KR100685596B1 - Color filter, color image display device, and electronic apparatus - Google Patents

Abstract

The present invention provides a color image display device which can improve color reproducibility by using a filter of six color configurations of RGB and YMC. In the color image display device of the present invention, the area constituting one pixel is a red filter area. A display panel having a color filter having a green filter region, a blue filter region, a yellow filter region, a magenta filter region and a cyan filter region, and a red signal, a green signal, a blue signal, and a yellow based on an RGB signal input from the outside. An image corresponding to a color calculation unit for generating a six-color signal including a signal, a magenta signal, and a cyan signal, and controlling the display of the filter area of each color of the display panel based on the six-color signal, and corresponding to the RGB signal. And a control unit for displaying on the display panel. In addition to the red, green, and blue filter regions, the filter regions of yellow, magenta, and cyan are provided, and the pixel ranges that can be displayed can be enlarged by forming one pixel region as a whole. In addition, even when the input image data is an RGB signal, yellow, magenta, and cyan signals are generated based on it, and the display is performed by six color signals, so that a commonly used RGB signal can be used.

Description

COLOR FILTER, COLOR IMAGE DISPLAY DEVICE, AND ELECTRONIC APPARATUS}

1 is a chromaticity diagram showing a color reproduction range of a color filter of the present invention,

2 is a diagram showing an arrangement of each color color filter region;

3 is a diagram showing the spectral characteristics of each color filter;

4 is a diagram schematically illustrating a configuration of a display device according to Embodiment 1;

FIG. 5 is a diagram showing an example of calculation in the color calculation unit shown in FIG. 4; FIG.

6 schematically shows a configuration of a modification of the display device according to the second embodiment;

7 is a diagram showing an example of calculation in the color calculation unit shown in FIG. 6;

8 is a block diagram showing a configuration of a display device according to a third embodiment;

9 is a block diagram showing a schematic configuration of a color conversion unit according to the third embodiment;

10 is a functional block diagram of a color conversion unit according to the third embodiment;

11 is a flowchart of a color conversion process according to the third embodiment;

12 is a diagram showing a matrix used in the line processing according to the third embodiment;

13 is a diagram showing an example of a color pixel rendering process according to the third embodiment;

14 is a diagram showing another example of the color pixel rendering process according to the third embodiment;

15 is a view showing the configuration of a liquid crystal display panel to which the present invention is applied;

16 is a diagram illustrating an example of an electronic apparatus to which the present invention is applied.

Explanation of symbols for the main parts of the drawings

10, 10a: display device 12, 12a: color calculator

14 liquid crystal display panel 16 driver

18: liquid crystal display 20: RGB signal

22: 6-color signal 24: YMC signal

The present invention belongs to the technical field of electro-optical devices such as liquid crystal devices and electronic devices. The present invention also belongs to the technical fields of electrophoretic devices such as electronic newspapers, and EL (electroluminescent) devices thereon.

In recent years, color image display apparatuses, such as a color liquid crystal display device, are used for portable terminal apparatuses, such as a mobile telephone and a PDA. For example, in the case of a liquid crystal display device, color display is enabled by providing a color filter on one side of a pair of transparent substrates which hold a liquid crystal between them. A general color filter is constructed by repeatedly arranging three color filter regions of red (R), green (G), and blue (B) according to an additive color mixing system. That is, a red filter area, a green filter area, and a blue filter area are formed adjacent to each other, and one color pixel is formed by these RGB tricolor filter areas.

Thus, in the color image display apparatus using the RGB three-color color filter, the color which can be expressed when color display is performed by RGB three colors is RGB color triangle on what is called a CIE chromaticity diagram. It is limited to the color in the area defined by. On the other hand, in a color printer or the like, three colors (four colors including black ink as necessary) of yellow (Y), magenta (M), and cyan (C) are applied to ink according to a subtractive color mixing system. To print a color image. The printer side originally has the ability to reproduce colors over the area defined by those YMC three colors on the chromaticity diagram. In general, however, since the source image to be printed in the printer is often RGB data suitable for a display device, the printer converts the input RGB data into YMC data internally and uses ink of each color of YMC. The source image is printing. For this reason, when the same source image is displayed on the display device and when printed by a printer, color reproducibility is different, and color matching between the display device and the print is not sufficient.

In addition, in the reflective color liquid crystal device, Patent Document 1 describes that a color filter having three colors of YMC is provided instead of three colors of RGB. Further, Patent Document 2 discloses that a red color filter and a cyan color filter having complementary colors are arranged adjacent to each other in one pixel, and displaying white, red, and black colors in one pixel. In addition, Patent Document 3 discloses a method of improving the resolution of a display image by controlling driving in units of RGB color dots in a color display device that constitutes one pixel by three colors of RGB.

(Patent Document 1) WO97 / 45766

(Patent Document 2) Japanese Patent Laid-Open Publication No. 9-230310

(Patent Document 3) Japanese Patent Laid-Open Publication No. 3-201788

An object of this invention is to provide the color image display apparatus which can improve color reproducibility by using the filter of the six color structure of RGB and YMC.

In one aspect of the present invention, in the color filter used in the color image display device, a region constituting one pixel includes a red filter region, a green filter region, a blue filter region, a yellow filter region, a magenta filter region, and a cyan filter region. Have In this manner, in addition to the red, green, and blue filter regions, the filter regions of yellow, magenta, and cyan are provided, and the pixel ranges that can be displayed can be enlarged by constituting an area of one pixel as a whole.

In one embodiment of the above-described color filter, the red filter region and the cyan filter region are adjacent to each other and are arranged side by side in one direction, and the green filter region and the magenta region are adjacent to each other, and the one Are arranged side by side, and the blue filter region and the yellow region are adjacent to each other, and are arranged side by side in the one direction.

According to this aspect, since combinations of complementary colors in which red and cyan, green and magenta, and blue are yellow are provided adjacent to each other, black and white (gray) display is possible by each combination. That is, the three combinations independently perform black and white display, whereby the actual resolution can be tripled, whereby the resolution in black and white display such as text can be improved. In addition, since black and white display is performed by a combination having a complementary color relationship, color bleeding does not occur.

In one form of the above-described color filter, the red filter region, the green filter region and the blue filter region are arranged in a line perpendicular to the one direction to form an RGB filter region, and the yellow filter region, the magenta filter region and The cyan filter regions are arranged in a line perpendicular to the one direction to form a YMC filter region, and the RGB filter region and the YMC filter region are adjacent to each other.

In this embodiment, black and white display is possible by the RGB filter area and black and white display is also possible by the YMC filter area, so that the resolution can be doubled for black and white display.

In another aspect of the present invention, a color image display device includes a display in which a region constituting one pixel includes a color filter having a red filter region, a green filter region, a blue filter region, a yellow filter region, a magenta filter region, and a cyan filter region. A color calculator which generates a six-color signal including a red signal, a green signal, a blue signal, a yellow signal, a magenta signal, and a cyan signal based on a panel, an RGB signal input from the outside, and based on the six-color signal. And a control unit which controls the display of the filter area of each color of the display panel and displays an image corresponding to the RGB signal on the display panel.

According to the said color image display apparatus, in addition to the red, green, and blue filter area | region, the filter area of yellow, magenta, and cyan is provided, and the 1-pixel area is comprised by them all, and the displayable color range is expanded. can do. In addition, even when the input image data is an RGB signal, signals of yellow, magenta, and cyan are generated based on it, and the display is performed by six color signals, so that a generally used RGB signal can be used.

In one aspect of the above-mentioned color image display device, the color calculating unit generates means for generating the yellow signal by an AND operation of the R signal and the G signal included in the RGB signal, the R signal included in the RGB signal, and Means for generating the magenta signal by an AND operation of a B signal, and means for generating the cyan signal by an AND operation of a G signal and a B signal included in the RGB signal. In this manner, signals of yellow, magenta, and cyan can be generated by simple arithmetic processing using an RGB signal.

On the other hand, for red, green, and blue signals among the six color signals, the color calculating unit uses the R, G, and B signals included in the RGB signal, respectively, among the red, green, and blue signals, respectively. It may be output as. Further, instead, the sum of the yellow signal and the magenta signal is subtracted from the R signal at a predetermined ratio to generate the red signal, and the sum of the yellow signal and the cyan signal is subtracted from the G signal at a predetermined ratio. The green signal may be generated by subtracting, and the blue signal may be generated by subtracting the sum of the magenta signal and the cyan signal by a predetermined ratio from the B signal.

According to another aspect of the above-described color image display device, the color calculating section determines a line that determines whether the RGB signal is a monochrome image or a color image, and a line segment from the RGB signal when it is determined that the RGB signal is a monochrome image. And a black and white image processing unit for generating a six-color signal representing the detected line segment, and a color image processing unit for generating a six-color signal representing the color image from the RGB signal when it is determined that the RGB signal is a color image. It is provided.

In this aspect, it is determined whether the RGB signal to be input is a black and white image or a color image, and a six-color signal is generated by another method based thereon. Specifically, when the RGB signal to be input is a black and white image, the image is expected to be an image containing a character, a figure, or the like. Therefore, the line segment included therein is detected, and a six-color image representing the line segment is generated. Since the six-color color filter according to the present invention can increase the resolution in the vertical and horizontal directions with respect to a black-and-white image by the arrangement, it is possible to clearly display image data indicating text or the like by generating the six-color signal in the above-described manner. It becomes possible. On the other hand, when the input RGB signal is a color image, six color signals corresponding to the color image are generated. Accordingly, the color image can be displayed in a wide color reproduction region by using the six color filters of the present invention.

In a preferred example, the determination unit determines means for converting the RGB signal into a YUV signal, and determines that the RGB signal is a black and white image when the U signal and the V signal of the YUV signal are less than a predetermined value, and the U signal and the V signal are A means for determining that the RGB signal is a color image when the predetermined value or more is provided can be provided. In this case, the luminance signal (Y signal) component and the chrominance signal (U, V signal) component are obtained from the RGB signal, and based on the comparison of the chrominance signal components, it is possible to determine with good precision whether the RGB signal is a monochrome image or a color image. Can be.

In a preferred example, the monochrome image processing unit may detect the line segment by a line segment detection matrix.

The color image processing unit may generate the six color signals by weighting a predetermined number of pixels constituting the RGB signal. When generating a six color signal from an RGB signal, a six color signal is generated based on a predetermined number of pixels of the RGB signal. In this case, the color image processing unit may generate the six-color signal by performing a matrix operation on the predetermined number of pixels, thereby substantially increasing the resolution of the color image.

In addition, by using the above-described color image display device, an electronic device can be provided, whereby an electronic device capable of displaying a wide color reproduction range can be provided.

EMBODIMENT OF THE INVENTION Hereinafter, the best form for implementing this invention with reference to drawings is demonstrated. In addition, in the following description, a liquid crystal display panel is demonstrated as an example of the electro-optical panel to which this invention is applied.

(Color filter)

First, the color filter which concerns on this invention is demonstrated. In the present invention, in addition to the RGB three colors used as the normal color filter, there is a feature in configuring a color filter of six colors having a YMC three-color region. In addition, in the following description, when referring to all three colors of YMC, it expresses "YMC", and when referring only to yellow, "YL" is used as a symbol. In addition, "Y" is used as a symbol representing the luminance signal of the image signal to distinguish the notation between the yellow signal and the luminance signal.

In FIG. 1, the color reproduction area | region of the color filter shown on the CIE chromaticity diagram is shown. The triangular color reproduction area 2 represented by the broken line is an RGB tricolor color filter, and each vertex 5R, 5G, 5B corresponds to the display color of red, green, and blue, respectively. That is, the color reproducible when the RGB three-color color filter is used becomes the color in the color reproduction area 2.

On the other hand, the color reproduction area 3 of the six-color color filter using YMC in addition to RGB becomes a hexagon of a solid line. Each vertex 6YL, 6M, 6C corresponds to a color of yellow, cyan and magenta, respectively. By using the color filter of YMC in addition to RGB, the color reproduction area which can be displayed by the display device increases, and it becomes possible to display a colorful color. This is preferable in order to combine the display colors in the case where the color is expressed by ink such as a printer and when the color is displayed by a display device such as a liquid crystal display device.

2, the structural example of a color filter is shown. As shown in Fig. 2A, one pixel of a general RGB tricolor color filter is composed of one pixel by arranging filter regions of each of R, G, and B colors. In contrast, one pixel of the six-color filter according to the embodiment of the present invention is configured by arranging filter regions of R, G, B, YL, M, and C six colors, as shown in Fig. 2B. do. As described above, by using the color filter having the six-color filter region, the color reproduction region can be enlarged as described above.

As can be seen from FIG. 2 (a) and FIG. 2 (b), in the case of the six-color color filter shown in FIG. 2 (b), the area of one pixel compared with the three-color color filter shown in FIG. Will grow. In other words, the display resolution is reduced by that much. However, according to the present embodiment, it is possible to compensate for the decrease in the resolution in black and white display. This will be described below.

In general, it is known that the human visual characteristic has a high resolution when recognizing a black and white display, but the resolution when recognizing color is not so high. This is because of the large number of cells on the retina that recognize black and white, and the small number of cells on the retina that recognize color. Therefore, by employing the six-color color filter, as described above, a decrease in resolution occurs, but if it can be compensated for during black-and-white display, it can be said that no significant adverse effect occurs.

Therefore, in the present embodiment, as shown in Fig. 2B, first, the combination of RGB and YMC is arranged in the horizontal direction, respectively. Since black and white (gray) display is possible with a combination of three colors of RGB, black and white display is possible with a combination of three colors of YMC, and in the case of black and white display, one pixel shown in FIG. As shown in Fig. 2, monochrome display of two pixels in the vertical direction becomes possible. That is, even when the six-color color filter shown in FIG. 2 (b) is employed, the resolution in the vertical direction can be doubled as shown in FIG.

In addition, in the present embodiment, as shown in Fig. 2 (b), colors having complementary colors are arranged side by side in the vertical direction. Colors complementary to each other are specifically R and C, G and M, B and YL. Therefore, six colors of R, G, B, YL, M, and C filters are arranged in the vertical and horizontal directions so that they are side by side in the vertical direction.

3 shows examples of light transmission characteristics of six colors of filters. As shown in the figure, since the electric field is covered by the filters of R and C, if the filter areas of R and C are displayed with the same data (i.e., the same gradation values), black and white display is possible by these combinations. For example, in the case of 256-gradation image data, black is displayed when both gray levels of the filter area of R and C are 256, and white is displayed when it is 0. In addition, when the filter areas of R and C are displayed with the same tone value (for example, 128), gray display is possible. The same is true for the combination of G and M and the combination of B and YL. Therefore, one monochrome pixel can be constituted by the combination of colors which are complementary to each other.

The form is shown in FIG.2 (c). In the example of FIG. 2 (c), the combination of R and C and the combination of B and YL are respectively black display, and the combination of G and M is white display. Thus, when the combination which becomes complementary color is arrange | positioned adjacently, one monochrome pixel can be comprised by the combination. Therefore, as shown in Fig. 2 (c), three pixels in the horizontal direction can be displayed in the black and white display, and three times the resolution can be provided in the horizontal direction.

In recent years, a method of improving the resolution by controlling the display in units of sub-pixels of each RGB color, for example, when displaying colors using RGB three colors (for example, Patent Document 3 described above) has been proposed. Since the gradation values of the respective RGB colors must be different, it is inevitable that color bleeding occurs in the actual display pixels. On the other hand, the above-described method of using a combination of complementary colors has the advantage that color bleeding does not occur since the filter regions of colors having complementary colors are displayed at the same gradation value.

Thus, for example, since the resolution can be improved as compared with the case of performing monochrome display by the conventional RGB tricolor filter, it is considered that the display becomes easier to see when displaying monochrome text or the like on a display device.

In addition, in the example of FIG. 2B, the vertical relationship between the filter area of RGB and the filter area of CMY may be replaced. In addition, although the arrangement | positioning of the horizontal direction of RGB can also be changed (for example, from left to right, R, B, G etc.), also in this case, it is necessary to arrange two colors which are complementary in the vertical direction. Further, the orientations of the vertical and the horizontal directions may be reversed (that is, a configuration in which RGB is aligned in one column in the vertical direction and CMY is aligned in one column in the vertical direction, so that they are aligned in the horizontal direction).

[Display device]

(Example 1)

Next, Embodiment 1 of the display device to which the six color filters described above are applied will be described. 4 shows an example of the configuration of the display device 10 according to the first embodiment. This display device 10 can be applied to portable terminals such as mobile phones and PDAs. In FIG. 4, the display device 10 according to the present embodiment includes a color calculator 12 and a liquid crystal display panel 14. The liquid crystal display panel 14 includes a liquid crystal display device 18 and a driver 16.

The RGB signal 20 is input from the outside to the display device 10. RGB signal 20 includes R signal Sr, G signal Sg and B signal Sb. The color calculator 12 generates a six-color signal 22 from the input RGB signal 20. The six-color signal 22 is a signal corresponding to each color of R, G, B, YL, M, and C, and is supplied to the driver 16 in the liquid crystal display panel 14.

The liquid crystal display unit 18 is a liquid crystal display unit to which the six color filters described above are applied. The driver 16 drives each pixel of the liquid crystal display 18 based on the input six-color signal 22. Thereby, as shown in FIG.2 (b), each pixel comprised by a six color filter is driven, and the image input as RGB signal 20 is displayed on the liquid crystal display part 18. FIG.

Next, the detail of the color calculating part 12 is demonstrated. The color calculating unit 12 generates six color signals corresponding to respective filter regions of the six color filters provided in the liquid crystal display unit 18 from the input RGB signal.

First, a first generation method of six color signals will be described. The spectral characteristics of each RGB color and the spectral characteristics of each YMC color are as shown in FIG. Thus, for example, the cyan signal Sc may be generated by the AND of the blue signal Sb and the green signal Sg. Similarly, magenta signal Sm can be generated by the logical product of blue signal Sb and red signal Sr, and yellow signal Sy can be generated by the logical product of green signal Sg and red signal Sr. In Fig. 5, operations for generating signals of YL, M, and C colors are shown by logic circuits. On the other hand, the signal of each color of RGB can use the signal input as the RGB signal 20 as it is. Therefore, each color component of the six-color signal is obtained as follows.

Rout = Sr

Gout = Sg

Bout = Sb

Cout = Sg AND Sb

Mout = Sb AND Sr

YLout = Sr AND Sg

Next, a second generation method of the six color signals will be described. In the first generation method, signals of YL, M, and C colors are generated based on the input RGB signal 20, and each color signal of the input RGB signal 20 is used as an output as it is. The display image may be at a higher concentration than the original image. In the second generation method, signals of each of YL, M, and C colors are generated in the same manner as in the first generation method, but output signals of each of the RGB colors are reflected in the YMC signal from the respective color signals of the input RGB signal 20. The components are subtracted at a predetermined rate. Specifically, each color component of the six-color signal is obtained as follows.

Rout = b {Sr-a (Yout + Mout)}

Gout = b {Sg-a (Yout + Cout)}

Bout = b {Sb-a (Mout + Cout)}

Cout = Sg AND Sb

Mout = Sb AND Sr

YLout = Sr AND Sg

Here, a and b are coefficients determined by the design of the intensity component of each color of the six color filters.

In this manner, according to the second generation method, the density as a whole can be approximated to the density of the source image. In addition, by using this method, not only the YMC signal is generated from the input RGB signal but also the color reproducibility by the six-color color filter can be arbitrarily adjusted. That is, by determining the coefficients a and b in consideration of the characteristics of the six color filters, the color reproducibility required by the display device can be realized.

(Example 2)

Next, Embodiment 2 of the display device will be described. 6 shows a configuration of a display device 10a according to the second embodiment. In the display device 10 shown in FIG. 4, the RGB signal 20 was input, and the 6-color signal was produced based on it, and the image was displayed on the liquid crystal display panel 14 which mounts a 6-color filter. In this modification, the display apparatus 10a was comprised so that the YMC signal 24 could also be input. In other words, when the source image is input as the RGB signal 20, each color signal of six colors is generated from the RGB signal 20 and supplied to the liquid crystal display panel 14 similarly to the display device 10. On the other hand, when the source image is input as the YMC signal 24, the color calculating unit 12a generates the six color signals 26 from the YMC signal 24 and supplies them to the liquid crystal display panel 14.

When the YMC signal 24 is input, the color calculating part 12a performs color calculation which produces | generates an RGB signal from a YMC signal. This operation is similar to the operation from the RGB signal to the YMC signal described above. That is, as can be seen from FIG. 3, the R signal can be obtained by the OR of the M and Y signals, the G signal can be obtained by the OR of the C and Y signals, and the B signal is C. This can be obtained by the logical sum of the signal and the M signal. That is, the color calculator 12a can generate the RGB signal by the logic circuit shown in FIG. 7 with respect to the input of the YMC signal.

In this case, the YMC signal outputted as the six-color signal may use the input YMC signal as it is, as in the first generation method of the YMC signal described above, and the component of the RGB signal generated from the YMC signal, similarly to the second generation method. May be subtracted from the original YMC signal at a predetermined ratio.

The display device 10a according to this modification can be suitably used, for example, for displaying a source image printed by a printer with color reproducibility close to the print result. That is, by displaying the source image data input as the RGB signal or the YMC signal on the liquid crystal display panel 14 equipped with the six-color color filter, it is displayed on the display device 10a with the color reproducibility equivalent to the color reproducibility obtained by the printer. can do.

(Example 3)

Next, Embodiment 3 of the display device will be described. 8 shows a configuration of a display device 10b according to the third embodiment. As shown in the drawing, the display device 10b according to the third embodiment receives the RGB signal 20 as an input signal, similarly to the display device 10 according to the first embodiment. However, in the third embodiment, the color calculating unit 12b generates and outputs the six color signals 28 by a method different from that of the first embodiment.

As described above, the six-color color filter of the present invention has an advantage that the color image signal has a wider color reproduction area as compared to the color filter of ordinary RGB only. On the other hand, since one pixel consists of six colors of color, the resolution is reduced as it is, but the black and white image can compensate for the decrease in resolution by the six-color arrangement described above. Have

The third embodiment uses this feature to determine whether the input image is a monochrome image (achromatic color) or a color image (chromatic color), and performs different processing in each case. Specifically, when the input image is a black and white image, the line segment (vertical line and horizontal line) is detected from the input image, and white or black is assigned to each pixel to display the line segment. Accordingly, when the input image is text or the like, characters, figures, and the like can be displayed clearly.

On the other hand, when the input image is a color image, a six-color signal suitable for the six-color color filter of the present invention is generated from a predetermined number of pixel data of the input image data. At this time, by using a predetermined matrix, the gradation value of a specific pixel is also determined in consideration of the gradation value of the surrounding pixels, so that a process of substantially improving the resolution is also executed.

Fig. 9 is a block diagram showing the schematic configuration of the color conversion unit 12b in the case of performing color conversion to six color filters by software processing. The color converter 12b includes a CPU 30, a program memory 31, a network I / F 32, a display I / F 33, and an I / O device 34 connected to a bus 35. It is configured to be connected to. The program memory 31 stores a color conversion processing program described later. The network I / F 32 is used when acquiring a source image from a network. The display I / F 33 is an interface for supplying the six-color signal 28 obtained by the color conversion to the liquid crystal display panel 14. The I / O device 34 is a device used for executing a selection / instruction including a selection of a source picture and the like. In addition to controlling each component of the color conversion unit 12b, the CPU 30 executes a color conversion process described later by executing a color conversion program stored in the program memory 31.

10 is a functional block diagram of the color conversion unit 12b. The color conversion unit 12b functionally includes a determination unit 41, a black and white image processing unit 42, a color image processing unit 43, and a γ conversion unit 44. In addition, these components are basically realized by the CPU 30 executing a predetermined program stored in the program memory 31.

The RGB signal 20 input to the color conversion unit 12b is input to the determination unit 41, the monochrome image processing unit 42, and the color image processing unit 43. The determination unit 41 YUV-converts the RGB signal 20 to generate the luminance signal Y and the color difference signals U and V. Based on the obtained color difference signal, it is determined whether the input RGB signal is a monochrome image or a color image. Specifically, it is determined whether or not the color difference signals U and V are less than the predetermined value X. When the color difference signals U and V are less than the predetermined value X, it is determined that the input image is a black and white image. As the predetermined value X, for example, about "0.1" (that is, 10%) can be used. In this case, it is determined that an image having a color component of less than 10% is a monochrome image and an image having 10% or more is a color image. The determination result signal 61 thus obtained is sent to the monochrome image processing unit 42 and the color image processing unit 43.

The monochrome image processing unit 42 operates when the determination result signal 61 indicates that the input image is a monochrome image, generates line-weighted image signal 62 to be described later, and generates a gamma conversion unit 44. Send to). On the other hand, the color image processing unit 43 operates when the determination result signal 61 indicates that the input image is a color image, and generates an image signal 63 with improved resolution by the color pixel rendering process described later. The signal is sent to the gamma converter 44. The gamma conversion unit 44 performs gamma conversion on the supplied image signal 62 or the image signal 63 based on a predetermined gamma characteristic, and outputs it as the six-color signal 28.

11 is a flowchart of the color conversion processing executed by the color conversion unit 12b. In addition, as described above, this color conversion processing is realized by functioning as each component shown in FIG. 10 by the CPU 30 executing a color conversion program. First, the determination unit 41 receives image data (that is, the RGB signal 20) from the outside (step S1). Next, the determination unit 41 converts the image data into YUV to generate color difference signals U and V, and compares them with a predetermined value X to determine whether the input image is a monochrome image (achromatic color) or a color image (chromatic color). It determines (step S2).

If the input image is a monochrome image (step S2; Yes), the monochrome image processing unit 42 performs the line processing. On the other hand, when the input image is a color image (step S2; No), the color image processing unit 43 performs color pixel rendering processing. In this way, the monochrome image signal 62 or the color image signal 63 is generated. Then, after the γ conversion unit 44 performs γ conversion or the like on any one of them, the γ conversion unit 44 outputs the six color signals 28 to the liquid crystal display panel 14.

Next, the line processing performed by the monochrome image processing unit 42 will be described in detail.

(1) When generating six-color signal from six pixel data

When generating a six-color signal from data of six pixels (horizontal pixel x two pixels) of the input image, the black and white image processing unit 42 shows the horizontal line shown in FIG. 12 with respect to the Y signal of six pixels of the input image. A detection matrix and a vertical line detection matrix are applied to detect vertical and horizontal lines. Fig. 12 (a) is a horizontal line detection matrix, in which the matrix on the left detects a horizontal line (black line) located at the upper side of the region of six pixels, and the horizontal line (black line) at which the matrix on the right side is located below the region of the six pixels. Detect.

12 (b) and 12 (c) are vertical line detection matrices. The left matrix of Fig. 12 (b) detects the vertical line (black line) located on the left side in the area of 6 pixels, and the central matrix detects the vertical line (black line) located in the center of the area of 6 pixels, and the right side. The matrix of detects vertical lines (black lines) located on the right side in the area of 6 pixels. On the other hand, the matrix on the left side of FIG. 12 (c) detects the vertical line (white line) located on the left side in the region of six pixels, and the matrix on the center detects the vertical line (white line) located on the center in the region of six pixels. The matrix on the right side detects the vertical line (white line) located on the right side in the area of 6 pixels.

When a line segment (line) is detected in the input image using these matrices, the black and white image processing unit 42 assigns a gray value of black or white to a pixel located on the line segment. For example, if each pixel is 256 grayscales (white: grayscale value "0", black: grayscale value "255"), the black grayscale value "255" is assigned to the pixel located on the black line, and the pixel located on the white line The white tone value "0" is assigned to. Then, the monochrome image processing unit 42 outputs the image signal 62 obtained as described above as the six-color signal 28.

This six-color signal 28 is represented by the six-color color filter illustrated in FIG. As described with reference to FIG. 2, in the six-color color filter of the present invention, the monochrome resolution of two pixels in the vertical direction by the combination of RGB and YMC, and the monochrome resolution of three pixels in the horizontal direction by the combination of complementary colors are obtained. Since the image signal 62 obtained by the linearization process can be obtained, the monochrome image with high resolution can be displayed utilizing the monochrome resolution of 2 times vertically and 3 times horizontally.

(2) When generating six-color signal from three pixel data

When a six-color signal is generated from the image data of only three pixels (horizontal three pixels) of the input image, the vertical line cannot be detected. Therefore, only the horizontal line is detected using only the horizontal line detection filter shown in Fig. 12A. Subsequent processing is the same as in the case of generating a six-color signal from six pixel data. An image signal 62 is generated and output by allocating a black gray value to a pixel located on a black line. Also in this case, a black and white image with high resolution can be displayed utilizing the black and white resolution of two pixels in the vertical direction of the six color filters.

Next, the color pixel rendering process executed by the color pixel processing unit 43 will be described.

(1) When generating six-color signal from six pixel data

FIG. 13 schematically shows a process for generating a six-color signal from six pixel data. Now, as shown on the left side of FIG. 13, it is considered to generate six-color data corresponding to the area 51 of a part of 6 pixels (3 pixels × 2 pixels) of a part of an input image.

(a) first method

The first method is similar to the second generation method of Example 1. In other words, the input RGB signal is

Sr = (R1 + R2 + R3 + R4 + R5 + R6)

Sg = (G1 + G2 + G3 + G4 + G5 + G6)

Sb = (B1 + B2 + B3 + B4 + B5 + B6)

Since it is represented by, the six-color signal is represented by the following equation.

Rout = β {Sr-α (Yout + Mout)}

Gout = β {Sg-α (Yout + Cout)}

Bout = β {Sb-α (Mout + Cout)}

Cout = θ (Sg AND Sb)

Mout = θ (Sb AND Sr)

YLout = θ (Sr AND Sg)

Here, α, β and θ are coefficients determined by the design of the intensity component of each color of the six color filters.

In this method, the depth of gradation is expanded by six times, not the resolution of the vertical and horizontal directions of the display image, so that the gradation expression capability is higher than when RGB data for one pixel is input, resulting in rich color representation. For example, when the image data of the R color of the input is 8 bits (256 gradations), the output data Rout can be represented by 256 x 6 gradations.

(b) the second method

In the second method, matrix arithmetic is used as shown in FIG. As shown in FIG. 13, with respect to the data (3 pixels x 2 pixels) of the 6 pixel area 51 of a predetermined position of input image data, the 3 pixel area 52 located above or below the area ( In FIG. 13, every 9 pixel data (3 pixels wide x 3 pixels wide) including the data of the lower side is multiplied by a matrix 55 of 3x3, divided by "6", and normalized to obtain 6-color data of the output. . Since the matrix 55 has a coefficient of horizontal lines at the center of "1.0" and a coefficient of horizontal lines of upper and lower sides of "0.5", six colors of output data are generated even based on the pixels of the horizontal lines of the upper and lower sides. That is, the output six-color data is determined by the weighting operation of the peripheral pixels using the matrix 55, and as a result, the resolution in the vertical direction is substantially increased.

Specifically, each output data is obtained by the following formula.

Rout = (0.5R11 + 0.5R12 + 0.5R13 + 1.0R21 + 1.0R22 + 1.0R23 + 0.5R31 + 0.5R32 + 0.5R33) / 6

Gout = (0.5G11 + 0.5G12 + 0.5G13 + 1.0G21 + 1.0G22 + 1.0G23 + 0.5G31 + 0.5G32 + 0.5G33) / 6

Bout = (0.5B11 + 0.5B12 + 0.5B13 + 1.0B21 + 1.0B22 + 1.0B23 + 0.5B31 + 0.5B32 + 0.5B33) / 6

Cout = Gout AND Bout

Mout = Bout AND Rout

Yout = Rout AND Gout

As described above, pixel data of six colors of R, G, B, YL, M, and C suitable for the six color filter of the present invention can be generated from six pixels of the RGB input image data.

(2) When generating six-color signal from three pixel data

14, the process at the time of producing | generating a six-color signal from three pixel data is shown typically. As shown on the left side of FIG. 14, it is now considered to generate six color data corresponding to an area 57 constituted by three pixels of a part of an input image.

(a) first method

The first method is similar to the second generation method of Example 1. In other words, the input RGB signal is

Sr = (R1 + R2 + R3)

Sg = (G1 + G2 + G3)

Sb = (B1 + B2 + B3)

Since 6 color signals are represented by the following formula.

Rout = β {Sr-α (Yout + Mout)}

Gout = β {Sg-α (Yout + Cout)}

Bout = β {Sb-α (Mout + Cout)}

Cout = θ (Sg AND Sb)

Mout = θ (Sb AND Sr)

YLout = θ (Sr AND Sg)

Here, α, β and θ are coefficients determined by the design of the intensity component of each color of the six color filters.

In this method, the depth of gradation is tripled not by the resolution of the vertical and horizontal resolutions of the display image, so that the gradation representation ability is higher than when RGB data for one pixel is input, resulting in rich color representation. For example, when the input R color image data is 8 bits (256 gradations), the output data Rout can be represented by 256 x 3 gradations.

(b) the second method

In the second method, as shown in FIG. 14, matrix operation is used. As shown in FIG. 14, with respect to three pixel data (a horizontal three pixels) of the predetermined position of input image data, every data (a horizontal five pixel) of the five pixel area | region 57 including one pixel to the left and right of the area | region, By multiplying the matrix 58 of 1x5, dividing by " 2.5 " to normalize, six colors of output data are obtained. The matrix 58 has a center coefficient of "1.0", the coefficient of the left and right pixels is "0.5", and the coefficient of the left and right pixels is "0.25". Six colors of output data are generated, and as a result, the resolution in the left and right directions increases substantially.

Specifically, each output data is obtained by the following formula.

Rout = (0.25R11 + 0.5R12 + 1.0R13 + 0.5R14 + 0.25R15) /2.5

Gout = (0.25G11 + 0.5G12 + 1.0G13 + 0.5G14 + 0.25G15) /2.5

Bout = (0.25B11 + 0.5B12 + 1.0B13 + 0.5B14 + 0.25B15) /2.5

Cout = Gout AND Bout

Mout = Bout AND Rout

Yout = Rout AND Gout

As described above, the pixel data of six colors of R, G, B, YL, M, and C suitable for the six color filter of the present invention can be generated from three pixels of the RGB input image data.

(Liquid crystal display panel)

Next, an example of a liquid crystal display panel to which the color filter substrate of the present invention is applied will be described. This example is an example in which the color filter substrate to which the above six color filters are applied is applied to the transflective liquid crystal display panel 14, and a cross-sectional view of the liquid crystal display unit 18 is shown in FIG.

In FIG. 15, the liquid crystal display panel 14 is formed by bonding a substrate 101 made of glass, plastic, or the like to the substrate 102 through a sealing material 103, and sealing the liquid crystal 104 therein. In addition, the retardation plate 105 and the polarizing plate 106 are arranged in order on the outer surface of the substrate 102, and the retardation plate 107 and the polarizing plate 108 are arranged in this order on the outer surface of the substrate 101. Further, under the polarizing plate 108, a backlight 109 for generating illumination light when performing transmissive display is disposed.

The substrate 101 is a transparent substrate such as glass, and the six-color color filter CF described above is formed thereon. That is, six color filter areas of the RGBYMC are formed in the arrangement as described above. If necessary, a transparent resin scattering layer is formed on the substrate 101 by, for example, acrylic resin or the like. In addition, on the resin scattering layer, a metal film is formed in a reflection area. In the reflective region, color filters of respective colors are formed on the metal reflective film.

Moreover, as needed, a black matrix is formed in the boundary of the color filter of each color. Then, a transparent electrode 17 made of a transparent conductor such as indium tin oxide (ITO) is formed on the color filter CF. In the present embodiment, the transparent electrodes 17 are formed in a plurality of parallel stripe shapes. In addition, the transparent electrode 17 extends in a direction orthogonal to the transparent electrode 121 formed in a stripe shape on the substrate 102, and is included in an intersection region of the transparent electrode 17 and the transparent electrode 121. The component part of the liquid crystal display panel 14 which comprises becomes a pixel area | region.

On the other hand, the transparent electrode 121 is formed on the inner surface of the board | substrate 102, and is comprised so that it may cross | intersect the transparent electrode 17 on the opposing board | substrate 101. FIG. Moreover, on the transparent electrode 17 on the board | substrate 101, and the transparent electrode 121 on the board | substrate 102, an orientation film etc. are formed as needed.

In the liquid crystal display panel 14, when reflective display is performed, the external light incident on the region where the metal reflective film is formed travels along the path R shown in FIG. 15 and is reflected by the metal reflective film to the observer. It is admitted by. On the other hand, in the case where transmissive display is performed, the illumination light emitted from the backlight 109 enters the transmissive region, proceeds as shown in the path T, and is viewed by the observer.

In addition, the above-mentioned liquid crystal display panel is only an example in which the six-color color filter of this invention is applied, and the six-color color filter of this invention is applicable to the liquid crystal display panel of other various structures.

(Electronics)

Next, an example of an electronic device to which the liquid crystal display panel according to the present invention can be applied will be described with reference to FIG. 16.

First, the example which applied the liquid crystal display panel which concerns on this invention to the display part of a portable personal computer (so-called notebook computer) is demonstrated. Fig. 16A is a perspective view showing the structure of this personal computer. As shown in the figure, the personal computer 41 includes a main body portion 412 including a keyboard 411 and a display portion 413 to which the liquid crystal display panel according to the present invention is applied.

Next, the example which applied the liquid crystal display panel which concerns on this invention to the display part of a mobile telephone is demonstrated. Fig. 16B is a perspective view showing the structure of this mobile phone. As shown in the figure, the mobile telephone 42 includes a display section 424 to which the liquid crystal display panel according to the present invention is applied, together with a plurality of operation buttons 421, a handpiece 422 and a songwriter 423. Equipped.

Moreover, as an electronic device which can apply the liquid crystal display panel which concerns on this invention, in addition to the personal computer shown in FIG. 16 (a), and the mobile telephone shown in FIG. Type video tape recorders, car navigation devices, pagers, electronic notebooks, electronic calculators, word processors, workstations, video phones, POS terminals, digital still cameras, and the like.

(Variation)

In addition, the board | substrate, liquid crystal device, etc. which have the above-mentioned reflective layer and a color filter are not limited only to the above-mentioned example, Of course, various changes are possible within the range which does not deviate from the summary of this invention.

Although the liquid crystal display panel is illustrated in the Example demonstrated above, as an electro-optical device of this invention, it can apply similarly to electrophoretic devices, such as an electronic newspaper, and EL (electroluminescent) device on it.

According to the present invention, it is possible to provide a color image display device having improved color reproducibility by using a filter having six color configurations of RGB and YMC.

Claims (16)

delete delete delete A display panel including a color filter having a red filter region, a green filter region, a blue filter region, a yellow filter region, a magenta filter region, and a cyan filter region; A color calculator which generates a six-color signal including a red signal, a green signal, a blue signal, a yellow signal, a magenta signal, and a cyan signal based on an RGB signal input from the outside; A control unit for controlling the display of the filter area of each color of the display panel based on the six-color signal to display an image corresponding to the RGB signal on the display panel The color image display apparatus characterized by the above-mentioned. The method of claim 4, wherein The color calculator Means for generating the yellow signal by an AND operation of an R signal and a G signal included in the RGB signal; Means for generating the magenta signal by an AND operation of an R signal and a B signal included in the RGB signal; Means for generating the cyan signal by an AND operation of a G signal and a B signal included in the RGB signal The color image display apparatus characterized by the above-mentioned. The method of claim 5, And the color calculating unit outputs the R signal, the G signal, and the B signal included in the RGB signal as red, green, and blue signals among the six color signals, respectively. The method of claim 5, The color calculator Means for generating the red signal by subtracting the sum of the yellow signal and the magenta signal from the R signal by a predetermined ratio; Means for generating the green signal by subtracting the sum of the yellow signal and the cyan signal from the G signal by a predetermined ratio; Means for generating the blue signal by subtracting the sum of the magenta signal and the cyan signal from the B signal by a predetermined ratio The color image display apparatus characterized by the above-mentioned. The method of claim 4, wherein The color calculator A judging section for judging whether the RGB signal is a monochrome image or a color image; A black and white image processing unit for detecting a line segment from the RGB signal and generating a six-color signal representing the detected line segment when it is determined that the RGB signal is a black and white image; A color image processing unit that generates a six-color signal corresponding to the color image from the RGB signal when it is determined that the RGB signal is a color image The color image display apparatus characterized by the above-mentioned. The method of claim 8, The determination unit Means for converting the RGB signal into a YUV signal; Means for determining that the RGB signal is a black and white image when the U signal and the V signal of the YUV signal are less than a predetermined value, and determining the RGB signal as a color image when the U signal and the V signal are equal to or larger than a predetermined value. The color image display apparatus characterized by the above-mentioned. The method according to claim 8 or 9, And the black and white image processing unit detects the line segment by a line segment detection matrix. The method according to claim 8 or 9, And the color image processing unit generates the six-color signal by weighting a predetermined number of pixels constituting the RGB signal. The method of claim 11, And the color image processing unit generates the six-color signal by performing a matrix operation on the predetermined number of pixels. An electronic device comprising the color image display device according to any one of claims 4 to 9 as an image display unit. A display panel provided with pixels having an area corresponding to red, an area corresponding to green, an area corresponding to blue, an area corresponding to yellow, an area corresponding to magenta, and an area corresponding to cyan; A color calculator which generates a signal corresponding to six colors based on the input signal corresponding to three colors; A driver for driving the pixel based on the signal generated by the color calculator And a color image display device. The method of claim 14, The signal corresponding to the three colors is a signal corresponding to red, a signal corresponding to green, and a signal corresponding to blue. The method of claim 14, The signal corresponding to the three colors is a signal corresponding to a yellow color, a signal corresponding to a magenta color, and a signal corresponding to a cyan color.

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