KR20230018822A - Display device and method for driving the same - Google Patents

Abstract

The present specification relates to a display device capable of alleviating crosstalk. According to one embodiment of the present invention, an image processing part of the display device can receive first pixel data corresponding to first pixels of a first row line and second pixel data corresponding to second pixels adjacent to the first pixels in a second row line adjacent to the first row line, and apply a first weight in accordance with a data change between the first and second pixel data and a second weight in accordance with a driving frequency to correct at least one between the first pixel data and the second pixel data to third pixel data which are data values between the first and second pixel data to output corrected pixel data.

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 image quality by improving crosstalk and a method of driving the same.

The light emitting display device uses a self-light emitting element that emits light through recombination of electrons and holes, and has advantages of high luminance, low driving voltage, ultra-thin film, and free shape.

In each pixel of the light emitting display device, the storage capacitor charges the difference between the high-potential power supply voltage and the data voltage as a target voltage, and the driving thin film transistor (TFT) charges the light emitting element according to the target voltage charged in the storage capacitor. The current supplied can be controlled.

When the storage capacitor charges the target voltage, the high-potential power supply voltage may vary in the form of a ripple according to the transition of the data voltage due to a coupling phenomenon and then be stabilized.

However, while the light emitting display device is driven at high speed, the time required to charge the storage capacitor is shorter than the stabilization time of the high-potential power supply voltage, so that the storage capacitor cannot charge the target voltage.

Due to this, when an image pattern having a large luminance change is displayed on a light emitting display device, pixels in the periphery of the pattern output luminance higher or lower than the target luminance, so line-shaped crosstalk or plane-shaped crosstalk is recognized. Image quality deterioration is occurring.

The content of the background art described above is technical information that the inventor of the present specification possesses to derive examples of the present specification or acquired in the course of deriving examples of the present specification, and must be disclosed to the general public prior to filing the present specification. It cannot be said that it is a well-known technology.

The present specification provides a display device capable of improving image quality by improving crosstalk and a method of driving the same.

The problems to be solved according to the examples of the present specification are not limited to the above-mentioned problems, and other problems not mentioned are to those skilled in the art from the description below to which the technical spirit of the present specification belongs. will be clearly understood.

A display device according to an embodiment includes an image processing unit that corrects and outputs pixel data by reflecting a data variation between adjacent pixels and a driving frequency, a panel including a plurality of pixels, and a panel supplying an output of the image processing unit to the panel. The image processing unit includes a driver, and the image processing unit provides first pixel data corresponding to a first pixel of a first row line and second pixels corresponding to a second pixel adjacent to the first pixel in a second row line adjacent to the first row line. Data is received, and at least one of the first pixel data and the second pixel data is converted into first and second pixel data by applying a first weight according to a data change amount between the first and second pixel data and a second weight according to a driving frequency. It may be corrected and output with third pixel data, which is a data value between two pixel data.

The image processing unit of the display device according to an embodiment provides fourth pixel data corresponding to a fourth pixel of a first column line and a fifth pixel corresponding to a fourth pixel and adjacent second column line adjacent to a second column line. At least one of the fourth pixel data and the fifth pixel data is obtained by receiving the fifth pixel data and applying a first weight according to the amount of data change between the fourth and fifth pixel data and a second weight according to the driving frequency. It may be corrected and output with the sixth pixel data, which is a data value between the 4th and 5th pixel data.

A method of driving a display device according to an embodiment includes first pixel data corresponding to a first pixel of a first row line and data corresponding to a second pixel adjacent to the first pixel on a second row line adjacent to the first row line. Receiving second pixel data, and applying a first weight according to a data change amount between the first and second pixel data and a second weight according to a driving frequency to at least one of the first pixel data and the second pixel data. It may be corrected and outputted with third pixel data that is a data value between the first and second pixel data.

A method of driving a display device according to an exemplary embodiment includes fourth pixel data corresponding to a fourth pixel of a first column line and a fifth pixel corresponding to a fourth pixel and adjacent second column line adjacent to a second column line. Receiving fifth pixel data, and applying a first weight according to a data change amount between the fourth and fifth pixel data and a second weight according to a driving frequency to at least one of the fourth pixel data and the fifth pixel data. may be corrected with sixth pixel data, which is a data value between the fourth and fifth pixel data, and then output.

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 according to an embodiment corrects data of each pixel by reflecting a first weight according to a change in data (luminance) between adjacent pixels and a second weight according to a driving frequency, thereby correcting data between adjacent pixels that cause crosstalk ( luminance) can be reduced.

Accordingly, the display device according to an exemplary embodiment reduces line crosstalk and plane crosstalk due to the influence of the coupling between the first power supply voltage or the first gate signal and the data voltage and the decrease in stabilization time of the first power supply voltage, thereby improving image quality. can improve

1 is a block diagram illustrating a configuration of a display device according to an exemplary embodiment.
2 is a circuit diagram illustrating a configuration of each pixel according to an exemplary embodiment.
3 is a driving waveform diagram of each pixel according to an exemplary embodiment.
4 is a diagram illustrating line crosstalk and plane crosstalk of a display device according to a comparative example.
5 is a diagram illustrating a method of improving a line crosstalk phenomenon of a display device according to an exemplary embodiment.
6 is a diagram illustrating surface crosstalk of a display device according to a comparative example.
7 is a diagram illustrating a method of improving surface crosstalk of a display device according to an exemplary embodiment.
8 is a diagram for explaining a method of assigning pixel weights to a display device according to an exemplary embodiment.
9 is a flowchart illustrating a crosstalk improvement method of a display device according to an exemplary embodiment.
10 is a diagram illustrating a method of determining whether a display device is applied according to an exemplary embodiment.
11 is a diagram illustrating a comparison between a crosstalk improvement effect of a display device according to a comparative example and a display device according to an exemplary embodiment.
12 is a diagram illustrating a comparison between a crosstalk improvement effect of a display device according to a comparative example and 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., unless “immediately” or “directly” is used, it is not continuous. cases may 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, looking at the embodiments of the present specification through the accompanying drawings and embodiments are as follows. 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 FIG. 2 is a circuit diagram illustrating a configuration of one 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, a quantum-dot light emitting diode display device, or an inorganic light emitting diode display device may be applied to the electroluminescent display device. .

1 and 2 , the display device 1000 includes a display panel 100, a gate driver 200, a data driver 300, a timing controller 400 having an image processor 600, and 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 corresponding to a pixel array area in which pixels P are arranged in a matrix form. The basic pixel may consist of 3 or 4 color pixels among red pixels emitting red light, green pixels emitting green light, blue pixels emitting blue light, and white pixels emitting white light, or 2 color pixels. there is. Meanwhile, the display panel 100 may be a panel to which a touch sensor screen overlapping a pixel array is embedded or attached.

Each pixel 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 and a switching TFT for driving a light emitting element, and a storage capacitor. Various configurations such as 3T1C (3 TFTs, 1 capacitor) and 7T1C (7 TFTs, 1 capacitor) may be applied to the configuration of the pixel circuit, and the number of TFTs and storage capacitors may be variously changed.

A pixel circuit of each pixel 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 .

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 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 together with the TFTs of the pixel array and embedded in the 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 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 Dm. 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 a source image 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 400 . 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 include an image processing unit 600 that performs various image processing on a source image. The image processing unit 600 may be positioned to be separated from the timing controller 400 and connected to an input terminal of the timing controller 400. In this case, the output of the image processing unit 600 is output to the data driver 300 through the timing controller 400. ) can be supplied.

The image processing unit 600 may perform a plurality of image processing including picture quality correction, deterioration correction, luminance correction for reducing power consumption, and the like.

In particular, the image processing unit 600 may calculate the amount of change in data (luminance, grayscale) between adjacent pixels adjacent in the vertical and horizontal directions and generate a first weight determined according to the amount of data change. The image processing unit 600 may generate a second weight determined according to a display driving frequency. The image processing unit 600 may correct image data of each pixel by applying the first weight and the second weight.

The first weight may be determined to reduce the amount of data change between adjacent pixels when the amount of data change between adjacent pixels is relatively large enough to cause crosstalk. The second weight may be determined to reduce the amount of data change between adjacent pixels in order to prevent crosstalk from occurring due to insufficient data charging time of each pixel when the driving frequency of the display apparatus 1000 increases.

The timing controller 400 may further correct the output of the image processing unit 600 by applying a compensation value for characteristic deviation of each pixel stored in the memory before supplying the output to the data driver 300 . In the sensing mode, the timing controller 400 may sense the characteristics of each pixel P of the panel 100 through the data driver 300 and update the compensation value of each pixel stored in the memory using the sensing result. there is. 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 .

2 is an equivalent circuit diagram of each pixel circuit according to an exemplary embodiment, and FIG. 3 is a driving waveform diagram of each pixel circuit according to an exemplary embodiment.

Referring to FIG. 2 , the pixel circuit of each pixel 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. Any one of a polysilicon semiconductor, an amorphous silicon semiconductor, and an oxide semiconductor may be applied to the TFTs of each pixel circuit.

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 has 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 electrode 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 anode may be an independent pixel electrode for each pixel, and the cathode may be a common electrode shared by all pixels. 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 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, the n-1th row line and the nth row line (n is an integer greater than or equal to 2), and as a result, is embedded in the bezel area of the display panel 100 The size of the gate driver 200 and the size of the bezel may 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. (N) 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 second gate signal (SC3[n]) supplied through the third gate line 106, and is 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 N connected to the anode electrode 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 is 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 (T1), 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, variation in characteristics of the driving TFT (DT) between pixels can be compensated for.

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 target voltage charged in the storage capacitor Cst.

Referring to FIG. 3 , the operation of each pixel P in one frame may include an initialization period, a programming and sampling period, and an emission period, and may further include a holding period between the programming and sampling period and the emission period. .

The first gate signal SC1[n] of the first gate line 104 shared by the n-1st row line and the nth row line is the initialization period, programming and sampling period of the n-1st and nth row lines. And, it can be activated by the gate-on voltage during the holding period. While being activated by the gate-on voltage of the first gate signal SC1[n], the compensating TFT T4 is turned on to connect the gate electrode and drain electrode of the driving TFT DT.

In the initialization period, the third node N3 is formed through the first initialization TFT T3 turned on by the gate-on voltage of the third gate signal SC3[n] and the compensation TFT T4 in the turned-on state. and the second node N2 may be initialized with the first initialization voltage Vini[n]. In the initialization period, the fourth gate signal (SC3[n+1]) of the n+1th row line corresponding to the fourth gate signal is turned on by the gate-on voltage of the second initialization TFT (T6). Node N4 may be initialized with the second initialization voltage VAR.

During the programming and sampling period, the second node ( N2 is supplied with the data voltage Vdata-Vth compensated for the threshold voltage Vth of the driving TFT DT, so that the storage capacitor Cst is connected to the first power supply voltage VDDEL and the compensated data voltage Vdata-Vth. Vth) and the difference voltage (VDDEL-Vdata+Vth) can be charged as a target voltage.

The storage capacitor Cst may hold the charged target voltage during a holding period and an emission period.

During the light emission period, the first power supply voltage VDDEL is supplied to the source electrode of the driving TFT (DT) through the operation control TFT (T2) turned on by the gate-on voltage of the light emission control signal (EM[n]); The drain electrode of the driving TFT (DT) may be connected to the anode of the light emitting element EL through the turned-on emission control TFT (T5). Accordingly, during the light emitting period, the driving TFT DT provides the light emitting element EL with a current adjusted according to the target voltage charged in the storage capacitor Cst, so that the light emitting element EL outputs luminance corresponding to the target voltage. can do.

As the data voltage Vdata decreases, the target voltage charged in the storage capacitor Cst increases, thereby increasing the output luminance of the corresponding pixel P. In other words, as the grayscale value increases, the data voltage Vdata may decrease.

Referring to FIG. 3 , during a period in which the second gate signal SC2[n-1] of the n-1 th row line is activated, that is, during the programming and sampling period of the n-1 th row line, the n-1 th row line The data voltage Vdata of the first grayscale G1 may be supplied to the second node N2[n−1] of the first pixel belonging to . Then, during the programming and sampling period in which the second gate signal SC2[n] of the nth row line is activated, the second node N2[n] of the second pixel belonging to the nth row line has a first grayscale. The data voltage Vdata transitioned to the second grayscale G2 lower than (G1) may be supplied.

For example, when the first grayscale G1 is an intermediate grayscale of 127 grayscales and the second grayscale G2 is a black grayscale (0 grayscale), the data voltage Vdata is the data voltage Vdata of the 127th grayscale G1. ) to the data voltage Vdata of the black gradation G2 and rise.

When the data voltage Vdata of 128th gray level G1 is transitioned to the data voltage Vdata of black grayscale G2 and rises, the difference between the first power supply voltage VDDEL and the data voltage Vdata by the storage capacitor Cst Due to the coupling action, a ripple phenomenon that is stabilized after rising from the first power voltage VDDEL on the first power line 103 along the data voltage Vdata may occur. When driving at high speed, for example, at a driving frequency of 120 Hz, the time for stabilizing the ripple of the first power voltage VDDEL may be short due to the shortening of the programming and sampling period and the holding period. Accordingly, the voltages of the second nodes N2[n-1] and N2[n] in the n−1 th row line and the n th row line adjacent in the vertical direction and having a large fluctuation range of the data voltage Vdata are Crosstalk (N-1 crosstalk, N crosstalk) that is lower or higher than the target luminance may occur due to an increase or decrease of the value (dotted line).

In order to reduce crosstalk caused by coupling between the first power supply voltage VDDEL and the data voltage Vdata and lack of stabilization time of the ripple of the first power supply voltage VDDEL, the display device according to an embodiment includes a first power supply. A data variation amount (difference in data voltage) between adjacent pixels in the up, down, left, and right directions may be reduced so as to reduce the magnitude of the voltage VDDEL ripple.

4 is a diagram illustrating a crosstalk phenomenon occurring in a display device according to a comparative example.

Referring to FIG. 4 , a black image pattern (IP) causing crosstalk is displayed on a portion of the display panel 100A according to the comparative example, and a halftone (G1) image is displayed on the remaining areas A1 and A3. It can be.

At the boundary between the halftone G1 image of the first area A1 and the black image pattern IP, when the data voltage Vdata transitions from the halftone G1 to the black grayscale G2 and rises, the third Ripple is generated in the direction in which the power supply voltage VDDEL increases, and when the data voltage Vdata transitions from the black gray level G2 to the middle gray level G1 and falls, the first power voltage VDDEL also decreases. It can be seen that ripple occurs.

N-1st and N-2th (N is a positive integer) low that is vertically adjacent to the black image pattern IP and displays an intermediate gray level G1 by the rising ripple of the first power supply voltage VDDEL In the line, dark line crosstalk that appears darker than the target luminance L1 of the halftone G1 may occur. In addition, in the N-th row line displaying the intermediate grayscale G1 between the black image patterns IP, the luminance of the portion displaying the intermediate grayscale G1 is brighter than the target luminance L1 of the intermediate grayscale G1. Visible bright line crosstalk may occur.

M+1st and M+2th (M is a positive integer) row adjacent to the black image pattern IP in the vertical direction by the falling ripple of the first power supply voltage VDDEL and displaying an intermediate gray level G1 In the line, dark line crosstalk (CT) that appears darker than the target luminance L1 of the halftone G1 may occur. In addition, in the M-1th and Mth row lines displaying the intermediate grayscale G1 between the black image patterns IP, the luminance of the portion displaying the intermediate grayscale G1 is the target luminance of the intermediate grayscale G1 Bright line crosstalk that appears brighter than (L1) may occur.

On the other hand, in the surface area of the third area A3 displaying the intermediate gray level G1 between the black image patterns IP displaying the black luminance L2, the data of the black gray level G2 has a large left and right data variation. Under the influence of the voltage Vdata, crosstalk CT may occur if the halftone G1 is brighter than the target luminance L1. The surface crosstalk of the third region A3 is caused by the coupling between the first gate signal SC[n] and the second node N2 by the parasitic capacitor of the compensating TFT T4. This may occur when (SC[n]) fluctuates under the influence of the data voltage Vdata of the black gradation G2, which has a large left and right data fluctuation range.

5 is a diagram illustrating a method of improving line crosstalk of a display device according to an exemplary embodiment.

Referring to FIG. 5 , a black image pattern IP displaying black luminance L2 is displayed on a partial area of the display panel 100 according to an exemplary embodiment, and gray luminance L1 is displayed on the remaining areas A1 and A3. ) may be displayed.

The display device according to an embodiment corrects data so that the fluctuation range of the data voltage Vdata is reduced at a boundary portion where the variation range of the data voltage Vdata between vertically adjacent pixels is large, such as a border portion of a black box image pattern IP. Accordingly, the magnitude of the ripple of the first power supply voltage VDDEL coupled with the data voltage Vdata may be reduced.

For example, in at least one row line (N-1, M+1) adjacent to the black image pattern (IP) in the vertical direction and displaying the middle gray level (G1), the middle gray level (first gray level G1) and black The data voltage Vdata of the third grayscale G3 that reduces the grayscale difference between the grayscales (the second grayscale G2) may be supplied. Accordingly, the variation range of the data voltage Vdata between pixels adjacent in the vertical direction and the ripple size of the first power supply voltage VDDEL coupled with the data voltage Vdata are reduced, thereby reducing line crosstalk. The luminance L3 of the second grayscale G3 may be a luminance between the black luminance L2 and the gray luminance L1.

The display device according to an embodiment may reduce the amount of data change between adjacent pixels by correcting data of each pixel by applying a first weight according to the amount of data change of pixels adjacent in the vertical direction. The display device according to an embodiment corrects the data of each pixel by further assigning a second weight according to the driving frequency, thereby further reducing the amount of data change between adjacent pixels when the stabilization time of the first power supply voltage VDDEL is insufficient during high-speed driving. can

In another display device according to an embodiment, the data of each pixel may be adjusted by adding a third weight according to the position of each pixel so that the data voltage Vdata gradually decreases in the peripheral portion of the boundary where the data fluctuation range between adjacent pixels is large. .

6 is a diagram illustrating plane crosstalk in a display device according to a comparative example, and FIG. 7 is a diagram illustrating a method of improving plane crosstalk in a display device according to an exemplary embodiment.

Referring to FIGS. 6 and 7 , a black image pattern (IP) displaying black luminance is displayed on a partial area of the display panel 100, and a halftone image displaying gray luminance is displayed on the remaining areas A1 and A3. can be displayed

Referring to FIG. 6 , surface areas (I to J column lines) of the third area A3 displaying the gray luminance L1 between the black image patterns IP displaying the black luminance L2 (I, If J is a positive integer), the surface crosstalk (which appears brighter than the target luminance of the middle gray level of the first area A1) is affected by the data voltage Vdata of the black gray level, which has a large data variation range between the left and right adjacent pixels. CT) may occur.

For example, in each pixel P shown in FIG. 2, by a coupling action between the first gate signal SC[n] and the second node N2 by the parasitic capacitor of the compensating TFT T4, As the 1-gate signal SC[n] fluctuates under the influence of the data voltage Vdata of the black gradation, which has a large left-right data variation, in the third area A3 between the black image patterns IP, plane crosstalk occurs. can happen

In the display device according to an exemplary embodiment, the amount of change in the first gate signal SC[n] coupled with the data voltage Vdata is reduced by correcting the data so that the variation range of the data voltage Vdata between pixels adjacent to the left and right decreases. can reduce Accordingly, the width of variation of the data voltage between adjacent pixels in the left and right directions is reduced, and the amount of change in luminance is reduced, thereby improving surface crosstalk.

For example, at least one column line (I-2, I-1, J+1, J+2) displaying the black image pattern (IP) adjacent to the third area (A3) is a black grayscale and an intermediate grayscale. The data voltage of the third grayscale, which reduces the fluctuation range of the data voltage Vdata between the regions, may be supplied to the CD, where the luminance is higher than that of the black grayscale. However, the I-1-th column line located at the boundary of the black image pattern IP may have a luminance difference maintaining sharpness with the I-th column line, and the The J+1th column line may also have a luminance difference from the Jth column line maintaining sharpness.

The display device according to an embodiment may reduce the amount of data change between adjacent pixels by correcting data of each pixel by applying a first weight according to the amount of data change of adjacent pixels in the left and right directions. The display device according to an embodiment corrects the data of each pixel by further assigning a second weight according to the driving frequency, thereby further reducing the amount of data change between adjacent pixels when the stabilization time of the first power supply voltage VDDEL is insufficient during high-speed driving. can

In another display device according to an embodiment, the data of each pixel may be adjusted by adding a third weight according to the position of each pixel so that the data voltage Vdata gradually decreases in the peripheral portion of the boundary where the data fluctuation range between adjacent pixels is large. .

8 is a flowchart illustrating an image processing method of a display device according to an exemplary embodiment, and FIG. 9 is a diagram for explaining a pixel weighting method of a display device according to an exemplary embodiment.

The image processing method illustrated in FIG. 8 may be performed by the image processing unit 600 illustrated in FIG. 1 .

Referring to FIGS. 1, 8, and 9, the image processing unit 600 processes image data of a current pixel P(x,y) and pixels P(x, y−1) and P(x Image data of -1, y), P(x+1, y), and P(x, y+1) is input (S902).

The image processing unit 600 determines each of the adjacent pixels P(x, y−1), P(x−1, y), P(x+1, y), and P(x, y+1) and the current pixel P( A change in data (luminance) of x,y) may be calculated, and a first weight dp according to the calculated amount of change in data (luminance) may be generated (S904). The data of each of the adjacent pixels P(x, y-1), P(x-1, y), P(x+1, y), P(x, y+1) and the current pixel P(x,y) Weights for reducing the amount of change in each data (luminance) may be calculated according to the amount of change in (luminance), and a first weight dp may be generated by applying all of the calculated weights (S904).

The image processing unit 600 may receive a display driving frequency and generate a second weight value dh according to the supplied driving frequency (S906).

The image processing unit 600 applies the first weight dp generated according to the amount of data (luminance) change between the adjacent pixel and the current pixel and the second weight dh generated according to the driving frequency to the current pixel P(x, The image data of y) may be corrected, and the corrected image data may be output. The first weight dp may increase as the amount of data change increases. The second weight dh may increase as the driving frequency increases.

10 is a diagram illustrating a method of determining whether a display device is applied according to an exemplary embodiment.

Referring to FIG. 10( a ) , the display device according to an exemplary embodiment may display a crosstalk test image on the display panel 100 . In the crosstalk test image, a black image pattern (IP) in the form of a box displaying black luminance may be displayed on a partial area of the display panel 100, and a gray image displaying gray luminance may be displayed on the remaining area A1. . For example, the two black image patterns (IP) are positioned at 1/2 vertical length position (V/2) of the panel 100 and 1/3 horizontal length (H/3) width of the panel 100 in between. It can be positioned on the left and right sides respectively. It can be seen that crosstalk such as line crosstalk and plane crosstalk is improved unrecognized even when the display device according to the exemplary embodiment displays the crosstalk test image.

Referring to FIG. 10 (b), a crosstalk test image displayed on the display panel 100 is photographed using a measuring device, and the luminance of each of a plurality of measurement points (R1 to R5, C1 to C5) at different locations is measured. You can check it by

For example, the first to fifth column measurement points C1 to C5 having different column positions are two black image patterns along the horizontal direction at the 1/2 vertical length position (V/2) of the panel 100. (IP) and the black image pattern (IP), respectively, may be located in the gray area A1.

The first to fifth row measurement points R1 to R5 having different row positions may be respectively located in the gray area A1 and the right black image pattern IP along the vertical direction of the panel 100 .

Luminance of first to fifth column measurement points C1 to C5 of a panel displaying a crosstalk test pattern as shown in FIG. 10(b) in a display device according to a comparative example to which the display device according to an embodiment is not applied. The result of measuring is as shown in FIG. 10 (c). Referring to FIG. 10(c), while the black luminance L2 is measured at the column measuring points C1, C2, C4, and C5 located in the black image pattern IP, the black luminance L2 is measured between the black image patterns IP. It can be seen that surface crosstalk is generated at the column measuring point C3 of the gray area A1 and thus higher luminance than the luminance L1 of the other gray area A1 is measured.

In the display device according to an exemplary embodiment, the result of measuring the luminance of the first to fifth column measurement points C1 to C5 of the panel 100 displaying the crosstalk test pattern as shown in FIG. 10(b) is shown in FIG. As shown in d). Referring to FIG. 10(d), the black luminance L2 is measured at the column measurement points C1 and C5 located in the black image pattern IP, and the gray area A1 between the black image patterns IP is measured. It can be seen that at the column measuring point C3 of , gray luminance similar to the luminance L1 of the other gray area A1 was measured, and plane crosstalk was not recognized.

In particular, the column measurement points C2 and C4 positioned at the boundary adjacent to the gray area A1 in the black image patterns IP have an intermediate luminance L3 higher than the black luminance L2 and lower than the gray luminance L1. can be measured. Accordingly, it can be seen that the amount of change in data (luminance) between the black luminance L2 and the gray luminance L1 is reduced at the boundary of the black image patterns IP.

Luminance of first to fifth low measurement points R1 to R5 of a panel displaying a crosstalk test pattern as shown in FIG. 10(b) in a display device according to a comparative example to which a display device according to an embodiment is not applied. The result of measuring is as shown in FIG. 10 (e). Referring to FIG. 10(e), the gray luminance L1 is measured at the low measurement points R1, R2, R4, and R5 in the gray area A1, and the low measurement point R3 in the black image pattern IP It can be seen from that the black luminance (L2) has been measured.

In the display device according to an embodiment, the results of measuring the luminance of the first to fifth row measurement points R1 to R5 of the panel 100 displaying the crosstalk test pattern as shown in FIG. 10(b) are shown in FIG. As shown in f). Referring to FIG. 10(f), gray luminance L1 is measured at the low measurement points R1 and R5 in the gray area A1, and black luminance (L1) is measured at the low measurement point R3 in the black image pattern IP. It can be seen that L2) has been measured.

In particular, it can be seen that the middle luminance L4, higher than the black luminance L2 and lower than the gray luminance L1, was measured at the low measurement points R2 and R4 adjacent to the boundary of the black image pattern IP in the gray area A1. can Accordingly, it can be seen that the amount of change in data (luminance) between the black luminance L2 and the gray luminance L1 is reduced in the gray area A1 adjacent to the boundary of the black image pattern IP.

11 and 12 are diagrams illustrating a comparison between a crosstalk phenomenon of a display device according to a comparative example and a crosstalk improvement effect of a display device according to an exemplary embodiment.

Referring to FIG. 11(a) , when the crosstalk test image described above is displayed on the display panel 100A according to the comparative example, dark/bright line crosstalk and surface crosstalk in a gray area between black image patterns IP It can be seen that (CT1) occurs.

On the other hand, referring to FIG. 11(b), when the crosstalk test image described above is displayed on the display panel 100 according to an embodiment, crosstalk is not recognized in a gray area between black image patterns IP. It can be seen that it has improved.

Referring to FIG. 12(a) , when black horizontal lines IP2 and a gray image are displayed on the display panel 100A according to the comparative example, a horizontal line shape is displayed in a gray image area along the black horizontal lines IP. It can be seen that crosstalk (CT2) occurs.

On the other hand, referring to FIG. 12(b), when displaying the previously described black horizontal lines IP2 and a gray image on the display panel 100 according to an embodiment, crosstalk in the gray image area is improved so that it is not recognized. Able to know.

As described above, the display device according to an exemplary embodiment corrects data of each pixel by reflecting a first weight according to a change in data (luminance) between adjacent pixels and a second weight according to a driving frequency, thereby causing crosstalk. A variation in data (luminance) between adjacent pixels can be reduced.

Accordingly, the display device according to an exemplary embodiment reduces line crosstalk and plane crosstalk due to the influence of the coupling between the first power supply voltage or the first gate signal and the data voltage and the decrease in stabilization time of the first power supply voltage, thereby improving image quality. can improve

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.

A display device according to an embodiment includes an image processing unit that corrects and outputs pixel data by reflecting a data variation between adjacent pixels and a driving frequency, a panel including a plurality of pixels, and a panel supplying an output of the image processing unit to the panel. The image processing unit includes a driver, and the image processing unit provides first pixel data corresponding to a first pixel of a first row line and second pixels corresponding to a second pixel adjacent to the first pixel in a second row line adjacent to the first row line. Data is received, and at least one of the first pixel data and the second pixel data is converted into first and second pixel data by applying a first weight according to a data change amount between the first and second pixel data and a second weight according to a driving frequency. It may be corrected and output with third pixel data, which is a data value between two pixel data.

The image processing unit of the display device according to an embodiment may correct and output larger pixel data of the first pixel data and the second pixel data as the third pixel data.

The image processing unit of the display device according to an embodiment provides fourth pixel data corresponding to a fourth pixel of a first column line and a fifth pixel corresponding to a fourth pixel and adjacent second column line adjacent to a second column line. At least one of the fourth pixel data and the fifth pixel data is obtained by receiving the fifth pixel data and applying a first weight according to the amount of data change between the fourth and fifth pixel data and a second weight according to the driving frequency. It may be corrected and output with the sixth pixel data, which is a data value between the 4th and 5th pixel data.

The image processing unit of the display device according to an exemplary embodiment may correct smaller pixel data of the fourth pixel data and the fifth pixel data as the sixth pixel data and output the corrected data.

A method of driving a display device according to an embodiment includes first pixel data corresponding to a first pixel of a first row line and data corresponding to a second pixel adjacent to the first pixel on a second row line adjacent to the first row line. Receiving second pixel data, and applying a first weight according to a data change amount between the first and second pixel data and a second weight according to a driving frequency to at least one of the first pixel data and the second pixel data. It may be corrected and output with third pixel data that is a data value between the first and second pixel data.

A method of driving a display device according to an exemplary embodiment includes fourth pixel data corresponding to a fourth pixel of a first column line and a fifth pixel corresponding to a fourth pixel and adjacent second column line adjacent to a second column line. Receiving fifth pixel data, and applying a first weight according to a data change amount between the fourth and fifth pixel data and a second weight according to a driving frequency to at least one of the fourth pixel data and the fifth pixel data. may be corrected with sixth pixel data, which is a data value between the fourth and fifth pixel data, and then output.

In the display device according to an embodiment, the first weight may increase as the amount of data change increases, and the second weight may increase as the frequency increases.

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 600: image processor
1000: display device

Claims (10)

an image processing unit that corrects and outputs pixel data by reflecting the amount of data change between adjacent pixels and the driving frequency;
a panel including a plurality of pixels; and
A panel driver supplying an output of the image processing unit to the panel;
The image processing unit
receiving first pixel data corresponding to a first pixel of a first row line and second pixel data corresponding to a second pixel adjacent to the first pixel on a second row line adjacent to the first row line;
At least one of the first pixel data and the second pixel data is converted into the first and second pixel data by applying a first weight according to a data variation between the first and second pixel data and a second weight according to the driving frequency. A display device that corrects and outputs third pixel data that is a data value between two pixel data. The method of claim 1,
The image processing unit
A display device configured to correct and output larger pixel data of the first pixel data and the second pixel data with the third pixel data. The method of claim 1,
The image processing unit
receiving fourth pixel data corresponding to a fourth pixel of a first column line and fifth pixel data corresponding to a fifth pixel adjacent to the fourth pixel on a second column line adjacent to the first column line;
At least one of the fourth and fifth pixel data is converted into the fourth and fifth pixel data by applying a first weight according to a data variation between the fourth and fifth pixel data and a second weight according to the driving frequency. A display device that corrects and outputs sixth pixel data, which is a data value between 5 pixel data. The method of claim 3,
The image processing unit
A display device that corrects smaller pixel data of the fourth pixel data and the fifth pixel data with the sixth pixel data and outputs the corrected data. According to claim 1 or claim 3,
The first weight increases as the data change amount increases,
The second weight increases as the frequency increases. receiving first pixel data corresponding to a first pixel of a first row line and second pixel data corresponding to a second pixel adjacent to the first pixel on a second row line adjacent to the first row line; and
At least one of the first pixel data and the second pixel data is converted into the first and second pixel data by applying a first weight according to a data change amount between the first and second pixel data and a second weight according to a driving frequency. A method of driving a display device comprising the step of correcting and outputting third pixel data that is a data value between pixel data. The method of claim 6,
A method of driving a display device for correcting and outputting larger pixel data between the first pixel data and the second pixel data with the third pixel data. The method of claim 6,
receiving fourth pixel data corresponding to a fourth pixel of a first column line and fifth pixel data corresponding to a fifth pixel adjacent to the fourth pixel on a second column line adjacent to the second column line; and
At least one of the fourth and fifth pixel data is converted into the fourth and fifth pixel data by applying a first weight according to a data variation between the fourth and fifth pixel data and a second weight according to the driving frequency. A method of driving a display device, further comprising correcting and outputting sixth pixel data, which is a data value between 5 pixel data. The method of claim 8,
A method of driving a display device for correcting and outputting smaller pixel data between the fourth pixel data and the fifth pixel data with the sixth pixel data. According to claim 6 or claim 8,
As the data change amount increases, the first weight increases,
A method of driving a display device in which the second weight increases as the frequency increases.

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