KR20210031026A - Display device and method of driving display device - Google Patents

Abstract

A display device includes a display unit including a plurality of pixels. A data converter receives grayscale values respectively corresponding to the pixels, remaps each of the grayscale values in the first grayscale range to first compensated grayscale values in a second grayscale range, and generates second compensated grayscale values by compensating the grayscale values based on the first compensated grayscale values of adjacent pixels. A data driver generates data signals based on the second compensated grayscale values and provides the data signals to the pixels of a display unit. The pixels adjacent to the target pixel correspond to the pixels adjacent to the target pixel, and at least one of the adjacent pixels emits light in a color different from that of the target pixel, thereby preventing deterioration of display quality in a low grayscale region.

Description

Display device and method of driving the display device {DISPLAY DEVICE AND METHOD OF DRIVING DISPLAY DEVICE}

The present invention relates to a display device and a method of driving the display device.

The display device displays an image on a display panel using externally applied control signals.

In general, a display device includes a red pixel, a green pixel, and a blue pixel, and the color of a specific point (or a specific area) of the display device is obtained by a temporal or spatial sum of lights emitted from the red, green, and blue pixels Can be determined.

In a low gradation region where the gradation value is relatively low, the gamma characteristic of each of the pixels and the white balance of the pixels are different, and an image may not be displayed with a desired luminance and color.

An object of the present invention is to provide a display device and a method of driving the display device in which display quality is prevented from deteriorating in a low gray scale area.

In order to achieve an object of the present invention, a display device according to embodiments of the present invention includes: a display unit including a plurality of pixels; Receives grayscale values corresponding to each of the pixels, remaps each of the grayscale values in a first grayscale range to first compensated grayscale values in a second grayscale range, and performs the first compensated grayscale of adjacent pixels A data conversion unit for generating second compensated grayscale values by compensating the grayscale values based on values; And a data driver generating data signals based on the second compensated gray scale values and providing the data signals to the pixels of the display, wherein the adjacent pixels to the target pixel correspond to pixels adjacent to the target pixel. And, at least one of the adjacent pixels emit light in a color different from that of the target pixel.

According to an embodiment, the second grayscale range may be a subset of the first grayscale range.

According to an embodiment, the data conversion unit calculates a difference value by calculating a difference value of the target pixel from the first compensated gray level value of the target pixel, and the first compensation of the adjacent pixels A first compensation value for the target pixel is calculated based on the gray level values, and a second compensation value is calculated by calculating the first compensation value from an absolute value of the difference value, and the gray level value And calculating a second compensated gray level value of the target pixel based on the second compensation value, wherein the data conversion unit increases the first compensation value as one of the first compensated gray level values of the adjacent pixels increases. Can be increased.

According to an embodiment, when the first compensation value is less than 0, the data conversion unit may determine the compensation value as the second compensated gray scale value.

According to an embodiment, the data converter may calculate the first compensation value by adding weights of the adjacent gray level values based on compensation coefficients respectively preset corresponding to the adjacent gray level values.

According to an embodiment, a first compensation coefficient for a first adjacent pixel included in the same row as the target pixel among the adjacent pixels is applied to a second adjacent pixel included in the same column as the target pixel among the adjacent pixels. It may be different from the second compensation coefficient for.

According to an embodiment, when the difference value is greater than 0, the data conversion unit may calculate the second compensated gray level value by summing the first compensated gray level value and the second compensation value.

According to an embodiment, when the difference value is less than 0, the data conversion unit may calculate the second compensated gray level value by performing a difference calculation between the first compensated gray level value and the second compensation value.

According to an embodiment, the first compensation value may be proportional to the gray level value of the target pixel, but may be inversely proportional to the first compensated gray level value.

According to an embodiment, the adjacent pixels may be included in the same row as the target pixel.

In order to achieve an object of the present invention, a method of driving a display device according to embodiments of the present invention includes remapping grayscale values in a first grayscale range to first compensated grayscale values in a second grayscale range. ; Calculating a first compensation value for a first gray level value of a target pixel based on the first compensated gray level values of adjacent pixels; Calculating a second compensated gray level value by compensating the first gray level value of the target pixel based on the first compensated gray level value and the first compensation value of the target pixel; And generating a data signal based on the second compensated grayscale value, wherein the adjacent pixels to the target pixel are pixels adjacent to the target pixel, and at least one of the adjacent pixels is Emits light in a different color.

According to an embodiment, in the calculating of the second compensated gray level value, a difference value is calculated by performing a difference operation of the first gray level value of the target pixel from the first compensated gray level value of the target pixel. The step of doing; Calculating a second compensation value by calculating the difference between the first compensation value from the absolute value of the difference value; And calculating a second compensated gray level value of the target pixel based on the gray level value and the second compensation value. As one of the first compensated gray level values of the adjacent pixels increases, the first 1 The compensation value can be increased.

According to an embodiment, the calculating of the first compensation value may include calculating the first compensation value for summing the adjacent gray level values by weight based on compensation coefficients respectively preset corresponding to the adjacent gray level values. I can.

According to an embodiment, a first compensation coefficient for a first adjacent pixel included in the same row as the target pixel among the adjacent pixels is applied to a second adjacent pixel included in the same column as the target pixel among the adjacent pixels. It may be different from the second compensation coefficient for.

According to an embodiment, the first compensation value may be proportional to the gray level value of the target pixel, but may be inversely proportional to the first compensated gray level value.

In the display device and the driving method of the display device according to exemplary embodiments of the present invention, a gray scale value in a low gray scale area is remapped, a first compensation value is calculated based on the remapped gray scale values of adjacent pixels, and a first compensation value is obtained. 1 The grayscale value of the target pixel may be compensated based on the compensation value. Accordingly, deterioration of the display quality in the low gradation area can be alleviated or prevented.

1 is a diagram illustrating a display device according to an exemplary embodiment of the present invention.
2 is a circuit diagram illustrating an example of a pixel included in the display device of FIG. 1.
3 is a diagram illustrating a relationship between a pixel of FIG. 2 and an adjacent pixel.
FIG. 4 is a diagram illustrating changes in light emission characteristics of pixels by adjacent pixels of FIG. 3.
5 is a block diagram illustrating an example of a control unit included in the display device of FIG. 1.
FIG. 6 is a diagram illustrating grayscale remapping by a first data compensating unit included in the control unit of FIG. 5.
7 is a diagram illustrating an example of a lookup table used in a first data compensating unit included in the control unit of FIG. 5.
8 is a diagram illustrating a change in a gamma curve by the control unit of FIG. 5.
9 is a block diagram illustrating an example of a second data compensating unit included in the control unit of FIG. 5.
10A is a diagram illustrating an example of a compensation filter used in a second data compensation unit included in the control unit of FIG. 5.
10B is a diagram illustrating embodiments of the compensation filter of FIG. 9A.
FIG. 11 is a diagram illustrating an example of a process of compensating gray levels by using the compensation filter of FIG. 10A in the control unit of FIG. 5.
FIG. 12 is a diagram illustrating another example of a process of compensating gray levels by using the compensation filter of FIG. 10B in the control unit of FIG. 5.
13 is a diagram illustrating an example of a first gain used in the control unit of FIG. 5.
14 is a diagram illustrating an example of a second gain used in the control unit of FIG. 5.
15 is a block diagram illustrating another example of a second data compensating unit included in the control unit of FIG. 5.
16A is a diagram illustrating compensation values calculated by the second data compensating unit of FIG. 15 for a white image.
16B is a diagram illustrating compensation values calculated by the second data compensating unit of FIG. 15 for a monochrome image.
17 is a diagram illustrating an example of test data provided to the control unit of FIG. 5.
18 is a diagram illustrating various examples of a compensation filter used in a second data compensation unit included in the control unit of FIG. 5.
19 is a flowchart illustrating a method of driving a display device according to an exemplary embodiment.

1 is a diagram illustrating a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the display device 1 may include a display unit 110, a data driver 120, a gate driver 130, and a controller 140.

The display unit 110 may display an image. The display unit 110 may be implemented as a display panel.

The display unit 110 may include data lines DL1 to DLm (where m is a positive integer), gate lines GL1 to GLn (where n is a positive integer), and a pixel PX. The pixel PX may be disposed in a region partitioned by the data lines DL1 to DLm and the gate lines GL1 to GLn. The pixel PX may be electrically connected to the data lines DL1 to DLm and the gate lines GL1 to GLn.

For example, the pixels PX positioned in the first row and the first column may be connected to the first data line DL1 and the first gate line GL1. For another example, the pixels PX positioned in the n-th row and m-th column may be connected to the m-th data line DLm and the n-th gate line GLn.

However, the pixel PX is not limited thereto, and for example, the pixel PX includes gate lines corresponding to adjacent rows (for example, a gate line corresponding to a previous row of the row including the pixel PX). And a gate line corresponding to a subsequent row). Further, although not shown, the pixel PX is electrically connected to the first power line and the second power line to receive the first power voltage VDD and the second power voltage VSS. Here, the first power voltage VDD and the second power voltage VSS may be voltages required for driving the pixel PX.

The pixel PX may emit light with a luminance corresponding to the data signal provided through the data line in response to the gate signal provided through the corresponding gate line. A detailed configuration and operation of the pixel PX will be described later with reference to FIG. 2.

The data driver 120 may generate a data signal based on the data control signal DCS and the image data DATA, and provide the data signal to the data lines DL1 to DLm. Here, the data control signal DCS is a signal that controls the operation of the data driver 120 and may include a data enable signal or the like.

The data driver 120 may be implemented as an IC (eg, a driver IC), and may be mounted on a flexible circuit board to be connected to the display unit 110.

The gate driver 130 (or the scan driver, the scan driver) may generate a gate signal based on the gate control signal GCS and provide the gate signal to the gate lines GL1 to GLn. Here, the gate control signal GCS is a signal that controls the operation of the gate driver 130 and may include a start signal and clock signals. For example, the gate driver 130 may sequentially generate and output a gate signal (eg, a gate signal having the same or similar waveform as the start signal) corresponding to the start signal using clock signals. The gate driver 130 may include a shift register. The gate driver 130 may be formed on one region of the display unit 110 (or one region of the display panel), or may be implemented as an IC and mounted on a flexible circuit board to be connected to the display unit 110.

The control unit 140 receives input image data (RGB) (eg, RGB data) and a control signal CS from an external (eg, graphic processor), and based on the control signal CS, a gate control signal (GCS) and data control signals (DCS) can be generated. Here, the input image data RGB may include a gray scale value corresponding to the pixel PX.

The control signal CS may include a clock signal, a horizontal synchronization signal, a data enable signal, and the like.

In addition, the controller 140 may convert the input image data RGB into image data DATA corresponding to the pixel arrangement of the display unit 110 and output the converted image data.

In embodiments, the control unit 140 remaps a grayscale value included in the input image data RGB to within the second grayscale range from the first grayscale range, and remapped grayscale (or, A first compensated grayscale value) may be generated. Here, the second grayscale range may be a subset of the first grayscale range. For example, the controller 140 may remap the grayscale value from a first grayscale range between a grayscale value of 0 to a grayscale value of 255 to a second grayscale range between a grayscale value of 14 and a grayscale value of 255.

In addition, the control unit 140 compensates for the grayscale value based on the remapped grayscale value and the adjacent grayscale values (or remapped grayscale values of adjacent pixels) to compensate for the compensated grayscale value (or the second compensated grayscale value). ) Can be created. Here, the adjacent grayscale values are grayscale values (ie, remapped grayscale values) corresponding to adjacent pixels disposed adjacent to the target pixel (ie, the pixel PX corresponding to the grayscale value to be compensated). , At least one of the adjacent pixels may emit light in a color different from that of the target pixel. For example, the pixels adjacent to the pixels included in the area where the second row and the second column intersect each other are areas where the first to third rows and the first to fourth columns intersect (or the first to fourth columns shown in FIG. 1 ). It may be at least one of the pixels disposed in the first area A1).

In an embodiment, the controller 140 may generate a compensated gray level value of the target pixel by decreasing the remapped gray level value of the target pixel as at least one of the adjacent gray level values increases.

Hereinafter, in relation to the structure of the pixel PX, a grayscale redundancy and grayscale compensation for remapping a grayscale value in the control unit 140 will be described.

Meanwhile, in FIG. 1, the control unit 140 is shown to be implemented independently of the data driver 120, but is not limited thereto. For example, the controller 140 may be implemented as one IC together with the data driver 120 or may be included in the data driver 120.

2 is a circuit diagram illustrating an example of a pixel included in the display device of FIG. 1. 3 is a diagram illustrating a relationship between a pixel of FIG. 2 and an adjacent pixel.

1 and 2, the pixel PX may include a first transistor T1, a second transistor T2, a storage capacitor Cst, and a light emitting device LD.

The first transistor T1 and the second transistor T2 may be P-type transistors (eg, PMOS transistors), but are not limited thereto. For example, at least one of the first transistor T1 and the second transistor T2 may be implemented as an N-type transistor (eg, NMOS). Also, the pixel PX may further include other transistors in addition to the first transistor T1 and the second transistor T2.

The first transistor T1 (or driving transistor) includes a first electrode connected to a first power line to which a first power voltage VDD is applied, a second electrode connected to the second node N2, and a first A gate electrode connected to the node N1 may be included.

The second transistor T2 (or switching transistor) includes a first electrode connected to the data line DL, a second electrode connected to the first node N1, and a gate electrode connected to the gate line GL. Can include. Here, the data line DL may be one of the data lines DL1 to DLm illustrated in FIG. 1, and the gate line GL may be one of the gate lines GL1 to DLn illustrated in FIG. 1.

The second transistor T2 is turned on in response to a gate signal provided through the gate line GL, and may transmit a data signal provided through the data line DL to the first node N1. For example, the gate signal may be a pulse signal having a turn-on voltage level for turning on a transistor.

The storage capacitor Cst may be connected between the first node N1 and the first power line (ie, a power line to which the first power voltage VDD is applied). The storage capacitor Cst may temporarily store a data signal applied to the first node N1. In this case, the first transistor T1 may adjust the amount of driving current flowing from the first power line to the second node N2 in response to a data signal stored in the storage capacitor Cst.

The light emitting element LD (or light emitting diode) is connected to an anode electrode (or a first pixel electrode) connected to the second node N2 and a second power line to which a second power voltage VSS is applied. It may include a cathode electrode (or a second pixel electrode). For example, the light emitting device LD may be an organic light emitting diode or an inorganic light emitting diode. The light-emitting element LD may emit light with a luminance corresponding to the driving current (or the amount of current of the driving current).

Referring to FIG. 3, pixels PX1, PX2, and PX3 adjacent to each other around the light emitting element LD shown in FIG. 2 are schematically illustrated. The pixels PX1, PX2, and PX3 are included in the display unit 110 of FIG. 1 and may be substantially the same as the pixel PX of FIG. 2.

In embodiments, the first pixel PX1 includes a first light emitting device LD1 emitting light in a first color, and the second pixel PX2 includes a second light emitting device LD2 emitting light in a second color. And the third pixel PX3 may include a third light emitting device LD3 that emits light in a third color. For example, the first light emitting device LD1 may emit red light, the second light emitting device LD2 may emit green light, and the third light emitting device LD3 may emit blue light. The first to third light emitting devices LD1 to LD3 may include first to third parasitic capacitors C_LD1, C_LD2, and C_LD3, respectively.

Assuming that the driving current does not flow in the first pixel PX1 and the third pixel PX3 adjacent to the second pixel PX2 (i.e., IR = 0, IB = 0), the second pixel PX2 is Some of the flowing second driving current IG is in the common layer (for example, the first to third light emitting devices LD1, LD2, LD3) of the first to third light emitting devices LD1, LD2, and LD3. It may leak to the first pixel PX1 and the third pixel PX3 through a commonly included layer or layers adjacent to each other. Hereinafter, this leakage will be defined as lateral leakage. That is, a leakage charge Qleakage moving from the second pixel PX2 to the first and third pixels PX1 and PX3 occurs, and the second pixel PX2 corresponds to the reduced charge Q-Qleakage. Thus, it is possible to emit light with a lower luminance than the desired luminance.

When the second driving current IG is relatively larger than the leakage current (or when the total charge Q is relatively larger than the leakage charge Qleakage), the rate at which the luminance decreases is small and the user may not be able to see it. , When the second driving current IG is relatively small, the ratio of the reduction in luminance is relatively large, and the user can visually recognize it. That is, in a low current region in which the driving current is relatively small (or in a low luminance region having a relatively low luminance corresponding to a relatively small driving current, in a low gradation region in which the size of the gradation values is relatively small), The luminescence characteristics may be distorted or the gamma curve may be struck.

4 may be referred to to describe the change in the light emission characteristics of the pixel. FIG. 4 is a diagram illustrating changes in light emission characteristics of pixels by adjacent pixels of FIG. 3.

Referring to FIG. 4, first to fourth curves CURVE_D1 to CURVE_D4 represent luminance according to an input gray level value GRAY_IN (that is, a gray level value included in the input image data RGB of FIG. 1 ). The first to fourth curves CURVE_D1 to CURVE_D4 may correspond to gamma curves for each dimming level of the display device 1. The fourth curve CURVE_D4 may correspond to a dimming level lower than the dimming level of the first curve CURVE_D1. Here, the dimming level represents a ratio of the maximum display luminance to the maximum luminance of the display device 1, and the higher the dimming level, the higher the maximum display luminance.

The third actual curve CURVE_D3' having a 50% dimming level, such as the second area A2 (that is, a low gray level area with a gray level value within 0 to 32) shown in FIG. 4, is a third curve CURVE_D3. (Ie, an ideal gamma curve) shows a lower luminance. Similarly, the fourth actual curve (CURVE_D4') having a 25% dimming level exhibits lower luminance than the fourth curve (CURVE_D4), and for example, grayscale values of 14 or less on the fourth actual curve (CURVE_D4') are It can correspond to almost zero luminance.

Accordingly, the control unit 140 determines the input gradation value GRAY_IN of a gradation range in which the luminance of the input image data RGB does not appear (for example, a gradation range less than the gradation value of 14 shown in FIG. Remapping can be performed with a gray scale value of the displayed gray scale range (for example, a gray scale range larger than the gray scale value of 14).

5 is a block diagram illustrating an example of a control unit included in the display device of FIG. 1. In FIG. 5, the control unit 140 is exemplarily illustrated with a focus on a function of remapping and compensating a gray level value (eg, a data conversion function). Hereinafter, the control unit 140 performing the data conversion function will be referred to as the data conversion unit 200.

1 and 5, the data conversion unit 200 may include a first data compensation unit 210 and a second data compensation unit 220. In addition, the data conversion unit 200 may further include a memory device 230.

The first data compensating unit 210 (or grayscale remapping unit) remaps the input grayscale value GRAY_IN included in the input image data RGB to within the second grayscale range from the first grayscale range to remap the grayscale. Value (GRAY_RE) can be created. The remapped grayscale value GRAY_RE may be included in the first converted data DATA1.

The first data compensating unit 210 may convert the input image data RGB into a data format corresponding to the arrangement of the pixels PX in the display unit 110 before remapping the input grayscale value GRAY_IN. . For example, when the input image data RGB is RGB data, and the pixel PX has an RGBG pentile structure and is arranged on the display unit 110, the first data compensating unit 210 collects RGB data. It can be converted into RGBG data corresponding to the pentile pixel structure. In this case, the first data compensating unit 210 may perform a grayscale remapping operation on the RGBG data.

6 may be referred to to describe grayscale remapping. FIG. 6 is a diagram illustrating grayscale remapping by a first data compensating unit included in the control unit of FIG. 5.

6, the first graph GRAPH1 shows the relationship between the input grayscale value GRAY_IN and the remapped grayscale value GRAY_RE (or the first compensated grayscale value) included in the input image data RGB. Show.

In embodiments, the first grayscale range includes a first low grayscale area and a second low grayscale area that is a part (or a subset) of the first low grayscale area, and the first data compensator 210 And the first low grayscale values included in the second low grayscale regions may be remapped to the second low grayscale values in the second low grayscale region.

For example, the first data compensating unit 210 may apply an input grayscale value GRAY_IN included in a first low grayscale region having a grayscale value of 0 to 32 in a second low grayscale region having a grayscale value of 14 to 32. It can be remapped with the remapped grayscale value (GRAY_RE).

In one embodiment, the first data compensation unit 210 searches for a first gray scale value (for example, a gray scale value of 14) at which luminance starts to appear in the fourth actual curve CURVE_D4' described with reference to FIG. 4. , The first grayscale value may be set as a starting grayscale value (ie, a minimum grayscale value in the second grayscale range, or a minimum grayscale value in the second low grayscale area). In addition, the first data compensating unit 210 finds a second gray scale value that meets the fourth actual curve CURVE_D4' and the fourth curve CURVE_D4 (eg, 2.2 gamma curve) described with reference to FIG. 4, The second grayscale value may be set as an end grayscale value (ie, a maximum grayscale value in the second grayscale range, or a maximum grayscale value in the second low grayscale area). Thereafter, for example, the first data compensating unit 210 applies the input grayscale value GRAY_IN included in the first low grayscale region having a grayscale value of 0 to 32 to a second low grayscale region having a grayscale value of 14 to 32. It can be remapped with the included remapped grayscale value (GRAY_RE).

That is, the first data compensator 210 may remap the input grayscale value GRAY_IN within the first grayscale range to the remapped grayscale value GRAY_RE in the second grayscale range according to Equation 1 below. .

Here, GRAY_END is the end grayscale value or the maximum grayscale value of the second grayscale range (or the second low grayscale area), and GRAY_START is the start grayscale value or the minimum grayscale value of the second grayscale range (or the second low grayscale area). have.

In some embodiments, the first data compensator 210 may remap the input grayscale value GRAY_IN to the remapped grayscale value GRAY_RE using the lookup table LUT. Here, the lookup table LUT includes mapping information between the input grayscale value GRAY_IN and the remapped grayscale value GRAY_RE, and may be stored in the memory device 230.

To describe the lookup table (LUT), reference may be made to FIG. 7. FIG. 7 is a diagram illustrating an example of a lookup table (LUT) used in a first data compensating unit included in the control unit of FIG. 5.

Referring to FIG. 7, the lookup table LUT may include 14 to 32 remapped gray scale values GRAY_RE corresponding to 0 to 32 input gray scale values GRAY_IN.

For example, an input grayscale value of 0 (GRAY_IN) corresponds to a remapped grayscale value of 14 (GRAY_RE), and as the input grayscale value (GRAY_IN) increases by a grayscale value of 1, the remapped grayscale value (GRAY_RE) May be increased by a gray scale value such as 0.25 or 0.5, which is smaller than 1.

Referring back to FIG. 5, the second data compensating unit 220 includes an input grayscale value GRAY_IN based on the remapped grayscale value GRAY_RE and adjacent grayscale values (or remapped grayscale values of adjacent pixels). ) May be compensated to generate a compensated grayscale value GRAY_C (or a second compensated grayscale value). The compensated gray scale value GRAY_C may be included in the second converted data DATA2 (or data DATA, see FIG. 1 ).

8 may be referred to to describe the generation of the second converted data DATA2.

8 is a diagram illustrating a change in a gamma curve by the control unit of FIG. 5.

3 and 8, by performing grayscale remapping for each of the pixels PX1 to PX3 shown in FIG. 3, the light emission characteristics (or gamma characteristics) of each of the pixels PX1 to PX3 are determined by the reference gamma. It can be adjusted to match the characteristic (e.g., 2.2 gamma curve).

As shown in FIG. 8, the first gamma curve CURVE1 representing the light emission characteristics of the first pixel PX1 is a first compensation having the same shape as the reference gamma curve through gray scale remapping (or first compensation operation). Gamma curve (CURVE_RE1) can be converted. Similarly, the second gamma curve CURVE2 representing the light emission characteristics of the second pixel PX2 is converted into a second compensated gamma curve CURVE_RE2 having the same shape as the reference gamma curve, and the third pixel PX3 emits light. The third gamma curve CURVE3 representing the characteristic may be converted into a third compensated gamma curve CURVE_RE3 having the same shape as the reference gamma curve.

However, when merging the first to third compensated gamma curves (CURVE_RE1, CURVE_RE2, CUREV_RE3) into one white gamma curve (CURVE_W1), the white gamma curve (CUREV_W1) (or the first to third The white balance of the pixels PX1, PX2, and PX3) may have a different shape, that is, different gamma characteristics from the first to third compensated gamma curves CURVE_RE1, CURVE_RE2, and CURVE_RE3.

This is because, when the first to third pixels PX1, PX2, and PX3 simultaneously emit light, lateral leakage generated in each of the first to third pixels PX1, PX2, and PX3 decreases.

Accordingly, the second data compensating unit 220 shown in FIG. 5 performs a second compensation on the white gamma curve CURVE_W1, so that the white gamma curve CURVE_W1 can be readjusted to the corrected white gamma curve CURVE_W2. have. Here, the corrected white gamma curve CURVE_W2 may match the reference gamma curve.

In embodiments, the second data compensating unit 220 may correct the input gray level value GRAY_IN of the target pixel to the compensated gray level value GRAY_C through Equation 2 below.

Here, GRAY_Inij is an input grayscale value (GRAY_IN) corresponding to the pixel located in the i-th row and j-th column, GRAYij is the remapped grayscale value (GRAY_RE) for the input grayscale value (GRAY_IN), and GRAYij' is the input grayscale value. It may be a gray scale value (GRAY_C) compensated for (GRAY_IN). Δij may be a difference value between the remapped grayscale value GRAY_RE and the input grayscale value GRAY_IN. A0 may be a reference compensation coefficient for the input grayscale value GRAY_IN, a1 to a8 may be a compensation coefficient for each of the adjacent grayscale values, G may be a first gain, and D may be a second gain. As will be described later, the first gain G decreases as the remapped gray scale value GRAY_RE of the target pixel increases, and may be, for example, a value between 0 and 1. Similarly, the second gain D decreases as the dimming level of the display device 1 increases, and may be a value between 0 and 1, for example. F(x) may be a limit function for x.

For example, GRAY22', which is the compensated grayscale value (GRAY_C) of the pixels located in the second row and the second column, is "GRAY_IN22 + F(GRAY22-GRAY_IN22)-G * D * (a1 * GRAY11 + a2 * GRAY12 +) It can be calculated as a3 * GRAY13 + a4 * GRAY21 + a5 * GRAY23 + a6 * GRAY31 + a7 * GRAY32 + a8 * GRAY33))".

Meanwhile, in some cases, the input gray level value GRAY_IN of the target pixel may be remapped to gray level values rather than the input gray level value GRAY_IN. Accordingly, Equation 2 may be generalized and expressed as Equation 3 below.

Here, the sign of Δij is the sign of the difference value, and |Δij| may be the absolute value of Δij.

The second data compensating unit 220 for compensating the input grayscale value GRAY_IN according to Equation 3 may be implemented as a logic circuit according to the block diagram of FIG. 9.

9 is a block diagram illustrating an example of a second data compensating unit included in the control unit of FIG. 5.

Referring to FIG. 9, the second data compensation unit 220 includes a first operation circuit 910 (or a first logic operation circuit), a second operation circuit 920, a third operation circuit 930, and a fourth operation circuit. An operation circuit 940 and a fifth operation circuit 950 may be included.

The first operation circuit 910 differentially calculates the input gray level value GRAY_IN of the target pixel from the remapped gray level value GRAY_RE of the target pixel generated by the first data compensator 210 to obtain a difference value (Δ). Can be calculated.

The second calculation circuit 920 may calculate a first compensation value C_GRAY1 for the target pixel based on adjacent grayscale values. For example, the second operation circuit 920 may calculate the first compensation value C_GRAY1 using a compensation filter (or lateral leakage filter; LLF), which will be described later with reference to FIG. 10A. .

The third calculation circuit 930 may calculate a second compensation value C_GRAY2 by differentially calculating the first compensation value C_GRAY1 from the absolute value (|Δ|) of the difference value.

The fourth operation circuit 940 may multiply the sign of the difference value (Sign of Δ) and the second compensation value C_GRAY2 to determine the sign of the second compensation value C_GRAY2.

The fifth operation circuit 950 may calculate the compensated gray level value GRAY_C by summing the input gray level value GRAY_IN and the second compensation value C_GRAY2. For reference, when the compensated gray level value is generated by compensating the remapped gray level value GRAY_RE, the compensated gray level value may be smaller than the input gray level value GRAY_IN. The input grayscale value GRAY_IN may be compensated instead of the mapped grayscale value GRAY_RE.

In one embodiment, the second data compensator 220 (or the second calculation circuit) uses preset compensation coefficients a1 to a8 respectively corresponding to the adjacent gray level values as weights, and uses the adjacent gray level values as weights. A first compensation value may be calculated by summing the weights. Here, the compensation coefficients a1 to a8 may be included in the compensation filter.

For explanation of the compensation filter, reference may be made to FIGS. 10A and 10B. 10A is a diagram illustrating an example of a compensation filter used in a second data compensation unit included in the control unit of FIG. 5. 10B is a diagram illustrating embodiments of the compensation filter of FIG. 10A.

First, referring to FIG. 10A, the compensation filter FILTER1 has a size of 3 rows * 3 columns, and may include first to eighth compensation coefficients a1 to a8 and a reference compensation coefficient a0. The reference compensation coefficient a0 is a coefficient applied to the remapped gray scale value GRAY_RE corresponding to the target pixel, and may be, for example, 0.

In embodiments, the first to eighth compensation coefficients a1 to a8 are constants between 0.01 and 0.15, and the sum of the first to eighth compensation coefficients a1 to a8 may be less than 0.5.

In an embodiment, the first compensation coefficient for a first adjacent pixel included in the same row as the target pixel among adjacent pixels is a second compensation coefficient for a second adjacent pixel included in the same column as the target pixel among adjacent pixels May be different from. For example, the first compensation coefficient may be larger than the second compensation coefficient.

Referring to FIG. 10B, a first compensation filter FILTER_S1 and a second compensation filter FILTER_S2 are illustrated by way of example.

In the first compensation filter FILTER_S1, the first compensation coefficients for the first adjacent pixels included in the same row as the target pixel are, that is, the fourth compensation coefficient a4 and the fifth compensation coefficient a5 shown in FIG. 10A. ) Is 0.125, and the second compensation coefficient for the second adjacent pixel included in the same column as the target pixel is 0.1, that is, the second compensation coefficient a2 and the seventh compensation coefficient a7 shown in FIG. 10A are 0.1, The second and seventh compensation coefficients a2 and a7 may be greater than the fourth and fifth compensation coefficients a4 and a5.

As the display unit 110 (or the pixel PX) displays an image in a sequential driving method by the gate driver 130 described with reference to FIG. 1, the same This is because the side leakage caused by adjacent pixels included in the row and emitting light at the same time can be greatly affected.

On the other hand, the first compensation coefficient (a1), the third compensation coefficient (a3), the sixth compensation coefficient (a6), and the eighth compensation coefficient (a8) for adjacent pixels arranged in the diagonal direction based on the target pixel are 0.05. And may be very small compared to the remaining compensation coefficients a2, a4, a5, and a7. This is because adjacent pixels arranged in a diagonal direction with respect to the target pixel according to the pixel arrangement structure are relatively spaced apart from the target pixel, so that the influence of side leakage may be relatively small.

Similarly, in the second compensation filter FILTER_S2, the first compensation coefficients for the first adjacent pixels included in the same row as the target pixel, that is, the fourth compensation coefficient a4 and the fifth compensation coefficient a5 are The second compensation coefficient for the second adjacent pixel, which is the largest of 0.1 and included in the same column as the target pixel, is 0.05, that is, the second compensation coefficient a2 and the seventh compensation coefficient a7 are 0.05, and the first compensation coefficient ( a1), the third compensation coefficient a3, the sixth compensation coefficient a6, and the eighth compensation coefficient a8 may be the smallest as 0.025.

In embodiments, the second data compensating unit 220 moves the compensation filter FILTER (for example, the first compensation filter FILTER_S1 or the second compensation filter FILTER_S2) in units of pixels. The internal first compensation value or the compensated gray level value GRAY_C may be continuously calculated.

11 may be referred to to describe a process of calculating the compensated grayscale value GRAY_C by the second data compensating unit 220. FIG. 11 is a diagram illustrating an example of a process of compensating gray levels by using the compensation filter of FIG. 10A in the control unit of FIG. 5.

1, 10A, and 11, pixels in the first area A1 of FIG. 1 are illustrated by way of example, and the pixels may be arranged in an RGBG pentile structure.

In the first step (STEP1), the second data compensation unit 220 arranges a compensation filter FILTER corresponding to the 21st green pixel G21, and the eleventh red pixel R11 inside the compensation filter FILTER. , The eleventh green pixel G11, the twelfth blue pixel B12, the 21st blue pixel B21, the 22nd red pixel R22, the 31st red pixel R31, the 31st green pixel G31, and A compensation value corresponding to the 21st green pixel G21 or a compensated gray level value GRAY_C may be calculated by weighting the grayscale values corresponding to the 32nd blue pixel B32.

For reference, the second data compensation unit 220 calculates a compensation value or a compensated grayscale value GRAY_C by considering only the arrangement of pixels without considering the emission color of the pixels, and accordingly, the target pixel (for example, The gradation value of at least one pixel (eg, the eleventh red pixel R11, the twelfth blue pixel B12, etc.) that emits light in a color different from that of the 21st green pixel G21 is the compensation value of the target pixel Alternatively, it may be used to calculate the second compensated grayscale value.

Similarly, in the second step (STEP2), the second data compensation unit 220 moves or arranges the compensation filter in response to the 22nd red pixel R22, and A compensation value corresponding to the 22nd red pixel R22 or a second compensated gray level value may be calculated by weighting the grayscale values corresponding to the pixels.

When the calculation of the compensation value for one row or the second compensated gradation value is completed, as in the third step (STEP3), the second data compensation unit 220 applies the compensation filter (FILTER) to the 31st green color of the next row. A compensation value for the 31st green pixel G31 or a second compensated grayscale value may be calculated by placing it on the pixel G31.

Thereafter, as in the fourth step (STEP4), the second data compensating unit 220 moves the compensation filter in the row direction (or horizontal direction) in pixel units to determine the compensation value or the second compensated gray level value. The calculation can be performed iteratively.

In embodiments, the second data compensation unit 220 may calculate a compensation value or a compensated grayscale value GRAY_C by selectively applying a plurality of compensation filters.

12 may be referred to to describe a configuration for selectively applying compensation filters. FIG. 12 is a diagram illustrating another example of a process of compensating a gray level by using the compensation filter of FIG. 10A in the control unit of FIG. 5.

11 and 12, in the first to fourth steps (STEP1 to STEP4), the second data compensating unit 220 is a green filter (FILTER_G) set for each pixel type (or for each emission color), It is different from the operation of the second data compensator 220 in FIG. 11 in that the red filter FILTER_R and the blue filter FILTER_B are selectively applied. For example, the green filter FILTER_G may be the first compensation filter FILTER_S1 shown in FIG. 10B, and the red filter FILTER_R and the blue filter FILTER_B may be the second compensation filter FILTER_S2 shown in FIG. 10B. However, it is not limited thereto.

12, in the first step (STEP1), the second data compensator 220 applies a green filter (FILTER_G) to the 21st green pixel (G21), and the second step (STEP2) 2 The data compensation unit 220 applies a red filter (FILTER_R) to the 22nd red pixel R22, and in the third step (STEP3), the second data compensation unit 220 applies the second data compensation unit 220 to the 31st green pixel (G31). The green filter FILTER_G is applied to the green filter, and in the fourth step STEP4, the second data compensating unit 220 may apply the blue filter FILTER_B to the 32nd blue pixel B32.

That is, the second data compensation unit 220 selectively applies one of different filters (eg, a green filter (FILTER_G), a red filter (FILTER_R), and a blue filter (FILTER_B)) for each adjacent pixel, thereby compensating A value or a compensated grayscale value (GRAY_C) may be calculated.

In embodiments, the first gain G used in Equation 2 is set based on the first compensated gray level value of the target pixel, and decreases as the first compensated gray level value increases, and a value between 0 and 1 Can have.

13 may be referred to for explanation of the first gain G. 13 is a diagram illustrating an example of a first gain used in the control unit of FIG. 5.

Referring to FIG. 13, the first gain (G) (or global gain) is the maximum value (for example, 1) when the remapped grayscale value (GRAY_RE) is the same as the start grayscale value (GRAY_START) of the second grayscale range. And may have a minimum value (eg, 0) when the remapped grayscale value GRAY_RE is the same as the end grayscale value GRAY_END of the second grayscale range.

Referring to FIG. 6, for example, when the remapped grayscale value (GRAY_RE) is 14, the first gain (G) has a value of 1, and when the remapped grayscale value (GRAY_RE) is 32, the first gain (G) Can have a value of 0.

The first gain (G) linearly decreases as the remapped grayscale value (GRAY_RE) increases within the second grayscale range, and the remapped grayscale value (GRAY_RE) is greater than the end grayscale value (GRAY_END) of the second grayscale range. In this case, it may have a minimum value, for example, a value of 0.

As described with reference to FIGS. 3 and 4, as the remapped gray scale value GRAY_RE is smaller, side leakage of the target pixel may increase, and influence by adjacent pixels may increase. Therefore, in Equation 2, the compensation value (i.e., a value obtained by calculating the weight of adjacent gray levels corresponding to adjacent pixels) is inversely proportional to the remapped gray level value GRAY_RE, and the remapped gray level value GRAY_RE of the target pixel is small. As the value increases, the influence of adjacent grayscale values can be greatly reflected.

In embodiments, the second gain D used in Equation 2 is set based on the dimming level of the display device 1, decreases as the dimming level increases, and may have a value between 0 and 1. .

14 may be referred to for explanation of the second gain D. 14 is a diagram illustrating an example of a second gain used in the control unit of FIG. 5.

14, the second gain (D) (or dimming gain) has a maximum value (Max Dimming Gain, for example, 1) at a minimum dimming level (DIM_MIN), and a minimum value at the maximum dimming level (DIM_MAX). It has (Min Dimming Gain, for example, 0), and can decrease linearly as the dimming level increases. Referring to FIG. 4, for example, when the dimming level is 25%, the second gain D may have a value of 1, and when the dimming level is 100%, the second gain D may have a value of 0.1. .

As described with reference to FIGS. 3 and 4, the lower the dimming level, the smaller the first compensated grayscale values as a whole, and accordingly, the side leakage to the target pixel becomes relatively large, and the influence of the adjacent pixels is increased. Because it gets bigger.

Therefore, in Equation 2, the compensation value (that is, a value obtained by calculating the weight of adjacent gray levels corresponding to adjacent pixels) is inversely proportional to the dimming level, and the lower the dimming level, the greater the influence of adjacent gray levels can be reflected .

As described with reference to FIGS. 5 to 14, the data conversion unit 200 (or the control unit 140) performs grayscale remapping to each pixel in the low gradation region (or low current region, low luminance region). The gamma characteristic of may be corrected to be the same as the reference gamma characteristic, and the white gamma characteristic (or white balance) of the pixels may be corrected to be the same as the reference gamma characteristic through gray level compensation using adjacent gray levels. Accordingly, deterioration of the display quality of the display device 1 can be prevented.

Meanwhile, in FIG. 9, it has been described that the second data compensating unit 220 calculates the gray scale value GRAY_C compensated through Equation 3 (or Equation 2), but the present invention is not limited thereto.

In embodiments, the second data compensating unit 220 may correct the input gray level value GRAY_IN of the target pixel to the compensated gray level value GRAY_C through Equation 4 below.

The compensated grayscale value GRAY_C (that is, GRYAij') according to Equation 4 is different from the compensated grayscale value according to Equation 2 in that it is calculated in consideration of the gain GAIN.

The second data compensating unit 220 for compensating the input grayscale value GRAY_IN according to Equation 4 may be implemented as a logic circuit according to the block diagram of FIG. 15.

15 is a block diagram illustrating another example of a second data compensating unit included in the control unit of FIG. 5.

9 and 15, the second data compensation unit 220_1 of FIG. 15 includes a first operation circuit 1510 (or a first logic operation circuit), a second operation circuit 1520, and a third operation circuit. 1530, a fourth operation circuit 1540, a fifth operation circuit 1550, and a sixth operation circuit 1560 may be included. The first operation circuit 1510, the second operation circuit 1520, the third operation circuit 1530, the fourth operation circuit 1540, and the fifth operation circuit 1550 are the first operation described with reference to FIG. Substantially the same as the circuit 910 (or the first logic operation circuit), the second operation circuit 920, the third operation circuit 930, the fourth operation circuit 940, and the fifth operation circuit 950 Or similar, overlapping descriptions will not be repeated.

The third calculation circuit 1530 may calculate a second compensation value C_GRAY2 by differentially calculating the first compensation value C_GRAY1 from the difference value Δ.

The sixth operation circuit 1560 may calculate a gain GAIN by dividing the input grayscale value GRAY_IN by the first compensation value C_GRAY1.

The fourth calculation circuit 1540 may calculate a third compensation value C_GRAY3 by multiplying the second compensation value C_GRAY2 and the gain GAIN.

The fifth operation circuit 1550 may calculate the compensated gray level value GRAY_C by summing the input gray level value GRAY_IN and the third compensation value C_GRAY3.

16A and 16B may be referred to to describe the effect of the second data compensating unit 220_1 of FIG. 15.

FIG. 16A is a diagram illustrating compensation values calculated by the second data compensating unit of FIG. 15 for a white image, and FIG. 16B is a diagram illustrating compensation values calculated by the second data compensating unit of FIG. 15 for a monochrome image. to be.

15, 16A, and 16B, a difference value graph CURVE_D represents a difference value Δ according to a gray level value (that is, a difference between a remapped gray level value and an input gray level value), and a first compensation value The graph CURVE_LLF represents the first compensation value C_GRAY1 (that is, the compensation value calculated by applying the compensation filter) according to the gray level value, and the second compensation value graph CURVE_F is the second compensation value ( C_GRAY2) (that is, the result of applying the limit function to the difference between the difference value (Δ) and the first compensation value (C_GRAY1)). The third compensation value graph (CURVE_C) represents a third compensation value (C_GRAY3) (that is, a value obtained by multiplying the second compensation value (C_GRAY2) by the gain (GAIN)), and the third compensation value graph ( CURVE_C represents a third compensation value C_GRAY3 for a white image, and a third compensation value graph CURVE_C illustrated in FIG. 16B represents a third compensation value C_GRAY3 for a monochrome image.

When the second data compensating unit 220_1 uses Equation 3 (or Equation 2) described with reference to FIG. 9, the compensated gray level value GRAY_C is a second compensation value ( It can be calculated by adding C_GRAY2).

As described with reference to FIG. 3, side leakage due to the white image does not occur significantly, but as shown in FIG. 16A, the second compensation value C_GRAY2 has a relatively large value, and accordingly, the input gray level value GRAY_IN ) Can be overcompensated.

The second data compensating unit 220_1 according to an embodiment of the present invention uses the fourth equation described with reference to FIG. 15 to input the third compensation value C_GRAY3 in which the gain is reflected as an input grayscale value ( GRAY_IN) can be added to calculate the compensated gray scale value GRAY_C. Since the gain (that is, the ratio of the input grayscale value to the first compensation value (C_GRAY1)) has a relatively small value (compared to other images) according to the white image, as shown in FIG. The compensation value C_GRAY3 has a relatively small value, and overcompensation for the input gray level value GRAY_IN can be prevented.

On the other hand, side leakage due to a monochromatic image may be relatively large. In this case, since the gain (that is, the ratio of the input grayscale value to the first compensation value (C_GRAY1)) has a relatively large value (compared to the white image) according to the monochrome image, as shown in FIG. , The third compensation value C_GRAY3 has a relatively large value (eg, has a value similar to the second compensation value C_GRAY2), and the input gray level value GRAY_IN may be sufficiently compensated.

As described with reference to FIGS. 15 to 16B, the second data compensating unit 220_1 according to embodiments of the present invention is a compensation value (ie, a compensation value finally reflected in the input gray level value GRAY_IN). 3 By varying the compensation value GRAY_C3 in response to a change in side leakage, it is possible to prevent deterioration in display quality.

17 is a diagram illustrating an example of test data provided to the control unit of FIG. 5. In FIG. 17, line data DATA_L1 to DATA_L4 for pixels included in one row of the display unit 110 are illustrated in chronological order.

1 and 17, data signals corresponding to the line data DATA_L1 to DATA_L4 may be provided to the display unit 110 through the data lines DL1 to DLm illustrated in FIG. 1.

The line data DATA_L1 to DATA_L4 may include data values repeated every three data lines. Accordingly, the line data DATA_L1 to DATA_L4 will be described centering on the first to third data lines DL1 to DL3.

The line data DATA_L1 to DATA_L4 have a test value TEST corresponding to the second data line DL2, and a minimum gray scale value or a maximum gray scale value ( MAX). For example, the test value TEST is an arbitrary grayscale value included in the second low grayscale region described with reference to FIG. 6, and may have, for example, a grayscale value of 15. For example, the minimum grayscale value may be a grayscale value of 0, and the maximum grayscale value MAX may be a grayscale value of 255.

The first line data DATA_L1 may have a maximum gray scale value MAX corresponding to the first and third data lines DL1 and DL3. The second line data DATA_L2 has a minimum gray scale value corresponding to the first data line DL1, a maximum gray scale value MAX corresponding to the third data line DL3, and the third line data DATA_L3 is A maximum gray scale value MAX corresponding to the first data line DL1 and a minimum gray scale value corresponding to the third data line DL3, and the fourth line data DATA_L4 corresponds to the first line data DATA_L1 and It can be the same.

Since the display device 1 (or the control unit 140) compensates the gray level value of the target pixel by using the adjacent gray level values of the adjacent pixels, the gray level values corresponding to the first and third data lines DL1 and DL3 are According to the change, the grayscale value (or the compensated grayscale value GRAY_C) corresponding to the second data line DL2 changes, and accordingly, a change in the luminance of the pixel included in the second data line DL2 can be confirmed. I can.

Meanwhile, in FIG. 17, it has been described that data signals corresponding to each of the first line data DATA_L1 to the fourth line data DATA_L4 are provided to the display unit 110, but the present invention is not limited thereto.

For example, the first line data DATA_L1 and the second line data DATA_L2 are combined to correspond to the first data line DL1 (and the fourth data line DL4 and the seventh data line DL7). The gradation value to be performed may change stepwise from the maximum gradation value MAX (or a specific gradation value, for example, a gradation value of 30) to a minimum gradation value. Also, a gray scale value corresponding to the third data line DL3 (and the sixth data line DL6 and the ninth data line DL9) may also be changed stepwise. That is, the test data may correspond to a gradation image.

18 is a diagram illustrating various examples of a compensation filter used in a second data compensation unit included in the control unit of FIG. 5.

Referring to FIG. 18, the first line compensation filter FILTER_L1 differs from the compensation filter FILTER described with reference to FIG. 10A in that it has a size of 1 row * 3 columns.

In the first line compensation filter FILTER_L1, a size of a line memory for storing adjacent grayscale values of adjacent pixels may be reduced or the line memory may be removed.

When the first line compensation filter FILTER_L1 is used in the second data compensating units 220 and 220', LLF(i,j) included in Equations 2, 3, and 4 is Equation 5 below. Can be calculated as

Here, c0 may be a reference compensation coefficient for the input gray level value GRAY_IN, and c1 and c2 may be compensation coefficients for each of the adjacent gray level values.

Meanwhile, the second line compensation filter FILTER_L2 may have a size of 1 row * 5 columns.

When the second line compensation filter FILTER_L2 is used in the second data compensating units 220 and 220', LLF(i,j) included in Equations 2, 3, and 4 is Equation 6 below. It can be calculated as

Here, d0 may be a reference compensation coefficient for the input grayscale value GRAY_IN, and d1 to d4 may be compensation coefficients for each of the adjacent grayscale values.

Meanwhile, the third line compensation filter FILTER_L3 may have a size of 1 row * 6 columns.

When the third line compensation filter FILTER_L3 is used in the second data compensating units 220 and 220', LLF(i,j) included in Equations 2, 3, and 4 is Equation 7 below. It can be calculated as

Here, e0 is a reference compensation coefficient for the input gray level value GRAY_IN, and e1 to e5 may be compensation coefficients for each of the adjacent gray level values.

As described with reference to FIG. 18, the compensation filter is implemented as a line compensation filter of 1 row * k columns corresponding to one row (i.e., one of the first to third line compensation filters (FILTER_L1, FILTER_L2, FILTER_L3)). The size of the line compensation filter may be variously changed, for example, k may be greater than or equal to 3.

19 is a flowchart illustrating a method of driving a display device according to an exemplary embodiment.

1 and 19, the method of FIG. 19 may be performed in the display device 1 of FIG. 1.

The method of FIG. 19 may calculate a remapped gray level value GRAY_RE (or a first compensated gray level value) by remapping an input gray level value included in the input image data RGB (S1910).

As described with reference to FIGS. 6 and 7, in the method of FIG. 19, the input gray scale value GRAY_IN of the first gray scale range is converted to the first gray scale range of the second gray scale range using Equation 1 or the lookup table LUT. It can be remapped to the compensated gray scale value (GRAY_RE).

Thereafter, the method of FIG. 19 may calculate a first compensation value for the first input gray level value of the target pixel based on the first compensated gray level values of the adjacent pixels (S1920).

In the method of FIG. 19, the first compensation value C_GRAY1 may be calculated using Equation 2 (or Equation 4) described above, and the compensation described with reference to FIGS. 10A and 10B and FIG. 18 The first compensation value C_GRAY1 may be calculated using at least one of the filters. In addition, the method of FIG. 17 may continuously calculate the first compensation value C_GRAY1 while moving the compensation filter in pixel units, as described with reference to FIG. 11.

The method of FIG. 19 compensates for the first input gray level value GRAY_IN of the target pixel based on the first compensated gray level value GRAY_C1 and the first compensation value C_GRAY1 of the target pixel, thereby compensating the second compensated gray level value ( GRAY_C2) can be calculated (S1930).

In embodiments, as described with reference to FIGS. 9 and 15, the method of FIG. 19 differs by calculating an input gray level value GRAY_IN of the target pixel from the first compensated gray level value GRAY_C1 of the target pixel. Calculate the value, calculate the first compensation value (C_GRAY1) from the absolute value of the difference value to calculate the second compensation value (C_GRAY2), and calculate the input gray level value (GRAY_IN) and the second compensation value (C_GRAY2) Based on, a second compensated gray scale value GRAY_C2 of the target pixel may be calculated. The second compensated gray level value GRAY_C2 is the compensated gray level value GRAY, and is included in the image data DATA described with reference to FIG. 1, and the data DATA may be provided to the data driver 120.

In one embodiment, the method of FIG. 19 calculates a gain (GAIN) by dividing the input gray scale value (GRAY_IN) by the first compensation value (C_GRAY1), as described with reference to FIG. 15, and the second compensation value (C_GRAY2). ) And gain (GAIN) may be multiplied to calculate a third compensation value (C_GRAY3). In this case, the third compensated gray level value GRAY_C3 is the compensated gray level value GRAY, and is included in the image data DATA described with reference to FIG. 1, and the data DATA is provided to the data driver 120. I can.

Thereafter, the method of FIG. 19 may generate a data signal based on the second compensated gray level value (or the third compensated gray level value) (S1940).

As described with reference to FIG. 1, the data driver 120 generates a data signal based on the image data DATA, that is, the compensated gray scale value GRAY_C included in the image data DATA, and generates a data signal. It may be provided to the display unit 110 through the data lines DL1 to DLm.

The drawings referenced so far and the detailed description of the invention described are merely illustrative of the present invention, which are used only for the purpose of describing the present invention, but are used to limit the meaning or the scope of the invention described in the claims. It is not. Therefore, those of ordinary skill in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

1: display device
110: display
120: data driver
130: gate driver
140: control unit
200: data conversion unit
210: first data compensation unit
220: second data compensation unit
230: memory device
910, 920, 930, 940, 950: first to fifth operation circuits
1510, 1520, 1530, 1540, 1550, 1560: first to sixth operation circuits

Claims (15)

A display unit including a plurality of pixels;
Receives grayscale values corresponding to each of the pixels, remaps each of the grayscale values in a first grayscale range to first compensated grayscale values in a second grayscale range, and performs the first compensated grayscale of adjacent pixels A data conversion unit for generating second compensated grayscale values by compensating the grayscale values based on values; And
A data driver generating data signals based on the second compensated gray scale values and providing them to the pixels of the display unit,
The adjacent pixels to the target pixel correspond to pixels adjacent to the target pixel, and at least one of the adjacent pixels emit light in a different color than the target pixel. The display device according to claim 1, wherein the second grayscale range is a subset of the first grayscale range. The method of claim 1, wherein the data converter calculates a difference value by calculating a difference value of the target pixel from the first compensated gray level value of the target pixel, and the first compensation of the adjacent pixels A first compensation value for the target pixel is calculated based on the grayscale values, and a second compensation value is calculated by calculating the first compensation value from an absolute value of the difference value, and the grayscale value And calculating a second compensated gray level value of the target pixel based on the second compensation value,
The data conversion unit increases the first compensation value as one of the first compensated gray level values of the adjacent pixels increases. The display device of claim 3, wherein when the first compensation value is less than 0, the data conversion unit determines the compensation value as the second compensated gray scale value. The display device of claim 3, wherein the data conversion unit calculates the first compensation value by adding weights of the adjacent gray level values based on compensation coefficients respectively preset corresponding to the adjacent gray level values. The method of claim 5, wherein a first compensation coefficient for a first adjacent pixel included in the same row as the target pixel among the adjacent pixels is a second adjacent pixel included in the same column as the target pixel among the adjacent pixels. Different from the second compensation coefficient for, the display device. The display device of claim 5, wherein when the difference value is greater than 0, the data conversion unit calculates the second compensated gray level value by summing the first compensated gray level value and the second compensation value. The display device of claim 7, wherein when the difference value is less than 0, the data conversion unit calculates the second compensated gray level value by performing a difference operation between the first compensated gray level value and the second compensation value. The display device of claim 3, wherein the first compensation value is proportional to the gray level value of the target pixel, but is inversely proportional to the first compensated gray level value. The display device of claim 1, wherein the adjacent pixels are included in the same row as the target pixel. Remapping grayscale values in the first grayscale range to first compensated grayscale values in the second grayscale range;
Calculating a first compensation value for a first gray level value of a target pixel based on the first compensated gray level values of adjacent pixels;
Calculating a second compensated gray level value by compensating the first gray level value of the target pixel based on the first compensated gray level value and the first compensation value of the target pixel; And
Generating a data signal based on the second compensated grayscale value,
The adjacent pixels to the target pixel are pixels adjacent to the target pixel, and at least one of the adjacent pixels emit light in a different color than the target pixel. The method of claim 11, wherein calculating the second compensated grayscale value comprises:
Calculating a difference value by performing a difference operation on a first gray level value of the target pixel from the first compensated gray level value of the target pixel;
Calculating a second compensation value by calculating the difference between the first compensation value from the absolute value of the difference value; And
And calculating a second compensated gray level value of the target pixel based on the gray level value and the second compensation value,
The first compensation value increases as one of the first compensated gray scale values of the adjacent pixels increases. The method of claim 12, wherein the calculating of the first compensation value comprises: calculating the first compensation value for summing the adjacent gray level values by weight based on compensation coefficients respectively preset corresponding to the adjacent gray level values. , The driving method of the display device. The method of claim 13, wherein a first compensation coefficient for a first adjacent pixel included in the same row as the target pixel among the adjacent pixels is applied to a second adjacent pixel included in the same column as the target pixel among the adjacent pixels. A method of driving a display device that is different from the second compensation coefficient for. 14. The method of claim 13, wherein the first compensation value is proportional to the gray level value of the target pixel, but inversely proportional to the first compensated gray level value.

Images