KR20230103681A - Display device and method for driving the same - Google Patents

Abstract

The present invention relates to a display device which can improve short-term afterimages in real time. In the display device according to one embodiment of the present invention, when the first image frame including a high grayscale area with a reference luminance or higher continues for more than a set frame, a timing controller may extract a stress area from the high grayscale area and compensate for the data in the stress area during a compensation period for each stress considering the data in the stress area.

Description

Display device and its driving method {DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME}

The present specification relates to a display device capable of improving short-term afterimage in real time and a method for driving the same.

The light emitting display device uses a self-light emitting device and has advantages such as high luminance, low driving voltage, ultra-thin film, and free shape.

A light emitting display device displays an image by supplying a current corresponding to a data signal to a light emitting element of each of a plurality of pixels to cause the light emitting element to emit light.

When the light emitting display device is driven for a long time, a light emitting element or a thin film transistor is deteriorated and a luminance deviation occurs between pixels, which may cause an afterimage phenomenon.

For example, when a light emitting display device displays an image including a high gradation region for several frames and then switches to the next image, the stress of the high gradation region increases the luminance for some time, resulting in a short-term afterimage recognized as a stain. phenomena can occur. Although the luminance of the short-term afterimage is restored after a certain amount of time has elapsed, there is a disadvantage in that image information is distorted or annoying when watching an image while the short-term afterimage occurs.

The present specification provides a display device capable of improving short-term afterimage in real time and a driving method thereof.

The problem to be solved in this specification is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the description below to which the technical idea of this specification belongs. You will be able to.

A display device according to an embodiment includes a display panel displaying an image, a panel driver, and a timing controller, and the timing controller has a high gray level when a plurality of image frames including a high gray level region equal to or higher than a reference luminance lasts longer than a set frame. The region may be extracted as a stress region, data of the stress region may be compensated during a compensation time for each stress considering the data of the stress region, and the compensated data may be output to a panel driver.

A method of driving a display device according to an embodiment includes extracting, by a timing controller, a high grayscale region as a stress region when a plurality of image frames including a high grayscale region equal to or greater than a reference luminance lasts longer than a set frame; and Compensating for the data of the stress area may be performed during the compensation time for each stress considering the data of .

According to an embodiment, the timing controller calculates a stress level using frame durations of stress areas in a plurality of image frames and data for each color of the stress areas, and compensates for each stress in proportion to the calculated stress level. , and during the compensation time for each stress, the data of the stress area may be compensated by calculating a compensation amount reflecting the data of the stress area.

A display device according to an embodiment includes a display panel displaying an image, a panel driver, and a timing controller, and the timing controller is configured when a plurality of first image frames including a high grayscale region equal to or higher than a reference luminance lasts longer than a set frame. A high grayscale region is extracted as a stress region, and when an image is switched from the first image frame to the second image frame, a compensation region overlapping with the stress region is extracted from the second image frame, and compensation for each stress considering the data of the stress region During the time, the data of the compensation area may be compensated by reflecting the data of the stress area and the data of the compensation area, and the compensated data may be output to the panel driver.

According to an embodiment, a method of driving a display device includes extracting, by a timing controller, a high grayscale region as a stress region when a plurality of first image frames including a high grayscale region equal to or higher than a reference luminance lasts longer than a set frame; When the image is switched from the first image frame to the second image frame, extracting a compensation region overlapping the stress region in the second image frame, and during a compensation time for each stress considering the data of the stress region, the stress region and the compensation region Data in the compensation area may be compensated by reflecting the data.

According to an embodiment, the timing controller calculates a stress level using frame durations of stress areas in a plurality of first image frames and data for each color of the stress areas, and calculates a stress level for each stress level according to the calculated stress level. A compensation time is derived, a compensation amount reflecting the data of the stress area and the compensation area is derived during the compensation time for each stress, and compensation is performed by applying the derived compensation amount to the data of the compensation area of the plurality of second image frames. can

According to an embodiment, the timing controller calculates a first compensation amount of the stress area by applying a frame duration of the stress area, data for each color of the stress area, and different weights for each color, and calculates the calculated first compensation amount. A second compensation amount may be calculated by applying a weighting ratio for each color using data for each color of the compensation area, and the data of the compensation area may be compensated by applying the calculated second compensation amount.

During the compensation time for each stress, the timing controller according to an embodiment may gradually reduce the amount of compensation applied to data of the compensation area of the plurality of second image frames as time elapses.

During the compensation time for each stress, the timing controller according to an embodiment compensates for the luminance of the compensation region of the second image frame to a luminance lower than the input luminance, and converts the data of the compensation region to gradually increase from the compensated low luminance to the input luminance. can compensate

Specific details according to various examples of the present specification other than the means for solving the problems mentioned above are included in the description and drawings below.

A display device and a driving method thereof according to some embodiments remove short-term afterimages by reducing short-term stress due to a temperature increase in the high-grayscale part through gradation compensation when a first image including a high-grayscale part is displayed for a set frame or more. or improved to provide a distortion-free image to viewers.

A display device and a method of driving the same according to some embodiments, when displaying a first image including a high grayscale part for a set frame or more and then converting and displaying a second image, short-term stress due to the high grayscale part and compensation time for each stress , By reducing the short-term stress portion of the second image through grayscale compensation in consideration of the grayscale information of the second image, the short-term afterimage can be removed or improved to provide a distortion-free image to the viewer.

1 is a block diagram illustrating a configuration of a display device according to an exemplary embodiment.
2 is an equivalent circuit diagram illustrating a configuration of each pixel according to an exemplary embodiment.
3 is an equivalent circuit diagram illustrating a configuration of each pixel according to an exemplary embodiment.
4 is a diagram illustrating short-term afterimages of a display device by way of example.
5 is a graph showing luminance over time of a short-term afterimage region of a display device by way of example.
6 is a diagram illustrating a short-term afterimage improvement effect of a display device according to an exemplary embodiment.
7 is a flowchart illustrating an image processing method for improving a short-term afterimage of a display device according to an exemplary embodiment.
8 is a graph showing compensation time according to stress in a display device according to an exemplary embodiment.
9 is a graph illustrating a short-term afterimage improvement effect of a display device according to an exemplary embodiment.
10 to 24 are diagrams illustrating a short-term afterimage improvement effect according to various test patterns of a display device according to an exemplary embodiment.

Advantages and features of this specification, and methods of achieving them, will become clear with reference to embodiments described below in detail in conjunction with the accompanying drawings. However, this specification is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments make the disclosure of this specification complete, and common knowledge in the art to which this specification belongs. It is provided to completely inform the person who has the scope of the invention, and this specification is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of this specification are illustrative, so this specification is not limited to the matters shown. Like reference numbers designate like elements throughout the specification. In addition, in describing the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present specification, the detailed description will be omitted. When "comprises," "has," "consists of," etc. mentioned in this specification is used, other parts may be added unless "only" is used. In the case where a component is expressed in the singular, the case including the plural is included unless otherwise explicitly stated.

In interpreting the components, even if there is no separate explicit description of the error range, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described as “on top,” “upper,” “lower,” “next to,” etc., for example, “right” Or, unless "directly" is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, when a temporal precedence relationship is described with “after,” “next to,” “next to,” “before,” etc., when it is not continuous unless “immediately” or “directly” is used may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present specification.

In describing the components of the present specification, terms such as first, second, A, B, a, b, etc. may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being "connected," "coupled to," or "connected to" another element, that element is directly connected or capable of being connected to the other element, but indirectly unless specifically stated otherwise. It should be understood that other components may be “interposed” between each component that is or can be connected.

“At least one” should be understood to include all combinations of one or more of the associated elements. For example, "at least one of the first, second, and third elements" means not only the first, second, or third elements, but also two of the first, second, and third elements. It can be said to include a combination of all components of one or more.

Each feature of the various embodiments of the present specification can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in an association relationship. may be

Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. Since the scales of the components shown in the drawings have different scales from actual ones for convenience of explanation, they are not limited to the scales shown in the drawings.

1 is a block diagram illustrating a configuration of a display device according to an exemplary embodiment, and FIGS. 2 and 3 are equivalent circuit diagrams illustrating a configuration of a pixel circuit according to an exemplary embodiment.

An electroluminescent display using a self-luminous element may be applied to the display device 1000 according to an embodiment. An organic light emitting diode (OLED) display device or a quantum-dot light emitting diode (QD) display device may be applied to the electroluminescent display device.

The display device 1000 may be any one of a flexible display device, a rollable display device, a curved display device, a bending display device, a transparent display device, and a mirror display device. .

Referring to FIG. 1 , a display device 1000 may include a display panel 100, a gate driver 200, a data driver 300, a timing controller 400, a gamma voltage generator 500, and the like. The gate driver 200 and the data driver 300 may be defined as panel drivers that drive the display panel 100 . The gate driver 200, the data driver 300, the timing controller 400, the gamma voltage generator 500, and the like may be defined as a display driver.

The display panel 100 displays an image through a display area DA in which subpixels P are arranged in a matrix form. The display panel 100 may be a panel to which a touch sensor screen overlapping a pixel matrix of the display area DA is embedded or attached. The subpixels P include a red (hereinafter referred to as R) subpixel emitting red color light, a green (hereinafter referred to as G) subpixel emitting green color light, and a blue (hereinafter referred to as B) subpixel emitting blue color light. pixels, and may further include a white (W) sub-pixel emitting white color light to increase luminance. A unit pixel may include two, three, or four subpixels having different colors among the R, G, B, and W subpixels.

Each subpixel P includes a light emitting element and a pixel circuit independently driving the light emitting element. As the light emitting device, organic light emitting diodes, quantum dot light emitting diodes, and inorganic light emitting diodes may be applied. The pixel circuit may include TFTs of various configurations including a driving TFT (Thin Film Transistor) and a switching TFT for driving a light emitting device, and a storage capacitor. A pixel circuit of each subpixel P may be connected to signal lines including a gate line, a data line, a power line, and the like disposed on the display panel 100 .

For example, as shown in FIG. 2 , each subpixel P includes a first power line PW1 supplying a high potential driving voltage (first driving voltage; EVDD) and a low potential driving voltage (second driving voltage). The light emitting element EL connected between the second power line PW2 supplying a voltage; EVSS, and the first and second switching TFTs ST1 and ST2 to independently drive the light emitting element EL, and A pixel circuit including at least a TFT (DT) and a storage capacitor (Cst) may be provided.

The light emitting element EL may include an anode connected to the source node N2 of the driving TFT DT, a cathode connected to the second power line PW2, and an organic light emitting layer between the anode and the cathode. The anode is independent for each subpixel, but the cathode may be a common electrode shared by all subpixels. In the light emitting element EL, when a driving current is supplied from the driving TFT DT, electrons from the cathode are injected into the organic light emitting layer, and holes from the anode are injected into the organic light emitting layer. By emitting the phosphor, light of brightness proportional to the current value of the driving current can be generated.

The first switching TFT (ST1) is driven by the scan gate signal (SCn) supplied from the gate driver 200 to the first gate line (Gn1) and data supplied from the data driver 300 to the data line (Dm). The voltage Vdata is supplied to the gate node N1 of the driving TFT DT.

The second switching TFT (ST2) is driven by the sense gate signal (SEn) supplied from the gate driver 200 to the second gate line (Gn2), and the reference is supplied from the data driver 300 to the reference line (Rm). The voltage Vref is supplied to the source node N2 of the driving TFT DT. Meanwhile, in the sensing mode, the second switching TFT ST2 may provide a current reflecting the characteristics of the driving TFT DT or the light emitting element EL to the reference line Rm.

The first and second switching TFTs ST1 and ST2 may be controlled by different gate lines Gn1 and Gn2 or the same gate line as shown in FIG. 2 .

The storage capacitor Cst connected between the gate node N1 and the source node N2 of the driving TFT DT connects the gate node N1 and the source node ( The difference between the data voltage (Vdata) and the reference voltage (Vref) supplied to N2) is charged as the driving voltage (Vgs) of the driving TFT (DT), and the first and second switching TFTs (ST1, ST2) are turned off. The driving voltage (Vgs) charged during the light emission period is held.

The driving TFT DT can control the light emitting intensity of the light emitting element EL by controlling the current Ids flowing to the light emitting element EL according to the driving voltage Vgs charged in the storage capacitor Cst.

Referring to FIG. 3 , the pixel circuit of each subpixel P includes a light emitting element EL, a driving TFT DT supplying current to the light emitting element EL, a plurality of TFTs T1 to T6, and a storage capacitor ( Cst) may be included. The TFTs of each pixel circuit may be TFTs using any one of a polysilicon semiconductor, an amorphous silicon semiconductor, and an oxide semiconductor.

For example, the driving TFT (DT) and the TFTs (T1 to T3, T5, T6) excluding the compensating TFT (T4) may be composed of P-type channel polysilicon TFTs using high-mobility polysilicon. The compensation TFT (T4) connecting the driving TFT (DT) in a diode structure may be composed of an N-type channel oxide TFT using an oxide semiconductor having a smaller leakage current than polysilicon. During low-speed driving with a relatively slow screen update rate, the fourth switching TFT T4 blocks leakage current to prevent flicker.

The light emitting element EL includes an anode connected to the drain electrode of the driving TFT DT through the light emission control TFT T5, a cathode connected to the second power supply line 110 supplying the second power supply voltage VSSEL, and , It may be provided with an organic light emitting layer between the anode and the cathode. The light emitting element EL may generate light of brightness proportional to the current value of the driving current supplied from the driving TFT DT.

The compensating TFT (T4) is controlled by the first gate line 104 and has a second node N3 connected to the gate electrode of the driving TFT (DT) and a third node connected to the drain electrode of the driving TFT (DT). (N3) can be connected. The compensating TFT (T4) is turned on by the gate-on voltage of the first gate signal (SC1[n]) supplied through the first gate line 104, and the gate electrode and the drain electrode of the driving TFT (DT) are turned on. By connecting, the driving TFT (DT) can be connected in a diode structure. The first gate line 104 can be shared by two row lines, n-1st and nth (n is an integer of 2 or more) row lines, and as a result, in the bezel area of the display panel 100 The size of the built-in gate driver 200 and the size of the bezel can be reduced.

The switching TFT (T1) is controlled by the second gate line 105 and may connect the data line 102 and the first node N1 connected to the source electrode of the driving TFT (DT). The switching TFT (T1) is turned on by the gate-on voltage of the second gate signal (SC2[n]) supplied through the second gate line 105, and is supplied through the data line 102 to the data voltage ( Vdata) can be supplied to the source electrode of the driving TFT (DT).

The operation control TFT (T2) is controlled by the emission control line 111 and may connect the first power line (VDDEL) and the first node (N1) connected to the source electrode of the driving TFT (DT). The operation control TFT (T2) is turned on by the gate-on voltage of the light emission control signal EM[n] supplied through the light emission control line 111, and the first power supply line 103 supplies the first The power voltage EVDD may be supplied to the source electrode of the driving TFT DT.

The light emission control TFT (T5) is controlled by the light emission control line 111, and a third node N3 connected to the drain electrode of the driving TFT (DT) and a fourth node connected to the anode electrode of the light emitting element EL. (N4) can be connected. The emission control TFT (T5) is turned on by the gate-on voltage of the emission control signal (EM[n]) supplied through the emission control line 111, and the drain electrode of the driving TFT (DT) and the light emitting element (EL) ) can be connected to the anode electrode.

The first initialization TFT T3 may connect a third node N3 controlled by the third gate line 106 and connected to the drain electrode of the driving TFT DT to the first initialization line 108. . The first initialization TFT (T3) is turned on by the gate-on voltage of the third gate signal (SC3[n]) supplied through the third gate line 106 and connected to the drain electrode of the driving TFT (DT). The first initialization voltage Vini[n] supplied through the first initialization line 108 may be supplied to the third node N3 .

The second initialization TFT T6 is controlled by the fourth gate line 107 and may connect the second initialization line 109 and the fourth node N4 connected to the anode of the light emitting element EL. The second initialization TFT ( T6 ) is turned on by the gate-on voltage of the fourth gate signal ( SC3 [n+1]) supplied through the fourth gate line 107 and serves as an anode electrode of the light emitting element (LED). The second initialization voltage VAR supplied through the second initialization line 109 may be supplied to the fourth node N4 connected to . The fourth gate line 107 may share a third gate line supplying the third gate signal SC3 [n+1] in an n+1th (n is a positive integer) row line.

The storage capacitor Cst may be connected between the first power line 103 and the second node N2 connected to the gate electrode of the driving TFT DT. The storage capacitor Cst connects the first power supply voltage VDDEL supplied through the first power line 103, the switching TFT T2, the driving TFT DT, and the compensation TFT T1 from the data line 102. The difference voltage from the data voltage Vdata supplied to the second node N2 via the second node N2 may be charged. While the driving TFT (DT) is connected in a diode structure through the compensating TFT (T4), the storage capacitor (Cst) can sample and store the threshold voltage (Vth) of the driving TFT (DT). A data voltage (Vdata-Vth) in which the threshold voltage (Vth) is compensated may be provided to the gate electrode. Accordingly, the storage capacitor Cst generates a target voltage difference (VDDEL-Vdata+Vth) between the first power supply voltage VDDEL and the data voltage Vdata obtained by compensating the threshold voltage Vth of the driving TFT DT. It can be charged with a voltage, and the charged target voltage can be provided as a driving voltage (Vgs) between the gate and source electrodes of the driving TFT (DT). Accordingly, the variation in characteristics of the driving TFT (DT) between subpixels can be compensated for.

The driving TFT DT controls the light emitting intensity of the light emitting element EL by controlling the current Ids flowing to the light emitting element EL according to the driving voltage charged in the storage capacitor Cst.

The gate lines 104, 105, 106, and 107 may be driven by the gate driver 200, and the emission control line 111 is disposed in the bezel area of the display panel 100 together with the gate driver 200. It can be driven by a light emission control driver (not shown).

Referring to FIG. 1 , the gate driver 200 is controlled according to a plurality of gate control signals supplied from the timing controller 400 and can individually drive the gate lines of the display panel 100 . The gate driver 200 may supply a gate-on voltage scan signal to the corresponding gate line during the driving period of each gate line, and supply a gate-off voltage to the corresponding gate line during the non-driving period of each gate line. The gate driver 200 may be formed in the bezel area along with the TFTs of the pixel matrix of the display area DA and embedded in the display panel 100 in the form of a gate in panel (GIP).

The gamma voltage generator 500 generates a plurality of reference gamma voltages having different gamma voltage levels and supplies them to the data driver 300 . The gamma voltage generator 500 may generate a plurality of reference gamma voltages corresponding to the gamma characteristics of the display device under the control of the timing controller 400 and supply them to the data driver 300 . The gamma voltage generator 500 may adjust the reference gamma voltage level according to the gamma data supplied from the timing controller 400 and output the adjusted reference gamma voltage level to the data driver 300 . The gamma voltage generator 500 may adjust the high-potential power supply voltage, which is the maximum gamma voltage, according to the peak luminance control from the timing controller 400, and adjust a plurality of standard reference gamma voltages according to the high-potential power supply voltage to drive the data driver. (300).

The data driver 300 is controlled according to the data control signal supplied from the timing controller 400, converts the digital data supplied from the timing controller 400 into an analog data signal through a digital-to-analog converter, and Each data signal may be supplied to each data line. In this case, the data driver 300 may convert digital data into an analog data signal using grayscale voltages in which a plurality of reference gamma voltages supplied from the gamma voltage generator 500 are subdivided.

The timing controller 400 may receive source image data and timing control signals from an external host system. The host system may be any one of a system of a portable terminal such as a computer, a TV system, a set-top box, a tablet or a mobile phone. The timing control signals may include a dot clock, a data enable signal, a vertical sync signal, a horizontal sync signal, and the like.

The timing controller 400 may control the gate driver 200 and the data driver 300 using timing control signals supplied from the host system and timing setting information stored therein. The timing controller 400 may generate a plurality of gate control signals for controlling driving timing of the gate driver 200 and supply them to the gate driver 200 . The timing controller 400 may generate and supply a plurality of data control signals for controlling driving timing of the data driver 300 to the data driver 300 .

The timing controller 400 may perform various image processing including picture quality correction, deterioration correction, luminance correction for reducing power consumption, etc. on the source image data supplied from the host system, and transmit the image processed data to a data driver ( 300) can be supplied.

The timing controller 400 may improve the afterimage phenomenon through image processing. Afterimages occurring in the display device 1000 may be classified into long-term afterimages and short-term afterimages.

Long-term afterimages may occur in the form of deterioration of luminance due to deterioration of the light emitting element due to long-term driving of the display panel 100 . The timing controller 400 can improve the long-term afterimage lifetime, which means the point in time at which long-term afterimage occurs, by shifting the image according to time and distributing the cumulative stress of each subpixel. The timing controller 400 accumulates data of each subpixel or senses the characteristics of each subpixel through the data driver 300 to detect a deterioration amount of each subpixel and compensates for the detected amount of deterioration of each subpixel. Long-term afterimages can be improved through image processing.

When an image including a high gradation region is continuously displayed on the display panel 100 for several frames, the temperature rise due to heat in the high gradation display region of the display panel 100 increases the mobility of the driving TFT. As a result, short-term afterimages may occur. The short-term afterimage may occur in a form in which the luminance of the high-grayscale display area is increased compared to the peripheral area, and may return to the original luminance after a certain period of time.

The timing controller 400 determines at least one of short-term stress due to temperature rise in the high grayscale region, temperature drop time (compensation time), and grayscale information of adjacent frames when the source image continuously includes the high grayscale region beyond the set frame. Short-term afterimages can be improved through image processing using the image processing method. A detailed description of this will be described with reference to FIGS. 4 to 9 .

The timing controller 400 may further compensate by applying a compensation value for characteristic deviation of each subpixel stored in the memory before supplying image-processed data to the data driver 300 . In the sensing mode, the timing controller 400 senses the characteristics of each subpixel P of the panel 100 through the data driver 300 and updates the compensation value of each subpixel stored in the memory using the sensing result. can do. The sensing mode of the display device may be performed according to an instruction of the host system, a user request through the host system, or a driving sequence of the timing controller 400 .

When displaying a first image including a high grayscale portion for a set frame or more, the display device 1000 according to an embodiment reduces short-term stress caused by a temperature rise in the high grayscale portion through grayscale compensation to remove short-term afterimages or By improving the image quality, distortion-free images can be provided to viewers.

When the display device 1000 according to an embodiment displays a first image including a high grayscale portion for a set frame or more and then converts and displays the second image, short-term stress due to the high grayscale portion, compensation time for each stress, In consideration of the grayscale information of the second image, the short-term stress portion of the second image is reduced through grayscale compensation, thereby removing or improving the short-term afterimage and providing a distortion-free image to the viewer.

4 is a diagram showing a short-term afterimage of a display device by way of example, FIG. 5 is a graph showing a change in luminance over time in a short-term afterimage region of the display device by way of example, and FIG. 6 is a graph of a display device according to an exemplary embodiment. It is a diagram showing the short-term afterimage improvement effect by image processing by way of example.

Referring to FIGS. 4(a) and 5(a) , when the display device continuously displays the first image 101 including the high gray area 102 for N frames (N is a natural number), the high gray level In the region 102 , a short-term stress in which electron mobility increases due to a temperature rise may be received, and the output luminance 116A may increase over time from the original high gray luminance 114A.

Referring to FIGS. 4(b), 5(b), and 6(a) , when the image is converted from the first image 101 to the second image 103, that is, the high gray level of the first image 101 When the luminance 114B of the region 102 is converted to the low gradation luminance 114C of the second image 103, the high luminance of the first image 101 in the second region 104 of the second image 103 The gradation portion 102 may be affected by a short-term stress caused by a temperature rise for a certain period of time. In the second region 104 of the second image 103 due to the short-term stress caused by the high gray region 102 of the first image 101, the output luminance 116B is higher than the original low gray luminance 114C. A short-term afterimage that increases and becomes distorted may occur. The distorted luminance 116B of the short-term afterimage may gradually decrease from the image switching time point t1 to the temperature drop time t2 and return to the original low grayscale luminance 114C of the second image 103, but the temperature During the fall time (t2-t1), the viewer may perceive the distorted luminance 116B of the short-term afterimage.

In order to improve such a short-term afterimage, the timing controller 400 according to an embodiment may extract a high grayscale region 102 as a short-term stress region from the first image 101 that lasts for a set (N) frames or longer. . The timing controller 400 determines the stress according to the gradation of the extracted high gradation region 102, the temperature drop time (t2-t1), and the second region 104 of the second image 103 where the image has been switched. The R/G/B gradation of the second region 104 of the second image 103 may be compensated for by considering the gradation information. The timing controller 400 performs grayscale compensation so that the luminance of the second region 104 temporally overlapping the high grayscale region 102 of the first image 101 in the second image 103 is lower than the target luminance. I did.

Accordingly, as shown in FIG. 6(b) , the display device according to an exemplary embodiment may output the second image 103 from which the short-term afterimage is removed in the short-term stress region.

7 is a flowchart illustrating an image processing method for improving a short-term afterimage of a display device according to an embodiment, FIG. 8 is a graph showing a compensation time according to a stress level according to an embodiment, and FIG. 9 is a graph according to an embodiment. It is a graph showing the short-term afterimage improvement effect by image processing of the display device according to the present invention.

Referring to FIGS. 1 and 7 , the timing controller 400 may input an image signal (S502) and determine whether there is a high grayscale region of the first image that is maintained over a set frame (S504).

For example, the timing controller 400 may determine a high grayscale region that is higher than the reference luminance (eg, 100 nit) and maintained for a set frame or longer from the first image of the plurality of frames and extract it as a short-term stress region (S504). , Yes).

The timing controller 400 may calculate the short-term stress considering weights for each R/G/B color using the high-grayscale data of the high-grayscale region (short-term stress region) extracted from the first image (S506). The timing controller 400 determines at least one of a frame duration for which a high grayscale region lasts in the first image of a plurality of frames, a grayscale ratio for each R/G/B color, and a different color weight for each R/G/B color. It is possible to calculate the stress of the high grayscale region lasting for a plurality of frames.

The grayscale ratio for each R/G/B color may mean a ratio of each R/G/B grayscale value to the first reference grayscale value. The first reference grayscale value may be the maximum grayscale value 255 . The weight for each R/G/B color may be a value reflecting a difference in temperature stress for each color. The frame duration of the high grayscale region may be determined by the number of consecutive frames of images including the high grayscale region and the time of each frame. The number of frames may be calculated by counting vertical synchronization signals in the timing controller 400 .

For example, the timing controller 400 may determine the frame duration of the high grayscale region (short-term stress region) in the first image of the plurality of frames and the grayscale ratio (R/255, G/255 B/255) and the weights for each R/G/B color may be applied to calculate the short-term stress of the high gradation region (short-term stress region).

The timing controller 400 derives the gray level compensation amount for each stress by using the short-term stress in the high gray level region and a look-up table (hereinafter referred to as LUT) for the gray level compensation amount for each stress stored in the first memory 600. It can (S508). The gradation compensation amount for each stress level may be set in advance to a level at which afterimages are cognitively removed for each stress level. As the gradation value of the high gradation region increases, the magnitude (step) of the stress may increase, and as the magnitude of the stress increases, the gradation compensation amount for each stress may increase.

The timing controller 400 may derive a compensation time for each stress using the short-term stress of the high grayscale region and the temperature drop time LUT for each stress stored in the first memory 600 (S510). As the stress level (magnitude) increases, the compensation time may increase.

Referring to the graphs of compensation time for each stress 602_1 to 602_k shown in FIG. 8 , as the temperature T of the high gradation region increases, the magnitude of stress (stress 1 to stress k) increases, and the magnitude of stress (stress 1 It can be seen that as ~stress k) increases, the temperature lowering completion time (t1~t(k)) increases. In FIG. 8 , the temperature lowering completion time (t1 to t(k)) according to the magnitude of stress (stress 1 to stress k) may mean a compensation time according to the magnitude of stress (stress 1 to stress k).

The timing controller 400 may compare image data of at least two adjacent frames among multiple frames of images to determine whether a screen (image) is switched (S520).

The timing controller 400 compares the first image of the adjacent first frame with the second image of the second frame to determine whether or not the screen is switched (S520), and if there is no screen (image) switch (No), the first image The grayscale compensation amount for each stress derived from the high grayscale region (short-term stress region) of can be derived as the final grayscale compensation amount (S512).

The timing controller 400 compensates data in the high grayscale region (short-term stress region) of the first image by applying the derived compensation time for each stress and the final grayscale compensation amount (S524), and a third image including the compensated data. can be output (S526). During the compensation time for each stress, the timing controller 400 may compensate for data in a high grayscale region (short-term stress region) of the first image by gradually changing the grayscale compensation amount as the compensation time elapses.

Accordingly, in the display device according to an exemplary embodiment, in the case of maintaining the screen for continuously displaying the first image including the high grayscale region for a set frame or longer, as shown in FIG. The luminance 118A can be output at the same level as the luminance 114A of the source image, and short-term afterimage can be improved without distortion of the luminance 116A due to a temperature increase in the high grayscale region.

The timing controller 400 compares the first image of the first frame with the second image of the second frame, which is the next frame, in step S520, and if there is a screen (image) transition (Yes), the high grayscale region of the first image ( A weighting ratio for each color may be calculated using grayscale information of the second region (compensation region) of the second image corresponding to the short-term stress region (S522). The timing controller 400 may extract grayscale information of a second region corresponding to the high grayscale region of the first image from the second image of the second frame stored in the second memory 610 . The timing controller 400 may calculate a grayscale ratio of each R/G/B color to a second reference grayscale value (eg, a halfway grayscale value) from grayscale information of the second region extracted from the second image.

The timing controller 400 adjusts the gradation ratio for each color derived from the second area (compensation area) of the second image where the image is switched to the gradation compensation amount for each stress derived from the high gradation area (short-term stress area) of the first image. A final gradation compensation amount may be derived by applying as a weighting ratio for each color (S512). The final grayscale compensation amount may vary according to grayscale information of the second area (compensation area) of the second image.

The timing controller 400 compensates the data of the second region (compensation region) extracted from the second image by applying the compensation time for each stress derived from the high gray region (short-term stress region) of the first image and the final gray level compensation amount. (S524), and a third image including compensation data may be output (S526).

The high grayscale region of the first image and the second region of the second image may mean a short-term stress region. A high grayscale region of the first image may mean a short-term stress region, and a second region of the second image may mean a compensation region.

Referring to FIG. 9(b) , when the screen displayed on the display device is switched, the timing controller 400 during the compensation time (t2-t1) from the image switching time (t1) to the compensation completion time (t2), As the compensation time elapses, the data of the compensation area may be compensated by gradually changing the gray level compensation amount 118B. For example, during the compensation time (t2-t1), as the compensation time elapses, the compensation amount of grayscale may decrease proportionally, and the compensated grayscale value 118B is compensated with a grayscale value lower than the grayscale value of the source image. It may be gradually increased to the gradation value of the source image. Accordingly, the luminance 118C compensated for in the compensation region of the second image can be output at the same level as the luminance 114B of the source image, and the luminance 116B due to the temperature rise of the high grayscale region of the first image can be output. Short-term afterimages can be improved without distortion.

10 to 24 are views illustrating a short-term afterimage improvement effect using various test pattern images of a display device according to an exemplary embodiment.

10 is a diagram illustrating a short-term afterimage improvement effect using a first test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 10(a) and 10(c) , the display device 1000 (FIG. 1) according to an exemplary embodiment displays a first image 120 including a low grayscale region 122 and a high grayscale region 124. After displaying at least a set frame, the second image 120B including the low grayscale region 122 may be compensated and displayed through image processing.

Referring to FIG. 10(b) , the display apparatus 1000 transmits the luminance 114B of the high gradation region 124 of the first image 120 to the first region of the display panel 100 (Fig. 1) at the time of image conversion. After continuous display until (t1), the compensated luminance 118C of the low gray level region 122 of the second image 120B may be displayed from the image switching time point t1.

During the compensation time (t2-t1) from the image switching time point (t1) to the compensation completion time (t2), the display apparatus 1000 determines the source grayscale value of the compensation region among the low grayscale region 122 of the second image 120B. By applying a grayscale compensation amount to , the grayscale value 118B lower than the source grayscale value may be compensated and output. The amount of compensation for grayscale is the stress level (size) considering the grayscale information and the frame duration (t1) of the high grayscale region 124 of the first test image 120, the compensation time (t2-t1) for each stress level, and the first It may be calculated by considering the gray level value of the compensation area of the second image 120B corresponding to the high gray level area 124 of the image 120, and the gray level compensation amount may gradually decrease during the compensation time t2-t1. can The display apparatus 1000 may gradually increase the compensation grayscale value 118B of the compensation area of the second image 120B to the source grayscale value 114C during the compensation time period t2-t1. Accordingly, the display apparatus 1000 can improve short-term afterimage by outputting the output luminance 118C of the compensated grayscale value 118B to be equal to the target luminance 114C of the source grayscale value.

Referring to FIG. 10(c) , the second image 120A displayed on the display device to which compensation is not applied has a peripheral portion in the short-term stress region 126 corresponding to the high grayscale region 124 of the first image 120. A short-term afterimage having an increased luminance than the low grayscale region 122 may occur. On the other hand, the display apparatus 1000 according to an exemplary embodiment may improve short-term afterimages in the second image 120B by applying compensation.

11 is a diagram illustrating a short-term afterimage improvement effect using a second test pattern image of a display device according to an exemplary embodiment.

Referring to FIG. 11(a), the display device 1000 (FIG. 1) according to an exemplary embodiment continuously displays a first image 150 including a low grayscale region 152 and a high grayscale region 154 over a set frame. In case of displaying, the first image 150 may be compensated for and displayed through image processing.

Referring to FIG. 11( b ) , the display apparatus 1000 may display the compensated luminance 111D of the high grayscale region 154 on the first region of the display panel 100 ( FIG. 1 ). The display apparatus 1000 may compensate for the grayscale value 111C lower than the input grayscale value by applying a grayscale compensation amount that varies with time to the input grayscale value of the high grayscale region 154 and output the same. As time passes, the compensation grayscale value 111C of the high grayscale region 154 gradually decreases to compensate for the increase in luminance 111B due to temperature rise. Accordingly, the display apparatus 1000 may output the output luminance 111D of the compensated grayscale value 111C at a level equal to the target luminance 111A of the source grayscale value.

Referring to FIG. 11(c) , the first image 150A displayed on the display device to which compensation is not applied may have distortion in which the luminance of the high grayscale region 154A increases. On the other hand, the display apparatus 1000 according to an embodiment may apply compensation to maintain the luminance of the high grayscale region 154 of the first image 150B at the same level as that of the source image without distortion.

12 is a diagram illustrating a short-term afterimage improvement effect using a third test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 12(a) and 12(c) , the display device 1000 (FIG. 1) according to an exemplary embodiment displays a first image 160 including a black gradation area 162 and a white gradation area 164. After displaying a set frame or more as a previous image, the second image 166 including the gray gradation area 168 can be displayed as a subsequent image. When displaying the second image 166, the display apparatus 1000 performs image processing on the B region corresponding to the white gradation region 164 of the first image 160, so that the white gradation region 164 By compensating for the stress and displaying the second image 166 with improved short-term afterimages, it is possible to display the second image 166 .

Referring to FIG. 12(b) , when displaying the first image 160, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the white grayscale region 164. . When displaying the second image 166, the display device 1000 outputs the second pixel data R2, G2, B2, and W2 to area A of the gray gradation area 168, and area B is compensated for. 3 pixel data (R3, G3, B3, W3) can be output. The luminance of the compensated third pixel data R3 , G3 , B3 , and W3 of region B may be lower than the luminance of the second pixel data R2 , G2 , B2 , and W2 of region A. For example, the luminance of W3 data among the third pixel data R3 , G3 , B3 , and W3 may be lower than the luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 .

13 is a diagram illustrating a short-term afterimage improvement effect using a fourth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 13(a) and 13(c) , in the display device 1000 (FIG. 1) according to an exemplary embodiment, a black gradation area 174 and a white gradation area 172 have a checker board shape. After displaying the first image 170 including the previous image over a set frame, the second image 176 including the gray gradation area 178 may be displayed as the subsequent image. When displaying the second image 176, the display apparatus 1000 performs image processing on area B corresponding to the white gradation area 172 of the first image 170, and By compensating for the stress and displaying the second image 176 with improved short-term afterimages, it is possible to display the second image 176 .

Referring to FIG. 13(b) , when displaying the first image 170, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the white grayscale region 172. . When displaying the second image 176, the display device 1000 outputs the second pixel data R2, G2, B2, and W2 to area A of the gray gradation area 178, and area B is compensated for. 3 pixel data (R3, G3, B3, W3) can be output. The luminance of the compensated third pixel data R3 , G3 , B3 , and W3 of region B may be lower than the luminance of the second pixel data R2 , G2 , B2 , and W2 of region A. For example, the luminance of W3 data among the third pixel data R3 , G3 , B3 , and W3 may be lower than the luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 .

14 is a diagram illustrating a short-term afterimage improvement effect using a fifth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 14(a) and 14(c) , the display device 1000 (FIG. 1) according to an exemplary embodiment alternates a first image 180 and a second image 186 as previous images to set frames. After displaying the above, the third image 190 including the gray gradation area 192 may be displayed as a subsequent image.

The first image 180 includes a low gradation area 182 and a first high gradation area 182 equal to or greater than the reference luminance, and the second image 186 includes a low gradation area 182 and a second high gradation area 182 equal to or greater than the reference luminance. area 188. The first high gradation region 182 of the first image 180 and the second high gradation region 188 of the second image 186 overlap temporally, and may display different high luminance.

When displaying the third image 190, the display apparatus 1000 displays an image of region B corresponding to the first and second high grayscale regions 184 and 188 of the first and second images 180 and 186. Through processing, the stress caused by the first and second high grayscale regions 184 and 188 is compensated for and displayed, so that the short-term afterimage is removed or the third image 190 with an improvement can be improved.

Referring to FIG. 14(b) , the display device 1000 outputs first pixel data R1, G1, B2, and W1 to the first high grayscale region 184 of the first image 180, and second The second pixel data R2 , G2 , B2 , and W2 may be output to the second high grayscale region 188 of the image 186 . For example, luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 may be higher than luminance of W1 data of the first pixel data R1 , G1 , B2 , and W1 .

When displaying the third image 190, the display device 1000 outputs the third pixel data R3, G3, B3, and W3 to area A of the gray gradation area 192, and area B is compensated for. 4 pixel data (R4, G4, B4, W4) can be output. The luminance of the compensated fourth pixel data R4 , G4 , B4 , and W4 of region B may be lower than the luminance of the third pixel data R3 , G3 , B3 , and W3 of region A. For example, luminance of W4 data among the fourth pixel data R4 , G4 , B4 , and W4 may be lower than luminance of W3 data of the third pixel data R3 , G3 , B3 , and W3 .

15 is a diagram illustrating a short-term afterimage improvement effect using a sixth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 15(a) and 15(c) , the display device 1000 (FIG. 1) according to an exemplary embodiment alternates a first image 186 and a second image 210 as previous images to set frames. After displaying the above, the third image 190 including the gray gradation area 192 may be displayed as a subsequent image.

The first image 186 includes a low grayscale region 182 and a first high grayscale region 188 equal to or greater than the reference luminance, and the second image 210 includes a low grayscale region 212 and a second high grayscale region equal to or greater than the reference luminance. area 214. The first high gradation region 188 of the first image 186 and the second high gradation region 214 of the second image 210 may include regions (circular regions) temporally overlapping each other but having different shapes, , can display the same high luminance. The low gradation area 182 of the first image 186 and the low gradation area 212 of the second image 210 may display the same low luminance.

When the display device 1000 displays the third image 190, the B region corresponding to the overlapping region of the first and second high grayscale regions 188 and 214 of the first and second images 186 and 210 The third image 190, in which short-term afterimages are removed or improved, can be improved by compensating for and displaying the stress caused by the overlapping region of the first and second high grayscale regions 188 and 214 through image processing. .

Referring to FIG. 15(b) , the display device 1000 outputs first pixel data R1, G1, B2, and W1 to the first high grayscale region 188 of the first image 186, and second The second pixel data R2 , G2 , B2 , and W2 may be output to the second high grayscale region 214 of the image 210 . For example, the first pixel data R1 , G1 , B2 , and W1 and the second pixel data R2 , G2 , B2 , and W2 may be the same.

When displaying the third image 190, the display device 1000 outputs the third pixel data R3, G3, B3, and W3 to area A of the gray gradation area 192, and area B is compensated for. 4 pixel data (R4, G4, B4, W4) can be output. The luminance of the compensated fourth pixel data R4 , G4 , B4 , and W4 of region B may be lower than the luminance of the third pixel data R3 , G3 , B3 , and W3 of region A. For example, luminance of W4 data among the fourth pixel data R4 , G4 , B4 , and W4 may be lower than luminance of W3 data of the third pixel data R3 , G3 , B3 , and W3 .

16 is a diagram illustrating a short-term afterimage improvement effect using a seventh test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 16(a) and 16(c) , the display apparatus 1000 (FIG. 1) according to an exemplary embodiment alternates a first image 220 and a second image 226 as previous images to set frames. After displaying the above, the third image 228 including the gray gradation area 229 may be displayed as a subsequent image.

The first image 220 includes a background area 222 of a first high gradation higher than the standard luminance th and a logo area 224 of a second high gradation higher than the standard luminance th, and the second image 226 may include the background area 227 and the logo area 224 of the second high gradation. The first and second images 220 and 226 may include a logo area 224 that temporally overlaps.

When displaying the third image 228, the display apparatus 1000 provides information about area A corresponding to the background areas of the first and second images 220 and 226 and area B corresponding to the logo area 224. Through image processing, the stress caused by the high gradation of the first and second images 220 and 226 is compensated for and displayed, so that the short-term afterimage is removed or the third image 228 is improved.

Referring to FIG. 16(b), the display device 1000 outputs first pixel data R1, G1, B2, and W1 to the background area 222 of the first image 220, and the first and second pixel data R1, G1, B2, and W1 are displayed. The second pixel data R2 , G2 , B2 , and W2 and the third pixel data R3 , G3 , B3 , and W3 may be output to the logo area 224 of the images 220 and 226 . For example, the second pixel data (R2, G2, B2, W2) and the third pixel data (R3, G3, B3, W3) greater than the first pixel data (R1, G1, B2, W1) are identical to each other, , W1, W2, and W3 data may have luminance greater than or equal to the reference luminance (th).

When displaying the third image 228, the display apparatus 1000 outputs the compensated fourth pixel data (R4, G4, B4, W4) to area A of the gray gradation area 229, and compensates for area B. The processed fifth pixel data R5, G5, B5, and W5 may be output. Since the stress of the logo area 224 is greater than the stress of the background areas 222 and 227 of the first and second images 220 and 226, the compensation value of area B may be greater than that of area A. The luminance of the compensated fifth pixel data R5, G5, B5, and W5 of region B may be lower than the luminance of the compensated fourth pixel data R4, G4, B4, and W4 of region A. For example, the luminance of W5 data among the fifth pixel data (R5, G5, B5, and W5) may be lower than the luminance of the W4 data of the fourth pixel data (R4, G4, B4, and W4), and the W4 and W5 data The luminance of can be compensated for lower than the luminance of the source W0 data.

17 is a diagram illustrating a short-term afterimage improvement effect using an eighth test pattern image of a display device according to an exemplary embodiment, and FIGS. 18 and 19 are diagrams illustrating a compensation amount change according to a color of a second image.

Referring to FIGS. 17(a) and 17(c) , the display apparatus 1000 ( FIG. 1 ) according to an exemplary embodiment converts a black gradation area 232 and a first color area 234 equal to or greater than the reference luminance into a previous image. After the first image 230 including the first image 230 is displayed at a set frame or higher, the second image 236 including the second color region 238 having a standard luminance or higher may be displayed as a subsequent image. When the display apparatus 1000 displays the second image 238, the first color region 234 is displayed through image processing of region B corresponding to the first color region 234 of the first image 230. By compensating for the stress caused by and displaying the second image 236 with improved short-term afterimages, it is possible to display the second image 236 . The first color area 234 of the first image 230 and the second color area 238 of the second image 236 display different colors, but may have the same current (luminance) value.

Referring to FIG. 17(b) , when displaying the first image 230, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the first color region 234. there is. When displaying the second image 236, the display apparatus 1000 outputs the second pixel data R2, G2, B2, and W2 to area A of the second color area 238, and area B is compensated. Third pixel data R3 , G3 , B3 , and W3 may be output. The luminance of the compensated third pixel data R3 , G3 , B3 , and W3 of region B may be lower than the luminance of the second pixel data R2 , G2 , B2 , and W2 of region A. For example, the luminance of W3 data among the third pixel data R3 , G3 , B3 , and W3 may be lower than the luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 .

18 and 19, even if the stress level of the first color region 244 of the first image 240, which is the previous image, is the same, the second color region 248 of the second image 246, the subsequent image and, when the third color region 252 of the third image 250, which is the subsequent image, displays different colors, the amount of compensation applied to region B among the second color region 248 of the second image 246 249 and the amount of compensation 253 applied to region B of the third color region 252 of the third image 250 may be different from each other.

20 is a diagram illustrating a short-term afterimage improvement effect using a ninth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 20(a) and 20(c) , the display apparatus 1000 (FIG. 1) according to an exemplary embodiment includes a black gradation area 262 as a previous image and a first color area equal to or greater than the reference luminance (th) ( 264), the second image 266 including the second color area 268 may be displayed as a subsequent image after displaying the set frame or more. When the display apparatus 1000 displays the second image 266, the first color region 264 is displayed through image processing of region B corresponding to the first color region 264 of the first image 260. By compensating for the stress caused by and displaying the second image 266 with improved short-term afterimages, it is possible to display the second image 266 . The first color area 264 of the first image 260 and the second color area 268 of the second image 266 display different colors, but may have the same current (luminance) value.

Referring to FIG. 20(b) , when displaying the first image 260, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the first color region 264. there is. When displaying the second image 266, the display apparatus 1000 outputs the second pixel data R2, G2, B2, and W2 to area A of the second color area 268, and area B is compensated. Third pixel data R3 , G3 , B3 , and W3 may be output. The luminance of the compensated third pixel data R3 , G3 , B3 , and W3 of region B may be lower than the luminance of the second pixel data R2 , G2 , B2 , and W2 of region A. For example, the luminance of W3 data among the third pixel data R3 , G3 , B3 , and W3 may be lower than the luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 .

21 is a diagram illustrating a short-term afterimage improvement effect using a tenth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 21(a) and 21(c) , the display apparatus 1000 (FIG. 1) according to an exemplary embodiment includes a black gradation area 272 as a previous image and a first color area equal to or greater than the reference luminance (th) ( 274), the second image 276 including the second color area 278 may be displayed as a subsequent image after displaying the set frame or more. When the display apparatus 1000 displays the second image 276, the first color region 274 is displayed through image processing of region B corresponding to the first color region 274 of the first image 270. By compensating for the stress caused by and displaying the second image 276 with improved short-term afterimages, it is possible to display the second image 276 . The first color area 274 of the first image 270 and the second color area 278 of the second image 276 may display the same color.

Referring to FIG. 21(b) , when displaying the first image 270, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the first color region 274. there is. When displaying the second image 276, the display apparatus 1000 outputs the second pixel data R2, G2, B2, and W2 to area A of the second color area 278, and area B is compensated. Third pixel data R3 , G3 , B3 , and W3 may be output. The luminance of the compensated third pixel data R3 , G3 , B3 , and W3 of region B may be lower than the luminance of the second pixel data R2 , G2 , B2 , and W2 of region A. For example, the luminance of W3 data among the third pixel data R3 , G3 , B3 , and W3 may be lower than the luminance of W2 data of the second pixel data R2 , G2 , B2 , and W2 .

22 is a diagram illustrating a short-term afterimage improvement effect using an 11th test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 22(a) and 22(c) , the display device 1000 (FIG. 1) according to an exemplary embodiment includes a background area 282 of a first color equal to or greater than a reference luminance th as a previous image and a reference luminance (th) After displaying the first image 280 including the white logo area 284 or more for a set frame or more, the second image 286 including the second color area 288 may be displayed as a later image. When displaying the second image 286, the display apparatus 1000 performs image processing on an area corresponding to the background area 282 of the first color and the white logo area 284 of the first image 280. , the second image 286 with improved short-term afterimages can be displayed by compensating for and displaying the stress caused by the background area 282 of the first color and the white logo area 284 . The background area 282 of the first color of the first image 280 and the second color area 288 of the second image 286 may display different colors.

Referring to FIG. 22(b) , when displaying the first image 280, the display device 1000 outputs first pixel data R1, G1, B2, and W1 to the background area 282 of the first color. and output the second pixel data R2 , G2 , B2 , and W2 to the white logo area 284 . For example, the luminance of the W2 data of the second pixel data (R2, G2, B2, W2) is higher than the luminance of the W1 data of the first pixel data (R1, G1, B2, W1), and the luminance of the W1 and W2 data may be equal to or greater than the reference luminance (th).

When displaying the second image 286, the display apparatus 1000 compensates for the third pixel data in the first region corresponding to the background region 282 of the first image 280 among the second color regions 288. (R3, G3, B3, W3) is output, and the second area corresponding to the logo area 284 of the first image 280 outputs the compensated fourth pixel data (R4, G4, B4, W4). can do. Since the stress of the logo area 284 is greater than that of the background area 282 of the first image 280, the compensation value of the second area may be greater than that of the first area. The luminance of the compensated fourth pixel data R4, G4, B4, and W4 of the second area may be lower than the luminance of the compensated third pixel data R3, G3, B3, and W3 of the first area. . For example, the luminance of W4 data among the fourth pixel data R4, G4, B4, and W4 may be lower than the luminance of W3 data of the third pixel data R3, G3, B3, and W3, and the W4 and W5 data The luminance of can be compensated for lower than the luminance of the source W0 data.

23 is a diagram illustrating a short-term afterimage improvement effect using a twelfth test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 23(a) and 23(c) , the display apparatus 1000 (FIG. 1) according to an exemplary embodiment includes a background area 292 of a first color equal to or greater than a reference luminance th as a previous image and a reference luminance (th) After displaying the first image 290 including the white logo area 294 or more for a set frame or more, the second image 296 including the second color area 298 may be displayed as a later image. When displaying the second image 296, the display apparatus 1000 performs image processing on an area corresponding to the background area 292 and the white logo area 294 of the first color of the first image 290. , the stress caused by the background area 292 of the first color and the white logo area 294 is compensated for and displayed, thereby displaying the second image 296 with improved short-term afterimage. The background area 292 of the first color of the first image 290 and the second color area 288 of the second image 296 display different colors, but may have the same current (luminance) value.

Referring to FIG. 23(b), when displaying the first image 290, the display apparatus 1000 outputs first pixel data R1, G1, B2, and W1 to the background area 292 of the first color. and output the second pixel data R2 , G2 , B2 , and W2 to the white logo area 294 . For example, the luminance of the W2 data of the second pixel data (R2, G2, B2, W2) is higher than the luminance of the W1 data of the first pixel data (R1, G1, B2, W1), and the luminance of the W1 and W2 data may be equal to or greater than the reference luminance (th).

When displaying the second image 296, the display apparatus 1000 compensates for the third pixel data in the first region corresponding to the background region 292 of the first image 290 among the second color regions 298. (R3, G3, B3, W3) is output, and the second area corresponding to the logo area 294 of the first image 290 outputs the compensated fourth pixel data (R4, G4, B4, W4). can do. Since the stress of the logo area 294 is greater than that of the background area 292 of the first image 290, the compensation value of the second area may be greater than that of the first area. The luminance of the compensated fourth pixel data R4, G4, B4, and W4 of the second area may be lower than the luminance of the compensated third pixel data R3, G3, B3, and W3 of the first area. . For example, the luminance of W4 data among the fourth pixel data R4, G4, B4, and W4 may be lower than the luminance of W3 data of the third pixel data R3, G3, B3, and W3, and the W4 and W5 data The luminance of can be compensated for lower than the luminance of the source W0 data.

24 is a diagram illustrating a short-term afterimage improvement effect using a 13th test pattern image of a display device according to an exemplary embodiment.

Referring to FIGS. 24(a) and 24(c) , in the display device 1000 (FIG. 1) according to an exemplary embodiment, a black gradation area 314 and a first color area 312 equal to or greater than the reference luminance th are After the first image 310 including the checker board form is displayed as the previous image, the second image 316 including the second color region 318 of low gradation may be displayed as the subsequent image. When the first color region 312 of the first image 310 has a reference luminance th or higher but relatively low luminance or a small frame duration, since the stress caused by the first color region 312 is relatively small, the display device 1000 may display the second color area 318 of low gradation as the second image 316 without compensation.

Referring to FIG. 24(b) , when displaying the first image 310, the display device 1000 may output first pixel data R1, G1, B2, and W1 to the first color region 312. there is. When the display apparatus 1000 displays the second image 316, the second pixel data R2, G2, B2, and W2 and the third pixel data are not compensated for regions A and B of the second color region 318. (R3, G3, B3, W3) may be output, and the second pixel data R2, G2, B2, W2 and the third pixel data R3, G3, B3, W3 may be the same.

As described above, the display device and its driving method according to some embodiments reduce the short-term stress due to the temperature of the high-grayscale part through gradation compensation when the first image including the high-grayscale part is displayed for a set frame or more. It is possible to provide a distortion-free image to a viewer by removing or improving afterimages.

A display device and a method of driving the same according to some embodiments, when displaying a first image including a high grayscale part for a set frame or more and then converting and displaying a second image, short-term stress due to the high grayscale part and compensation time for each stress , By reducing the temperature stress portion of the second image through grayscale compensation in consideration of the grayscale information of the second image, short-term afterimages can be removed or improved to provide a distortion-free image to the viewer.

A display device according to the present specification can be applied to all electronic devices. For example, the display device according to the present specification includes a mobile device, a video phone, a smart watch, a watch phone, a wearable device, a foldable device, and a rollable device ( rollable device), bendable device, flexible device, curved device, electronic notebook, e-book, portable multimedia player (PMP), personal digital assistant (PDA), MP3 player, Mobile medical device, desktop PC, laptop PC, netbook computer, workstation, navigation, vehicle navigation, vehicle display, television, wallpaper display, It can be applied to a shiny signage device, a game device, a laptop computer, a monitor, a camera, a camcorder, and home appliances.

Features, structures, effects, etc. described in various examples of the above-described specification are included in at least one example of the present specification, and are not necessarily limited to only one example. Furthermore, the features, structures, effects, etc. illustrated in at least one example in this specification can be combined or modified with respect to other examples by those skilled in the art to which the technical idea of this specification belongs. Therefore, contents related to these combinations and variations should be construed as being included in the technical scope or scope of rights of this specification.

The present specification described above is not limited to the foregoing embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes are possible within a range that does not deviate from the technical spirit of the present specification. It will be clear to those who have knowledge of Therefore, the scope of the present specification is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present specification.

100: panel 200: gate driver
300: data driver 400: timing controller
500: gamma voltage generator 1000: display device

Claims (21)

a display panel displaying images;
a panel driver driving the display panel; and
a timing controller controlling the panel driver;
The timing controller
When a plurality of image frames including a high grayscale region equal to or higher than a reference luminance lasts longer than a set frame, extracting the high grayscale region as a stress region;
A display device that compensates for data of the stress region during a compensation time for each stress considering the data of the stress region and outputs the compensated data to the panel driver. The method of claim 1,
The timing controller
calculating a stress level using a frame duration for which the stress area lasts in the plurality of image frames and data for each color of the stress area;
A display device for deriving a compensation time for each stress that is proportional to the magnitude of the calculated stress. The method of claim 2,
The timing controller
Compensating for the data of the stress area by calculating a compensation amount reflecting the data of the stress area during the compensation time for each stress;
During the compensation time for each stress, the display device adjusts the compensation amount according to the lapse of time. a display panel displaying images;
a panel driver driving the display panel; and
a timing controller controlling the panel driver;
The timing controller
When a plurality of first image frames including a high grayscale region equal to or higher than a reference luminance lasts longer than a set frame, extracting the high grayscale region as a stress region;
When an image is switched from the first image frame to the second image frame, a compensation region overlapping the stress region is extracted from the second image frame;
During a compensation time for each stress in consideration of the stress region data, the display device reflects the stress region data and the compensation region data, compensates for the compensation region data, and outputs the compensated data to the panel driver. The method of claim 4,
The timing controller
The display apparatus of claim 1 , wherein the stress level is calculated using frame durations of the stress areas in the plurality of first image frames and data for each color of the stress areas. The method of claim 5,
The timing controller
Deriving a compensation time for each stress according to the magnitude of the calculated stress,
During the compensation time for each stress, a display that derives a compensation amount reflecting the data of the stress area and the data of the compensation area, and compensates by applying the derived compensation amount to the data of the compensation area of the plurality of second image frames. Device. The method of claim 6,
The size of the screen is proportional to at least one of a grayscale value of the high grayscale region and the frame duration;
The compensation time for each stress is proportional to the magnitude of the stress. The method of claim 5,
The timing controller
A first compensation amount of the stress area is calculated by applying the frame duration of the stress area, data for each color of the stress area, and different weights for each color, and calculating the first compensation amount for the compensation area. A display device that calculates a second compensation amount by applying a weighting ratio for each color using data for each color, and compensates for the data of the compensation area by applying the calculated second compensation amount. The method of claim 6,
The timing controller
During the compensation time for each stress, a compensation amount applied to data of the compensation area of the plurality of second image frames is gradually reduced as time elapses. The method of claim 6,
The timing controller
During the compensation time for each stress, a display device that compensates for the luminance of the compensation area of the second image frame to a luminance lower than the input luminance, and compensates data of the compensation area so that the luminance gradually increases from the compensated low luminance to the input luminance. . The method of claim 6,
When the input data of the compensation area and the peripheral area of the second image frame have the same first luminance lower than that of the stress area of the first image frame,
The timing controller compensates the input data of the compensation region to have a second luminance lower than the first luminance;
A display device configured to output data of the peripheral area having the first luminance and data of the compensation area having the second luminance. The method of claim 11,
The timing controller
When first and second high grayscale regions alternate in the plurality of first image frames, an overlapping region of the first and second high grayscale regions is derived as the stress region;
When the input data of the compensation area and the peripheral area of the second image frame have the same first luminance lower than that of the stress area,
The timing controller compensates the input data of the compensation region to have a second luminance lower than the first luminance;
A display device configured to output data of the peripheral area having the first luminance and data of the compensation area having the second luminance. The method of claim 11,
The timing controller
When the input data of the compensation area and the peripheral area of the second image frame have a different color or the same color as the stress area,
The timing controller compensates the input data of the compensation region to have a second luminance lower than the first luminance;
A display device configured to output data of the peripheral area having the first luminance and data of the compensation area having the second luminance. The method of claim 11,
The timing controller
When the stress region of the first image frame has a first color equal to or greater than the reference luminance, and the compensation region of the second image frame has a second color or a third color having the same luminance but different colors,
wherein the timing controller differently applies a compensation amount of the second color and a compensation amount of the third color of the compensation area. in the timing controller,
extracting the high grayscale region as a stress region when a plurality of image frames including a high grayscale region equal to or higher than a reference luminance lasts longer than a set frame; and
and compensating for the data of the stress region during a compensation time for each stress in consideration of the data of the stress region. The method of claim 15
In the step of compensating for the data of the stress area,
Calculating a stress level using a frame duration for which the stress area lasts in the plurality of image frames and data for each color of the stress area, and deriving a compensation time for each stress proportional to the calculated stress level step; and
Compensating for the data of the stress area by calculating a compensation amount reflecting the data of the stress area during the compensation time for each stress;
During the compensation time for each stress, the driving method of the display device adjusts the compensation amount according to the lapse of time. in the timing controller,
extracting the high grayscale regions as a stress region when a plurality of first image frames including high grayscale regions equal to or higher than the reference luminance last for a set frame or longer;
extracting a compensation region overlapping the stress region from the second image frame when an image is switched from the first image frame to the second image frame; and
and compensating for the data of the compensation area by reflecting the data of the stress area and the compensation area during a compensation time for each stress in consideration of the data of the stress area. The method of claim 17
The step of compensating for the data of the compensation area is
calculating a stress magnitude proportional to at least one of a frame duration for which the stress region lasts in the plurality of first image frames and data for each color of the stress region;
deriving a compensation time for each stress that is proportional to the magnitude of the calculated stress;
deriving a compensation amount reflecting data of the stress area and data of the compensation area during the compensation time for each stress; and
and compensating data of the compensation area of the plurality of second image frames by applying the derived compensation amount. The method of claim 18
The step of deriving the compensation amount is
A first compensation amount of the stress area is calculated by applying the frame duration of the stress area, data for each color of the stress area, and different weights for each color, and calculating the first compensation amount for the compensation area. A method of driving a display device, comprising calculating a second compensation amount by applying a weighting ratio for each color using data for each color. The method of claim 18
In the timing controller,
During the compensation time for each stress, a compensation amount applied to data of the compensation area of the plurality of second image frames is gradually reduced as time elapses. The method of claim 18
In the timing controller,
During the compensation time for each stress, a display device that compensates for the luminance of the compensation area of the second image frame to a luminance lower than the input luminance, and compensates data of the compensation area so that the luminance gradually increases from the compensated low luminance to the input luminance. driving method.

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