KR101862608B1 - Display device - Google Patents

Abstract

The present invention relates to a display device capable of reducing power consumption and minimizing color shift during 3-color-4-color conversion, and a video modulator according to an embodiment of the present invention converts 3-color video data into 3-color luminance data Converts the three-color luminance data into a tristimulus value using a conversion matrix, and calculates a color coordinate corresponding to the tristimulus value in the chromaticity coordinate system. The image modulator calculates the color coordinates of the first to third color areas divided by each of the three color vertex coordinates of the color area represented by the display device in the chromaticity coordinate system and each boundary line that connects the white point coordinates in the color area with a straight line And determines the corresponding color area to be located. The image modulating unit generates two-color modulated luminance data and white luminance data corresponding to the corresponding color area by inverse transforming the tristimulus value using any one of the first to third inverse transformation matrices according to the corresponding color area, And outputting the black image data as data for the remaining one color, outputting the four-color image data by outputting the black image data by outputting the two-color modulated luminance data and the white luminance data by inverse gamma conversion.

Description

Display device {DISPLAY DEVICE}

The present invention relates to a display device capable of reducing the power consumption of a display device having white pixels.

In order to increase the brightness of the display device, four color pixels including red, green, and blue pixels and white pixels are used as one unit pixel. In this case, there is an advantage that the luminance is relatively increased, but the consumption current is increased because the four pixels must be driven.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above, and it is an object of the present invention to provide an image display apparatus capable of reducing power consumption while controlling light emitting diodes provided in any one of four pixels according to a color coordinate of image data, And it is an object of the present invention to provide a display device which can be minimized.

The display device according to one embodiment includes an image modulator that converts three-color image data into four-color image data and outputs the converted image. The image modulator converts the three-color image data into three-color luminance data through gamma conversion, converts the three-color luminance data to a tristimulus value using a conversion matrix, and calculates a color coordinate corresponding to the tristimulus value in the chromaticity coordinate system. The image modulator calculates the color coordinates of the first to third color areas divided by each of the three color vertex coordinates of the color area represented by the display device in the chromaticity coordinate system and each boundary line that connects the white point coordinates in the color area with a straight line And determines the corresponding color area to be located. The image modulating unit generates two-color modulated luminance data and white luminance data corresponding to the corresponding color area by inverse transforming the tristimulus value using any one of the first to third inverse transformation matrices according to the corresponding color area, And outputting the black image data as data for the remaining one color, outputting the four-color image data by outputting the black image data by outputting the two-color modulated luminance data and the white luminance data by inverse gamma conversion.

The transform matrix is determined by using the coordinate components of each of the three color vertexes as shown in Equation (1), and each of the first to third inverse transform matrices is an inverse transformation matrix for the transform matrix, 2 to 4, which will be described later, using the vertex coordinate component and the white point coordinate component instead of the remaining one color vertex coordinate component that does not belong to the corresponding color region.

The first color area is a first triangular area having white point coordinates and green and blue vertex coordinates of three color vertex coordinates. The second color area is a white triangle area having white point coordinates, blue vertex coordinates, And a second triangular area having coordinates. The third color region is a third triangular region having white point coordinates and red and green vertex coordinates.

The image modulator determines that the color coordinate located at the boundary line between the first and second color regions belongs to one of the first and second color regions and the color coordinates located at the boundary line between the second and third color regions are the second and The third color region, and the third color region, and the color coordinates located on the third and first boundary lines belong to any one of the third and first color regions.

The display device is a light emitting diode display device, and the three-color vertex coordinates are determined according to a color area in which the light emitting diode display device can express.

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The display device according to the present invention has the following effects.

In the present invention, in converting three-color image data into four-color image data, one of the image data included in the three-color image data is processed in black according to the color coordinates of the three-color image data, By not emitting light, the power consumption can be reduced. That is, by driving only three of the four pixels included in each unit pixel, power consumption can be reduced. At this time, the remaining two pieces of image data (two pieces of image data not processed in black) contained in the three-color image data are modulated based on the white coordinate components, and these red image data, green image data, and blue image data By resetting the luminance, it is possible to minimize color shift caused by the above-described black processing.

1 is a view showing a display device according to a first embodiment of the present invention;
2 is a view showing a chromaticity coordinate system according to the present invention;
3 is a detailed configuration diagram of the video modulator of FIG.
4 is a view for explaining the outputs from the XYZ-WRGB inverse transform unit and the inverse gamma transform unit according to the selected color gamut;
5 is a diagram showing the operation states of the four color pixels according to the position of the color coordinate of the three-color image data (Data_3c)
6 is a diagram for explaining a degree of reduction in power consumption when a specific image is displayed using a display device including a video modulator according to the present invention
7 is a view showing a display device according to a second embodiment of the present invention

1 is a view illustrating a display device according to a first embodiment of the present invention.

1, the display device according to the first embodiment of the present invention includes a display panel DSP, a system SYS, a gate driver GD, a data driver DD, a timing controller TC, And an image modulator (IMP).

The display panel DSP includes a plurality of pixels PXL, a plurality of gate lines GL1 to GLi for transmitting a plurality of gate signals for sequentially driving the pixels PXL on a horizontal line basis, And a plurality of data lines DL1 to DLj for transmitting the analog four-color image data Data_4c to the pixels PXL.

These pixels PXL are arranged in a matrix form on the display panel DSP. These pixels PXL are divided into a white pixel W for displaying white, a red pixel R for displaying red, a green pixel G for displaying green and a blue pixel B for displaying blue. The white pixel W, the red pixel R, the green pixel G and the blue pixel B adjacent to each other constitute a unit pixel UPX for displaying one unit image. The four pixels W, R, G and B in the unit pixel UPX are arranged in a quad shape. Meanwhile, any one of the red pixel R, the green pixel G and the blue pixel B included in the unit pixel UPX in the present invention is processed in black. A white pixel W, a red pixel R, a green pixel B, and a blue pixel B each include a light emitting diode. In the display device of the present invention, a light emitting diode display may be used. At this time, the red pixel R includes a red color filter, the green pixel G includes a green color filter, and the blue pixel B further includes a blue color filter, while the white pixel W includes a white Of color filters or no color filters.

The system SYS outputs a vertical synchronizing signal, a horizontal synchronizing signal, a clock signal, and three-color image data through an interface circuit through a low voltage differential signaling (LVDS) transmitter of the graphic controller. The vertical / horizontal synchronizing signal and the clock signal output from the system SYS are supplied to the timing controller TC. The three-color image data Data_3c sequentially output from the system SYS is supplied to the timing controller TC through the image modulator IMB.

The timing controller TC generates a data control signal DSC and a gate control signal GSC using a horizontal synchronizing signal, a vertical synchronizing signal and a clock signal input to the timing controller TC and supplies them to the data driver DD and the gate driver GD ). The timing controller TC receives the four-color image data Data_4c from the image modulator IMB and re-supplies the four-color image data Data_4c to the data driver DD.

The data driver DD samples the four-color video data Data_4c in accordance with the data control signal from the timing controller TC and then outputs one horizontal line per horizontal period (1H, 2H, ...) And supplies the latched image data to the data lines DL1 to DLj. That is, the data driver DD converts the four-color image data Data_4c from the timing controller TC into analog image data using the gamma voltage input from the power supply unit and supplies the analog image data to the data lines DL1 to DLj do.

The gate driver CD outputs gate signals in accordance with a control signal from the timing controller TC. At this time, the gate driver GD sequentially outputs i gate signals from the first gate signal to the i < th > gate signal every frame, and sequentially supplies the i gate signals to the i gate lines GL1 through GLi.

The image modulator IMB analyzes the tri-color image data Data_3c from the system SYS and calculates the color coordinates of the tri-color image data Data_3c. Then, one of the image data included in the three-color image data (Data_3c) is replaced with the black image data based on the determined color region, the color region in which the calculated color coordinates are located is determined from the chromaticity coordinate system, Color image data (Data_4c) by adding white image data to the three-color image data (Data_3c). Here, the chromaticity coordinate system is divided into a plurality of color regions based on a white coordinate at which a white color is located.

Here, this chromaticity coordinate system will be explained in more detail.

2 is a view showing a chromaticity coordinate system according to the present invention.

The chromaticity coordinate system according to the present invention is a CIE (Commission Internationale de l'Eclairage) chromaticity coordinate system. As shown in FIG. 2, according to the chromaticity coordinate system, a chromaticity coordinate system (green coordinate (G_P) An inner region including a border of a large triangle having a coordinate B_P and a red coordinate R_P as vertexes is divided into three color regions CD1, CD2 and CD3. That is, this large triangle has vertexes as red coordinates (R_P) corresponding to red, green coordinates (G_P) corresponding to green, and blue coordinates (B_P) corresponding to blue. On the other hand, a white coordinate (W_P) corresponding to white is located at the center of this large triangle.

The first color gamut CD1 includes an inner area of a triangle having white coordinates W_P, green coordinates G_P, and blue coordinates B_P as vertexes. The first color gamut CD1 includes color coordinates corresponding to green-based colors and blue-based colors.

The second color gamut CD2 includes an inner area of a triangle having white coordinates W_P, blue coordinates B_P, and red coordinates R_P as vertexes. The second color region CD2 includes color coordinates corresponding to red-based colors and blue-based colors.

The third area includes an inner area of a triangle having white coordinates (W_P), red coordinates (R_P), and green coordinates (G_P) as vertexes. The third color gamut CD3 includes color coordinates corresponding to red-based colors and green-based colors.

Among the color coordinates located on the straight line (a straight line connecting the white coordinate W_P and the blue coordinate B_P) corresponding to the boundary between the first color region CD1 and the second color region CD2, white coordinates W_P ) May belong to any one of the first color region CD1 and the second color region CD2. For example, among the color coordinates located on the straight line connecting the green coordinate G_P and the white coordinate W_P, all the remaining color coordinates except for the white coordinate W_P can be set to belong to the first color area CD1.

Among the color coordinates located on a straight line (a straight line connecting the white coordinate W_P and the red coordinate R_P) corresponding to the boundary between the second color region CD2 and the third color region CD3, white coordinates W_P ) May belong to any one of the second color region CD2 and the third color region CD3. For example, among the color coordinates located on the straight line connecting the white coordinate W_P and the red coordinate R_P, all the remaining color coordinates except for the white coordinate W_P can be set to belong to the second color area CD2.

 The white coordinate W_P among the color coordinates located on a straight line (a straight line connecting the white coordinate W_P and the green coordinate G_P) corresponding to the boundary between the third color region CD3 and the first color region CD1, May belong to any one of the third color region CD3 and the first color region CD1. For example, among the color coordinates located on the straight line connecting the white coordinate W_P and the green coordinate G_P, all the remaining color coordinates except for the white coordinate W_P can be set to belong to the third color area CD3.

Among the color coordinates located on the straight line connecting the green coordinate G_P and the blue coordinate B_P, the remaining color coordinates except for the green coordinate G_P and the blue coordinate B_P belong to the first color area CD1, Of the color coordinates located on the straight line connecting the blue coordinate B_P and the red coordinate R_P, the remaining color coordinates except for the blue coordinate B_P and the red coordinate R_P belong to the second color area CD2, Among the color coordinates located on the straight line connecting the red coordinate R_P and the green coordinate G_P, all the remaining color coordinates except for the red coordinate R_P and the green coordinate G_P belong to the third color area CD3.

On the other hand, the white coordinate W_P does not belong to any one of the first to third color areas CD1 to CD3.

The image modulator (IMB) according to the present invention analyzes the 3-color image data (Data_3c), calculates the color coordinates of the 3-color image data (Data_3c), determines the color area in which the calculated color coordinates are located from the chromaticity coordinate system Color image data Data_3c is replaced with black image data and white image data is added to the three-color image data Data_3c based on the determined color region to generate four-color image data Data_4c, .

To this end, the image modulator (IMB) may have the following configuration.

FIG. 3 is a detailed configuration diagram of the image modulator (IMB) of FIG. 1, and FIG. 4 is a block diagram illustrating the XYZ-WRGB inverse transform unit 302 and the inverse gamma transform unit 305, FIG.

3, the image modulator (IMB) according to the present invention includes a gamma converter 301, an RGB-XYZ converter 302, a gamut determiner 303, an XYZ-WRGB inverse transformer 304 and an inverse gamma conversion unit 305. [

The gamma conversion unit 301 gamma-converts the three-color image data Data_3c (Rd, Gd, Bd) provided from the system SYS to generate the red luminance data Yr, the green luminance data Yg, and the blue luminance data Yb, . The tri-color image data Data_3c is composed of red image data Rd, green image data Gd, and blue image data Bd. The red luminance data Yr represents the luminance component of the red image data Rd and the green luminance data Yg represents the luminance component of the blue image data Bd and the blue luminance data Yb represents the blue component of the blue image data Bd. (Bd).

The RGB-XYZ conversion unit 302 converts the red luminance data Yr, the green luminance data Yg and the blue luminance data Yb provided from the gamma conversion unit 301 into a standard color stimulus value X, Y, Z). That is, in order to know the color coordinates of the three-color image data Data_3c in the chromaticity coordinate system described above, the red luminance data Yr, the green luminance data Yg, and the blue luminance data Yb, XYZ conversion unit 302 converts these luminance data into the RGB-XYZ conversion matrix defined by Equation (1) below to convert the standard color stimulus values X, Y, Z).

Yr and yb are constants preset by the color characteristics of the light emitting diodes provided in the red pixel R, the green pixel G and the blue pixel B, respectively, The meaning of each constant is as follows.

In other words, xr and yr represent red coordinate (R_P) components of the red coordinate (R_P) in the above-described chromaticity coordinate system. Specifically, xr is the x coordinate component of the red coordinate (R_P), yr is the red coordinate ).

Specifically, xg is the x-coordinate component of the green coordinate (G_P), yg is the green coordinate (G_P) of the green coordinate (G_P), and xg and yg are the green coordinate Coordinate component of the y-coordinate.

Specifically, xb is an x coordinate component of a blue coordinate (B_P), yb is a blue coordinate (B_P) of a blue coordinate (B_P), and xb and yb are blue coordinate (B_P) Coordinate component of the y-coordinate.

The values of xr, xg, xb, yr, yg, and yb described above may be changed depending on the characteristics of the LED display device.

The color gamut determination unit 303 analyzes the standard color stimulus value (X, Y, Z) provided from the RGB-XYZ conversion unit 302 and calculates the color coordinates of the three-color image data Data_3c in the chromaticity coordinate system described above. Then, a color region in which the calculated color coordinates are located is determined. The color coordinates of the tri-color image data Data_3c belong to one of the above-described first to third color areas CD1 to CD3.

The XYZ-WRGB inversely transforming unit 304 transforms the red, green, and blue coordinates (R_P) components, the green coordinate (G_P) components, and the blue coordinate (W_P) components are replaced with white coordinate (W_P) components to generate an XYZ-WRGB inverse transformation matrix. By using the XYZ-WRGB inverse transformation matrix, the standard color stimulus value (X, Y, Z) provided from the RGB-XYZ conversion unit 302 is inversely transformed to obtain the remaining two color coordinate components And generates white luminance data Yw corresponding to the white coordinate (W_P) components and generates black image data (Kd).

If the color coordinate of the three-color image data Data_3c is located in the first color gamut CD1, the XYZ-WRGB inverse transformer 304 transforms the XYZ-RGB inverse transform matrix (W_P) components by replacing the red coordinate (R_P) components with the white coordinate (W_P) components to generate the XYZ-WRGB inverse transformation matrix defined by Equation (2) below.

In Equation (2), xw and yw are constants previously set by the color characteristics of the light emitting diode included in the white pixel W, and the meaning of each constant is as follows.

That is, xw and yw are the white coordinate (W_P) components of the white coordinate W_P in the chromaticity coordinate system described above. Specifically, xw is the x coordinate component of the white coordinate W_P and yw is the white coordinate W_P ).

The values of xw and yw described above may be changed depending on the characteristics of the light emitting diode display device.

When the color coordinate of the tri-color image data Data_3c is located in the first color gamut CD1, the XYZ-WRGB inverse transforming unit 304 generates two modulation luminance data, white luminance data Yw ) And black image data (Kd). Specifically, when the chromaticity coordinates of the tri-color image data Data_3c are located in the first color gamut CD1, the XYZ-WRGB inverse transform unit 304 adds the standard chromatic aberration value to the XYZ-WRGB inverse transformation matrix defined by Equation (2) White luminance data Yw, modulated green luminance data Yg` and modulated blue luminance data Yb` are generated by substituting (X, Y, Z). In addition, in place of the modulated red luminance data Yr ', which has not been generated in this case, the black image data Kd previously set is outputted. 4 (a), the XYZ-WRGB inverse transform unit 304 transforms the white luminance data Yw into the first color gamut Y1, , The black image data (Kd), the modulated green luminance data (Yg '), and the modulated blue luminance data (Yb').

On the other hand, when it is determined by the color gamut determination unit 303 that the color coordinate of the three-color image data Data_3c is located in the second color gamut CD2, the XYZ-WRGB inverse transform unit 304 transforms the XYZ-RGB inverse transform matrix (W_P) components by replacing the green coordinate (G_P) components with the white coordinate (W_P) components to generate an XYZ-WRGB inverse transformation matrix defined by Equation (3) below.

Therefore, when the chromaticity coordinate of the tri-color image data Data_3c is located in the second color region CD2, the XYZ-WRGB inverse transforming unit 304 generates two modulated luminance data, white luminance data (Yw) and black image data (Kd). Specifically, when the chromaticity coordinates of the tri-color image data Data_3c are located in the second color region CD2, the XYZ-WRGB inverse transforming unit 304 adds the standard chromatic aberration value to the XYZ-WRGB inverse transformation matrix defined by Equation (3) (Yw), modulated red luminance data (Yr) and modulated blue luminance data (Yb ') by substituting (X, Y, Z) In addition, instead of the modulated green luminance data Yg 'not generated in this case, the black image data Kd previously set is output. As a result, when the color coordinate of the tri-color video data Data_3c is located in the second color gamut CD2, the XYZ-WRGB inverse transform unit 304 transforms the white luminance data Yw, , The modulated red luminance data Yr ', the black image data Kd, and the modulated blue luminance data Yb'.

On the other hand, when it is determined by the color gamut determination unit 303 that the color coordinate of the tri-color video data Data_3c is located in the third color gamut CD3, the XYZ-RGB inverse transform unit converts the chromaticity coordinate of the XYZ- ) Components with white coordinate (W_P) components to generate the XYZ-WRGB inverse transformation matrix defined by Equation (4) below.

Therefore, when the chromaticity coordinate of the tri-color image data Data_3c is located in the third color gamut CD3, the XYZ-WRGB inverse transform unit 304 generates two modulated luminance data, white luminance data (Yw) and black image data (Kd). Specifically, when the chromaticity coordinates of the tri-color image data Data_3c are located in the third color region CD3, the XYZ-WRGB inverse transform unit 304 adds the standard chromatic aberration value to the XYZ-WRGB inverse transformation matrix defined by Equation (5) (Yw), modulated red luminance data (Yr) and modulated green luminance data (Yg ') by substituting (X, Y, Z) In addition, in place of the modulated blue luminance data Yb 'not generated in this case, the black image data Kd previously set is output. 4C, the XYZ-WRGB inversely transforming unit 304 converts the white luminance data Yw into the white luminance data Yb, and outputs the white luminance data Yw to the XYZ- , Modulated red luminance data Yr ', modulated green luminance data Yg', and black image data Kd.

The inverse gamma conversion unit 305 performs inverse gamma conversion on the two modulated luminance data and one white luminance data Yw provided from the XYZ-WRGB inverse transform unit 304 to generate two modulated image data and one white image data (Wd) and outputs the black image data (Kd) provided from the XYZ-WRGB inverse transform unit (304) by bypassing the black image data (Kd).

Specifically, as shown in FIG. 4A, the white luminance data Yw, the black image data Kd, the modulated green luminance data Yg ', and the modulated blue luminance data Yw are supplied from the XYZ-WRGB inverse transformer 304, Gamma conversion unit 305 performs inverse gamma conversion on the white luminance data Yw, the modulated green luminance data Yg ', and the modulated blue luminance data Yb' to generate white image data Yb ' (Wd), the modulated green image data Gd ', and the modulated blue image data Bd'. On the other hand, since the black image data Kd is image data that is not gamma-converted by itself, the inverse gamma converter 305 bypasses the black image data Kd without further inverse gamma conversion and outputs the black image data Kd as it is. As a result, when the color coordinate of the tri-color video data Data_3c is located in the first color gamut CD1, the inverse gamma converting unit 305 outputs the white video data Wd, the black video data Kd, The four-color image data Data_4c composed of the data Gd 'and the modulated blue image data Bd' is output.

On the other hand, as shown in FIG. 4 (b), the white luminance data Yw, the modulated red luminance data Yr ', the black image data Kd, and the modulated blue luminance data The inverse gamma conversion unit 305 inversely gamma converts the white luminance data Yw, the modulated red luminance data Yr and the modulated blue luminance data Yb ' Wd, modulated red image data Rd ', and modulated blue image data Bd'. On the other hand, since the black image data Kd is image data that is not gamma-converted by itself, the inverse gamma converter 305 bypasses the black image data Kd without further inverse gamma conversion and outputs the black image data Kd as it is. As a result, when the color coordinate of the tri-color video data Data_3c is located in the second color gamut CD2, the inverse gamma converting unit 305 outputs the white video data Wd, the modulated red video data Rd ' Four-color image data (Data_4c) composed of the image data (Kd) and the modulated blue image data (Bd ') is outputted.

On the other hand, as shown in FIG. 4C, the white luminance data Yw, the modulated red luminance data Yr ', the modulated green luminance data Yg', and the black image data Yg 'from the XYZ- Gamma conversion unit 305 performs inverse gamma conversion of the white luminance data Yw, the modulated red luminance data Yr 'and the modulated green luminance data Yg', respectively, to generate white image data Wd, modulated red image data Rd ', and modulated green image data Gd'. On the other hand, since the black image data Kd is image data that is not gamma-converted by itself, the inverse gamma converter 305 bypasses the black image data Kd without further inverse gamma conversion and outputs the black image data Kd as it is. As a result, when the color coordinate of the tri-color video data Data_3c is located in the third color gamut CD3, the inverse gamma converting unit 305 outputs the white video data Wd, the modulated red video data Rd ' The four-color image data (Data_4c) composed of the green image data (Gd ') and the black image data (Kd) is output.

The 4-color image data (Data_4c) output from the inverse gamma converter 305 is rearranged through the timing controller (TC) roll, and is output to the data driver (DD) in accordance with a preset timing under the control of the timing controller . Then, the data driver DD converts the four-color video data (Data_4c) to analog and supplies them to the pixels through the data lines. The operation of the pixels according to the four-color image data (Data_4c) will now be described.

5 is a diagram showing the operation states of the four color pixels according to the positions of the color coordinates of the three-color image data Data_3c.

5, when the color coordinate CP of the tri-color image data Data_3c is located in the first color region CD1, only the red pixel R displays black and the remaining white pixels W, The green pixel G and the blue pixel B display their own colors. That is, the light emitting diodes included in the red pixel R maintain the off state by the black image data Kd, while the light emitting diodes included in the white pixel W maintain the luminance corresponding to the gray level of the white image data Wd The light emitting diode included in the green pixel G emits light with a luminance corresponding to the gray level of the modulated green image data Gd` and the light emitting diode included in the blue pixel B emits modulated blue image data Bd &Quot;). ≪ / RTI >

5, when the color coordinate CP of the tri-color image data Data_3c is located in the second color region CD2, only the green pixel G displays black and the remaining white pixels W ), The red pixel R and the blue pixel B display their own colors. That is, the light emitting diodes included in the green pixel G maintain the off state by the black image data Kd, while the light emitting diodes included in the white pixel W maintain the brightness according to the gray level of the white image data Wd The light emitting diode included in the red pixel R emits light with the luminance corresponding to the gray level of the modulated red image data Rd` and the light emitting diode included in the blue pixel B emits the modulated blue image data Bd &Quot;). ≪ / RTI >

5, when the color coordinate CP of the tri-color image data Data_3c is located in the third color region CD3, only the blue pixel B displays black and the remaining white pixels W ), The red pixel R and the green pixel G display their own colors. That is, the light emitting diodes included in the blue pixel B maintain the off state by the black image data Kd, while the light emitting diodes included in the white pixel W maintain the brightness according to the gray level of the white image data Wd The light emitting diode included in the red pixel R emits light with a luminance corresponding to the gradation of the modulated red image data Rd` and the light emitting diode included in the green pixel G emits the modulated green image data Gd &Quot;). ≪ / RTI >

As described above, according to the present invention, in converting the 3-color image data (Data_3c) into the 4-color image data (Data_4c), the 3-color image data (Data_3c) It is possible to reduce the power consumption by processing any one of the image data into black so that the light emitting diode of one pixel does not emit light. That is, by driving only three of the four pixels included in each unit pixel, power consumption can be reduced. At this time, the remaining two pieces of image data (two pieces of image data not processed in black) contained in the three-color image data Data_3c are modulated based on the white coordinate (W_P) , Green image data (Gd), and blue image data (Bd), it is possible to minimize the color shift caused by the black process.

As described above, the white coordinate W_P does not belong to any one of the first to third color areas CD1 to CD3, and if the color coordinates CP of the three-color image data Data_3c are the same as the color coordinates The XYZ-WRGB inversely transforming unit 304 generates one white luminance data Yw and three black image data Kd when corresponding to the white coordinate W_P instead of the three color regions. That is, the XYZ-WRGB inverse transforming unit 304 transforms the white luminance data Yw and the preset black color data (Yw) independently of the standard color stimulus value (X, Y, Z) provided from the RGB- Kd) are generated and output. This white luminance data Yw is white luminance data Yw corresponding to the white coordinate W_P and is white luminance data Yw which is not converted by the XYZ-WRGB inverse transformation matrix. When the one white luminance data Yw and three black image data Kd are supplied to the inverse gamma conversion unit 305, the inverse gamma conversion unit 305 converts the white luminance data Yw into inverse gamma conversion Converts it into white image data Wd, and bypasses and outputs three black image data Kd. The white luminance data Yw output from the inverse gamma conversion unit 305 is output through the timing controller TC and the data driver DD and supplied to the white pixel W. [ The three black image data Kd output from the inverse gamma conversion unit 305 are output through the timing controller TC and the data driver DD and output to the red pixel R, And is supplied to the blue pixel B. Accordingly, when the color coordinate CP of the tri-color image data Data_3c corresponds to the white coordinate W_P, the light emitting diodes included in the red pixel R, the green pixel G, and the blue pixel B, The light emitting diode included in the white pixel W emits light with the luminance corresponding to the gray level of the white image data Wd while keeping the off state by the data Kd.

FIG. 6 is a diagram for explaining a degree of reduction in power consumption when displaying a specific image using a display device including a video modulator (IMB) according to the present invention.

6A shows the input image data (tri-color image data Data_3c) including grapes and wine, the coordinates (color coordinates in the chromaticity coordinate system) of the color mapping image with respect to the input image data, When the data is converted into the 4-color image data (Data_4c) through the image conversion process of the present invention, the degree of reduction of the current generated from the light emitting diodes inputted thereto is shown. That is, when the input image data as shown in FIG. 6A is modulated through the image modulating unit (IMB) of the present invention, the total consumption current of all the light emitting diodes in the display panel DSP is about 18.32% .

6 (b) shows input image data (tri-color image data Data_3c) including flowers and mountains, coordinates (color coordinates in a chromaticity coordinate system) of the color mapping image with respect to the input image data, When the data is converted into the 4-color image data (Data_4c) through the image conversion process of the present invention, the degree of reduction of the current generated from the light emitting diodes inputted thereto is shown. That is, if the input image data as shown in FIG. 6 (b) is modulated through the image modulating unit (IMB) of the present invention, the total consumption current of all light emitting diodes in the display panel DSP is about 6.39% .

7 is a view showing a display device according to a second embodiment of the present invention.

The configuration of Fig. 7 is the same as that of Figs. 1 to 5 described above. However, pixels provided in the display panel DSP are arranged in a stripe manner. That is, the image modulator (IMB) according to the present invention is also applied to a display panel (DSP) including a white pixel W, a red pixel R, a green pixel G and a blue pixel B arranged in a stripe manner .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of.

Rd: Red image data Gd: Green image data
Bd: blue image data Yr: red luminance data
Yg: green luminance data Yb: blue luminance data
X, Y, Z: Standard color stimulus value Yw: White image data
Yr`: Modulated red luminance data Yg`: Modulated green luminance data
Yb`: modulated blue luminance data Rd`: modulated red image data
Gd`: Modulated green image data Bd`: Modulated blue image data
Kd: black image data 301: gamma conversion unit
302: RGB-XYZ conversion unit 303: Color gamut determination unit
304: XYZ-WRGB Inverse transform unit 305: Inverse gamma conversion unit
IMB: video modulation section

Claims (15)

A display device including a video modulator converting three-color video data into four-color video data and outputting the converted video data,
The image modulator
Converts the three-color image data into three-color luminance data through gamma conversion,
Converting the three-color luminance data into a tristimulus value using a conversion matrix,
Calculating a color coordinate corresponding to the tristimulus value in a chromaticity coordinate system,
The color coordinate system of the first to third color areas divided by each of the three color vertex coordinates of the color area represented by the display device and each of the boundary lines connecting the white point coordinates in the color area with a straight line, The color gamut of the color gamut is determined,
Color modulation luminance data and white luminance data corresponding to the corresponding color region by inversely transforming the tristimulus value using any one of the first to third inverse transformation matrices according to the corresponding color region, The black image data is outputted as the data for the remaining one color that does not belong,
Color-modulation luminance data and white luminance data, and outputs the black-color image data, thereby outputting the four-color image data,
Wherein the transformation matrix is determined using the coordinate components of each of the three color vertices, and each of the first to third inverse transformation matrices is an inverse transformation matrix for the transformation matrix, And white point coordinate components instead of the other one-color vertex coordinate components not belonging to the corresponding color area. The method according to claim 1,
Wherein the first color region is a first triangular region having the white point coordinates and the green and blue vertex coordinates of the three color vertex coordinates,
Wherein the second color region is a second triangular region having the white point coordinates, the blue vertex coordinates, and the red vertex coordinates of the three color vertex coordinates,
The third color region is a third triangular region having the white point coordinates and the red and green vertex coordinates,
The image modulator
Wherein a color coordinate located at a boundary between the first and second color regions is determined to belong to one of the first and second color regions, And a third color region, and determines that the color coordinates located on the third and first boundary lines belong to any one of the third and first color regions. delete delete 3. The method of claim 2,
Wherein the transformation matrix is defined by: < EMI ID = 1.0 >
(1)

In Equation (1), x _r and y _r denote the red vertex coordinate components, x _g and y _g denote the green vertex coordinate components, x _b and y _b denote the blue vertex coordinate components, XYZ denotes the tristimulus value, Yr denotes red luminance data, Yg denotes green luminance data, and Yb denotes blue luminance data. 6. The method of claim 5,
The image modulator
When the corresponding color area is the first color area, replacing the red vertex coordinate components with the white point coordinate components in the inverse transformation matrix for the transformation matrix, and using the first inverse transformation matrix defined by the following equation (2) and;
(2)

If the corresponding color region is the second color region, replacing the green vertex coordinate components with the white point coordinate components in the inverse transformation matrix for the transformation matrix, and transforming the second inverse transformation matrix defined by Equation (3) Use;
(3)

If the corresponding color region is the third color region, replacing the blue vertex coordinate components with the white point coordinate components in an inverse transformation matrix for the transformation matrix, and replacing the third inverse transformation matrix defined by Equation (4) And,
(4)

In the above Equations 2 to 4, x _w and y _w mean the white point coordinate components, Y w means white luminance data, Y r 'denotes modulated red luminance data, Y g' denotes modulated green luminance data, And Yb 'denotes modulated blue luminance data. The method according to claim 6,
The image modulator
Modulated green luminance data Yg 'and modulated blue luminance data Yb' using the equation (2) when the corresponding color gamut is the first color gamut, generating the white luminance data Yw, the modulated green luminance data Yg ' Green, and blue image data and the black image data obtained by performing inverse gamma conversion on the image data,
The modulated red luminance data Yr 'and the modulated blue luminance data Yb' using the equation (3) when the corresponding color area is the second color area, and generates the white luminance data Yw, the modulated red luminance data Yr ' Gamma-converted white, red, and blue image data and the black image data,
Modulated red luminance data Yr 'and modulated green luminance data Yg' using the equation (4) when the corresponding color area is the third color area, and generates the white luminance data Yw, the modulated red luminance data Yr ' And outputs the white image data, the red image data, and the green image data, which are respectively subjected to inverse gamma conversion. delete 8. The method of claim 7,
When the corresponding color area is the first color area, white, green, blue, and black image data output from the image modulator are supplied to corresponding white pixels, green pixels, blue pixels, and red pixels in the display panel, respectively ,
When the corresponding color area is the second color area, white, red, blue, and black image data output from the image modulator are supplied to corresponding white pixels, red pixels, blue pixels, and green pixels in the display panel, respectively And,
When the corresponding color area is the third color area, the white, red, green, and black image data output from the image modulator are supplied to corresponding white pixels, red pixels, green pixels, and blue pixels in the display panel / RTI > The method according to claim 1,
Wherein the image modulator replaces the three-color image data with black image data when the color coordinates corresponding to the three-color image data correspond to the white point coordinates, and generates white image data corresponding to the white point coordinates , And outputs the four-color image data. The method according to any one of claims 1, 2, 5, 6, 7, 9,
Wherein the display device is a light emitting diode display device, and the three-color vertex coordinates are determined according to a color gamut that the light emitting diode display device can express. delete delete delete delete

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