Field sequential display of color video picture with color breakup prevention

• US 20020024618A1
• Filed: 08/30/2001
• Published: 02/28/2002
• Est. Priority Date: 08/31/2000
• Status: Active Grant

• Current Assignee: Vista Peak Ventures LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: NEC Corporation
• Inventors: Imai, Masao
• Granted Patent: US 7,042,527 B2
• Time in Patent Office: Days
• US Class Current: 348/743
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A method of displaying a color video picture according to a field sequential process is provided. A display device displays an image comprising a matrix of pixels. One frame image is composed of four field images ranging from a first field image to a fourth field image. With four adjacent pixels handled as one unit, the colors R, G, B, W of illuminating lights applied to the pixels in each unit are different from each other, and the arrangement of the colors is successively switched or changed in each field period. Information representing the colors R, G, B, W separated from a video signal is displayed sequentially in successive fields at positions corresponding to the colors of the illuminating lights applied to the pixels and times at which the illuminating lights are applied to the pixels.

Claims

1. A method of displaying a color video picture by sequentially displaying color images on a display device and switching illumination light colors depending on the displayed color images according to a field sequential process, said method comprising the steps of:

illuminating a display device having a matrix of pixels, with adjacent four pixels as a unit, with illuminating lights including a red illuminating light, a green illuminating light, a blue illuminating light, and an achromatic illuminating light, such that the illuminating lights applied to the pixels in each unit have different colors from each other and the colors of the illuminating lights are switched in each field period;

generating a red video signal, a green video signal, a blue video signal, and an achromatic video signal from a color video signal so as to correspond to the colors of the illuminating lights applied to the pixels in each unit; and

energizing said display device with the generated video signals to display a color video picture thereon.

2. A method according to claim 1, further comprising the step of:

projecting the color video picture displayed on said display device.

3. A method according to claim 1, wherein the pixels in each unit are arranged in a square matrix with green and achromatic pixels positioned diagonally opposite in relation to each other.

4. A method according to claim 2, wherein the pixels in each unit are arranged in a square matrix with green and achromatic pixels positioned diagonally opposite in relation to each other.

5. An apparatus for displaying a color video picture by sequentially displaying color images on a display device and switching illumination light colors depending on the displayed color images according to a field sequential process, said apparatus comprising:

a display device having a matrix of pixels;

color switching illumination means for illuminating said display device, with adjacent four pixels as a unit, with illuminating lights including a red illuminating light, a green illuminating light, a blue illuminating light, and an achromatic illuminating light, such that the illuminating lights applied to the pixels in each unit have different colors from each other and the colors of the illuminating lights are switched in each field period; and

video signal processing means for generating a red video signal, a green video signal, a blue video signal, and an achromatic video signal from a color video signal so as to correspond to the colors of the illuminating lights applied to the pixels in each unit, and energizing said display device with the generated video signals to display a color video picture thereon.

6. An apparatus according to claim 5, further comprising the step of:

projecting means for projecting the color video picture displayed on said display device.

7. An apparatus according to claim 5, wherein said color switching illumination means comprises four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, with only one at a time of said four regions being energizable to emit the illuminating light in each field period.

8. An apparatus according to claim 6, wherein said color switching illumination means comprises four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, with only one at a time of said four regions being energizable to emit the illuminating light in each field period.

9. An apparatus according to claim 5, wherein said color switching illumination means comprises a region for emitting either one of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, with the color of said one illuminating light being switchable in each field period.

10. An apparatus according to claim 6, wherein said color switching illumination means comprises a region for emitting either one of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, with the color of said one illuminating light being switchable in each field period.

11. An apparatus according to claim 5, wherein said color switching illumination means comprises a region for emitting either one of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, and means for moving the relative position of said region and said display device by a distance corresponding to one pixel in each filed period.

12. An apparatus according to claim 6, wherein said color switching illumination means comprises a region for emitting either one of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light to each pixel of said display device, and means for moving the relative position of said region and said display device by a distance corresponding to one pixel in each field period.

14. An apparatus according to claim 13, further comprising the step of:

projecting means for projecting the color video picture displayed on said display device.

15. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, respectively, said color switching illumination means being arranged to energize either one at a time of said four regions to emit the illuminating light in each field period.

16. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, respectively, said color switching illumination means being arranged to energize either one at a time of said four regions to emit the illuminating light in each field period.

17. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, respectively, said color switching illumination means being arranged to energize either one at a time of said four regions to emit the illuminating light in each field period, said regions being arranged in a matrix.

18. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, respectively, said color switching illumination means being arranged to energize either one at a time of said four regions to emit the illuminating light in each field period, said regions being arranged in a matrix.

19. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means being arranged to switch the colors of the illuminating lights in each field period.

20. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means being arranged to switch the colors of the illuminating lights in each field period.

21. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means being arranged to switch the colors of the illuminating lights in each field period, said regions being arranged in a matrix.

22. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means being arranged to switch the colors of the illuminating lights in each field period, said regions being arranged in a matrix.

23. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means having means for moving the relative position of said collimator lens and said four regions by a distance corresponding to one light-emitting region in each field period.

24. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said color switching illumination means having means for moving the relative position of said collimator lens and said four regions by a distance corresponding to one light-emitting region in each field period.

25. An apparatus according to claim 13, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said regions being arranged in a matrix, said color switching illumination means having means for moving the relative position of said collimator lens and said four regions by a distance corresponding to one light-emitting region in each field period.

26. An apparatus according to claim 14, wherein said color switching illumination means has a collimator lens associated with four sets of four regions for emitting either one at a time of said red illuminating light, said green illuminating light, said blue illuminating light, and said achromatic illuminating light, said regions being arranged in a matrix, said color switching illumination means having means for moving the relative position of said collimator lens and said four regions by a distance corresponding to one light-emitting region in each field period.

27. An apparatus according to claim 13, wherein the pixels in each unit are arranged in a square matrix with green and achromatic pixels positioned diagonally opposite in relation to each other.

28. An apparatus according to claim 14, wherein the pixels in each unit are arranged in a square matrix with green and achromatic pixels positioned diagonally opposite in relation to each other.

13. An apparatus for displaying a color video picture by sequentially displaying color images on a display device and switching illumination light colors depending on the displayed color images according to a field sequential process, said apparat us comprising:

a display device having a matrix of pixels and a condensing lens disposed on a surface thereof for applying illuminating light in association with every four pixels of said matrix;

color switching illumination means for applying illuminating lights including a red illuminating light, a green illuminating light, a blue illuminating light, and an achromatic illuminating light at different angles to said condensing lens, switching the colors of the illuminating lights in each field period, such that, with adjacent four pixels as a unit, the illuminating lights applied to the pixels in each unit have different colors from each other, and switching the colors of the illuminating lights in each field period; and

video signal processing means for generating a red video signal, a green video signal, a blue video signal, and an achromatic video signal from a color video signal so as to correspond to the colors of the illuminating lights applied to the pixels in each unit, and energizing said display device with the generated video signals to display a color video picture thereon.