KR102364081B1 - Data conveter device and display device including thereof - Google Patents

Abstract

A data conversion device and a display device including the same according to an embodiment of the present invention are red (Red, hereinafter R), green (Green, hereinafter G), blue (Blue, hereinafter B) and white (hereinafter W) of an image. ) based on the data signal, detecting the average luminance brightness of the image, and stretching the histogram of the W data according to the detected average luminance brightness.

Description

DATA CONVERTER DEVICE AND DISPLAY DEVICE INCLUDING THEREOF

The present invention relates to a data conversion device and a display device including the same.

Recently, interest in realizing high-definition image quality and reducing power consumption by increasing the luminance of a display device is increasing. In particular, a high-contrast image is implemented through the existing multi-frame high-contrast technology, and the histogram stretch method is additionally applied to further emphasize the image. However, in the prior art, in the process of outputting an input image, only the gradation of RGB (R: Red, G: Green, B: Blue) image data is varied without consideration of the average image brightness (average picture level), maximum luminance, and gradation. Concentrated on saving detailed information of image quality.

9 is a histogram of RGB input image data and expanded to show changes in the histogram, and FIG. 10 is a view showing changes in the screen accordingly. Referring to FIGS. 9 and 10 , HDR refers to a high-luminance display of about 1000 nits or more. Compared to a general display, noise is more visible in the low-grayscale region, and glare problem occurs in the high-gradation region due to the high luminance. As described above, the conventional histogram expansion technique of RGB image data has a problem in that it is not optimized for a high-brightness display, which has problems such as glare and contour generation of the image.

An embodiment according to the present invention may provide a data conversion device having a luminance increased by additionally including a white pixel, and a display device including the same.

In addition, an embodiment according to the present invention provides a data conversion device capable of optimizing an image enhancement technique by varying an extension value of a histogram in consideration of an average image brightness of a white data signal, a maximum brightness of an input image, and an image grayscale, and a display device including the same may also provide

A data conversion device and a display device including the same according to an embodiment of the present invention are red (Red, hereinafter R), green (Green, hereinafter G), blue (Blue, hereinafter B) and white (hereinafter W) of an image. ) Based on the data signal, the average luminance brightness of the image is detected, and when the luminance expression range is increased by stretching the histogram of the W data according to the detected average luminance brightness, the increase in contrast ratio, which is an advantage of HDR, and high While the expression of the luminance region is maintained as it is, it is possible to prevent low-grayscale noise and glare of a high-luminance image, and further reduce power consumption.

In addition, the display device according to and including the embodiment of the present invention detects a maximum luminance pixel based on the RGBW data, compares it with a maximum luminance reference value, and sets the luminance of the maximum luminance pixel equal to or greater than the maximum luminance reference value to the maximum luminance reference value. By including a maximum luminance pixel detector that is lowered to , it is possible to prevent glare of an image and to prevent a sudden increase in power consumption.

Data capable of optimizing the image enhancement technique by increasing the luminance by additionally including a white pixel, and varying the extension value of the histogram in consideration of the average image brightness and maximum luminance of the white data signal and the image grayscale It is possible to provide a converter and a display device including the same.

1 is a diagram illustrating a data conversion unit according to an embodiment of the present invention.
2 is a flowchart illustrating an operation process of the W data converter according to the first embodiment.
3 is a detailed block diagram of the W data conversion unit according to the first embodiment and a diagram illustrating an operation relationship thereof.
4 is a flowchart illustrating an operation process of the W data converter according to the second embodiment.
5 is a detailed block diagram of a W data conversion unit according to the second embodiment and a diagram illustrating an operation relationship thereof.
6 is a diagram illustrating the effect of improving image quality and reducing power consumption when image data that has passed through a data converter according to an embodiment of the present invention is displayed as an image.
7 is a view showing a display device including a data conversion unit according to an embodiment of the present invention.
Fig. 8 is a diagram showing an arrangement relationship of sub-pixels;
9 is a view showing a conventional histogram stretch method.
10 is a view showing a screen transformation according to a conventional histogram stretch.

Hereinafter, a data conversion apparatus according to an embodiment of the present invention and a display apparatus including the same will be described in detail with reference to the drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers refer to like elements throughout.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description.

Reference to an element or layer to another element or “on” or “on” includes not only directly on the other element or layer, but also with other layers or other elements interposed therebetween. do. On the other hand, reference to an element "directly on" or "directly on" indicates that there are no intervening elements or layers.

Spatially relative terms "below, beneath", "lower", "above", "upper", etc. are one element or component as shown in the drawings. and can be used to easily describe the correlation with other devices or components. The spatially relative term should be understood as a term including different directions of the device during use or operation in addition to the directions shown in the drawings. For example, when an element shown in the figures is turned over, an element described as "beneath" or "beneath" another element may be placed "above" the other element. Accordingly, the exemplary term “below” may include both directions below and above.

The terminology used herein is for the purpose of describing the embodiments, and thus is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, “comprise” and/or “comprising” refers to the presence of one or more other components, steps, operations, and/or elements mentioned. or addition is not excluded.

<Data conversion unit>

1 is a diagram illustrating a data conversion unit according to an embodiment of the present invention.

Referring to FIG. 1 , the data conversion apparatus 100 according to an embodiment of the present invention converts input red (Red; hereinafter R), green (Green; hereinafter G), and blue (Blue; hereinafter B) data signals to RGB and It may have a function of converting to a white (hereinafter W) data signal, reinforcing the saturation of the RGB data signal, and reinforcing the brightness of the W signal and outputting it. The data conversion apparatus 100 may include an inverse-gamma unit 110 , an RGB to RGBW conversion unit 130 , a W data conversion unit 150 , a color temperature compensator 170 , and a rendering unit 190 . .

The inverse gamma unit 110 (De-Gamma) may perform inverse-gamma processing on the RGB data signals of the input image for each frame. To explain this in more detail, the inverse gamma unit 110 converts the received inverse gamma to inverse gamma in order to prevent a bit overflow occurring during an operation for converting RGB data signals into RGBW data signals. After processing and changing it to a linear form, do bit stretching. The inverse gamma unit 110 may perform bit stretching using an inverse-gamma lookup table (DE-Gamma LUT). As a result, the RGB data signals RGB may be output by increasing the number of bits by bit stretching by the inverse gamma unit 110 .

The RGB to RGBW conversion unit 130 serves to convert the RGB data signals output through the inverse gamma unit 110 into RGBW data signals. The reason for converting RGB data signals into RGBW data signals using the RGB to RGBW converter 130 is to drive a display panel including RGBW sub-pixels. The RGB to RGBW converter 130 subtracts RGB data signals based on measured or calculated values having the same luminance and color coordinates as the W data signal from the RGB data signals to optimize power consumption without changing the color coordinates. W data signal can be added. Also, as an example, the RGB to RGBW converter 130 extracts a common grayscale value as in Equation 1 or a minimum grayscale value as in Equation 2 from R, G, and B data to generate the W data, and R The R, G, and B data may be generated by subtracting the W data from each of the input data of , G, and B.

Equation 1

Equation 2

As another example, the RGB to RGBW converter 130 may perform R, It is possible to convert G and B data to R data, G data, and B data to W data.

In this case, according to the conversion method disclosed in Korean Patent Application Laid-Open No. 10-2013-0060476 or 10-2013-0030598, mapping from RGB grayscale to WRGB grayscale can be performed.

Hereinafter, the RGB data signals input to the RGB to RGBW converter 130 are referred to as RGB data signals, and RGB data signals obtained by converting RGB data signals among the RGBW data signals output from the RGB to RGBW converter 130 are referred to as RGB data signals. are called

The W data conversion unit 150 calculates the average luminance, that is, the average image brightness (APL) of the image in units of one screen based on the input RGBW data, and adjusts the gain of the histogram stretch based on the calculated average image brightness. A new histogram of W data may be generated based on the adjusted histogram stretch gain.

The color temperature compensator 170 may compensate for the color temperature of RGB data. As an example of color temperature compensation that implements this, the RGB data signal output from the W data conversion unit 150 and W in which the histogram is stretched are received, the light source of the display panel 200 can be detected, and the RGB data can be compensated. . In this case, the color temperature compensator 170 may include an optical sensor, and when the ambient light of the display panel 200 measured from the optical sensor has a strong blue color, the red color and green color of the input image Either or both of the (Green) colors can be compensated, and when the measured ambient light is red, either or both of the Blue and Green colors of the input image can be compensated. can In addition, when the measured ambient light is strong in green, any one or both of red and blue colors of the input image may be compensated.

The rendering unit 190 may improve resolution by reproducing one pixel using two or more pixels based on input RGBW data signals.

<W data conversion unit according to the first embodiment>

2 is a flowchart illustrating an operation process of the W data converter according to the first embodiment. 3 is a detailed block diagram of the W data conversion unit according to the first embodiment and a diagram illustrating an operation relationship thereof.

Referring to FIG. 2 , the RGB to RGBW converter 130 generates an RGBW data signal based on input RGB data, and the W data converter 150 according to the first embodiment is based on the input RGBW data. The histogram stretch of W data may be changed based on the adjusted stretch gain by calculating the average image brightness (APL) and adjusting the stretch gain according to the calculation result. A detailed configuration for implementing this will be described with reference to FIG. 3 , the W data conversion unit 150 may include an average image brightness detection unit 151 , a stretch gain control unit 152 and a histogram stretch application unit 153 . there is.

The average image brightness detection unit 151 detects the average luminance, ie, the average image brightness (APL) of the image, in units of one frame based on the RGB data signal, and digitizes the detected average image brightness into an arithmetic value of 0 to 100 for brightness can be compared with the baseline. The brightness reference values (a, b) may include a lower brightness reference value (a) and an upper brightness reference value (b). When the average image brightness value is greater than 0 and less than the lower brightness reference value (a), the first level of It is determined as the average image brightness, and when the average image brightness value is greater than or equal to the lower brightness reference value (a) but less than the upper brightness reference value (b), it is determined as the average image brightness of the second level, and the average image brightness value is higher than the upper brightness reference value (b) If it is greater than or equal to the brightness reference value (b) but less than 100, it may be determined as the average image brightness of the third level. Meanwhile, the brightness reference value may further include additional reference values in addition to the lower and upper brightness reference values a and b, and accordingly, the classification of the average image brightness of the detected image may be further subdivided.

The stretch gain adjusting unit 152 may adjust a stretch gain, which is a stretch degree of W data, based on the average image brightness. Specifically, as a first step, W data among RGBW data generated based on the RGB data signal may be histogrammed. The histogram may be defined as a set of numbers indicating the frequency of occurrence of pixels having a specific intensity in W data. In a second step, a low gray scale gain value and a high gray scale gain value for emphasizing a specific gray scale by stretching the histogram of the W data may be respectively set based on the detected average image brightness.

For example, when the average image brightness of the input image is detected as the average image brightness of the first level, which is a low level, the low gray scale gain is 0.2 and the high gray scale gain is 0.8, and the high gray scale is relatively more emphasized than the low gray scale. When the average image brightness of the input image is detected as the average image brightness of the second level, which is an intermediate level, the low gray scale gain value is set to 0.4 and the high gray scale gain value is set to 0.6 to separate the low gray scale and the high gray scale. It is converted to an image that emphasizes the balance in a balanced way but emphasizes the high gradation slightly more. If the average image brightness of the input image is detected as the average image brightness of the third level, which is a high level, the low gradation gain is set to 0.5 and the high gradation gain is set to 0.5. It is possible to convert the image to an image emphasizing the low and high grays in a balanced way by setting to 0.5.

The histogram stretch application unit 153 may stretch and output a histogram of W data using the low grayscale and high grayscale gain values input from the stretch gain adjustment unit 152 . That is, the distribution state of all W data for each gray level may be changed using the low gray level and high gray level gain values.

<W data conversion unit according to the second embodiment>

4 is a flowchart illustrating an operation process of the W data converter according to the second embodiment. 5 is a detailed block diagram of the W data conversion unit according to the second embodiment and a diagram illustrating an operation relationship thereof.

Referring to FIG. 4 , the RGB to RGBW converter 130 generates an RGBW data signal based on the input RGB data, and the W data converter 150 according to the second embodiment is based on the input RGBW data. The histogram stretch of the W data may be changed based on the adjusted stretch gain by calculating the average image brightness (APL) and adjusting the stretch gain of the W data according to the calculation result. In addition, as a control signal input from the outside, the maximum luminance pixel is detected based on the RGBW data based on the maximum luminance limit signal, and it is compared with a preset maximum luminance reference value. You can lower the luminance. 5, the W data conversion unit 150 according to the second embodiment includes an average image brightness detection unit 151, a stretch gain control unit 152, and a histogram stretch application unit ( 153) and a maximum luminance pixel detection unit 154 .

The average image brightness detection unit 151 detects the average luminance, ie, the average image brightness (APL) of the image, in units of one frame based on the RGB data signal, and digitizes the detected average image brightness into an arithmetic value of 0 to 100 for brightness can be compared with the baseline. The brightness reference values (a, b) may include a lower brightness reference value (a) and an upper brightness reference value (b). When the average image brightness value is greater than 0 and less than the lower brightness reference value (a), the first level of It is determined as the average image brightness, and when the average image brightness value is greater than or equal to the lower brightness reference value (a) but less than the upper brightness reference value (b), it is determined as the average image brightness of the second level, and the average image brightness value is higher than the upper brightness reference value (b) If it is greater than or equal to the brightness reference value (b) but less than 100, it may be determined as the average image brightness of the third level. Meanwhile, the brightness reference value may further include additional reference values in addition to the lower and upper brightness reference values a and b, and accordingly, the classification of the average image brightness of the detected image may be further subdivided.

The stretch gain control unit 152 may histogram the W data signal as a first step. In a second step, a low grayscale gain value and a high grayscale gain value for emphasizing a specific grayscale by stretching the histogram may be set based on the average image brightness. The low gradation and the high gradation are not absolute values, and based on a specific standard, for example, 150 gradations, 0 to 149 gradations may be set as low gradations, and 150 to 255 gradations may be set as high gradations.

Also, the maximum luminance pixel detector 154 may output the maximum luminance pixel to the histogram stretch application unit 153 when the maximum luminance pixel is equal to or greater than a preset maximum luminance reference value based on the input RGBW data signal. The maximum luminance pixel detector 154 may prevent glare of an image and prevent a sudden increase in power consumption. At this time, the maximum luminance pixel detector 154 operates when the maximum luminance limit signal, which is a control signal provided from the timing controller 500, which will be described later, is input, and the maximum luminance pixel is set at a preset maximum luminance based on the input RGBW data signal. It can be determined whether it is above the standard value. In addition, whether the timing controller 500 outputs the maximum luminance limit signal may vary depending on the user's mode setting or the type of displayed image. Therefore, when it is desired to display a realistic image by expressing very bright brightness such as sunlight, the maximum luminance limit signal becomes a low logic level to deactivate the maximum luminance pixel detection unit 154, and to display very bright brightness such as sunlight. When it is desired to display a comfortable image by limiting , the maximum luminance limit signal becomes a high logic level to activate the maximum luminance pixel detection unit 154 .

The histogram stretch application unit 153 stretches the histogram of W data using the low gray level and high gray level gain values input from the stretch gain control unit 152, and the maximum luminance input from the maximum luminance pixel detection unit 154 is RGBW data may be output by lowering the luminance of the luminance pixel to the maximum luminance reference value.

Meanwhile, the maximum luminance pixel detection unit 154 may be provided in the data conversion apparatus 100 separately from the W data conversion unit 150 .

6 is a diagram illustrating the effect of improving image quality and reducing power consumption when image data passed through a data converter according to an embodiment of the present invention is displayed as an image.

As shown in FIG. 6 , when the luminance expression range is increased, the increase in the contrast ratio and the expression of the high luminance region, which are advantages of HDR, are maintained, while preventing low grayscale noise and glare of the high luminance image, and further reducing power consumption. It can be seen that it has an effect. In addition, the image enhancement technique can be optimized by varying the extension value of the histogram in consideration of the average image brightness of the white data signal, the maximum luminance of the input image, and the image gradation.

<Display device including data conversion unit>

7 is a diagram illustrating a display device including a data converter according to an embodiment of the present invention, and FIG. 8 is a diagram illustrating an arrangement relationship of sub-pixels.

Referring to FIG. 7 , a display device 600 according to an embodiment of the present invention may include a display panel 200 , a data driver 300 , a gate driver 400 , and a timing controller 500 . The timing controller 500 may include the data conversion device 100 , and the data conversion device 100 may be provided separately from the timing controller 500 .

The data conversion device 100 may be a part of the timing controller 500 , and may be a separate device from the timing controller 500 . In addition, although the data conversion device 100 has been described as being included in the display device 600, it is not limited thereto and may include a wireless communication device (eg, a wireless mobile handset), or a digital camera, a video camera, and a digital multimedia. It may be part of a player, personal digital assistant (PDA), video game console, other video device, or dedicated viewing station (such as a television).

The display device 600 may also include, for example, image data captured by a digital video or still photo camera, image data obtained from a video or still port archive, image data generated by a software application, or image data obtained from broadcast and streaming media. Various types of image data including image data can be displayed. The display device 600 is a desktop computer or a laptop computer, a computer workstation, a personal digital assistant, a mobile device such as a mobile phone, a wireless communication device, a multimedia device, various devices such as a dedicated viewing station such as a camera and television It may be integrated with, coupled to, and associated with, the various devices. The display device 600 may include a liquid crystal display (LCD), a cathode ray tube (CRT) display, a plasma display, a projection display, an organic light emitting diode display, and the like.

A plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm are formed on the display panel 200 , and the plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm are formed. A sub-pixel Pix may be formed at the intersection of .

The gate driver 400 supplies a plurality of scan signals SP to the plurality of gate lines GL1 to GLn correspondingly in response to the gate control signal GCS from the timing controller 500 . The plurality of scan signals SP may sequentially enable the plurality of gate lines GL1 to GLn by one horizontal synchronization signal period. The gate driver 400 may include a plurality of gate integrated circuits.

The data driver 300 generates a data voltage whenever any one of the plurality of gate lines GL1 to GLn is enabled in response to the data control signals DCS from the timing controller 500 to generate the data voltage. Each of the plurality of data lines DL1 to DLm of the display panel 200 may be supplied.

The timing controller 500 uses various control signals O_CS supplied from an external system (eg, a graphic module of a computer system or an image demodulation module of a television reception system, not shown) to the gate driver A gate control signal GCS for controlling 300 and a data control signal DCS for controlling the data driver 300 may be generated.

A sub-pixel (Pixel) of the display panel 200 may include sub-pixels (pixels) corresponding to R, G, B, and W colors. In addition, the sub-pixels for each color may be arranged as shown in FIG. 6 . In detail, in the odd-numbered horizontal line n, sub-pixels for each color are consecutive in order of W sub-pixel 101 , R sub-pixel 102 , G sub-pixel 103 , and B sub-pixel 104 . In the even-th horizontal line (n+1), the sub-pixels for each color are consecutive in the order of the G sub-pixel 103 , the B sub-pixel 104 , the W sub-pixel 101 , and the R sub-pixel 102 . can be arranged to do so. That is, the sub-pixels for each color in the odd-numbered horizontal line (n) and the sub-pixels for each color in the even-th horizontal line (n+1) are not arranged in the same color in the vertical direction, but in a zigzag form. there is. For example, the W sub-pixel 101 may be disposed at a point where the m-th vertical line and the odd-numbered horizontal line (n) intersect and the m+2-th vertical line and the even-th horizontal line (n+1) intersect. there is. That is, in any vertical line, any one of W, R, G, and B of the odd-numbered horizontal line (n) is vertically moved by two spaces from the arbitrary vertical line in the even-th horizontal line (n+1). The same can be arranged on the line. (Move two spaces in units of sub-pixels) In this way, the same sub-pixel is moved two spaces in sub-pixel units on the odd-numbered horizontal line (n) and the even-th horizontal line (n+1), and the zigzag structure is repeated in the vertical direction. Compared with a structure in which the same sub-pixel appears, a phenomenon in which a line is visually recognized can be prevented.

Meanwhile, when the display panel 200 is a liquid crystal display panel, the sub-pixel Pix includes a thin film transistor TFT connected to the gate line GL and data line DL and a pixel connected to the thin film transistor TFT. including electrodes. In addition, the thin film transistor TFT supplies data from the data lines DL1 to DLm to the liquid crystal cell in response to the scan signal SP from the gate lines GL1 to GLn. To this end, the gate electrode of the thin film transistor TFT is connected to the gate lines GL1 to GLn, the source electrode is connected to the data lines DL1 to DLm, and the drain electrode is connected to the pixel electrode of the liquid crystal cell. In addition, a storage capacitor for maintaining the voltage of the liquid crystal cell is formed on the lower glass substrate of the display panel 200 . In addition, on the upper glass substrate of the display panel 200, a color filter corresponding to each pixel area in which the thin film transistor TFT is formed, the gate lines GL1 to GLn, and the data lines DL1 to DLm) and a thin film transistor (TFT) and the like may additionally include a black matrix. In addition, the liquid crystal cells included in each of the R, G, B, and W sub-pixels may be liquid crystal cells for R, G, B and W colors.

In addition, when the display panel 200 is an organic light emitting diode display panel, each of R, G, B, and W sub-pixels may include an organic light emitting diode, and light emitted from each sub-pixel when the organic light emitting diode emits light. can display the image. The organic light emitting diode may be formed to have a structure of a hole transport layer/organic emission layer/electron transport layer or a structure of a hole injection layer/hole transport layer/organic emission layer/electron transport layer/electron injection layer. Furthermore, a functional layer for improving luminous efficiency and/or lifespan of the organic light emitting layer may be additionally formed in the organic light emitting cell.

In the detailed description of the present invention described above, although it has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary knowledge in the technical field of the present invention described in the claims to be described later It will be understood that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

100 data converter
101 W sub-pixel
102 R sub-pixel
103 G sub-pixel
104 B sub-pixel
110 inverse gamma
130 RGB to RGBW converter
150 W data converter
151 Average image brightness detector
152 Stretch Gain Control
153 Histogram stretch application part
154 Maximum luminance pixel detection unit
170 color temperature compensation unit
190 rendering unit
200 display panel
300 data driver
400 gate driver
500 Timing Controller
600 display

Claims (11)

Based on the red (Red, hereinafter R), green (hereinafter G), blue (Blue, hereinafter B) and white (White, hereinafter W) data signals of the image, the average luminance brightness of the image is detected and detected It includes a W data conversion unit that stretches the histogram of the W data according to the average luminance brightness,
The W data conversion unit,
According to the detected average luminance brightness, a histogram stretch gain for a low gradation having a first preset gradation range and a histogram stretch gain for a high gradation having a second preset gradation range are respectively set,
The data conversion apparatus of claim 1, wherein the distribution state of the W data for each gray level is changed by applying the respective gain values of the low gray level and the high gray level. According to claim 1,
The W data conversion unit,
and an average luminance and luminance detector configured to calculate the average luminance of the image in units of one frame and detect the average luminance and luminance. 3. The method of claim 2,
The W data conversion unit,
The data conversion apparatus further comprising a; a stretch gain adjusting unit for histogram the W data, and to adjust the histogram stretch gain of the W data based on the detected average luminance brightness. 3. The method of claim 2,
a maximum luminance pixel detection unit that compares the maximum luminance pixel detected based on the R, G, B, and W data with a maximum luminance reference value to the W data conversion unit;
The W data conversion unit,
and lowering the luminance of the maximum luminance pixel equal to or greater than the maximum luminance reference value to the maximum luminance reference value according to the comparison result. delete The data conversion device according to claim 1;
a display panel including sub-pixels corresponding to each of the R, G, B, and W data; and
and a timing controller aligning the R, G, B, and W data output from the data conversion device to match the sub-pixels. 7. The method of claim 6,
The W data conversion unit,
and an average luminance and brightness detector configured to detect the average luminance and brightness by calculating the average luminance of the image in units of one frame. 8. The method of claim 7,
The W data conversion unit,
and a stretch gain control unit to histogram the W data and adjust the histogram stretch gain of the W data based on the detected average luminance brightness. 9. The method of claim 8,
a maximum luminance pixel detection unit that compares the maximum luminance pixel detected based on the R, G, B, and W data with a maximum luminance reference value to the W data conversion unit;
The W data conversion unit,
and lowering the luminance of the maximum luminance pixel equal to or greater than the maximum luminance reference value to the maximum luminance reference value according to the comparison result. delete 10. The method of claim 9,
The maximum luminance pixel detector is driven by the maximum luminance limit signal provided from the timing controller.

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