cumulative degradation amount read from the volatile lifetime memory is equal to the first cumulative degradation amount calculated in the first frame, the input image data is compensated in the second frame using the second cumulative degradation amount read from the volatile lifetime memory. In a second case where the second cumulative degradation amount read from the volatile lifetime memory is different from the first cumulative degradation amount calculated in the first frame, the input image data is compensated in the second frame using the backup cumulative degradation amount stored in the internal lifetime memory.

3. The display device according to claim 2, wherein, The image persistence compensation circuit is configured as follows: Calculate a first checksum of the second cumulative degradation amount read from the volatile lifetime memory; Calculate a second checksum of the first cumulative degradation amount, which is calculated by summing the current degradation amount; as well as The second cumulative degradation amount read from the volatile lifetime memory is determined by comparing the first checksum with the second checksum. This determines whether the second cumulative degradation amount is equal to the first cumulative degradation amount calculated by summing the current degradation amount.

4. The display device according to claim 2, wherein, The first cumulative degradation amount is calculated on a unit of the first pixel block. The cumulative degradation of the backup is calculated on a unit of the second pixel block, and The size of the second pixel block is larger than the size of the first pixel block.

5. The display device according to claim 2, wherein, The image persistence compensation circuit includes: The internal lifetime memory; The current lifetime calculator circuit is configured to divide the input image data into multiple block image data corresponding to multiple first pixel blocks in the first frame, and calculate the current degradation amount of the multiple first pixel blocks based on the multiple block image data; The cumulative lifetime calculator circuit is configured to calculate the first cumulative degradation amount of the plurality of first pixel blocks by accumulating the current degradation amount of the plurality of first pixel blocks, write the first cumulative degradation amount of the plurality of first pixel blocks to the volatile lifetime memory, generate the backup cumulative degradation amount of the plurality of second pixel blocks by merging the first cumulative degradation amounts of the plurality of first pixel blocks, and write the backup cumulative degradation amount of the plurality of second pixel blocks to the internal lifetime memory; A data compensator circuit is configured to read the second cumulative degradation amount of the plurality of first pixel blocks from the volatile lifetime memory; and A lifetime comparator circuit is configured to compare a second cumulative degradation amount read by the data comparator circuit with a first cumulative degradation amount calculated by the cumulative lifetime calculator circuit; generate a fault flag signal with a first level when the second cumulative degradation amount read by the data comparator circuit is equal to the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit; and generate a fault flag signal with a second level when the second cumulative degradation amount read by the data comparator circuit is different from the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit. In response to a fault flag signal having the first level, the data compensator circuit compensates for the input image data by using the second cumulative degradation amount of the plurality of first pixel blocks, and In response to a fault flag signal having the second level, the data compensator circuit reads the backup cumulative degradation amount of the plurality of second pixel blocks from the internal lifetime memory, and compensates the input image data by using the backup cumulative degradation amount of the plurality of second pixel blocks.

6. The display device according to claim 5, wherein, The size of each of the plurality of second pixel blocks is larger than the size of each of the plurality of first pixel blocks.

7. The display device according to claim 5, wherein, The lifetime comparator circuit is configured as follows: Calculate the first checksum of the second cumulative degradation amount read by the data compensator circuit; Calculate the second checksum of the first cumulative degradation amount calculated by the cumulative lifetime calculator circuit; as well as A fault flag signal is generated by comparing the first checksum with the second checksum.

8. The display device according to claim 5, wherein, The image persistence compensation circuit also includes: The weight determiner circuit is configured to determine the block degradation weight of the plurality of first pixel blocks based on at least one of the driving frequency of the display panel, the temperature of the display panel, and the position of the plurality of first pixel blocks.

9. A method for compensating for image retention in a display device, the method comprising: Calculate the current degradation amount based on the input image data in the first frame; The first cumulative degradation amount is calculated by summing the current degradation amount; The first cumulative degradation amount is written to a volatile lifetime memory located outside the image retention compensation circuit to form a second cumulative degradation amount; The backup cumulative degradation amount is generated based on the first cumulative degradation amount; The cumulative degradation amount of the backup is written into the internal lifetime memory of the image persistence compensation circuit; The second cumulative degradation amount is read from the volatile lifetime memory in the second frame; The second cumulative degradation amount read from the volatile lifetime memory is compared with the first cumulative degradation amount calculated by summing the current degradation amount; as well as The input image data is compensated in the second frame by selectively using the second cumulative degradation amount read from the volatile lifetime memory or the backup cumulative degradation amount stored in the internal lifetime memory, based on the comparison results.

10. A method for compensating for image retention in a display device, the method comprising: Prescaled input image data is generated by applying a prescale factor to the input image data; The current degradation is calculated based on the prescaled input image data in the first frame; The first cumulative degradation amount is calculated by summing the current degradation amount; The first cumulative degradation amount is written to the first memory to form the second cumulative degradation amount; The backup cumulative degradation amount is generated based on the first cumulative degradation amount; Write the accumulated degradation amount of the backup to the second memory; The second cumulative degradation amount is read from the first memory in the second frame; Compare the second cumulative degradation amount with the first cumulative degradation amount; as well as The prescaled input image data is compensated in the second frame by selectively using either the second cumulative degradation amount or the backup cumulative degradation amount based on the comparison results.

Images