COLOR DISPLAY DEVICE AND METHOD FOR REPRODUCING COLOR WITH AN INCREASED NUMBER OF GRADATION LEVELS

• US 20080238952A1
• Filed: 03/28/2008
• Published: 10/02/2008
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: OKI Electric Industry Company Limited
• Inventors: KANOU, Hideki
• Granted Patent: US 8,159,509 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127

Abstract

A color display device has a display screen having pixels arrayed, each of which is composed of primary color sub-pixels capable of reproducing respective primary colors and at least one subsidiary color sub-pixel capable of reproducing gray. While gradation signals are generated and supplied to the primary color sub-pixels on the basis of the primary color components of an image to be displayed, the gradation signal to be supplied to the subsidiary color sub-pixel is generated on the basis of the intensity component of the image. The color display device is attained in which the number of gradation levels can be substantially increased without increasing the number of gradation levels of the primary colors.

Claims

1. A method of controlling a color display device comprising a display screen having a plurality of pixels arranged in an array, each of the plurality of pixels including primary color sub-pixels for reproducing at least respective, three primary colors and at least one subsidiary color sub-pixel for reproducing a color different from the primary colors, comprising the steps of:

generating a primary color data signal for the respective primary colors on a basis of a luminance signal and color-difference signals by a processor to output the primary color data signal to a timing controller together with the luminance signal, and

generating by the timing controller a subsidiary color data signal on the basis of the luminance signal to output the primary color data signals to a source driver together with the subsidiary color data signal.

2. A method of displaying at least three primary colors and at least one subsidiary color different from the primary colors, wherein the subsidiary color is displayed as a color corresponding to luminance information.

3. The method in accordance with claim 2, wherein a color is displayed at a pixel by a combination of sub-pixels for reproducing the respective primary colors and a sub-pixel for reproducing the subsidiary color.

4. The method in accordance with claim 2, wherein the subsidiary color is displayed in correspondence with each of the primary colors in a pixel.

5. The method in accordance with claim 2, wherein the luminance information is supplied in a form of luminance signal.

6. The method in accordance with claim 5, further comprising the steps of:

inputting or generating the luminance information and color-difference information of an image to be displayed on a display device;

generating a data signal of the primary colors on a basis of the luminance information and color-difference information; and

converting the luminance information and primary color information into data to be displayed on the display device.

7. The method in accordance with claim 6, further comprising the step of separately transferring the luminance and the primary color information from each other to said step of converting.

8. The method in accordance with claim 6, further comprising the step of using correction data for correcting gradation of the luminance information to correct the luminance information with respect to a gradation level.

9. A color display device for displaying at least three primary colors and at least one subsidiary color different from the primary colors, wherein the subsidiary color is displayed as a color corresponding to luminance information.

10. The color display device in accordance with claim 9, comprising a display screen including a plurality of pixels arranged in an array, each of said plurality of pixels being composed of a first plurality of sub-pixels for reproducing the respective primary colors and a second plurality of sub-pixels for reproducing the subsidiary color and provided in a one-to-one correspondence with the first sub-pixels.

11. The color display device in accordance with claim 10, wherein each of the second sub-pixels is controlled separately from each other with respect to a gradation level.

12. The color display device in accordance with claim 9, comprising a display screen including a plurality of pixels, each of which is composed of first sub-pixels for reproducing the respective primary colors and a second sub-pixel for reproducing the subsidiary color.

13. The color display device in accordance with claim 9, wherein said color display device receives or generates a luminance signal representative of the luminance information.

14. The color display device in accordance with claim 13, wherein said color display device includes a data processor and a display controller,

said data processor receiving or generating the luminance information and color-difference information of an image to be displayed on said display screen, and producing a primary color data signal on a basis of the luminance information and color-difference information to output the luminance information and the primary color data signal to said display controller,

said display controller converting the luminance information and primary color data signal into data to be displayed on said display screen.

15. The color display device in accordance with claim 14, wherein said data processor separately transfers the luminance information and the primary color data signal from each other to said display controller.

16. The color display device in accordance with claim 15, wherein said data processor is provided with correction data for gradation correction, and references the correction data to perform gradation correction on the luminance information.

17. A color display device comprising:

a display screen having a plurality of pixels arranged in an array, each of the plurality of pixels including primary color sub-pixels for reproducing at least respective, three primary colors and at least one subsidiary color sub-pixel for reproducing a color different from the primary colors;

a processor for generating a primary color data signal for the respective primary colors on a basis of a luminance signal and color-difference signals to output the primary color data signal to a timing controller together with the luminance signal; and

a timing controller for generating a subsidiary color data signal on the basis of the luminance signal to output the primary color data signal to a source driver together with the subsidiary color data signal.