Display device, control method, and program

Abstract

In the present invention, a control unit performs: a step (step S120) of updating compensation data of a first storage area on the basis of video data; a step (step S130) of calculating a difference between the compensation data of the first storage area and compensation data of a second storage area; and, when a result thereof exceeds a threshold value (Yes in step S132), a step (step S140) of overwriting, in the first storage area, the compensation data of the second storage area or compensation data of a nonvolatile memory.

Description

Display device, control method, and program

[0001] The present disclosure relates to a display device, a control method, and a program.

[0002] Patent document 1 discloses a method for an organic display that includes a volatile memory that stores accumulated values ​​of stress data, a non-volatile memory that has a slower write speed than the volatile memory, and a control unit, in which the control unit executes an accumulation process that repeatedly updates the accumulated values ​​in the volatile memory every first period, and executes a transfer process that transfers the accumulated values ​​from the volatile memory to the non-volatile memory every second period that is longer than the first period.

[0003] International Publication No. WO 2016 / 021172 A1

[0004] However, the method disclosed in Patent Document 1 has a problem that if the accumulated value in the nonvolatile memory becomes corrupted, the corrupted accumulated value must be transferred to the nonvolatile memory.

[0005] In order to solve the above problem, a display device according to one embodiment of the present disclosure comprises a display unit including a plurality of sub-pixels, a first storage area, a second storage area, and a control unit that can access a non-volatile memory in which compensation data corresponding to stress values ​​of one or more sub-pixels is stored and controls the display unit using video data and the compensation data, wherein the control unit performs the steps of recording updated compensation data in the first storage area, recording comparison compensation data in the second storage area, updating the compensation data in the first storage area based on the video data, and calculating a difference between the compensation data in the first storage area and the compensation data in the second storage area, and if the result exceeds a threshold, overwriting the first storage area with the compensation data in the second storage area or the compensation data in the non-volatile memory.

[0006] A control method according to one aspect of the present disclosure is a control method for controlling a display device that has a display unit, a first storage area, and a second storage area, and that can access a non-volatile memory in which compensation data corresponding to stress values ​​of one or more sub-pixels is stored, using video data and the compensation data, the control method comprising the steps of: recording compensation data for update in the first storage area; recording compensation data for comparison in the second storage area; updating the compensation data in the first storage area based on the video data; and calculating a difference between the compensation data in the first storage area and the compensation data in the second storage area, and if the result exceeds a threshold, overwriting the first storage area with the compensation data in the second storage area or the compensation data in the non-volatile memory.

[0007] A program according to one aspect of the present disclosure is a program that causes a processor to execute a control method according to one aspect of the present disclosure.

[0008] A recording medium according to one aspect of the present disclosure is a computer-readable recording medium on which a program according to one aspect of the present disclosure is recorded.

[0009] According to one aspect of the present disclosure, corrupted compensation data can be corrected.

[0010] FIG. 1 is a block diagram showing an example of a configuration of a display device according to an embodiment of the present disclosure. FIG. 2 is a flow diagram showing an example of an operation of the control unit shown in FIG. 1. FIG. 3 is a flow diagram showing an example of an update and backup shown in FIG. 2. FIG. 4 is a flow diagram showing another example of an operation of the control unit shown in FIG. 1. FIG. 5 is a flow diagram showing an example of a backup for termination shown in FIG. 4. FIG. 5 is a block diagram showing another example of a configuration of a display device according to an embodiment of the present disclosure. FIG. 6 is a block diagram showing an example of a configuration of a display device according to an embodiment of the present disclosure. FIG. 7 is a flow diagram showing an example of an operation of the control unit of a display device according to an embodiment of the present disclosure. FIG. 8 is a flow diagram showing another example of an operation of the control unit of a display device according to an embodiment of the present disclosure. FIG. 9 is a diagram showing an example of compensation data supplementation by a control unit of a display device according to an embodiment of the present disclosure. FIG. 10 is a flow diagram showing a continuation of the example of the operation shown in FIG. 12. FIG. 11 is a block diagram showing an example of a configuration of a display device according to an embodiment of the present disclosure. FIG. 12 is a flow diagram showing an example of an operation of the control unit shown in FIG. 14. FIG. 13 is a flow diagram showing an example of an update and backup shown in FIG. 15.

[0011] [Embodiment 1] Fig. 1 is a block diagram showing an example of the configuration of a display device according to an embodiment of the present disclosure. As shown in Fig. 1, the display device 100 according to this embodiment includes a display unit DA including a plurality of subpixels PX, a frame portion NA surrounding the display unit DA, a first storage area A1, a second storage area A2, and a control unit CP that can access a non-volatile memory NVM that stores compensation data corresponding to stress values ​​of one or more subpixels PX among the plurality of subpixels PX, and controls the display unit DA using video data and the compensation data. The non-volatile memory NVM is also referred to as "storage."

[0012] (Operation of the Control Unit) FIG. 2 is a flow diagram showing an example of the operation of the control unit shown in FIG. 1. As shown in FIG. 2, when the power is turned on, the control unit CP records the compensation data of the non-volatile memory NVM in the first storage area A1 for updating (step S10) and records the compensation data of the non-volatile memory NVM in the second storage area A2 for comparison (step S12). In the present disclosure, each compensation data may be distinguished by its storage location, such as "compensation data of the first storage area," "compensation data of the second storage area," and "compensation data of the non-volatile memory," or by its main purpose, such as "compensation data for updating," "compensation data for comparison," and "compensation data for storage." The compensation data for updating is recorded in the first storage area A1, the compensation data for comparison is recorded in the second storage area A2, and the compensation data for storage is recorded in the non-volatile memory NVM.

[0013] The control unit CP then controls the display unit DA using the video data and compensation data to display the video on the display unit DA (step S20). In parallel with or between video display, the control unit CP updates and backs up the compensation data (step S100). In this disclosure, "backup" refers to saving data to the non-volatile memory NVM.

[0014] Fig. 3 is a flow diagram showing an example of the update and backup shown in Fig. 2. As shown in Fig. 3, the control unit CP first sets or resets the backup timer T to 0 and starts counting the timer T (step S110), and then updates the compensation data in the first storage area A1 based on the video data (step S120). In step S120, the compensation data in the second storage area A2 is not updated, and the compensation data in the non-volatile memory NVM is not updated.

[0015] The control unit CP compares the timer T with a given period, e.g., 10 minutes (step S112) and repeats step S120 until the period has elapsed. After the period has elapsed, the control unit CP calculates the difference between the compensation data in the first storage area A1 and the compensation data in the second storage area A2 (step S130). The result of the difference calculation in step S130 is compared with a given threshold (step S132). If the result exceeds the threshold (Yes), it is assumed that data corruption has occurred. Data corruption is induced by external noise. Because the compensation data for update is more likely to come into contact with external noise than the compensation data for comparison, it is assumed that the compensation data for update is corrupted. Therefore, the first storage area A1 is overwritten with the compensation data in the second storage area A2 or the compensation data in the non-volatile memory NVM (step S140).

[0016] Since the corrupted compensation data for updating is not stored in the nonvolatile memory NVM, the display device 100 can return to normal display from an abnormal display caused by the corrupted data.

[0017] The internal processing in step S120 is diverse, and verifying data corruption at each stage of the internal processing significantly increases the workload of the control unit CP. Even if verification were performed after each process, it would be difficult to correct the corrupted data. Periodic data corruption verification such as step S130 and step S132 can reduce the load on the control unit CP. Furthermore, step S140 makes it easy to correct corrupted update compensation data.

[0018] The maximum amount of change in the compensation data when no data corruption occurs can be used as the threshold for the difference in the compensation data. The amount of change in the compensation data is approximately proportional to the length of the period during which the compensation data changes, and the proportionality coefficient is maximum when the display unit DA continues to display white all over the screen. For example, if the timer T is set to 10 minutes in step S112, the amount of change in the compensation data when the display unit DA continues to display white all over the screen for 10 minutes is used as the threshold. The proportionality coefficient or threshold may be calculated in advance and stored in the non-volatile memory NVM.

[0019] On the other hand, if the result of the difference calculation in step S130 does not exceed the given threshold (No), it is assumed that no data corruption has occurred. Therefore, the compensation data in the first storage area A1 is overwritten in the second storage area A2 (step S142), and the compensation data in the first storage area A1 is saved in the non-volatile memory NVM (step S144).

[0020] The control unit CP may perform a step of overwriting the first storage area A1 with the compensation data of the second storage area A2 when the result of the difference calculation exceeds a threshold, and may perform a step of overwriting the second storage area A2 with the compensation data of the first storage area A1 when the result of the difference calculation does not exceed the threshold. By reducing the number of accesses to the non-volatile memory NMV, the execution speed of the control unit CP can be improved.

[0021] The control unit CP may repeatedly perform the difference calculation of step S130 at intervals. Each time the difference calculation is performed, the following series of steps may be performed: if the result of the difference calculation does not exceed the threshold (No), overwriting the second storage area A2 with updated compensation data and saving the updated compensation data in the non-volatile memory NVM; and if the result of the difference calculation exceeds the threshold (Yes), overwriting the first storage area A1 with compensation data for comparison or saving. After step S140, or after steps S142 and S144, the control unit CP returns to step S110.

[0022] The control unit CP checks whether a power-off request has been received (step S30). This check may be performed each time the compensation data is updated. If a power-off request has not been received (No), the previous processing continues. If a power-off request has been received (Yes), the update and backup of the compensation data is terminated, the image display is terminated, and the main power supply of the display device 100 is turned off. This allows the main power supply to be turned off quickly, and is suitable for laptop computers.

[0023] In the image display of step S20, the control unit CP may generate display data using the image data and the compensation data in the first storage area. The display data allows an image in which the stress of the subpixels PX has been compensated for to be displayed on the display unit DA. By using the compensation data for updating, it is possible to reduce the occurrence rate of data corruption in the compensation data for comparison and storage.

[0024] (Another Operation of the Control Unit) Fig. 4 is a flow chart showing another example of the operation of the control unit shown in Fig. 1. As shown in Fig. 4, the control unit CP may back up compensation data (step S200) after finishing the video display.

[0025] FIG. 5 is a flow diagram illustrating an example of the termination backup shown in FIG. 4. As shown in FIG. 5, the control unit CP may calculate the difference between the compensation data in the first storage area A1 and the compensation data in the second storage area A2 when the power is OFF (step S230). The result of the difference calculation in step S230 is compared with a given threshold (step S232). If the result exceeds the threshold (Yes), the compensation data in the first storage area A1 is not saved to the non-volatile memory NVM, and the main power is turned off. On the other hand, if the result of the difference calculation does not exceed the threshold (No), the compensation data in the first storage area A1 is saved to the non-volatile memory NVM (step S244), and then the main power is turned off. This is suitable for smartphones and in-vehicle devices.

[0026] (Configuration of Display Device) Referring again to FIG. 1 , the display device 100 may be a self-emitting panel, and the display unit DA may include subpixels including an organic light-emitting layer as the plurality of subpixels PX. Alternatively, the display device 100 may include subpixels including a quantum dot light-emitting layer. The display device 100 may include a drive circuit DC in the frame area NA that drives the display unit DA. The control unit CP may be a processor of the timing controller TC.

[0027] The display device 100 may include or have built-in non-volatile memory NVM. The non-volatile memory NVM may be one or more integrated circuit elements mounted on the same substrate SB as the control unit CP, and may be, for example, a flash IC. The display device 100 may include volatile memory M1 including both a first memory area A1 and a second memory area A2. The volatile memory M1 may be, for example, a DRAM or an SRAM. The display device 100 may include a timing controller TC including the volatile memory M1.

[0028] The second storage area A2 may be equal to or larger than the first storage area A1. Since all of the compensation data can be recorded in the second storage area A2, the number of accesses to the non-volatile memory NVM can be reduced, and the power consumption of the display device 100 can be reduced.

[0029] The compensation data may be a collection of multiple unit data, and each unit data may correspond to one or more subpixels PX of the multiple subpixels PX included in the display unit DA. For example, one unit data corresponds to one subpixel PX and represents the stress value of the one subpixel PX. For example, one unit data corresponds to two or more subpixels PX that are close to each other and represents the average value of the stress values ​​of the two or more subpixels PX.

[0030] (Another Configuration of Display Device) Fig. 6 is a block diagram showing another example configuration of a display device according to an embodiment of the present disclosure. As shown in Fig. 6, the display device 100 may include a volatile memory M1 including a first storage area A1 and another volatile memory M2 including a second storage area A2. The display device 100 may include a timing controller TC including two volatile memories M1 and M2, for example, a DRAM and an SRAM.

[0031] [Embodiment 2] Fig. 7 is a block diagram showing an example of the configuration of a display device according to an embodiment of the present disclosure. As shown in Fig. 7, the display device 100 according to this embodiment may further include a third storage area A3 and a fourth storage area A4 for storing error detection codes such as a checksum and a cyclic redundancy check (CRC). The third storage area A3 and the fourth storage area A4 may be included in the same volatile memory as the first storage area A1 and the second storage area A2, respectively, or may be included in different volatile memories.

[0032] (Operation of the control unit) Fig. 8 is a flow chart showing an example of the operation of the control unit shown in Fig. 7. As shown in Fig. 8, each time compensation data is recorded in the second storage area A2 in step S12 or step S142, an initial checksum of the compensation data recorded in the second storage area A2 is calculated (step S150). The initial checksum is recorded in the third storage area A3.

[0033] After repeating step S120 for a given period, the control unit CP reads the compensation data recorded in the second storage area A2 and calculates its final checksum (step S152) before performing the difference calculation in step S130. The final checksum is then recorded in the fourth storage area A4. The initial checksum is then compared with the final checksum (step S154). If the initial checksum matches the final checksum (Yes), the control unit CP performs the difference calculation in step S130. The compensation data in the second storage area A2 is not accessed while the compensation data in the first storage area A1 is being updated. Therefore, although the probability of data corruption occurring in the comparison compensation data is low, data corruption may occur due to phenomena such as ESD. If the initial checksum matches the final checksum, it can be determined that the comparison compensation data is not corrupted.

[0034] On the other hand, if the initial checksum does not match the final checksum (No), it is assumed that the compensation data for comparison is corrupted. Therefore, the compensation data in the non-volatile memory NVM is overwritten in the second storage area A2 (step S156), and then the difference calculation in step S130 is performed.

[0035] [Embodiment 3] (Operation of Control Unit) Figure 9 is a flow diagram showing an example of the operation of the control unit of the display device according to one embodiment of the present disclosure. As shown in Figure 9, the control unit CP sets or resets the backup timer U to 0 and starts counting the backup timer U (step S110a). After updating the compensation data, the control unit CP compares the timer T with a second period longer than the first period, e.g., 10 minutes (step S112), and compares the timer U with the first period, e.g., 4 minutes (step S112a). Step S120 is repeated until either the first period or the second period has elapsed.

[0036] If the timer U has exceeded the first period (Yes in step S112a), the control unit CP calculates the difference between the compensation data in the first storage area A1 and the compensation data in the second storage area A2 (step S130a) and compares the result of this difference calculation with a given threshold (step S132a). If the result of the difference calculation performed in the first period of step S130a exceeds the given threshold (Yes), the control unit CP overwrites the first storage area A1 with the compensation data in the second storage area A2 or the compensation data in the non-volatile memory NVM (step S140). On the other hand, if the result does not exceed the given threshold (No), the control unit CP overwrites the second storage area A2 with the compensation data in the first storage area A1 (step S142a) and returns to step S110a.

[0037] If the timer T has exceeded the second period (Yes in step S112), the control unit CP performs steps S130 and S132. If the result of the difference calculation performed in the second period of step S130 exceeds a given threshold (Yes), the control unit CP overwrites the first storage area A1 with the compensation data in the second storage area A2 or the compensation data in the non-volatile memory NVM (step S140). On the other hand, if the result does not exceed the given threshold (No), the control unit CP overwrites the second storage area A2 with the compensation data in the first storage area A1 (step S142) and saves the compensation data in the first storage area A1 in the non-volatile memory NVM (step S144). The threshold for the difference in the compensation data may be different between the first and second periods. After step S140 or steps S142 and S144, the control unit CP returns to step S110.

[0038] 10 is a flow diagram showing another example of the operation of the control unit of the display device according to an embodiment of the present disclosure. As shown in FIG. 10, if the result of the difference calculation performed in the first cycle of step S130a does not exceed a given threshold (No), the compensation data in the first storage area A1 does not need to be overwritten in the second storage area A2. The threshold value for the difference in the compensation data may be the same for the first cycle and the second cycle.

[0039] [Embodiment 4] (Operation of Control Unit) Figure 11 is a diagram illustrating an example of compensation data filling by the control unit of a display device according to an embodiment of the present disclosure. As illustrated in Figure 11, when n minutes and (n+10) minutes have elapsed since the start of operation, updated compensation data is stored in the second storage area A2 and the non-volatile memory NVM, and the compensation data roughly corresponds to the amount of stress of the subpixel PX. When (n+20) minutes have elapsed, the first storage area A1 is overwritten with compensation data for comparison or storage, and the compensation data in the second storage area A2 or the non-volatile memory NVM is overwritten. As a result, the increment X of the compensation data is discarded, widening the discrepancy between the actual amount of stress and the compensation data.

[0040] Then, when (n+22) minutes have passed, the compensation data increment M is integrated by the time ratio to obtain the corrected increment M(F), and the compensation data is updated. This compensates for the discrepancy between the stress amount and the compensation data, thereby reducing the discrepancy between the actual stress amount and the compensation data.

[0041] 12 is a flow diagram showing an example of the operation of the control unit of the display device according to an embodiment of the present disclosure. As shown in FIG. 12, the number of failures F is set or reset to 0 (step S160), and the compensation data is updated and backed up. If the result of the difference calculation in step S130 does not exceed a given threshold, steps S142 and S144 are performed, and the process returns to step S160. On the other hand, if the result of the difference calculation in step S130 exceeds a given threshold, step S140 is performed, and then the process proceeds to another step.

[0042] FIG. 13 is a flow diagram showing a continuation of the operation example shown in FIG. 12. As shown in FIG. 13, following step S140, the failure count F is incremented by 1 (step S162b). This allows the control unit CP to count the number of times the difference calculation result exceeds the threshold (failure count F). The control unit CP then sets or resets the backup timer U to 0 and starts counting the timer U (step S110b). The control unit CP then corrects and updates the compensation data in the first storage area A1 based on the video data, the period ratio, and the failure count F (step S120b). In step S120b, the control unit CP first calculates a raw increment M based on the compensation data for update and the video data, and then calculates a corrected increment M(F) according to the count results of the period ratio and the failure count F, as shown in Equation (1) below.

[0043] M(F) = M × (Pt ÷ Pu + F) (1) Here, Pt is the length of the normal period, that is, the length of the period compared with the backup timer T when F = 0. Pu is the length of the supplementary period, that is, the length of the period compared with the backup timer U when F > 0. (Pt ÷ Pu) is the period ratio.

[0044] The timer U is compared with a given period, e.g., 10 minutes or 2 minutes (step S112b), and step S120b is repeated until the period has elapsed. After the period has elapsed, the difference between the compensation data in the first storage area A1 and the compensation data in the second storage area A2 is calculated (step S130b). The result of the difference calculation in step S130b is compared with a given threshold (step S132b). If the result exceeds the threshold (Yes), the first storage area A1 is overwritten with the compensation data in the second storage area A2 or the compensation data in the non-volatile memory NVM (step S140b). On the other hand, if the result does not exceed the given threshold (No), the compensation data in the first storage area A1 is overwritten in the second storage area A2 (step S142b), and the compensation data in the first storage area A1 is saved in the non-volatile memory NVM (step S144b).

[0045] The threshold used in step S132b may be corrected using the period ratio and the number of failures F. A raw threshold Y is set based on the length of the period compared with the timer U in step S112b, and a corrected threshold Y(F) is calculated according to the count results of the period ratio and the number of failures F, as shown in the following formula (2).

[0046] Y(F)=Y×(Pt / Pu+F) (2) The control unit CP returns to step S162b after step S140b, and returns to step S160 after steps S142b and S144b.

[0047] [Embodiment 5] Figure 14 is a block diagram illustrating an example configuration of a display device according to an embodiment of the present disclosure. As shown in Figure 14, in the display device 100 according to this embodiment, the second storage area A2 may be smaller than the first storage area A1. The compensation data in the first storage area A1 may be divided into several blocks. For example, assuming that the compensation data is divided into eight blocks, the first storage area A1 may correspond to eight blocks and the second storage area A2 may correspond to one block. This can save memory capacity. Using natural numbers n and k, where k < n, the compensation data in the first storage area A1 and the non-volatile memory NVM may each be divided into n blocks, and the kth block of the compensation data for updating may correspond to the kth block of the compensation data for saving.

[0048] (Operation of control unit) Fig. 15 is a flow chart showing an example of the operation of the control unit shown in Fig. 14. As shown in Fig. 15, when the power is turned on, the control unit CP records the compensation data in the non-volatile memory NVM in the first storage area A1 for updating (step S10), and updates and backs up the compensation data in parallel with or in between video display (step S300).

[0049] Fig. 16 is a flow diagram showing an example of the update and backup shown in Fig. 15. As shown in Fig. 16, the control unit CP repeats step S120 for a given period, and then sets or resets the count k to 1 (step S310). Next, the kth block of the compensation data in the nonvolatile memory NVM is recorded in the second storage area A2 as the kth compensation data for comparison (step S320).

[0050] Then, the control unit CP calculates the difference between the kth block of the compensation data in the first storage area A1 and the compensation data in the second storage area A2 (step S330). The result of the difference calculation in step S330 is compared with a given threshold (step S132). If the result exceeds the threshold (Yes), the control unit CP overwrites the first storage area A1 with the compensation data in the non-volatile memory NVM (step S340). On the other hand, if the result of the difference calculation in step S330 does not exceed the given threshold (No), the control unit CP compares the count k with the number of divisions of the compensation data, for example, 8 (step S312). If the count k is less than the number of divisions (Yes), the control unit CP increments the count k by 1 (step S314) and returns to step S320. If the count k is equal to or greater than the number of divisions (No), the control unit CP saves the entire compensation data in the first storage area A1 to the non-volatile memory NVM (step S144). After step S340 or step S144, the control unit CP returns to step S110.

[0051] In steps S314, S320, and S330, the control unit CP divides the compensation data corresponding to the display unit DA and sequentially records it from the non-volatile memory NVM to the second storage area A2, and sequentially calculates the difference between the compensation data recorded in the second storage area A2 and the corresponding compensation data in the first storage area A1.

[0052] Sixth Embodiment The present disclosure also encompasses a program for causing a processor or the like to execute a control method for the display device 100 according to the present disclosure. The control unit CP may be realized by a computer. In this case, the present disclosure also encompasses a control program for the display device that causes the computer to operate as the control unit CP, thereby realizing the control unit CP on the computer, and a computer-readable recording medium on which the program is recorded.

[0053] The functions of the control unit CP of the display device 100 can be realized by a program for causing a computer to function as the control unit CP, and by a program for causing a computer to function as each control block of the control unit CP.

[0054] In this case, the control unit CP includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program to realize the functions described in each of the above embodiments.

[0055] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0056] In addition, some or all of the functions of each of the control blocks can be realized by logic circuits. For example, integrated circuits in which logic circuits that function as each of the control blocks are formed are also included in the scope of the present disclosure. In addition, the functions of each of the control blocks can also be realized by, for example, a quantum computer.

[0057] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0058] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0059] 100 Display device A1 First storage area A2 Second storage area B1 Increment CP Control unit TC Timing controller DA Display unit DC Drive circuit M1, M2 Volatile memory NVM Non-volatile memory PX Sub-pixel

Claims

1. A display device comprising: a display unit including a plurality of sub-pixels; a first storage area, a second storage area; and a control unit that can access non-volatile memory in which compensation data corresponding to stress values of one or more sub-pixels is stored, and that controls the display unit using video data and the compensation data, wherein the control unit performs the steps of: recording updated compensation data in the first storage area; recording comparison compensation data in the second storage area; updating the compensation data in the first storage area based on the video data; and calculating the difference between the compensation data in the first storage area and the compensation data in the second storage area, and if the result exceeds a threshold, overwriting the first storage area with the compensation data in the second storage area or the compensation data in the non-volatile memory.

2. The display device according to claim 1, wherein the control unit performs a step of storing compensation data for the first storage area in the non-volatile memory when the result does not exceed a threshold value.

3. The display device according to claim 2, wherein the control unit performs the difference calculation when the power is off, and if the result exceeds a threshold, does not store the compensation data in the first storage area in the non-volatile memory.

4. The display device of claim 2, wherein the control unit performs a step of overwriting the compensation data of the second memory area in the first memory area when the result exceeds a threshold, and a step of overwriting the compensation data of the first memory area in the second memory area when the result does not exceed a threshold.

5. The display device according to claim 4, wherein the control unit records the compensation data in the nonvolatile memory in the first storage area and the second storage area when the power is turned on.

6. The display device according to claim 4, wherein the control unit calculates an initial checksum of the recorded compensation data when the compensation data is recorded in the second storage area.

7. The display device of claim 6, wherein the control unit calculates a final checksum of the compensation data recorded in the second memory area before performing the difference calculation, and performs the difference calculation if the initial checksum and the final checksum match.

8. The display device according to claim 4, wherein the control unit repeatedly calculates the difference at intervals.

9. The display device of claim 8, wherein the control unit overwrites the compensation data in the second storage area and stores it in the non-volatile memory each time the difference calculation is performed if the result does not exceed the threshold value, and overwrites the compensation data in the first storage area if the result exceeds the threshold value.

10. The display device of claim 8, wherein the control unit, in the difference calculation performed in a first cycle, overwrites the compensation data in the second memory area if the result does not exceed a threshold, and overwrites the compensation data in the first memory area if the result exceeds a threshold; and, in the difference calculation performed in a second cycle longer than the first cycle, overwrites the compensation data in the second memory area and saves it in the non-volatile memory if the result does not exceed the threshold, and overwrites the compensation data in the first memory area if the result exceeds the threshold.

11. The display device of claim 8, wherein the control unit, in the difference calculation performed in a first cycle, does not overwrite the compensation data in the second memory area if the result does not exceed a threshold, and overwrites the compensation data in the first memory area if the result exceeds the threshold; and, in the difference calculation performed in a second cycle longer than the first cycle, overwrites the compensation data in the second memory area and saves it in the non-volatile memory if the result does not exceed the threshold, and overwrites the compensation data in the first memory area if the result exceeds the threshold.

12. The display device according to claim 10 or 11, wherein the control unit counts the number of times the result exceeds a threshold value, and corrects the compensation data in the first storage area using the count result.

13. The display device of claim 1, wherein the control unit performs a step of overwriting the compensation data in the non-volatile memory in the first storage area if the result exceeds a threshold, and a step of saving the compensation data in the first storage area in the non-volatile memory if the result does not exceed the threshold.

14. The display device according to claim 13, wherein the control unit divides the compensation data corresponding to the display unit and sequentially records the divided data from the non-volatile memory into a second storage area, and sequentially calculates the difference between the compensation data recorded in the second storage area and the corresponding compensation data in the first storage area.

15. The display device according to any one of claims 1 to 14, wherein the display section includes sub-pixels including an organic light-emitting layer or a quantum dot light-emitting layer.

16. The display device according to any one of claims 1 to 15, comprising the nonvolatile memory.

17. The display device according to any one of claims 1 to 16, further comprising a volatile memory including both the first storage area and the second storage area.

18. A display device according to any one of claims 1 to 16, comprising a volatile memory including the first storage area and another volatile memory including the second storage area.

19. The display device according to any one of claims 1 to 18, further comprising a timing controller including the first storage area and the second storage area.

20. A display device according to any one of claims 1 to 19, wherein the compensation data is a collection of a plurality of unit data, each unit data corresponding to one or more sub-pixels of the display section.

21. The display device according to any one of claims 1 to 20, wherein the control unit generates display data using the video data and the compensation data in the first storage area.

22. A control method for controlling a display device that has a display unit, a first storage area, and a second storage area, and that can access a non-volatile memory in which compensation data corresponding to stress values of one or more sub-pixels is stored, using video data and the compensation data, the control method comprising the steps of: recording updated compensation data in the first storage area; recording comparison compensation data in the second storage area; updating the compensation data in the first storage area based on the video data; and calculating the difference between the compensation data in the first storage area and the compensation data in the second storage area, and if the result exceeds a threshold, overwriting the first storage area with the compensation data in the second storage area or the compensation data in the non-volatile memory.

23. A program that causes a processor to execute each step of claim 22.

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