Display device and driving method of display device

Abstract

A display device and a driving method of the display device are provided. The display device includes a display panel displaying an image, an image data receiving unit receiving the image data, a compensation unit generating life compensation data by compensating the image data based on life data, and a panel driving unit providing a data signal corresponding to the life compensation data to the display panel to drive the display panel. The compensation unit includes a compensation unit receiving first accumulated data and generating the life data based on the first accumulated data, and outputting the life compensation data in which the image data is compensated based on the life data, a memory control unit receiving second accumulated data and the life data from the compensation unit, a volatile memory storing the second accumulated data received from the memory control unit, a main non-volatile memory storing the second accumulated data received from the memory control unit, and a sub non-volatile memory storing the life data received from the memory control unit.

Description

TECHNICAL FIELD

[0001] The present application relates to a display device and a driving method of the display device, and more particularly, to a display device and a driving method of the display device which compensate for residual images occurring in an image displayed in a display panel. BACKGROUND

[0002] In order to provide image information, various forms of display devices are being used. As the display device, an organic light emitting display device (OLED), a liquid crystal display device (LCD), a plasma display device, etc. are being used.

[0003] In particular, the organic light emitting display device (OLED) refers to a display device which can display information such as images, characters, etc. using light generated by the combination of holes and electrons provided from an anode and a cathode, respectively, in an organic light emitting layer located between the anode and the cathode. The organic light emitting display device (OLED) has various advantages such as a wide viewing angle, a fast response speed, a low power consumption, etc., and thus is spotlighted as a promising next-generation display device.

[0004] On the other hand, the organic light emitting display device (OLED) can be deteriorated due to an increase in current stress when driven for a long time, and thus residual images can occur in a portion where a fixed pattern or logo is displayed for a long time. SUMMARY

[0005] An object of the present application is to provide a display device which can prevent residual images from occurring in a display panel.

[0006] An embodiment of the present application relates to a display device including a display panel that displays an image, an image retention compensation section that receives image data, generates life compensation data by compensating the image data based on life data, and stores second accumulated data and the life data, and a panel drive section that provides a data signal corresponding to the life compensation data to the display panel to drive the display panel. The image retention compensation section includes a compensation section that receives first accumulated data, generates the life data based on the first accumulated data, outputs the life compensation data that is compensated based on the life data from the image data, and generates the second accumulated data based on the first accumulated data. The image retention compensation section includes a memory control section that receives the second accumulated data and the life data from the compensation section, and transmits the first accumulated data to the compensation section, and a volatile memory that stores the second accumulated data received from the memory control section. The image retention compensation section further includes a main nonvolatile memory that stores the second accumulated data received from the memory control section, and a sub nonvolatile memory that stores the life data received from the memory control section.

[0007] As an embodiment of the present application, the storage capacity of the sub nonvolatile memory can be smaller than the storage capacity of the main nonvolatile memory.

[0008] As an embodiment of the present application, the compensation section can generate degradation data of a current frame based on the life compensation data. The first accumulated data can be data that is generated by accumulating degradation data up to a previous frame, and the second accumulated data can be data that is generated by accumulating the degradation data of the current frame on the first accumulated data.

[0009] As an embodiment of the present application, the first accumulated data and the second accumulated data can be formed of n-bit data, and the life data can be formed of m-bit data, where n and m are natural numbers of 1 or more, and n is a natural number larger than m.

[0010] As an embodiment of the present application, the compensation section can receive the first accumulated data from the memory control section, and the memory control section can read past second accumulated data stored in the main nonvolatile memory at the previous frame when the display device is turned on, and store the read past second accumulated data in the volatile memory as the first accumulated data.

[0011] As one embodiment of the present application, the memory control section can read the life data stored in the sub nonvolatile memory and store the read life data in the main nonvolatile memory in the case where at least a part of the main nonvolatile memory is damaged.

[0012] As one embodiment of the present application, the memory control section can expand the life data to n-bit data and store the n-bit data in the main nonvolatile memory.

[0013] As one embodiment of the present application, the memory control section can read the life data stored in the sub nonvolatile memory and store the read life data in the volatile memory as the first accumulated data when the display device is turned on.

[0014] As one embodiment of the present application, the memory control section can expand the life data to n-bit data and store the n-bit data in the volatile memory as the first accumulated data.

[0015] As one embodiment of the present application, the memory control section can read the second accumulated data stored in the volatile memory at a predetermined first period and store the read second accumulated data in the main nonvolatile memory. The memory control section can receive the life data from the compensation section at a predetermined second period and store the received life data in the sub nonvolatile memory.

[0016] As one embodiment of the present application, the first period and the second period can be set to be different.

[0017] As one embodiment of the present application, the main nonvolatile memory can include a first main module and a second main module, and the memory control section can alternately store the second accumulated data in the first main module and the second main module.

[0018] As one embodiment of the present application, the sub nonvolatile memory can include a first sub module and a second sub module, and the memory control section can alternately store the life data in the first sub module and the second sub module.

[0019] As one embodiment of the present application, the display panel can include a controller that receives an image signal from the outside and generates the image data based on the image signal.

[0020] An embodiment of the present invention relates to a method for driving a display device including the steps of receiving image data and first accumulated data and generating life compensation data by compensating the image data based on life data. The method for driving a display device includes the steps of storing second accumulated data and life data, providing a data signal corresponding to the life compensation data to a display panel, and displaying an image corresponding to the data signal. The step of generating the life compensation data includes the steps of receiving the first accumulated data and generating the life data based on the first accumulated data, and generating the life compensation data which is compensated based on the life data. The step of storing the second accumulated data and the life data includes the steps of generating the second accumulated data based on the first accumulated data, receiving second accumulated data from a memory control section and storing the second accumulated data in a volatile memory, receiving the second accumulated data from the memory control section and storing the second accumulated data in a main non-volatile memory, and receiving the life data from the memory control section and storing the life data in a sub non-volatile memory.

[0021] As an embodiment of the present invention, the storage capacity of the sub non-volatile memory can be smaller than the storage capacity of the main non-volatile memory.

[0022] As an embodiment of the present invention, the step of generating the life compensation data can further include the step of generating degradation data of a current frame based on the life compensation data. The first accumulated data can be data generated by accumulating degradation data up to a previous frame, and the second accumulated data can be data generated by accumulating the degradation data of the current frame on the first accumulated data. The first accumulated data and the second accumulated data can be formed of n-bit data, and the life data can be formed of m-bit data, where n and m are natural numbers of 1 or more, and n is a natural number larger than m.

[0023] As an embodiment of the present invention, the step of generating the life compensation data can include the step of reading the life data stored in the sub non-volatile memory in the case where at least a part of the main non-volatile memory is damaged. The step of generating the life compensation data can further include the step of expanding the read life data to n-bit data, and the step of storing the n-bit data in the main non-volatile memory as the first accumulated data.

[0024] As an embodiment of the present application, it can be that the step of generating the life compensation data further includes a step of reading the life data stored in the sub-nonvolatile memory when the display device is turned on, a step of expanding the read life data to n-bit data, and a step of storing the n-bit data in the volatile memory as the first accumulated data.

[0025] As an embodiment of the present application, it can be that the step of storing the second accumulated data in the main nonvolatile memory includes a step of storing the second accumulated data in a first main module and a step of storing the second accumulated data in a second main module. It can be that the step of storing the life data in the sub-nonvolatile memory includes a step of storing the life data in a first sub-module and a step of storing the life data in a second sub-module.

[0026] (EFFECT OF INVENTION)

[0027] According to the present application, when the display device is turned on, image data can be compensated based on degradation data, which is data accumulated based on image data provided to the display panel until the last operation. Thus, it is possible to prevent afterimage from appearing in an image displayed in the display panel. Furthermore, even if the main nonvolatile memory in which the accumulated degradation data is stored is damaged, it is possible to compensate image data based on the life data stored in the sub-nonvolatile memory, so that afterimage compensation can be normally performed even in the case where the main nonvolatile memory is damaged. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a plan view of a display device to which an embodiment of the present application relates.

[0029] Figure 2 is a block diagram of a display device to which an embodiment of the present application relates.

[0030] Figure 3 is a block diagram showing an afterimage compensation section to which an embodiment of the present application relates.

[0031] Figure 4 In (a), (b) is a diagram for explaining the structure of a sub-nonvolatile memory to which an embodiment of the present application relates.

[0032] Figure 5 is a block diagram showing an afterimage compensation section to which an embodiment of the present application relates. Figure 3 is a sequence chart showing the operation of the afterimage compensation section shown in

[0033] Figure 6is a block diagram for explaining the operation of the residual image compensation section to which an embodiment of the present application relates, when at least a part of the main nonvolatile memory is damaged.

[0034] Figure 7 is a graph for explaining the effect related to the presence or absence of the sub nonvolatile memory to which an embodiment of the present application relates.

[0035] Figure 8 is a sequence chart showing the operation of the residual image compensation section shown in Figure 6

[0036] Figure 9 is a block diagram for explaining the operation of the residual image compensation section to which an embodiment of the present application relates, when the display device is turned on.

[0037] Figure 10 is a graph for explaining the effect related to the operation of the residual image compensation section shown in Figure 9

[0038] Figure 11 is a sequence chart showing the operation of the residual image compensation section shown in Figure 9

[0039] Figure 12 is a block diagram showing the residual image compensation section to which an embodiment of the present application relates. DETAILED DESCRIPTION

[0040] In the present specification, in the case where it is mentioned that a certain constitutional element (or region, layer, portion, etc.) is located on, connected to, or combined with another constitutional element, it means that it can be directly disposed / connected / combined on the other constitutional element, or a third constitutional element can be further disposed therebetween.

[0041] The same symbols refer to the same constitutional elements. Further, in each drawing, the thickness, ratio, and size of each constitutional element are exaggerated for the effective explanation of the technical content.

[0042] The "and / or" includes all one or more combinations of the related constitutional elements that can be defined.

[0043] The first, second, and the like terms can be used to explain various constitutional elements, but the constitutional elements described should not be limited to the terms described. The terms described are used only for the purpose of distinguishing one constitutional element from another constitutional element. For example, a first constitutional element can be named a second constitutional element, and similarly, a second constitutional element can be named a first constitutional element, without departing from the scope of the present application. The singular expression in the present specification includes the plural expression unless it is explicitly stated to the contrary.

[0044] ​​​Furthermore, terms such as "below," "on the lower side," "above," and "on the upper side" are used to explain the connection relationships between the components in the diagram. These terms are relative concepts and are explained based on the direction shown in the diagram.

[0045] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) shall have the same meaning as commonly understood by those skilled in the art. Furthermore, terms defined in commonly used dictionaries shall be interpreted as having a meaning consistent with the relevant technical context, and shall not be interpreted as having an idealized or overly formal meaning unless expressly defined in this application.

[0046] Terms such as “including” or “having” should be understood as referring to the presence of features, figures, steps, operations, constituent elements, components, or combinations thereof as recorded in the instruction manual, and do not preclude the existence or additional possibilities of one or more other features, figures, steps, operations, constituent elements, components, or combinations thereof.

[0047] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings.

[0048] Figure 1 This is a plan view of a display device according to an embodiment of the present invention. Figure 2 This is a block diagram of a display device according to an embodiment of the present invention.

[0049] Reference Figure 1 and Figure 2 The display device DD has a rectangular shape, having a long side extending in a first direction DR1 and a short side extending in a second direction DR2 intersecting the first direction DR1. As an example of the invention, the second direction DR2 may be a direction perpendicular to the first direction DR1. However, the shape of the display device DD is not limited to this, and display devices DD of various shapes can be provided.

[0050] The display devices DD involved in this invention can be large display devices such as televisions and screens, as well as small and medium-sized display devices such as mobile phones, tablets, car navigation systems, and game consoles. These are provided only as examples, and can of course be used in other electronic devices without departing from the concept of this invention.

[0051] Reference Figure 1 and Figure 2 An embodiment of the present invention relates to a display device DD that may include a display panel DP for displaying images, a controller CP, an image retention compensation unit AIC, and a panel driving unit PCP.

[0052] The display panel DP includes a display area DA for displaying the image IM and a non-display area NDA adjacent to the periphery of the display area DA. The display area DA is the area that actually displays the image, while the non-display area NDA is a border area where no image is displayed. Figure 1 The diagram illustrates a non-display area NDA configured to surround a display area DA, but the invention is not limited thereto. The non-display area NDA may be configured only on at least one side of the display area DA.

[0053] Image IM can be displayed in the display area DA. Image IM may include a first image IM1 and a second image IM2. The first image IM1 may be an image displayed at a fixed position with a specific grayscale value for a certain period of time. The first image IM1 may be a static image, and the second image IM2 may be a dynamic image or a static image. For example, the first image IM1 may include a broadcasting station logo, subtitles, date, time, etc. The first image IM1 may also include the name of a program, etc. Hereinafter, for ease of explanation, all images displayed at a fixed position with a specific grayscale value for a certain period of time will be referred to as the first image IM1. In the display area DA, the area where the first image IM1 is displayed is called the fixed area. The second image IM2 may be an image displayed in the remaining part of the display area DA excluding the fixed area.

[0054] The display panel DP includes multiple scan lines SL1 to SLn, multiple data lines DL1 to DLm, and multiple pixels PX. The multiple scan lines SL1 to SLn extend in a first direction DR1 and are arranged parallel to each other in a second direction DR2 that intersects the first direction DR1. The multiple data lines DL1 to DLm can be arranged parallel to each other in the first direction DR1 and extend in the second direction DR2.

[0055] Multiple pixels PX can be arranged on a first direction DR1 and a second direction DR2. As an example of the present invention, the multiple pixels PX can be arranged in a matrix. Each of the multiple pixels PX is electrically connected to one of a plurality of scan lines SL1 to SLn and a plurality of data lines DL1 to DLm. Each pixel PX is turned on according to a scan signal applied from the corresponding scan line and receives a data signal DS from the corresponding data line to display an image of the desired grayscale. Each of the multiple pixels PX includes a light-emitting element (not shown) and a circuit section (not shown) for controlling the light emission of the light-emitting element. As an embodiment, the light-emitting element may be an organic light-emitting diode (OLED).

[0056] An organic light-emitting diode (OLED) comprises multiple electrodes and a light-emitting layer formed by organic material disposed between the electrodes. Due to prolonged exposure to a first image IM1 displayed through the same pixel, the OLEDs within a fixed area of ​​the pixel PX may degrade. Therefore, when an image different from the first image IM1 is displayed after the first image IM1 has been displayed in the fixed area, the first image IM1 may unintentionally remain in the fixed area. This retained first image IM1 is referred to as image sticking.

[0057] The circuit section may include multiple transistors and capacitors electrically connected to the transistors.

[0058] The controller CP receives the image signal RGB and the control signal CTRL from an external source. The controller CP transforms the RGB data format into a specification suitable for the interface with the source driver unit (SDB), thereby generating the image data IMD. The controller CP transforms the control signal CTRL to generate the gate control signal GCS and the source control signal SCS. The controller CP outputs the image data IMD, the source control signal SCS, and the gate control signal GCS.

[0059] The image retention compensation unit (AIC) receives image data IMD from the controller CP and compensates for the received image data IMD to generate lifetime compensation data ACD. The function, structure, and operation of the image retention compensation unit (AIC) will be explained in [reference needed]. Figures 3 to 12 To be continued later.

[0060] The panel driver unit PCP receives lifetime compensation data ACD from the image retention compensation unit AIC, and receives source control signal SCS and gate control signal GCS from the controller CP. The panel driver unit PCP can provide a data signal DS corresponding to the lifetime compensation data ACD to the display panel DP to drive the display panel DP. As an example of the present invention, the panel driver unit PCP may include a source driver unit SDB and a gate driver unit GDB.

[0061] The source driver unit SDB receives the source control signal SCS from the controller CP and the lifetime compensation data ACD from the image retention compensation unit AIC. In response to the source control signal SCS, the source driver unit SDB converts the lifetime compensation data ACD into a data signal DS and outputs the data signal DS to multiple data lines DL1-DLm. The data signal DS is an analog voltage corresponding to the grayscale value of the lifetime compensation data ACD.

[0062] The gate drive unit (GDB) receives the gate control signal (GCS) from the controller (CP). Based on the gate control signal (GCS), the gate drive unit (GDB) generates scan signals (SS1-SSn) and outputs the scan signals (SS1-SSn) to multiple gate lines (SL1-SLn).

[0063] The gate driving section (GDB) can be integrated into the display panel (DP). That is, the gate driving section (GDB) can be formed in the non-display area (NDA) of the display panel (DP) through a thin film process that forms a pixel (PX) in the display area (DA) of the display panel (DP).

[0064] Figure 3 This is a block diagram illustrating an image retention compensation unit according to an embodiment of the present invention. Figure 4 In the diagram, (a) is a diagram illustrating the structure of a main non-volatile memory according to an embodiment of the present invention, and (b) is a diagram illustrating the structure of a sub-non-volatile memory according to an embodiment of the present invention. Figure 5 It means Figure 3 The diagram shows the sequence of operations for the image retention compensation unit.

[0065] Reference Figure 3 The image retention compensation unit (AIC) includes a compensation unit (CSP), a memory control unit (MCP), a volatile memory (VLM), a main non-volatile memory (NVM1), and a sub-non-volatile memory (NVM2).

[0066] Image retention compensation unit AIC from controller CP (reference) Figure 2 The image retention unit (IMD) receives image data (IMD) and first accumulated data (CUD1) from the memory control unit (MCP). The image retention compensation unit (AIC) compensates for the image data IMD based on lifetime data (AGD), thereby generating lifetime compensation data (ACD). The image retention compensation unit (AIC) stores second accumulated data (CUD2) and lifetime data (AGD). To prevent users of the display device (DD) from recognizing image retention, the image retention compensation unit (AIC) generates lifetime compensation data (ACD) that compensates for the image data IMD. The functions of the image retention compensation unit (AIC) will be explained below based on its constituent components CSP, MCP, VLM, NVM1, and NVM2.

[0067] The compensation unit CSP receives image data IMD from the controller CP and first accumulated data CUD1 from the memory control unit MCP. The compensation unit CSP generates lifetime data AGD based on the first accumulated data CUD1. The compensation unit CSP outputs lifetime compensation data ACD, which compensates for the image data IMD based on the lifetime data AGD.

[0068] The Compensation Service Provider (CSP) can generate degradation data based on lifetime compensation data (ACD). The degradation data is represented by the image IM (refer to...). Figure 1 Displayed on the display panel DP (refer to)Figure 1 When the display panel DP includes each pixel PX (refer to) Figure 2 The degree of degradation is determined by the data signal DS corresponding to the lifetime compensation data ACD provided to the display panel DP in the current frame, while the image IM is displayed on the display panel DP. The compensation unit CSP can generate degradation data for the current frame based on the lifetime compensation data ACD. The data generated by accumulating the degradation data up to the previous frame is called the first accumulated data CUD1. The compensation unit CSP generates the second accumulated data CUD2 based on the first accumulated data CUD1 and the degradation data. The compensation unit CSP can accumulate the degradation data of the current frame on the first accumulated data CUD1 to generate the second accumulated data CUD2. As an example of the present invention, the first accumulated data CUD1 can be data generated by accumulating the degradation data up to the previous frame, and the second accumulated data CUD2 can be data generated by accumulating the degradation data up to the current frame. Therefore, the first accumulated data CUD1 and the second accumulated data CUD2 can be formed with a number of bits larger than the number of bits used to form the degradation data for each frame.

[0069] The compensation unit CSP can determine the degree of pixel PX degradation up to the previous frame based on the first accumulated data CUD1. To prevent image retention in the display panel DP in the current frame due to pixel PX degradation, and to prevent this retention from being recognized by the user, the compensation unit CSP can compensate for the image data IMD. As an example of the present invention, the compensation unit CSP can compensate for the image data IMD, making the grayscale value of the lifetime compensation data ACD larger than the grayscale value of the image data IMD. The data generated by the compensation unit CSP based on the first accumulated data CUD1 to compensate for the image data IMD is called lifetime data AGD.

[0070] At this time, the first cumulative data CUD1 and the second cumulative data CUD2 can each be formed from n bits of data, and the lifetime data AGD can be formed from m bits of data. Here, n and m are natural numbers greater than 1, and n is a natural number greater than m. Furthermore, as an example of the present invention, the lifetime data AGD used to compensate for the image data IMD can be formed from m bits of data selected from the n bits of data forming the first cumulative data CUD1. At this time, the reference for selecting the m bits of data from the n bits of data forming the first cumulative data CUD1 can vary depending on the size of the display panel DP, the driving speed of the display device DD, the accumulation time of the displayed image IM, the grayscale of the image IM, etc. As an example of the present invention, n can be 42 and m can be 10. However, the present invention is not limited to this, and the lifetime data AGD and the first cumulative data CUD1 can have the same number of bits.

[0071] The memory control unit (MCP) receives second accumulated data CUD2 and lifetime data AGD from the compensation unit (CSP). The memory control unit (MCP) stores the second accumulated data CUD2 received from the compensation unit (CSP) in the volatile memory (VLM).

[0072] The memory control unit (MCP) reads the second accumulated data CUD2 from the volatile memory (VLM) and stores the read second accumulated data CUD2 in the main non-volatile memory (NVM1). As an example of the present invention, the memory control unit (MCP) can read the second accumulated data CUD2 from the volatile memory (VLM) at a preset first cycle and store the read second accumulated data CUD2 in the main non-volatile memory (NVM1).

[0073] The memory control unit (MCP) receives lifetime data AGD from the compensation unit (CSP) and stores the received lifetime data AGD in the sub-nonvolatile memory (NVM2). As an example of the present invention, the memory control unit (MCP) may receive lifetime data AGD from the compensation unit (CSP) at a preset second cycle and store the received lifetime data AGD in the sub-nonvolatile memory (NVM2). In this case, as an example of the present invention, the first cycle and the second cycle may be set differently. For example, the second cycle may be set to be longer than the first cycle.

[0074] The volatile memory VLM receives the second accumulated data CUD2 from the memory control unit MCP and stores it. The main non-volatile memory NVM1 receives the second accumulated data CUD2 from the memory control unit MCP and stores it, while the sub-non-volatile memory NVM2 receives lifetime data AGD from the memory control unit MCP and stores it.

[0075] Memory is broadly classified into volatile memory (VLM) and non-volatile memory (NVM1, NVM2). While volatile memory (VLM) offers fast read and write speeds, its stored content is lost when the external power supply is interrupted. VLM includes DRAM (Dynamic RAM) and SRAM (Static RAM). Conversely, non-volatile memory (NVM1, NVM2) retains its stored content even when the external power supply is interrupted. NVM1, NVM2 includes EEPROM (Electrically EPROM) and flash memory. Therefore, display devices (DDs) use volatile memory (VLM) when reading and writing data to memory in real time. However, non-volatile memory (NVM1, NVM2) is used to store data that should be preserved even when the power supply to the display device (DD) is interrupted. In an embodiment of the present invention, when power is being supplied to the display device DD, the image retention compensation unit AIC outputs lifetime compensation data ACD in real time to compensate for image data IMD in the compensation unit CSP, and uses volatile memory VLM. Conversely, when power supply to the display device DD is interrupted and then resumed, the image retention compensation unit AIC uses main non-volatile memory NVM1 and sub-non-volatile memory NVM2 to effectively utilize second accumulated data CUD2, which accumulates degradation data of pixel PX up to the point before the power supply to the display device DD was interrupted.

[0076] Reference Figure 4 As an example of the present invention, the storage capacity of the sub-nonvolatile memory NVM2 can be smaller than the storage capacity of the main nonvolatile memory NVM1.

[0077] The second accumulated data CUD2 stored in the main non-volatile memory NVM1 can be formed from n bits (0 to n-1) of data. Of these n bits (0 to n-1), only m bits (nm to n-1) are used for image retention compensation in the image retention compensation algorithm logic included in the compensation unit CSP; the remaining bits are not used for image retention compensation. However, the main non-volatile memory NVM1 should not only store the degradation data for each frame, but also the second accumulated data CUD2, which accumulates the degradation data up to the current frame. This ensures that the degradation of pixel PX caused by the image IM displayed up to the current frame is correctly reflected when compensating the image data IMD in the next frame. Therefore, the main non-volatile memory NVM1 has a storage capacity capable of storing the second accumulated data CUD2 formed from n bits (0 to n-1) of data.

[0078] Conversely, the lifetime data AGD stored in the sub-nonvolatile memory NVM2 can be formed from m bits (0 to m-1) of data. The sub-nonvolatile memory NVM2 can store m bits (0 to m-1) of data used in the image retention compensation algorithm logic for image retention compensation. The lifetime data AGD is data generated in the previous frame based on the first accumulated data CUD1 for compensating for image data IMD. Even if the sub-nonvolatile memory NVM2 does not store the n bits of the second accumulated data CUD2, but only stores m bits (0 to m-1) of lifetime data AGD, it can still partially reflect the degradation information of pixel PX caused by the image IM displayed up to the current frame, thereby compensating for image data IMD in the next frame. The sub-nonvolatile memory NVM2 has a storage capacity capable of storing lifetime data AGD formed from m bits (0 to m-1) of data. Therefore, the storage capacity of the sub-nonvolatile memory NVM2 can be smaller than the storage capacity of the main nonvolatile memory NVM1. Therefore, even if the sub-nonvolatile memory NVM2 is added to the image retention compensation unit AIC, the increase in the overall size of the image retention compensation unit AIC due to the addition of the sub-nonvolatile memory NVM2 can be minimized. Furthermore, the latency required for the memory control unit MCP to read data stored in the sub-nonvolatile memory NVM2 can be shorter than the latency required for the memory control unit MCP to read data stored in the main nonvolatile memory NVM1. However, it is also possible to store n bits of second accumulated data CUD2 in the sub-nonvolatile memory NVM2. In this case, the storage capacity of the sub-nonvolatile memory NVM2 can be the same as the storage capacity of the main nonvolatile memory NVM1. In this case, the latency required for the memory control unit MCP to read data stored in the sub-nonvolatile memory NVM2 can be equal to the latency required for the memory control unit MCP to read data stored in the main nonvolatile memory NVM1.

[0079] The following is through Figure 5 The operation of the image retention compensation unit (AIC) is explained in detail when the display device DD is working.

[0080] Reference Figure 2 , Figure 3 and Figure 5After the display device DD is turned on, the image retention compensation unit AIC of the display device DD receives image data IMD and first accumulated data CUD1 to perform image retention compensation. The image retention compensation unit AIC compensates for the image data IMD based on lifetime data AGD to generate lifetime compensation data ACD. Then, the image retention compensation unit AIC stores second accumulated data CUD2 and lifetime data AGD. The panel driver unit PCP provides the display panel DP with a data signal DS corresponding to the lifetime compensation data ACD. The display panel DP displays the image IMD corresponding to the data signal DS (see reference). Figure 1 The following is a detailed explanation of the operation of the image retention compensation unit (AIC).

[0081] The steps of the image retention compensation unit (AIC) generating lifetime compensation data (ACD) include: step S100, receiving first accumulated data (CUD1) and generating lifetime data (AGD) based on the first accumulated data (CUD1); and step S200, generating lifetime compensation data (ACD) based on lifetime data (AGD) to compensate for image data (IMD).

[0082] In step S100 of generating lifetime data AGD, the memory control unit MCP reads second accumulated data CUD2 from the volatile memory VLM, and the compensation unit CSP receives the read second accumulated data CUD2 from the memory control unit MCP as first accumulated data CUD1. The compensation unit CSP generates lifetime data AGD based on the received first accumulated data CUD1.

[0083] In step S200 of generating lifetime compensation data ACD, the compensation unit CSP generates lifetime compensation data ACD that compensates the received image data IMD based on lifetime data AGD.

[0084] The steps of storing the second accumulated data CUD2 and lifetime data AGD in the image retention compensation unit AIC include: step S300, generating the second accumulated data CUD2 based on the first accumulated data CUD1; and step S400, receiving the second accumulated data CUD2 and storing the second accumulated data CUD2 in the volatile memory VLM.

[0085] In step S300 of generating the second cumulative data CUD2, the second cumulative data CUD2 is generated based on the deterioration data, which is generated according to the received first cumulative data CUD1 and lifetime compensation data ACD.

[0086] In step S400, where the second accumulated data CUD2 is stored in the volatile memory VLM, the memory control unit MCP receives the second accumulated data CUD2 from the compensation unit CSP and stores the received second accumulated data CUD2 in the volatile memory VLM. By storing the second accumulated data CUD2 in the volatile memory VLM, the compensation unit CSP can read the second accumulated data CUD2 stored in the volatile memory VLM in real time to compensate for the image data IMD.

[0087] Then, the image retention compensation unit AIC determines whether a preset first cycle has passed (S500). If the first cycle has not passed (S500: No), the image retention compensation unit AIC repeats the above steps S100-S400.

[0088] If the first cycle has elapsed (S500: Yes), the image retention compensation unit AIC receives the second accumulated data CUD2 and stores it in the main non-volatile memory NVM1 (S600). After storing the second accumulated data CUD2 in the main non-volatile memory NVM1, the image retention compensation unit AIC determines whether a preset second cycle has elapsed (S700). If the second cycle has not elapsed (S700: No), the image retention compensation unit AIC repeats the above steps S100-S600. If the second cycle has elapsed (S700: Yes), the image retention compensation unit AIC receives lifetime data AGD and stores the received lifetime data AGD in the sub-non-volatile memory NVM2 (S800).

[0089] In step S600, where the second accumulated data CUD2 is stored in the main non-volatile memory NVM1, the memory control unit MCP receives the second accumulated data CUD2 from the compensation unit CSP and stores the received second accumulated data CUD2 in the main non-volatile memory NVM1. By storing the second accumulated data CUD2 in the main non-volatile memory NVM1, the second accumulated data CUD2 can be preserved even if the power supply to the display device DD is interrupted. Furthermore, when the display device DD is turned on again, the second accumulated data CUD2 stored in the main non-volatile memory NVM1 is read and stored in the volatile memory VLM, so that the compensation unit CSP can compensate for the image data IMD based on the degradation data of the pixel PX up to the point before the power supply to the display device DD was interrupted.

[0090] Then, the image retention compensation unit (AIC) can determine whether the preset second cycle has been completed (S700).

[0091] In step S800, where lifetime data AGD is stored in sub-nonvolatile memory NVM2, the memory control unit MCP receives lifetime data AGD from the compensation unit CSP and stores the received lifetime data AGD in sub-nonvolatile memory NVM2. By storing lifetime data AGD in sub-nonvolatile memory NVM2, lifetime data AGD can be preserved even if the power supply to the display device DD is interrupted. Furthermore, even if at least a portion of the main nonvolatile memory NVM1 is damaged and the second accumulated data CUD2 stored in the main nonvolatile memory NVM1 cannot be read, lifetime data AGD stored in sub-nonvolatile memory NVM2 can be read and stored in volatile memory VLM. Therefore, the compensation unit CSP can compensate for image data IMD in the current frame based on lifetime data AGD used to compensate for image data IMD in the frame before the power supply to the display device DD was interrupted.

[0092] Figure 6 This is a block diagram illustrating the operation of an image retention compensation unit according to an embodiment of the present invention when at least a portion of the main non-volatile memory is damaged. Figure 7 This is a diagram illustrating the effects of the presence or absence of a sub-nonvolatile memory according to an embodiment of the present invention. Figure 8 It means Figure 6 The diagram shows the sequence of operations for the image retention compensation unit.

[0093] The following omits references and discussions. Figure 3 The description is the same as the detailed description of the structure.

[0094] Reference Figure 6 and Figure 8 If at least a portion of the main non-volatile memory NVM1 is damaged, the second accumulated data CUD2 stored in the main non-volatile memory NVM1 may disappear or be corrupted. If the display device DD is turned on while the second accumulated data CUD2 is missing or corrupted, the memory control unit MCP will be unable to read the second accumulated data CUD2 from the main non-volatile memory NVM1.

[0095] The memory control unit MCP can determine whether at least a portion of the main non-volatile memory NVM1 is damaged before reading the second accumulated data CUD2 (S101). If it is determined that at least a portion of the main non-volatile memory NVM1 is damaged (S101: Yes), the memory control unit MCP reads the lifetime data AGD stored in the sub-non-volatile memory NVM2 (S102). The memory control unit MCP can expand the lifetime data AGD read from the sub-non-volatile memory NVM2 to n bits (S103) and store the expanded n-bit data BED in the main non-volatile memory NVM1 as the first accumulated data CUD1 (S104). However, as an example of the present invention, the memory control unit MCP may not expand the number of bits of the read lifetime data AGD, but directly store it in the main non-volatile memory NVM1 as the first accumulated data CUD1.

[0096] Then, the memory control unit MCP can read the first accumulated data CUD1 stored in the main non-volatile memory NVM1 (S105).

[0097] The memory control unit MCP can store the first accumulated data CUD1 read again in the volatile memory VLM (S106).

[0098] The compensation unit CSP can receive the first accumulated data CUD1 stored in the volatile memory VLM from the memory control unit MCP, and generate lifetime data AGD based on the received first accumulated data CUD1 (S107).

[0099] Therefore, even if at least a portion of the main non-volatile memory NVM1 is damaged, the compensation unit CSP can compensate for the image data IMD based on the lifetime data AGD, thereby generating lifetime compensation data ACD.

[0100] Assuming that when the display device DD is turned on, the memory control unit MCP determines that there is no damaged portion of the main non-volatile memory NVM1 (S101: No), the memory control unit MCP reads the past second accumulated data PCD stored in the main non-volatile memory NVM1 (refer to...). Figure 9 (S102a). Then, the memory control unit MCP stores the read past second accumulated data PCD in the volatile memory VLM as the first accumulated data CUD1 (S106a). The past second accumulated data PCD may be the second accumulated data CUD2 stored in the main non-volatile memory NVM1 in the frame before the power supply to the interrupted display device DD.

[0101] The compensation unit CSP can receive the first accumulated data CUD1 stored in the volatile memory VLM from the memory control unit MCP, and generate lifetime data AGD based on the received first accumulated data CUD1 (S107).

[0102] Reference Figure 6 and Figure 7 The image shown represents the first image IM1 (referencing). Figure 1 The first curve G1 and the second curve G2 represent the brightness maintenance rate of a fixed region.

[0103] When the first case is defined as a situation where at least a portion of the main non-volatile memory NVM1 is damaged and compensation for image data IMD is impossible, the first curve G1 is a curve representing the brightness maintenance rate of a fixed area under the first case. The first curve G1 represents the case where the brightness maintenance rate of the fixed area decreases.

[0104] In the second case, where the image data IMD can be compensated using lifetime data AGD stored in the sub-nonvolatile memory NVM2 even if at least a portion of the main nonvolatile memory NVM1 is damaged, the second curve G2 represents the brightness maintenance rate of the fixed area in the second case. The second curve G2 indicates that the brightness maintenance rate of the fixed area is maintained.

[0105] If at least a portion of the main non-volatile memory NVM1 is damaged, and the sub-non-volatile memory NVM2 is absent, then when the display device DD is turned on, the compensation unit CSP cannot receive the first accumulated data CUD1, which accumulates the degradation data of pixel PX up to the point before the power supply to the display device DD is interrupted. Therefore, the image retention compensation algorithm of the compensation unit CSP cannot function properly, and the degradation of pixel PX in the fixed area cannot be compensated, resulting in a gradual decrease in the brightness maintenance rate of the fixed area.

[0106] Conversely, even if at least a portion of the main non-volatile memory NVM1 is damaged, if a sub-non-volatile memory NVM2 exists, when the display device DD is turned on, the compensation unit CSP can receive first accumulated data CUD1, reflecting the degradation data of some pixels PX up to the point before the power supply to the display device DD was interrupted, based on the lifetime data AGD stored in the sub-non-volatile memory NVM2. Therefore, the image retention compensation algorithm of the compensation unit CSP can function normally, the degradation of pixels PX in the fixed area can be compensated, and the brightness maintenance rate of the fixed area can be restored to the level before the power supply to the display device DD was interrupted.

[0107] The period up to the point before the power supply to the display device DD is interrupted can be referred to as the first interval Ta. During the first interval Ta, the compensation unit CSP can receive the second accumulated data CUD2 stored in the volatile memory VLM as the first accumulated data CUD1 via the memory control unit MCP. Therefore, the afterimage compensation algorithm of the compensation unit CSP functions normally, thus maintaining the brightness maintenance rate of the fixed area at a constant value in both the first and second cases.

[0108] The second interval Tb can be defined as the period from when the power supply to the display device DD is interrupted and then re-energized until the compensation unit CSP receives the first accumulated data CUD1 through the memory control unit MCP. In the second interval Tb, the brightness maintenance rate of the fixed area decreases in both the first and second cases.

[0109] After the power supply to the interrupted display device DD is restored and the display device DD is turned on again, the interval after the compensation unit CSP receives the first accumulated data CUD1 through the memory control unit MCP is called the third interval Tc. In the first case, the brightness maintenance rate of the fixed area continues to decrease. However, in the second case, the brightness maintenance rate of the fixed area recovers to the level of the brightness maintenance rate in the first interval Ta before the power supply was interrupted.

[0110] Therefore, even if at least a portion of the main non-volatile memory NVM1 is damaged, the user can be prevented from recognizing the image retention when the image retention compensation unit AIC includes the sub-non-volatile memory NVM2.

[0111] Figure 9 This is a block diagram illustrating the operation of an image retention compensation unit according to an embodiment of the present invention when the display device is turned on. Figure 10 It is used to explain and Figure 9 The diagram shows the effects of the image retention compensation unit on its operation. Figure 11 It means Figure 9 The diagram shows the sequence of operations for the image retention compensation unit.

[0112] The following omits references and discussions. Figure 3 The description is the same as the detailed description of the structure.

[0113] Reference Figure 9 and Figure 11 As an example of the present invention, in the display device DD (refer to...) Figure 2 When the circuit is activated, the memory control unit (MCP) can adjust the display panel (DP) according to the circuit. Figure 2 Does the image IM (refer to) display? Figure 1 This makes the operation of storing the first accumulated data CUD1 in the volatile memory VLM different.

[0114] Before storing the first accumulated data CUD1 in the volatile memory VLM, the memory control unit MCP determines whether the image IM is displayed on the display panel DP when the display device DD is turned on (S101a).

[0115] If it is determined that an image is displayed on the display panel DP (S101a: Yes), the memory control unit MCP reads the lifetime data AGD stored in the sub-non-volatile memory NVM2 (S102). The memory control unit MCP can expand the lifetime data AGD read from the sub-non-volatile memory NVM2 to n bits (S103), and store the expanded n-bit data BED in the volatile memory VLM as the first accumulated data CUD1 (S104a). However, as an example of the present invention, the memory control unit MCP may not expand the number of bits of the read lifetime data AGD, but directly store it in the volatile memory VLM as the first accumulated data CUD1.

[0116] If it is determined that no image is displayed on the display panel DP (S101a: No), the memory control unit MCP reads the past second accumulated data PCD stored in the main non-volatile memory NVM1 (S102a). Then, the memory control unit MCP stores the read past second accumulated data PCD in the volatile memory VLM as the first accumulated data CUD1 (S106a).

[0117] Reference Figure 10 The image shown indicates that the first image IM1 is displayed (refer to...). Figure 1 The third curve G3 and the fourth curve G4 represent the brightness maintenance rate of the fixed area.

[0118] When the display device DD is turned on, the case in which the first cumulative data CUD1 is stored in the volatile memory VLM after step S102 of reading lifetime data AGD from the sub-nonvolatile memory NVM2 through the memory control unit MCP is called the third case. The third curve G3 is a curve representing the brightness maintenance rate of the fixed area in the third case.

[0119] In the display device DD (reference) Figure 2 When the circuit is turned on, the step of reading the second accumulated data PCD from the main non-volatile memory NVM1 through the memory control unit MCP (S102a) and storing the first accumulated data CUD1 in the volatile memory VLM is called the fourth case. The fourth curve G4 is a curve representing the brightness maintenance rate of the fixed area in the fourth case.

[0120] As an example of the present invention, the second interval Tb (refer to...) Figure 7 It includes the first subinterval Tb1 and the second subinterval Tb2.

[0121] When the power supply to the display device DD is interrupted and then reconnected, the interval from which the compensation unit CSP receives the first accumulated data CUD1 through the memory control unit MCP, which is considered a third case, can be called the first sub-interval Tb1.

[0122] When the power supply to the display device DD is interrupted and then reconnected, the interval from which the compensation unit CSP receives the first accumulated data CUD1 through the memory control unit MCP, which is considered the fourth case, can be called the second sub-interval Tb2.

[0123] The past second accumulated data PCD stored in the main non-volatile memory NVM1 is n bits of data, and the lifetime data AGD stored in the sub-non-volatile memory NVM2 is m bits of data. Therefore, the time required for the memory control unit MCP to read the lifetime data AGD stored in the sub-non-volatile memory NVM2 is shorter than the time required for the memory control unit MCP to read the past second accumulated data PCD stored in the main non-volatile memory NVM1.

[0124] Therefore, in the case where the compensation unit CSP receives the first accumulated data CUD1 as the third case rather than the fourth case, the time required for the compensation unit CSP to compensate for the image data IMD can be shortened.

[0125] Referring to the third curve G3 and the fourth curve G4, the first sub-interval Tb1 where the brightness of the fixed region decreases in the third case is shorter than the second sub-interval Tb2 where the brightness of the fixed region decreases in the fourth case.

[0126] When the image retention compensation unit AIC includes a sub-nonvolatile memory NVM2, when the display device DD is turned on, the compensation unit CSP can receive the first accumulated data CUD1 through the memory control unit MCP as a third case. Therefore, when the display device DD is turned on, even if the image IM is displayed in the display panel DP, the time required to compensate for the image data IMD can be shortened, thus shortening the time when the image retention is recognized by the user.

[0127] Then, in the third interval Tc, the compensation unit CSP can receive the first accumulated data CUD1 stored in the volatile memory VLM from the memory control unit MCP, and generate lifetime data AGD based on the received first accumulated data CUD1.

[0128] Figure 12 This is a block diagram illustrating an image retention compensation unit according to an embodiment of the present invention.

[0129] The following omits references and discussions. Figure 3 The description is the same as the detailed description of the structure.

[0130] Reference Figure 12 The main non-volatile memory NVM1 may include a first main module MB1 and a second main module MB2. The memory control unit MCP may alternately store the second accumulated data CUD2 in the first main module MB1 and the second main module MB2. As an example of the present invention, the main non-volatile memory NVM1 may also include two or more main modules.

[0131] As the memory control unit MCP alternately stores the second accumulated data CUD2 in the first main module MB1 and the second main module MB2, even if either the first main module MB1 or the second main module MB2 is damaged, the memory control unit MCP can read the second accumulated data CUD2 from the other main module.

[0132] The sub-nonvolatile memory NVM2 may include a first submodule SB1 and a second submodule SB2. The memory control unit MCP may alternately store lifetime data AGD in the first submodule SB1 and the second submodule SB2. As an example of the present invention, the sub-nonvolatile memory NVM2 may also include two or more submodules.

[0133] As the memory control unit (MCP) alternately stores lifetime data AGD in the first submodule SB1 and the second submodule SB2, even if either the first submodule SB1 or the second submodule SB2 is damaged, the memory control unit (MCP) can read lifetime data AGD from the other submodule.

[0134] The present invention has been described above with reference to preferred embodiments. However, those skilled in the art or those of ordinary skill in the art should understand that the present invention can be modified and altered in various ways without departing from the spirit and technical scope of the invention as set forth in the claims.

[0135] Therefore, the technical scope of this invention should not be limited to the contents described in the detailed specification, but should be determined solely by the claims.

Claims

1. A display device, comprising: Display panel; displays images. The image retention compensation unit receives image data, compensates the image data based on lifetime data to generate lifetime compensation data, and stores second accumulated data and the lifetime data. as well as The panel driving unit provides the display panel with a data signal corresponding to the lifespan compensation data to drive the display panel. The image retention compensation unit includes: The compensation unit receives first accumulated data, generates lifetime data based on the first accumulated data, outputs lifetime compensation data that compensates the image data based on the lifetime data, and generates second accumulated data based on the first accumulated data. The memory control unit receives the second accumulated data and the lifetime data from the compensation unit, and sends the first accumulated data to the compensation unit. The volatile memory receives the second accumulated data from the memory control unit for storage; The main non-volatile memory receives the second accumulated data from the memory control unit for storage; and The sub-nonvolatile memory receives the lifetime data from the memory control unit for storage. The compensation unit generates degradation data for the current frame based on the lifetime compensation data. The first accumulated data is generated by accumulating the degraded data up to the previous frame. The second accumulated data is generated by accumulating the degraded data of the current frame on top of the first accumulated data. When at least a portion of the main non-volatile memory is damaged, the memory control unit reads the lifetime data stored in the sub-non-volatile memory and stores the lifetime data in the main non-volatile memory as the first accumulated data.

2. The display device according to claim 1, wherein, The storage capacity of the sub-nonvolatile memory is smaller than that of the main nonvolatile memory.

3. The display device according to claim 1, wherein, The first and second accumulated data are formed by n bits of data. The lifetime data is formed from m-bit data. Here, n and m are natural numbers greater than 1, and n is a natural number greater than m.

4. The display device according to claim 1, wherein, The compensation unit receives the first accumulated data from the memory control unit. When the display device is turned on, the memory control unit reads the past second accumulated data stored in the main non-volatile memory in the previous frame, and stores the read past second accumulated data in the volatile memory as the first accumulated data.

5. The display device according to claim 4, wherein, After the memory control unit expands the lifetime data to n bits, it stores the n bits of data in the main non-volatile memory.

6. The display device according to claim 4, wherein, When the image is displayed on the display panel, the memory control unit reads the lifetime data stored in the sub-nonvolatile memory and stores the read lifetime data in the volatile memory as the first accumulated data.

7. The display device according to claim 6, wherein, After expanding the lifetime data to n bits, the memory control unit stores the n bits of data in the volatile memory as the first accumulated data.

8. The display device according to claim 1, wherein, The memory control unit reads the second accumulated data stored in the volatile memory at a preset first cycle, and stores the read second accumulated data in the main non-volatile memory. The memory control unit receives the lifetime data from the compensation unit at a preset second cycle and stores the received lifetime data in the sub-nonvolatile memory.

9. The display device according to claim 8, wherein, The first cycle and the second cycle are set to be different.

10. The display device according to claim 1, wherein, The main non-volatile memory includes: The first main module; and The second main module, The memory control unit alternately stores the second accumulated data in the first main module and the second main module.

11. The display device according to claim 1, wherein, The sub-nonvolatile memory includes: First submodule; and The second submodule, The memory control unit alternately stores the lifetime data in the first submodule and the second submodule.

12. The display device according to claim 1, wherein, The display panel includes a controller that receives image signals from the outside and generates image data based on the image signals.

13. A method for driving a display device, comprising: The steps of receiving image data and first accumulated data and generating lifetime compensation data by compensating the image data based on lifetime data; The step of storing the second accumulated data and the lifetime data; The step of providing the data signal corresponding to the life compensation data to the display panel; as well as The step of displaying an image corresponding to the data signal. The steps for generating the lifetime compensation data include: The steps of receiving the first accumulated data and generating the lifetime data based on the first accumulated data; and The step of generating lifetime-compensated data based on the lifetime data to compensate for the image data. The steps of storing the second accumulated data and the lifetime data include: The step of generating the second cumulative data based on the first cumulative data; The steps of receiving the second accumulated data from the memory control unit and storing the second accumulated data in volatile memory; The steps of receiving the second accumulated data from the memory control unit and storing the second accumulated data in the main non-volatile memory; and The steps of receiving the lifetime data from the memory control unit and storing the lifetime data in the sub-nonvolatile memory. The step of generating the lifetime compensation data further includes: a step of generating degradation data for the current frame based on the lifetime compensation data. The first accumulated data is generated by accumulating the degraded data up to the previous frame. The second accumulated data is generated by accumulating the degraded data of the current frame on top of the first accumulated data. When at least a portion of the main non-volatile memory is damaged, the memory control unit reads the lifetime data stored in the sub-non-volatile memory and stores the lifetime data in the main non-volatile memory as the first accumulated data.

14. The driving method for the display device according to claim 13, wherein, The storage capacity of the sub-nonvolatile memory is smaller than that of the main nonvolatile memory.

15. The driving method for a display device according to claim 14, wherein, The first and second accumulated data are formed by n bits of data. The lifetime data is formed from m-bit data. Here, n and m are natural numbers greater than 1, and n is a natural number greater than m.

16. The driving method for a display device according to claim 15, wherein, The step of generating the lifetime compensation data further includes: The step of reading the lifetime data stored in the sub-nonvolatile memory in the event that at least a portion of the main nonvolatile memory is damaged; The step of expanding the read lifetime data to n bits; and The step of storing the n-bit data in the main non-volatile memory as the first accumulated data.

17. The driving method for a display device according to claim 15, wherein, The step of generating the lifetime compensation data further includes: The step of reading the lifetime data stored in the sub-nonvolatile memory when the display device is turned on; The step of expanding the read lifetime data to n bits; and The step of storing the n-bit data in the volatile memory as the first accumulated data.

18. The driving method for a display device according to claim 13, wherein, The step of storing the second accumulated data in the main nonvolatile memory includes: The step of storing the second accumulated data in the first main module; and The step of storing the second accumulated data in the second main module. The step of storing the lifetime data in the sub-nonvolatile memory includes: The step of storing the lifetime data in the first submodule; and The step of storing the lifetime data in the second submodule.

Images