Display device and driving method thereof

Abstract

The invention relates to a display device and a driving method thereof. A display device of the present invention includes: a pixel; a gradation conversion unit that applies a compensation value to an input gradation for the pixel to convert the input gradation into an output gradation; and a controller supplying a data voltage corresponding to the output gray scale to the pixel, the gradation conversion unit independently generates a first stress and a second stress on the basis of the output gradation, applies a first accumulation coefficient to a first stress accumulation value, and adds the first stress to update the first stress accumulation value. Applying a second accumulation coefficient to a second stress accumulation value and adding the second stress to update the second stress accumulation value, and generating the compensation value based on the first stress accumulation value and the second stress accumulation value; the first accumulation coefficient and the second accumulation coefficient are different from each other.

Description

Technical Field

[0001] The present invention relates to a display device and a driving method thereof. Background Art

[0002] With the development of information technology, the importance of display devices as a connection medium between users and information has become increasingly prominent. Accordingly, the use of display devices such as liquid crystal display devices (Liquid Crystal Display Device) and organic light emitting display devices (Organic Light Emitting Display Device) is on the rise.

[0003] The display device uses a plurality of pixels to display an image. Each pixel includes a driving transistor. The driving transistor adjusts the amount of driving current based on the applied voltage, thereby being able to adjust the brightness of the pixel.

[0004] When a display device displays a second image after displaying a first image, an afterimage of the first image may remain in the display of the second image. The afterimage may be caused by a voltage stress (Voltagestress) applied to the driving transistor corresponding to the first image. Summary of the invention

[0005] An object of the present invention is to provide a display device and a driving method thereof that can compensate for both short-term image sticking and medium- to long-term image sticking.

[0006] A display device according to an embodiment of the present invention includes: a pixel; a grayscale conversion unit, applying a compensation value to an input grayscale for the pixel to convert the input grayscale into an output grayscale; and a controller, providing a data voltage corresponding to the output grayscale to the pixel; the grayscale conversion unit independently generates a first stress and a second stress based on the output grayscale, applies a first accumulation coefficient to a first stress accumulation value and then adds the first stress to update the first stress accumulation value, applies a second accumulation coefficient to a second stress accumulation value and then adds the second stress to update the second stress accumulation value, and generates the compensation value based on the first stress accumulation value and the second stress accumulation value; the first accumulation coefficient and the second accumulation coefficient are different from each other.

[0007] The first stress is a stress value when the data voltage is applied to the pixel during a first period, and the second stress is a stress value when the data voltage is applied to the pixel during a second period, and the second period may be longer than the first period.

[0008] The second accumulation coefficient may be greater than the first accumulation coefficient.

[0009] The grayscale conversion unit may generate the compensation value based on a first conversion cumulative value obtained by applying a first weighting value to the first stress cumulative value and a second conversion cumulative value obtained by applying a second weighting value to the second stress cumulative value.

[0010] The display device according to an embodiment of the present invention may further include a memory for storing the first transformed cumulative value and the second transformed cumulative value, the first transformed cumulative value being smaller than the first stress accumulated value, and the second transformed cumulative value being smaller than the second stress accumulated value.

[0011] The grayscale conversion section may calculate the first stress accumulation value by applying the inverse of the first weighting value to the first conversion accumulation value read from the memory.

[0012] The grayscale conversion section may calculate the second stress cumulative value by applying the inverse of the second weighting value to the second conversion cumulative value read from the memory.

[0013] The grayscale conversion unit may include: a first stress conversion unit, which converts the output grayscale into the first stress in a voltage domain; a second stress conversion unit, which converts the output grayscale into the second stress in the voltage domain; a memory, which stores a first conversion cumulative value obtained by applying a first weighted value to the first stress cumulative value and a second conversion cumulative value obtained by applying a second weighted value to the second stress cumulative value; a first stress accumulation unit, which calculates the first stress cumulative value by applying the inverse of the first weighted value to the first conversion cumulative value, and updates the first stress cumulative value by applying the first accumulation coefficient to the first stress cumulative value and adding the first stress; a second stress accumulation unit, which calculates the second stress cumulative value by applying the inverse of the second weighted value to the second conversion cumulative value, and updates the second stress cumulative value by applying the second accumulation coefficient to the second stress cumulative value and adding the second stress; and a stress compensation unit, which generates the compensation value based on the first conversion cumulative value and the second conversion cumulative value.

[0014] The number of bits used to represent the first stress and the number of bits used to represent the second stress may be different from each other.

[0015] The first stress is a stress value when the data voltage is applied to the pixel during a first period, and the second stress is a stress value when the data voltage is applied to the pixel during a second period, the second period is longer than the first period, and the number of bits used to represent the first stress can be greater than the number of bits used to represent the second stress.

[0016] A driving method for a display device according to an embodiment of the present invention comprises: a step of generating a compensation value; a step of applying the compensation value to an input grayscale for a pixel to convert the input grayscale into an output grayscale; and a step of providing a data voltage corresponding to the output grayscale to the pixel; a first stress and a second stress are independently generated based on the output grayscale, a first stress accumulation value is updated by adding the first stress after applying a first accumulation coefficient to the first stress accumulation value, a second stress accumulation value is updated by adding the second stress after applying a second accumulation coefficient to the second stress accumulation value, and the compensation value is generated based on the first stress accumulation value and the second stress accumulation value; the first accumulation coefficient and the second accumulation coefficient are different from each other.

[0017] The first stress is a stress value when the data voltage is applied to the pixel during a first period, and the second stress is a stress value when the data voltage is applied to the pixel during a second period, and the second period may be longer than the first period.

[0018] The second accumulation coefficient may be greater than the first accumulation coefficient.

[0019] The compensation value may be generated based on a first transformed cumulative value obtained by applying a first weighted value to the first stress accumulated value and a second transformed cumulative value obtained by applying a second weighted value to the second stress accumulated value.

[0020] The display device includes a memory for storing the first transformed cumulative value and the second transformed cumulative value, the first transformed cumulative value is smaller than the first stress accumulated value, and the second transformed cumulative value may be smaller than the second stress accumulated value.

[0021] The display device may calculate the first stress accumulation value by applying the inverse of the first weighting value to the first transformed accumulation value read from the memory.

[0022] The display device may calculate the second stress accumulation value by applying the inverse of the second weighting value to the second transformed accumulation value read from the memory.

[0023] The step of generating the compensation value may include: a step of transforming the output grayscale into the first stress in the voltage domain; a step of transforming the output grayscale into the second stress in the voltage domain; a step of reading a first transformation cumulative value and a second transformation cumulative value; a step of calculating the first stress accumulation value by applying the inverse of a first weighted value to the first transformation cumulative value, and updating the first stress accumulation value by applying the first accumulation coefficient to the first stress accumulation value and adding the first stress; a step of calculating the second stress accumulation value by applying the inverse of a second weighted value to the second transformation cumulative value, and updating the second stress accumulation value by applying the second accumulation coefficient to the second stress accumulation value and adding the second stress; a step of storing the first transformation cumulative value obtained by applying the first weighted value to the first stress accumulation value and the second transformation cumulative value obtained by applying the second weighted value to the second stress accumulation value; and a step of generating the compensation value based on the first transformation cumulative value and the second transformation cumulative value.

[0024] The number of bits used to represent the first stress and the number of bits used to represent the second stress may be different from each other.

[0025] The first stress is a stress value when the data voltage is applied to the pixel during a first period, and the second stress is a stress value when the data voltage is applied to the pixel during a second period, the second period is longer than the first period, and the number of bits used to represent the first stress can be greater than the number of bits used to represent the second stress.

[0026] (Effects of the Invention)

[0027] According to the display device and the driving method thereof of the present invention, both short-term image sticking and medium- to long-term image sticking can be compensated. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. 1 is a diagram for explaining a display device according to an embodiment of the present invention.

[0029] Figure 2 is a diagram for explaining a pixel according to an embodiment of the present invention.

[0030] Figure 3 It is used to illustrate Figure 2 FIG. 1 is a diagram of an exemplary driving method for a pixel.

[0031] Figure 4 It is a diagram for explaining a grayscale conversion unit according to an embodiment of the present invention.

[0032] Figures 5 to 10 1 is a diagram for explaining a method of calculating a cumulative coefficient according to an embodiment of the present invention.

[0033] Fig.11 It is a diagram for explaining a grayscale conversion unit according to another embodiment of the present invention.

[0034] Fig.12 is a block diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be implemented in various different ways and is not limited to the embodiments described herein.

[0036] In order to clearly explain the present invention, parts not related to the explanation are omitted, and the same or similar components are given the same reference numerals throughout the specification. Therefore, the reference numerals explained above can be used in other drawings.

[0037] In addition, the size and thickness of each structure shown in the figure are arbitrarily shown for the convenience of explanation, and therefore the present invention is not necessarily limited to the case shown in the figure. In the drawings, in order to clearly show each layer and region, the thickness may be exaggerated.

[0038] Furthermore, the expression "same" in the description may mean "substantially the same". That is, the same to a degree that can be recognized by a person skilled in the art. Other expressions may also be expressions in which "substantially" is omitted.

[0039] Figure 1 FIG. 1 is a diagram for explaining a display device according to an embodiment of the present invention.

[0040] Reference Figure 1 According to an embodiment of the present invention, a display device DD may include: a controller 11, a grayscale conversion unit 12, a scan driving unit 13, a pixel unit 14 and a light emitting driving unit 15.

[0041] The controller 11 may receive an input grayscale IG for a pixel from an external processor, which may be an application processor (AP), a central processing unit (CPU), a graphics processing unit (GPU), or the like.

[0042] The grayscale conversion unit 12 may apply a compensation value to the input grayscale IG for the pixel to convert it into an output grayscale OG. In the case where the grayscale conversion unit 12 and the controller 11 are separately constituted by an integrated chip (IC), the grayscale conversion unit 12 may receive the input grayscale IG from the controller 11 and provide the output grayscale OG to the controller 11. In other embodiments, the grayscale conversion unit 12 and the controller 11 may also be constituted as an integrated IC.

[0043] The controller 11 may provide a data voltage corresponding to the output grayscale OG to the pixel. The input grayscale IG and the output grayscale OG may be digital signals, and the data voltage may be an analog voltage. In other embodiments, the controller 11 may also be separately configured as a timing control unit and a data driving unit. Furthermore, the controller 11 may generate a control signal for applying a data voltage to the pixel unit 14 and provide it to the scanning driving unit 13 and the light emitting driving unit 15. In other embodiments, the light emitting driving unit 15 may also be omitted according to the structure of the pixel circuit.

[0044] The controller 11 may apply data voltages to the data lines DL1 ˜DLn in pixel row units (or horizontal line units). n may be an integer greater than 0. A pixel row may refer to pixels connected to the same scan line and light emitting line.

[0045] The scanning driving unit 13 may receive a clock signal, a scanning start signal, etc. from the controller 11, thereby generating a scanning signal for providing to the scanning lines SL0, SL1, SL2, ..., SLm. For example, the scanning driving unit 13 may sequentially provide scanning signals having turn-on level pulses to the scanning lines SL1 to SLm. For example, the scanning driving unit 13 may be configured in the form of a shift register, and may generate a scanning signal in a manner that a scanning start signal in the form of a turn-on level pulse is sequentially transmitted to a next-level circuit according to the control of a clock signal. m may be an integer greater than 0.

[0046] The light-emitting driving unit 15 may receive a clock signal, a light-emitting stop signal, etc. from the controller 11, thereby generating a light-emitting signal for providing to the light-emitting lines EL1, EL2, EL3, ..., ELo. For example, the light-emitting driving unit 15 may sequentially provide light-emitting signals having turn-off level pulses to the light-emitting lines EL1 to ELo. For example, the light-emitting driving unit 15 may be configured in the form of a shift register, and may generate a light-emitting signal in a manner that a light-emitting stop signal in the form of a turn-off level pulse is sequentially transmitted to a next-level circuit according to the control of a clock signal. o may be an integer greater than 0.

[0047] The pixel unit 14 includes pixels. Each pixel PXij can be connected to a corresponding data line, a scan line, and a light-emitting line. i and j can be integers greater than 0, respectively. The pixel PXij can refer to a pixel in which a scan transistor is connected to the i-th scan line and the j-th data line. The pixel PXij can emit light in one of a first color, a second color, and a third color.

[0048] The first color, the second color, and the third color may be different colors from each other. For example, the first color may be one of red, green, and blue, the second color may be one of red, green, and blue that is not the first color, and the third color may be the remaining color of red, green, and blue that is not the first color and the second color. Furthermore, magenta, cyan, and yellow may be used as the first to third colors instead of red, green, and blue. However, in this embodiment, for the sake of convenience of explanation, it is assumed that the first color is red, the second color is green, and the third color is blue.

[0049] The pixel portion 14 may be formed of a diamond corrugated tile. ), RGB-Stripe, S-Stripe, Real RGB, normal ) and other configurations.

[0050] It is assumed that the pixels of the pixel unit 14 are arranged along a first direction DR1 and a second direction DR2 perpendicular to the first direction DR1 , and it is assumed that the light emitting direction of the pixels is a third direction DR3 perpendicular to the first direction DR1 and the second direction DR2 .

[0051] Figure 2 is a diagram for explaining a pixel according to an embodiment of the present invention.

[0052] Reference Figure 2 , the pixel PXij includes: transistors T1, T2, T3, T4, T5, T6, T7, a storage capacitor Cst and a light emitting element LD.

[0053] Below, a circuit composed of P-type transistors is used as an example for explanation. However, anyone skilled in the art can design a circuit composed of N-type transistors by changing the polarity of the voltage applied to the gate terminal. Similarly, anyone skilled in the art can design a circuit composed of a combination of P-type transistors and N-type transistors. P-type transistors are generally referred to as transistors whose current increases when the voltage difference between the gate electrode and the source electrode increases in the negative direction. N-type transistors are generally referred to as transistors whose current increases when the voltage difference between the gate electrode and the source electrode increases in the positive direction. Transistors can be constructed in various forms such as thin film transistors (TFT), field effect transistors (FET), bipolar junction transistors (BJT), etc.

[0054] In the first transistor T1, a gate electrode may be connected to the first node N1, a first electrode may be connected to the second node N2, and a second electrode may be connected to the third node N3. The first transistor T1 may be named a driving transistor.

[0055] In the second transistor T2, a gate electrode may be connected to the scan line SLi1, a first electrode may be connected to the data line DLj, and a second electrode may be connected to the second node N2. The second transistor T2 may be named a scan transistor.

[0056] In the third transistor T3, a gate electrode may be connected to the scan line SLi2, a first electrode may be connected to the first node N1, and a second electrode may be connected to the third node N3. The third transistor T3 may be named a diode-connected transistor.

[0057] In the fourth transistor T4, a gate electrode may be connected to the scan line SLi3, a first electrode may be connected to the first node N1, and a second electrode may be connected to the initialization line INTL. The fourth transistor T4 may be named a gate initialization transistor.

[0058] In the fifth transistor T5, the gate electrode can be connected to the i-th light emitting line ELi, the first electrode is connected to the first power line ELVDDL, and the second electrode is connected to the second node N2. The fifth transistor T5 can be named as a light emitting transistor. In other embodiments, the gate electrode of the fifth transistor T5 can also be connected to a light emitting line different from the light emitting line connected to the gate electrode of the sixth transistor T6.

[0059] In the sixth transistor T6, the gate electrode can be connected to the i-th light emitting line ELi, the first electrode is connected to the third node N3, and the second electrode is connected to the anode of the light emitting element LD. The sixth transistor T6 can be named as a light emitting transistor. In other embodiments, the gate electrode of the sixth transistor T6 can also be connected to a light emitting line different from the light emitting line connected to the gate electrode of the fifth transistor T5.

[0060] In the seventh transistor T7, a gate electrode may be connected to the scan line SLi4, a first electrode may be connected to the initialization line INTL, and a second electrode may be connected to the anode of the light emitting element LD. The seventh transistor T7 may be named a light emitting element initialization transistor.

[0061] A first electrode of the storage capacitor Cst may be connected to the first power line ELVDDL, and a second electrode thereof may be connected to the first node N1.

[0062] In the light emitting element LD, the anode may be connected to the second electrode of the sixth transistor T6, and the cathode may be connected to the second power line ELVSSL. The light emitting element LD may be a light emitting diode. The light emitting element LD may include an organic light emitting diode, an inorganic light emitting diode, a quantum dot / well light emitting diode, etc. In the present embodiment, only one light emitting element LD is provided in each pixel PXij, but in other embodiments, a plurality of light emitting elements may also be provided in each pixel PXij. At this time, the plurality of light emitting elements may be connected in series, in parallel, in series and in parallel, etc. The light emitting element LD of each pixel PXij may emit light in one of the first color, the second color, and the third color.

[0063] A first power supply voltage may be applied to the first power supply line ELVDDL, a second power supply voltage may be applied to the second power supply line ELVSSL, and an initialization voltage may be applied to the initialization line INTL. For example, the first power supply voltage may be greater than the second power supply voltage. For example, the initialization voltage may be the same as or greater than the second power supply voltage. For example, the initialization voltage may correspond to a data voltage having the smallest voltage among data voltages corresponding to the output gray scale. In other examples, the magnitude of the initialization voltage may be smaller than the magnitude of the data voltage corresponding to the color gray scale.

[0064] Figure 3 It is used to illustrate Figure 2 FIG. 1 is a diagram of an exemplary driving method for a pixel.

[0065] In the following, for the sake of convenience, it is assumed that the scan lines SLi1, SLi2, and SLi4 are the i-th scan line SLi, and the scan line SLi3 is the i-1th scan line SL(i-1). However, the scan lines SLi1, SLi2, SLi3, and SLi4 may have a variety of connection relationships according to the embodiment. For example, the scan line SLi4 may also be the i-1th scan line, or the i+1th scan line.

[0066] First, a light signal of a cutoff level (logic high level) is applied to the i-th light line ELi, a data voltage DATA(i-1)j for the i-1-th pixel is applied to the data line DLj, and a scan signal of a conduction level (logic low level) is applied to the scan line SLi3. The high / low of the logic level can be changed according to whether the transistor is P-type or N-type.

[0067] At this time, since the scan signals of the off level are applied to the scan lines SLi1 and SLi2, the second transistor T2 is in the off state, thereby preventing the data voltage DATA(i-1)j for the i-1th pixel from being connected to the i-th pixel PXij.

[0068] At this time, since the fourth transistor T4 is in the on state, the first node N1 is connected to the initialization line INTL, so that the voltage of the first node N1 is initialized. Since the light-emitting signal of the cut-off level is applied to the light-emitting line ELi, the transistors T5 and T6 are in the cut-off state, thereby preventing the unnecessary light-emitting element LD from emitting light during the process of applying the initialization voltage.

[0069] Next, a data voltage DATAij for the i-th pixel PXij is applied to the data line DLj, and a scanning signal of a conduction level is applied to the scanning lines SLi1 and SLi2. As a result, the transistors T2, T1, and T3 are in a conduction state, and the data line DLj is electrically connected to the first node N1. As a result, a compensation voltage obtained by subtracting the threshold voltage of the first transistor T1 from the data voltage DATAij is applied to the second electrode (i.e., the first node N1) of the storage capacitor Cst, and the storage capacitor Cst maintains a voltage corresponding to the difference between the first power supply voltage and the compensation voltage. Such a period can be named a threshold voltage compensation period or a data writing period.

[0070] When the scanning line SLi4 is the i-th scanning line, the seventh transistor T7 is turned on, so the anode of the light emitting element LD is connected to the initialization line INTL, and the light emitting element LD is initialized to a charge amount corresponding to the voltage difference between the initialization voltage and the second power supply voltage.

[0071] Then, as the on-level light emission signal is applied to the i-th light emission line ELi, the transistors T5 and T6 are turned on, thereby forming a driving current path connecting the first power line ELVDDL, the fifth transistor T5, the first transistor T1, the sixth transistor T6, the light emitting element LD and the second power line ELVSSL.

[0072] The amount of driving current flowing in the first electrode and the second electrode of the first transistor T1 is adjusted according to the voltage maintained in the storage capacitor Cst. The light emitting element LD emits light at a brightness corresponding to the amount of driving current. The light emitting element LD emits light until a light emitting signal of a cutoff level is applied to the light emitting line ELi.

[0073] When the light-emitting signal is at the on level, the pixel receiving the corresponding light-emitting signal will be in the display state. Therefore, the period during which the light-emitting signal is at the on level can be referred to as the light-emitting period EP (or, the light-emitting period is allowed). And, when the light-emitting signal is at the off level, the pixel receiving the corresponding light-emitting signal will be in the non-display state. Therefore, the period during which the light-emitting signal is at the off level can be referred to as the non-light-emitting period NEP (or, the light-emitting period is not allowed).

[0074] Figure 3 The non-light emitting period NEP described in is to prevent the pixel PXij from emitting light with an undesired brightness during the initialization period and the data writing period.

[0075] During the period of retaining the data written into the pixel PXij (e.g., one frame period), one or more non-luminous periods NEP may be provided additionally. This is to effectively present low grayscale by reducing the luminous period EP of the pixel PXij, or to softly blur the motion of the image.

[0076] Figure 4 It is a diagram for explaining a grayscale conversion unit according to an embodiment of the present invention.

[0077] Reference Figure 4 According to an embodiment of the present invention, the grayscale conversion part 12a may include: a stress compensation part 121, a first stress conversion part 122, a second stress conversion part 123, a first stress accumulation part 124, a second stress accumulation part 125 and a memory 126.

[0078] For convenience of description, one input grayscale IG and one output grayscale OG for one pixel PXij are described below. In the same way, the grayscale conversion unit 12a can convert the input grayscale IG for all pixels included in the pixel unit 14 into the output grayscale OG.

[0079] The grayscale conversion unit 12a can independently generate a first stress V1(N) and a second stress V2(N) based on the output grayscale OG. The grayscale conversion unit 12a can apply the first accumulation coefficient AC1 to the first stress accumulation value STR1(N-1) and then add the first stress V1(N) to update the first stress accumulation value STR1(N). The grayscale conversion unit 12a can apply the second accumulation coefficient AC2 to the second stress accumulation value STR2(N-1) and then add the second stress V2(N) to update the second stress accumulation value STR2(N). The grayscale conversion unit 12a can generate a compensation value based on the first stress accumulation value STR1(N) and the second stress accumulation value STR2(N). The grayscale conversion unit 12a can apply the compensation value to the input grayscale IG for the pixel PXij to convert the input grayscale IG into the output grayscale OG.

[0080] In the following, it is assumed that the input grayscale IG and the output grayscale OG are values ​​corresponding to the pixel PXij in the Nth image frame.

[0081] The first stress conversion unit 122 can convert the output grayscale OG into a first stress V1(N) in the voltage domain. The first stress V1(N) can correspond to the output grayscale OG. If the output grayscale OG has a range of 0 to 255 represented by 8 bits, the smaller the output grayscale OG (the closer to black), the greater the first stress V1(N). This is because Figure 2 The first transistor T1 is composed of a P-type transistor. If the output grayscale OG is already a value in the voltage domain (e.g., a voltage code or a voltage value), the smaller the output grayscale OG is, the smaller the first stress V1(N) will be. For example, the output grayscale OG can also be the same as the first stress V1(N). However, even if the output grayscale OG is a value in the voltage domain, for logic optimization, the first stress transformation unit 122 can also generate the first stress V1(N) by applying a weighted value to the output grayscale OG and performing quantization.

[0082] The second stress conversion unit 123 can convert the output grayscale OG into a second stress V2(N) in the voltage domain. The second stress V2(N) can correspond to the output grayscale OG. If the output grayscale OG has a range of 0 to 255 represented by 8 bits, the smaller the output grayscale OG (the closer to black), the greater the second stress V2(N). This is because Figure 2The first transistor T1 is composed of a P-type transistor. If the output grayscale OG is already a value in the voltage domain (e.g., a voltage code), the smaller the output grayscale OG is, the smaller the second stress V2(N) will be. For example, the output grayscale OG can also be the same as the second stress V2(N). However, even if the output grayscale OG is a value in the voltage domain, for logic optimization, the second stress conversion unit 123 can also generate the second stress V2(N) by applying a weighted value to the output grayscale OG and quantizing it.

[0083] The first stress V1(N) may be a stress value when a data voltage is applied to the pixel PXij during a first period. The second stress V2(N) may be a stress value when a data voltage is applied to the pixel PXij during a second period. The second period may be longer than the first period. That is, the first stress V1(N) may be a short-term stress, and the second stress V2(N) may be a medium- to long-term stress.

[0084] The number of bits used to represent the first stress V1(N) and the number of bits used to represent the second stress V2(N) may be different from each other. For example, the number of bits used to represent the first stress V1(N) may be greater than the number of bits used to represent the second stress V2(N). Since the second stress V2(N) corresponding to the medium- and long-term stress is less sensitive to grayscale differences than the first stress V1(N) corresponding to the short-term stress, the number of bits may be reduced. For example, the first stress V1(N) may be a value quantized by 5 bits for the output grayscale OG, and the second stress V2(N) may be a value quantized by 4 bits for the output grayscale OG.

[0085] The memory 126 may store a first stress accumulation value STR1(N-1) and a second stress accumulation value STR2(N-1) for a frame before the current frame. For example, if the current frame is the Nth frame, the first stress accumulation value STR1(N-1) is the short-term stress accumulated during the 1st, 2nd, 3rd, ..., N-1st frames, and the second stress accumulation value STR2(N-1) is the medium- and long-term stress accumulated during the 1st, 2nd, 3rd, ..., N-1st frames.

[0086] The first stress accumulation unit 124 may apply the first accumulation coefficient AC1 to the first stress accumulation value STR1 (N−1) and then add the first stress V1 (N) to update the first stress accumulation value STR1 (N) (see Formula 1).

[0087] Mathematical formula 1

[0088] STR1(N)=V1(N)+AC1*STR1(N-1)

[0089] Wherein, AC1 may be the first cumulative coefficient. The method for deriving the first cumulative coefficient AC1 will refer to Figures 5 to 10This will be described later.

[0090] The second stress accumulation unit 125 may apply the second accumulation coefficient AC2 to the second stress accumulation value STR2(N−1) and then add the second stress V2(N) to update the second stress accumulation value STR2(N) (see Formula 2).

[0091] Mathematical formula 2

[0092] STR2(N)=V2(N)+AC2*STR2(N-1)

[0093] Wherein AC2 may be a second cumulative coefficient. The method for deriving the second cumulative coefficient AC2 will refer to Figures 5 to 10 The first cumulative coefficient AC1 and the second cumulative coefficient AC2 may be different from each other. For example, the second cumulative coefficient AC2 may be greater than the first cumulative coefficient AC1.

[0094] The updated first stress accumulation value STR1 (N) and the updated second stress accumulation value STR2 (N) may be stored in the memory 126 .

[0095] The stress compensating part 121 may generate a compensation value based on the first stress accumulated value STR1 (N) and the second stress accumulated value STR2 (N), and such a compensation value may be applied to the input grayscale IG of the next frame (eg, the N+1th frame).

[0096] First, the stress compensation unit 121 may calculate a final cumulative value using the first stress cumulative value STR1(N) and the second stress cumulative value STR2(N). For example, the stress compensation unit 121 may calculate the final cumulative value based on a first transformed cumulative value obtained by applying a first weighted value to the first stress cumulative value STR1(N) and a second transformed cumulative value obtained by applying a second weighted value to the second stress cumulative value STR2(N) (see Mathematical Formula 3).

[0097] Mathematical formula 3

[0098] STRsum(N)=K1*STR1(N)+K2*STR2(N)

[0099] Wherein, STRsum(N) may be the final cumulative value. K1 is the first weighted value, which may be less than 1 and greater than 0. K2 is the second weighted value, which may be less than 1 and greater than 0. K1 and K2 are optimal values ​​obtained based on repeated experiments, which may be predetermined coefficients. K1*STR1(N) may be referred to as the first transformed cumulative value. K2*STR2(N) may be referred to as the second transformed cumulative value.

[0100] Next, the stress compensation unit 121 may generate a compensation value using the final integrated value (see Formula 4).

[0101] Mathematical formula 4

[0102] compData=(STRsum(N)-STRexp(N))*GA

[0103] Where compData is the compensation value, STRsum(N) is the final cumulative value, STRexp(N) is the expected cumulative value, and GA is the grayscale gain. The expected cumulative value may be the final cumulative value when continuously subjected to the stress of V1(N) and V2(N) from the 1st frame to the Nth frame. Different grayscale gains may be applied to each grayscale or each grayscale interval.

[0104] The stress compensating unit 121 may apply the compensation value compData (refer to Mathematical Formula 4) to the input grayscale IG for the pixel PXij to transform the input grayscale IG into the output grayscale OG. For example, when the units of the input grayscale IG, the compensation value, and the output grayscale OG are the same (for example, when the input grayscale IG, the compensation value, and the output grayscale OG are in the voltage domain), the stress compensating unit 121 may generate the output grayscale OG by adding the compensation value compData to the input grayscale IG.

[0105] Figures 5 to 10 1 is a diagram for explaining a method of calculating a cumulative coefficient according to an embodiment of the present invention.

[0106] Reference Figure 5 According to an embodiment of the present invention, the accumulation coefficient generating device ED may include a camera EDCM and an inspection control unit EDCC.

[0107] The camera EDCM can capture the test image displayed by the pixels of the display device DD to generate a camera image. The camera EDCM can be composed of various brightness meters, optical meters, etc.

[0108] The inspection control unit EDCC can control the pixels of the display device DD to display the test image. The inspection control unit EDCC can be composed of a general or dedicated computing device. The computing device can include a recording medium and a processor. The recording medium and the processor can be physically included in the same device, but can also be physically included in different devices using cloud technology, etc.

[0109] Recording media include all kinds of recording devices that can store data or programs that can be read by a processor. Examples of processor-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, hard disk, external hard disk, SSD, USB storage device, DVD, Blu-ray disc, etc. In addition, the processor-readable recording medium can also be a combination of multiple devices, and can also be discrete in a computer system connected via a network. Such a recording medium can be a non-transitory computerreadable medium. A non-transitory recording medium refers to a medium that can store data or programs semi-permanently and can be read by a processor, rather than a medium that stores data or programs for a short period of time such as a register, cache, memory, etc.

[0110] Reference Figure 6 The display device DD may display a black grayscale image at a first time point t1, maintain the black grayscale image before a second time point t2, and display an intermediate grayscale image (eg, 48 grayscale) at a second time point t2 after the first time point t1.

[0111] Reference Figure 7 , which shows the brightness of the display device DD measured from the second time point t2. In the case of switching from a black grayscale image display to a 48 grayscale image, the brightness corresponding to a grayscale higher than 48 grayscale will be measured on the display device DD due to the afterimage. The first brightness curve Lm1 may correspond to a case where the time period from the first time point t1 to the second time point t2 is shorter (for example, 90 seconds), and the second brightness curve Lm2 may correspond to a case where the time period from the first time point t1 to the second time point t2 is longer (for example, 30 minutes). The reference brightness Lref is the ideal brightness corresponding to 48 grayscale when the afterimage disappears after a sufficiently long time from the second time point t2. Here, the case where the time period from the first time point t1 to the second time point t2 is shorter may correspond to the above-mentioned first time period, and the case where the time period from the first time point t1 to the second time point t2 is longer may correspond to the above-mentioned second time period.

[0112] When the reference brightness Lref is subtracted from the first brightness curve Lm1, it may be referred to as a short-term afterimage curve. When the first brightness curve Lm1 is subtracted from the second brightness curve Lm2, it may be referred to as a mid- to long-term afterimage curve.

[0113] Reference Figure 8 , which shows the short-term afterimage curve STN after the brightness is normalized.

[0114] Reference Fig. 9After modeling the curve corresponding to the short-term afterimage curve STN, a suitable first cumulative coefficient AC1 can be obtained. For example, the first cumulative coefficient AC1 can be a parameter for determining the slope of the curve. For example, the larger the first cumulative coefficient AC1, the smaller the change of the slope of the curve over time can be, and the smaller the first cumulative coefficient AC1, the larger the change of the slope of the curve over time can be.

[0115] For example, in Fig. 9 In the above, the curve model when the first accumulation coefficient AC1 is agB is most similar to the short-term afterimage curve STN. Therefore, the first accumulation coefficient AC1 can be determined to be agB.

[0116] Although Figure 8 as well as Fig. 9 The method for calculating the first cumulative coefficient AC1 based on the short-term afterimage curve STN is described in the figure, but the method for calculating the second cumulative coefficient AC2 based on the medium- and long-term afterimage curve is substantially the same, so repeated description will be omitted. Since the medium- and long-term afterimage curve is slower than the short-term afterimage curve STN, the second cumulative coefficient AC2 can be greater than the first cumulative coefficient AC1.

[0117] Reference Fig.10 It can be confirmed that the first brightness curve Lm1 corresponding to the short-term afterimage and the compensation value CPV1 match well. Also, it can be confirmed that the second brightness curve Lm2 corresponding to the medium- and long-term afterimage and the compensation value CPV2 match well.

[0118] Fig.11 It is a diagram for explaining a grayscale conversion unit according to another embodiment of the present invention.

[0119] In the right Fig.11 In the process of explaining the grayscale conversion unit 12b, Figure 4 The repeated description of the grayscale conversion unit 12a will be omitted.

[0120] The memory 126 may be in a state of storing a first transformed cumulative value K1*STR1(N-1) obtained by applying the first weighted value K1 to the first stress accumulated value STR1(N-1) and a second transformed cumulative value K2*STR2(N-1) obtained by applying the second weighted value K2 to the second stress accumulated value STR2(N-1) (refer to Mathematical Formula 3). As described above, the first weighted value K1 and the second weighted value K2 may be numbers greater than 0 and less than 1, respectively. Therefore, the first transformed cumulative value K1*STR1(N-1) will be smaller than the first stress accumulated value STR1(N-1), and the second transformed cumulative value K2*STR2(N-1) will be smaller than the second stress accumulated value STR2(N-1). Therefore, Fig.11 The memory 126 has a Figure 4 The memory 126 can be constructed with the advantage of a smaller capacity.

[0121] The first stress accumulation unit 124 may calculate the first stress accumulation value STR1(N-1) by applying the inverse (1 / K1) of the first weighted value K1 to the first transformed accumulated value K1*STR1(N-1) (e.g., multiplying). The first stress accumulation unit 124 may update the first stress accumulation value STR1(N) by applying the first accumulation coefficient AC1 to the first stress accumulation value STR1(N-1) and then adding the first stress V1(N). At this time, the memory 126 may store the first transformed accumulated value K1*STR1(N) obtained by applying the first weighted value K1 to the updated first stress accumulation value STR1(N).

[0122] The second stress accumulation unit 125 may calculate the second stress accumulation value STR2(N-1) by applying the inverse (1 / K2) of the second weighted value K2 to the second transformed accumulated value K2*STR2(N-1). The second stress accumulation unit 125 may update the second stress accumulated value STR2(N) by applying the second accumulation coefficient AC2 to the second stress accumulated value STR2(N-1) and then adding the second stress V2(N). At this time, the memory 126 may store the second transformed accumulated value K2*STR2(N) obtained by applying the second weighted value K2 to the updated second stress accumulated value STR2(N).

[0123] The stress compensation unit 121 may generate a compensation value based on the first conversion cumulative value K1* STR1 (N) and the second conversion cumulative value K2* STR2 (N).

[0124] According to this embodiment, Fig.11 The memory 126 has a Figure 4 The memory 126 can be constructed with the advantage of a smaller capacity.

[0125] Fig.12 is a block diagram of an electronic device according to an embodiment of the present invention.

[0126] The electronic device 101 outputs various information in the operating system through the display module 140. When the processor 110 runs the application program stored in the memory 180, the display module 140 provides the application information to the user through the display panel 141.

[0127] The processor 110 obtains external input through the input module 130 or the sensor module 191 and runs an application corresponding to the external input. For example, when the user selects the camera icon displayed on the display panel 141, the processor 110 obtains the user input through the input sensor 191-2 and activates the camera module 171. The processor 110 transmits the image data corresponding to the captured image obtained through the camera module 171 to the display module 140. The display module 140 can display the image corresponding to the captured image through the display panel 141.

[0128] As another example, when personal information authentication is performed on the display module 140, the fingerprint sensor 191-1 obtains the input fingerprint information as input data. The processor 110 compares the input data obtained by the fingerprint sensor 191-1 with the authentication data stored in the memory 180, and runs the application according to the comparison result. The display module 140 can display information executed according to the logic of the application through the display panel 141.

[0129] As another example, when the music streaming icon displayed on the display module 140 is selected, the processor 110 obtains the user input through the input sensor 191-2 and activates the music streaming application stored in the memory 180. When a music execution instruction is input in the music streaming application, the processor 110 activates the sound output module 193 and provides the user with sound information consistent with the music execution instruction.

[0130] The above briefly describes the operation of the electronic device 101. The following describes the structure of the electronic device 101 in detail. A part of the structure of the electronic device 101 described below may be provided as one structure, or one structure may be provided as two or more structures.

[0131] Reference Fig.12 , the electronic device 101 can communicate with the external electronic device 102 through a network (for example, a short-range wireless communication network or a long-range wireless communication network). According to one embodiment, the electronic device 101 may include: a processor 110, a memory 180, an input module 130, a display module 140, a power module 150, a built-in module 190, and an external module 170. According to one embodiment, the electronic device 101 may omit at least one of the above-mentioned components, or add one or more other components. According to one embodiment, some of the above-mentioned components (for example, the sensor module 191, the antenna module 192, or the audio output module 193) may be integrated into another component (for example, the display module 140).

[0132] The processor 110 can control at least one other component (e.g., hardware or software component) of the electronic device 101 connected to the processor 110 by running software, and can perform various data processing or operations. According to one embodiment, as at least a part of the data processing or operation, the processor 110 can store instructions or data received from other components (e.g., the input module 130, the sensor module 191, or the communication module 173) in the volatile memory 181, process the instructions or data stored in the volatile memory 181, and store the result data in the non-volatile memory 182.

[0133] The processor 110 may include a main processor 111 and an auxiliary processor 112. The main processor 111 may include one or more of a central processing unit (111-1, CPU: central processing unit) or an application processor (AP: application processor). The main processor 111 may also include one or more of a graphics processing device (111-2, GPU: graphic processing unit), a communication processor (CP: communication processor) and an image signal processor (ISP: image signal processor). The main processor 111 may also include a neural network processing device 111-3 (NPU: neural processing unit). The neural network processing device is a processor that specializes in processing artificial intelligence models, which can be generated by machine learning. The artificial intelligence model may include multiple artificial neural network layers. The artificial neural network can be a deep neural network (DNN), a convolutional neural network (CNN), a recurrent neural network (RNN), a restricted Boltzmann machine (RBM), a deep belief network (DBN), a bidirectional recurrent deep neural network (BRDNN), a deep Q-network or a combination of two or more of the above, but is not limited to the above examples. In addition to the hardware structure, the artificial intelligence model may also include a software structure in addition or instead. At least two of the above-mentioned processing unit and processors can be implemented in an integrated structure (e.g., a single chip), or in separate structures (e.g., multiple chips). Figure 1 The grayscale conversion unit 12 may be implemented by part of the functions of the processor 110 .

[0134] The auxiliary processor 112 may include a controller 112-1. The controller 112-1 may include an interface conversion circuit and a timing control circuit. The controller 112-1 receives an image signal from the main processor 111, and converts the data format of the image signal in accordance with the interface configuration of the display module 140 to output the image data. The controller 112-1 may output various control signals required for driving the display module 140. Figure 1The controller 11 can be connected with Fig.12 As described above, due to the controller 112-1 Figure 1 The grayscale conversion unit 12 may be manufactured into one IC together with the controller 112-1, and thus the grayscale conversion unit 12 may correspond to the controller 112-1.

[0135] The auxiliary processor 112 may further include a data conversion circuit 112-2, a gamma correction circuit 112-3, a rendering circuit 112-4, etc. The data conversion circuit 112-2 may receive image data from the controller 112-1, and compensate the image data so that the image can be displayed at a desired brightness according to the characteristics of the electronic device 101 or the user's settings, or convert the image data in order to reduce power consumption or compensate for afterimages, etc. The gamma correction circuit 112-3 may convert the image data or the gamma reference voltage, etc., so that the image displayed on the electronic device 101 has the desired gamma characteristics. The rendering circuit 112-4 may receive image data from the controller 112-1, and render the image data in consideration of the pixel arrangement of the display panel 141 applied to the electronic device 101, etc. At least one of the data conversion circuit 112-2, the gamma correction circuit 112-3, and the rendering circuit 112-4 may be integrated into other components (e.g., the main processor 111 or the controller 112-1). At least one of the data conversion circuit 112 - 2 , the gamma correction circuit 112 - 3 , and the rendering circuit 112 - 4 may also be integrated into a data driver 143 described later.

[0136] The memory 180 may store various data used by at least one component of the electronic device 101 (eg, the processor 110 or the sensor module 191) and input data or output data associated therewith for instructions. The memory 180 may include at least one of a volatile memory 181 and a nonvolatile memory 182.

[0137] The input module 130 may receive instructions or data for constituent elements of the electronic device 101 (eg, the processor 110 , the sensor module 191 , or the audio output module 193 ) from outside the electronic device 101 (eg, a user or an external electronic device 102 ).

[0138] The input module 130 may include: a first input module 131 for inputting instructions or data from a user; and a second input module 132 for inputting instructions or data from an external electronic device 102. The first input module 131 may include a microphone, a mouse, a keyboard, a key (e.g., a button), or a pen (e.g., a passive pen or an active pen). The second input module 132 may support a specified protocol that can be connected to the external electronic device 102 in a wired or wireless manner. According to one embodiment, the second input module 132 may include a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface. The second input module 132 may include a connector that can be physically connected to the external electronic device 102, such as an HDMI connector, a USB connector, an SD card connector, or an audio connector (e.g., a headphone connector).

[0139] The display module 140 provides information to the user in a visual manner. The display module 140 may include: a display panel 141 , a scan driver 142 , and a data driver 143 . The display module 140 may also include a window, a chassis, and a bracket for protecting the display panel 141 .

[0140] The display panel 141 may include a liquid crystal display panel, an organic light emitting display panel, or an inorganic light emitting display panel, and the type of the display panel 141 is not particularly limited. The display panel 141 may be a rigid type, or a flexible type that is rollable or foldable. The display module 140 may further include a support, a bracket, or a heat dissipation member that supports the display panel 141.

[0141] The scan driver 142 may be mounted on the display panel 141 as a driver chip. Also, the scan driver 142 may be integrated in the display panel 141. For example, the scan driver 142 may include an amorphous silicon TFT gate driver circuit (ASG), a low temperature polycrystalline silicon (LTPS) TFT gate driver circuit, or an oxide semiconductor TFT gate driver circuit (OSG) built into the display panel 141. The scan driver 142 receives a control signal from the controller 112-1, and outputs a scan signal to the display panel 141 in response to the control signal.

[0142] The display panel 141 may further include a light emitting driver. The light emitting driver outputs a light emitting control signal to the display panel 141 in response to a control signal received from the controller 112-1. The light emitting driver may be formed separately from the scan driver 142 or integrated into the scan driver 142.

[0143] The data driver 143 receives a control signal from the controller 112 - 1 , converts the image data into an analog voltage (eg, a data voltage) in response to the control signal, and then outputs the data voltage to the display panel 141 .

[0144] The data driver 143 may be integrated into other components (eg, the controller 112 - 1 ). The functions of the interface conversion circuit and the timing control circuit of the controller 112 - 1 may also be integrated into the data driver 143 .

[0145] The display module 140 may further include a light emitting driver and a voltage generating circuit, etc. The voltage generating circuit may output various voltages required for driving the display panel 141 .

[0146] The power module 150 supplies power to the components of the electronic device 101. The power module 150 may include a battery for charging the power supply voltage. The battery may include a non-rechargeable primary battery, a rechargeable secondary battery, or a fuel cell. The power module 150 may include a power management integrated circuit (PMIC). The PMIC supplies optimized power to each of the above-mentioned modules and the modules described later. The power module 150 may include a wireless power transceiver component electrically connected to the battery. The wireless power transceiver component may include a plurality of antenna radiators in the form of coils.

[0147] The electronic device 101 may further include an internal module 190 and an external module 170. The internal module 190 may include a sensor module 191, an antenna module 192, and an audio output module 193. The external module 170 may include a camera module 171, an illumination module 172, and a communication module 173.

[0148] The sensor module 191 can sense the input based on the user's body or the input based on the pen in the first input module 131 to generate an electric signal or data value corresponding to the input. The sensor module 191 can include at least one of a fingerprint sensor 191-1, an input sensor 191-2, and a digitizer 191-3.

[0149] The fingerprint sensor 191-1 may generate a data value corresponding to the user's fingerprint. The fingerprint sensor 191-1 may include one of an optical type or a capacitive type fingerprint sensor.

[0150] The input sensor 191-2 can generate a data value corresponding to the coordinate information of the input based on the user's body or the input based on the pen. The input sensor 191-2 generates the capacitance change amount based on the input as a data value. The input sensor 191-2 can sense the input based on the passive pen, or transmit and receive data with the active pen.

[0151] The input sensor 191-2 may also measure biometric signals such as blood pressure, water content, or body fat. For example, when a user places a body part in contact with the sensor layer or detection panel and does not move for a certain period of time, the input sensor 191-2 may sense the biometric signal based on the electric field change of the body part and output the information required by the user to the display module 140.

[0152] The digitizer 191-3 may generate a data value corresponding to the coordinate information based on the input of the pen. The digitizer 191-3 generates the electromagnetic change amount based on the input as a data value. The digitizer 191-3 may sense the input based on the passive pen, or transmit and receive data with the active pen.

[0153] At least one of the fingerprint sensor 191-1, the input sensor 191-2, and the digitizer 191-3 may also be implemented in the form of a sensor layer formed on the display panel 141 through a continuous process. The fingerprint sensor 191-1, the input sensor 191-2, and the digitizer 191-3 may be configured on the upper side of the display panel 141, and one of the fingerprint sensor 191-1, the input sensor 191-2, and the digitizer 191-3, for example, the digitizer 191-3 may be configured on the lower side of the display panel 141.

[0154] Two or more of the fingerprint sensor 191-1, the input sensor 191-2, and the digital converter 191-3 may be integrated into a detection panel through the same process. In the case of integration into a detection panel, the detection panel may be arranged between the display panel 141 and the window, and the window is arranged on the upper side of the display panel 141. According to one embodiment, the detection panel may also be arranged above the window, and there is no particular limitation on the position of the detection panel.

[0155] At least one of the fingerprint sensor 191-1, the input sensor 191-2, and the digitizer 191-3 may be built in the display panel 141. That is, at least one of the fingerprint sensor 191-1, the input sensor 191-2, and the digitizer 191-3 may be formed simultaneously by a process of forming elements (e.g., light emitting elements, transistors, etc.) included in the display panel 141.

[0156] In addition, the sensor module 191 can generate an electrical signal or data value corresponding to the internal state or external state of the electronic device 101. The sensor module 191 also includes, for example, a posture sensor, a gyro sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an infrared (IR) sensor, a biometric sensor, a temperature sensor, a humidity sensor, or an illumination sensor.

[0157] The antenna module 192 may include one or more antennas for transmitting or receiving signals or power to or from the outside. According to one embodiment, the communication module 173 may transmit signals to or receive signals from an external electronic device through an antenna suitable for the communication method. The antenna pattern of the antenna module 192 may be integrated into a structure of the display module 140 (e.g., the display panel 141) or the input sensor 191-2, etc.

[0158] The audio output module 193 is a device for outputting an audio signal to the outside of the electronic device 101, and may include, for example, a speaker for general use such as multimedia playback or recording playback and a receiver for telephone reception. According to one embodiment, the receiver may be integrally formed with the speaker or formed separately. The audio output pattern of the audio output module 193 may also be integrated into the display module 140.

[0159] The camera module 171 can capture still images and moving images. According to one embodiment, the camera module 171 may include one or more lenses, image sensors, or image signal processors. The camera module 171 may also include an infrared camera capable of measuring the presence or absence of a user, the position of the user, the line of sight of the user, etc.

[0160] The lighting module 172 may provide light. The lighting module 172 may include a light emitting diode or a xenon lamp. The lighting module 172 may operate in conjunction with the camera module 171 or independently.

[0161] The communication module 173 can support the construction of a wired or wireless communication channel between the electronic device 101 and the external electronic device 102 and perform communication through the constructed communication channel. The communication module 173 may include one or all of a wireless communication module such as a cellular communication module, a short-range wireless communication module or a global navigation satellite system (GNSS) communication module and a wired communication module such as a local area network (LAN) communication module or a power line communication module. The communication module 173 can communicate with the external electronic device 102 through a short-range communication network such as Bluetooth, WiFi direct or infrared data association (IrDA) or a long-range communication network such as a cellular network, the Internet or a computer network (e.g., LAN or WAN). The above-mentioned many types of communication modules 173 can be implemented by one chip, or respectively by separate chips.

[0162] The input module 130 , the sensor module 191 , the camera module 171 , etc. may be applied to control the operation of the display module 140 in conjunction with the processor 110 .

[0163] The processor 110 outputs instructions or data to the display module 140, the audio output module 193, the camera module 171, or the lighting module 172 according to the input data received from the input module 130. For example, the processor 110 may generate image data corresponding to the input data applied through a mouse or an active pen, etc. and output it to the display module 140, or generate instruction data corresponding to the input data and output it to the camera module 171 or the lighting module 172. If the processor 110 does not receive input data from the input module 130 during a prescribed period of time, the operation mode of the electronic device 101 may be converted to a low power consumption mode or a sleep mode, thereby reducing the power consumed by the electronic device 101.

[0164] The processor 110 outputs instructions or data to the display module 140, the audio output module 193, the camera module 171, or the lighting module 172 according to the detection data received from the sensor module 191. For example, the processor 110 may compare the authentication data applied by the fingerprint sensor 191-1 with the authentication data stored in the memory 180, and then run an application according to the comparison result. The processor 110 may run instructions according to the detection data sensed by the input sensor 191-2 or the digital converter 191-3, or output the corresponding image data to the display module 140. In the case where the sensor module 191 includes a temperature sensor, the processor 110 may receive temperature data for the measured temperature from the sensor module 191, and further perform brightness correction for the image data according to the temperature data.

[0165] The processor 110 may receive measurement data on the presence or absence of a user, the user's position, the user's line of sight, etc. from the camera module 171. The processor 110 may further perform brightness correction, etc. on the image data based on the measurement data. For example, the processor 110 that determines the presence or absence of a user through input from the camera module 171 may output the image data after brightness correction to the display module 140 through the data conversion circuit 112-2 or the gamma correction circuit 112-3.

[0166] Some of the components can be connected to each other and exchange signals (e.g., instructions or data) with each other through a communication method between peripheral devices, such as a bus, a general purpose input / output interface (GPIO), a serial peripheral interface (SPI), a mobile industry processor interface (MIPI), or an Ultrapath interconnect (UPI) link. The processor 110 and the display module 140 can communicate using an interface agreed upon by each other, for example, using one of the above-mentioned communication methods, but are not limited to the above-mentioned communication methods.

[0167] The electronic device 101 according to various embodiments disclosed herein may be a device in various forms. The electronic device 101 may include, for example, at least one of a portable communication device (e.g., a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. The electronic device 101 according to the embodiments of this document is not limited to the above-mentioned devices.

[0168] The drawings and the detailed description of the inventions referred to above are only examples of the present invention, which are intended to be used for the purpose of illustrating the present invention, and are not intended to limit the scope of the present invention recorded in the claims. Therefore, it should be understood by those skilled in the art that various variations and other equivalent embodiments can be realized therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical ideas of the attached claims.

Claims

1. A display device, in, include: Pixels; a grayscale conversion unit that applies a compensation value to an input grayscale for the pixel to convert the input grayscale into an output grayscale; and A controller provides a data voltage corresponding to the output grayscale to the pixel, The grayscale conversion unit generates a first stress and a second stress independently based on the output grayscale, applies a first accumulation coefficient to a first stress accumulation value and then adds the first stress to update the first stress accumulation value, applies a second accumulation coefficient to a second stress accumulation value and then adds the second stress to update the second stress accumulation value, and generates the compensation value based on the first stress accumulation value and the second stress accumulation value, The first accumulation coefficient and the second accumulation coefficient are different from each other.

2. The display device according to claim 1, wherein: The first stress is a stress value when the data voltage is applied to the pixel during a first period, The second stress is a stress value when the data voltage is applied to the pixel during a second period, The second period of time is longer than the first period of time.

3. The display device according to claim 2, wherein: The second accumulation coefficient is greater than the first accumulation coefficient.

4. The display device according to claim 1, wherein: The grayscale conversion unit generates the compensation value based on a first conversion cumulative value obtained by applying a first weighting value to the first stress cumulative value and a second conversion cumulative value obtained by applying a second weighting value to the second stress cumulative value.

5. The display device according to claim 4, wherein: Also includes a memory for storing the first transformed accumulated value and the second transformed accumulated value, The first transformation cumulative value is less than the first stress cumulative value, The second transformation cumulative value is less than the second stress cumulative value.

6. The display device according to claim 5, wherein: The grayscale conversion section calculates the first stress cumulative value by applying the inverse of the first weighting value to the first conversion cumulative value read from the memory.

7. The display device according to claim 6, wherein: The grayscale conversion section calculates the second stress cumulative value by applying the inverse of the second weighting value to the second conversion cumulative value read from the memory.

8. The display device according to claim 1, wherein: The grayscale conversion unit comprises: A first stress conversion unit, converting the output grayscale into the first stress in a voltage domain; A second stress conversion unit, converting the output grayscale into the second stress in the voltage domain; A memory, used for storing a first transformed cumulative value obtained by applying a first weighted value to the first stress accumulated value and a second transformed cumulative value obtained by applying a second weighted value to the second stress accumulated value; a first stress accumulation unit, which calculates the first stress accumulation value by applying the inverse of the first weighted value to the first transformed accumulation value, and updates the first stress accumulation value by applying the first accumulation coefficient to the first stress accumulation value and adding the first stress; a second stress accumulation unit, which calculates the second stress accumulation value by applying the inverse of the second weighted value to the second transformed accumulation value, and updates the second stress accumulation value by applying the second accumulation coefficient to the second stress accumulation value and adding the second stress; and The stress compensating unit generates the compensation value based on the first transformed cumulative value and the second transformed cumulative value.

9. The display device according to claim 8, wherein: The number of bits used to represent the first stress and the number of bits used to represent the second stress are different from each other.

10. The display device according to claim 9, wherein: The first stress is a stress value when the data voltage is applied to the pixel during a first period, The second stress is a stress value when the data voltage is applied to the pixel during a second period, the second period being longer than the first period, The number of bits used to represent the first stress is greater than the number of bits used to represent the second stress.

11. A method for driving a display device, in, include: Steps for generating compensation values; The step of applying the compensation value to the input gray scale of the pixel to transform the input gray scale into an output gray scale; and The step of providing a data voltage corresponding to the output gray scale to the pixel, A first stress and a second stress are independently generated based on the output grayscale, a first stress accumulation value is updated by adding the first stress after applying a first accumulation coefficient to the first stress accumulation value, a second stress accumulation value is updated by adding the second stress after applying a second accumulation coefficient to the second stress accumulation value, and the compensation value is generated based on the first stress accumulation value and the second stress accumulation value, The first accumulation coefficient and the second accumulation coefficient are different from each other.

12. The method for driving a display device according to claim 11, wherein: The first stress is a stress value when the data voltage is applied to the pixel during a first period, The second stress is a stress value when the data voltage is applied to the pixel during a second period, The second period of time is longer than the first period of time.

13. The method for driving a display device according to claim 12, wherein: The second accumulation coefficient is greater than the first accumulation coefficient.

14. The method for driving a display device according to claim 11, wherein: The compensation value is generated based on a first transformed cumulative value obtained by applying a first weighting value to the first stress accumulated value and a second transformed cumulative value obtained by applying a second weighting value to the second stress accumulated value.

15. The method for driving a display device according to claim 14, wherein: The display device includes a memory for storing the first transformed accumulated value and the second transformed accumulated value, The first transformation cumulative value is less than the first stress cumulative value, The second transformation cumulative value is less than the second stress cumulative value.

16. The method for driving a display device according to claim 15, wherein: The first stress accumulation value is calculated by applying the inverse of the first weighting value on the first transformed accumulation value read from the memory.

17. The method for driving a display device according to claim 16, wherein: The second stress accumulation value is calculated by applying the inverse of the second weighting value on the second transformed accumulation value read from the memory.

18. The method for driving a display device according to claim 11, wherein: The step of generating the compensation value comprises: The step of converting the output grayscale into the first stress in the voltage domain; The step of converting the output grayscale into the second stress in the voltage domain; The steps of reading the first transformed accumulated value and the second transformed accumulated value; A step of calculating the first stress accumulation value by applying the inverse of a first weighted value to the first transformed accumulation value, and updating the first stress accumulation value by applying the first accumulation coefficient to the first stress accumulation value and then adding the first stress; The step of calculating the second stress accumulation value by applying the inverse of the second weighted value to the second transformed accumulation value, and updating the second stress accumulation value by applying the second accumulation coefficient to the second stress accumulation value and then adding the second stress; storing the first transformed cumulative value obtained by applying the first weighted value to the first stress accumulated value and the second transformed cumulative value obtained by applying the second weighted value to the second stress accumulated value; and The step of generating the compensation value based on the first transformed cumulative value and the second transformed cumulative value.

19. The method for driving a display device according to claim 18, wherein: The number of bits used to represent the first stress and the number of bits used to represent the second stress are different from each other.

20. The method for driving a display device according to claim 19, wherein: The first stress is a stress value when the data voltage is applied to the pixel during a first period, The second stress is a stress value when the data voltage is applied to the pixel during a second period, the second period being longer than the first period, The number of bits used to represent the first stress is greater than the number of bits used to represent the second stress.

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