Projection-type color display device having a driving circuit for producing a mirror-like image

• US 5,191,450 A
• Filed: 04/03/1992
• Issued: 03/02/1993
• Est. Priority Date: 04/14/1987
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nakamura, Junichi, Yajima, Akitaka
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): TRAN, MINH LOAN
• Application Number:
  US07/863,387
• Time in Patent Office: 333 Days
• Field of Search: 350/331 R, 350/333, 350/334, 350/337, 350/342, 350/345, 340/784, 340/784 E, 340/794, 340/795, 353/31, 353/34, 353/37, 353/33, 353/81, 353/122, 359/40, 359/53, 359/58, 359/64, 359/54
• US Class Current: 349/8
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

A projection-type display device for producing a synthesized symmetrical projected image. The device includes three liquid crystal light valves associated with the three primary colors producing three separate images. One of the light valves is horizontally scanned in a direction opposite to the horizontal scanning direction of the other two light valves. The two images produced by the light valves which scan in the same horizontal direction are mirror images of the image produced by the third light valve.

Claims

1. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting at least one of the three images and transmitting at least one of the three images to produce a synthesized image; and

driving means associated with each light valve for driving each of the three light valves, each driving means includes horizontal scanning shift register means for horizontally scanning the image to be produced by the associated light valve;

wherein the horizontal scanning direction of the horizontal scanning shift register means associated with one of the light valves transmits an image opposite to the image transmitted by scanning direction of the horizontal scanning shift register means associated with the other two light valves so that the image produced by the one light valve is synchronized with the images of the other two light valves.

2. The projection type display device of claim 1, further including mask means associated with each light valve for shielding portions of that light valve from the associated primary color.

3. The projection-type display device of claim 1;

further including a light source for producing light having a plurality of colors; and

segregating means for segregating the light into the plurality of colors including the first, second and third primary colors;

wherein the optical lengths from the light source to the first light valve, second light valve and third light valve are different and are based on the luminous intensities of the primary colors, respectively.

4. The projection-type display device of claim 3, wherein the first primary color is red and has the greatest luminous intensity of all three primary colors produced by the light course and is associated with the longest optical length.

5. The projection-type display device of claim 4, in which a tungsten lamp serves as the light source.

6. The projection-type display device of claim 3, wherein the first primary color is blue and has the greatest luminous intensity of all three primary colors produced by the light source and is associated with the longest optical length.

7. The projection-type display device of claim 6, in which a xenon lamp serves as the light source.

8. The projection-type display device of claim 3, wherein the first primary color is green and has the greatest luminous intensity of all three primary colors produced by the light source and is associated with the longest optical length.

9. The projection-type display device of claim 8, in which a metal halide lamp serves as the light source.

10. The projection-type display device of claim 3, wherein the third primary color is blue and has the smallest luminous intensity of all three primary colors produced by the light source and is associated with the shortest optical length.

11. The projection-type display device of claim 10, in which a tungsten lamp serves as the light source.

12. The projection-type display device of claim 10, in which a metal halide lamp serves as the light source.

13. The projection-type display device of claim 3, wherein the third primary color is red and has the smallest luminous intensity of all three primary colors produced by the light source and is associated with the shortest optical length.

14. The projection-type display device of claim 13, in which a xenon lamp serves as the light source.

15. The projection-type display device of claim 3, in which a tungsten lamp serves as the light source.

16. The projection-type display device of claim 3, in which a xenon lamp serves as the light source.

17. The projection-type display device of claim 3, in which a metal halide lamp serves as the light source.

18. The projection-type display device of claim 1, wherein each light valve of the liquid crystal light valve means is a liquid crystal panel.

19. The projection-type display device of claim 1, wherein the horizontal scanning shift register means for each light valves receives the same horizontal scanning signal.

20. A method for producing an image projected from a liquid crystal display device which includes a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, comprising the steps of:

combining the three images by reflecting at least one of the three images and transmitting at least one of the three images; and

driving each of the three light valves to control production of the images, said driving of each light valve including horizontally scanning the image to be produced by the light valve;

wherein the horizontal scanning direction associated with light valves which produce images reflected and transmitted in combining the three images together are opposite in direction.

21. The method of claim 20, further providing light shielding protection to portions of each light valve from the associated primary color.

22. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting the first image twice, by first reflecting the second image and then transmitting the reflected image, and by transmitting the third image twice to produce a synthesized image; and

driving means for driving the image produced by the first and third light valves in a first direction and driving the second image in a second direction, each driving means includes a horizontal scanning shift register means for horizontally scanning the image to be produced by the associated light valve;

wherein the horizontal scanning directions of the horizontal scanning shift register means associated with the images of the first and third light valves transmit an image opposite to the scanning direction of the horizontal scanning shift register means associated with the image of the second light valve so that the image produced by one light valve is synchronized with the image of the other two light valves.

23. The projection-type device of claim 22, wherein the first primary color is green.

24. The projection-type device of claim 22, wherein the second primary color is blue.

25. The projection-type device of claim 22, wherein the third primary color is red.

26. The projection-type display device of claim 22, wherein the horizontal scanning shift register means for each light valve receives the same horizontal scanning signal.

27. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting at least one of the three images and transmitting at least one of the three images to produce a synthesized image; and

driving means for driving each of the three light valves, each driving means including one of a horizontal scanning means for horizontally scanning the image to be produced by the associated light valve and a vertical scanning means for vertically scanning the image to be produced by the associated light valve, the driving means further including bidirectional shift registers for shifting the image in one of the horizontal scanning direction and the vertical scanning direction;

wherein the horizontal scanning direction of the horizontal scanning means associated with one of the light valves transmits an image opposite to the scanning direction of the horizontal scanning means associated with the other two light valves and the vertical scanning direction of the vertical scanning means associated with one of the light valves transmits an image opposite to the scanning direction of the vertical scanning means associated with the other two light valves.

28. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a secondary primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting at least one of the three images and transmitting at least one of the three images to produce a synthesized image; and

driving means for driving each of the three light valves, the driving means for one light valve being invertedly by assembled with respect to the driving means for the other two light valves, each driving means including horizontal scanning means for horizontally scanning the image to be produced by the associated light valve;

wherein the horizontal scanning direction of the horizontal scanning means associated with the light valve of the invertedly assembled driving means transmits an image opposite to the scanning direction of the horizontal scanning associated with light valves of the other two driving means.

29. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting the first image twice, by first reflecting the second image and then transmitting the reflected image, and by transmitting the third image twice to produce a synthesized image; and

driving means for driving the image produced by the first and third light valves in a first direction and driving the second image in a second direction, each driving means including one of a horizontal scanning means for horizontally scanning the image to be produced by the associated light valve and a vertical scanning means for vertically scanning the image to be produced by the associated light valve, the driving means further including bidirectional shift registers for shifting the image in one of a horizontal scanning direction and a vertical scanning direction;

wherein the horizontal scanning directions of the horizontal scanning means associated with the images of the first and third light valves transmit an image opposite to the scanning direction of the horizontal scanning means associated with the image of the second light valve and the vertical scanning directions of the vertical scanning means associated with the images of the first and third light valves transmit an image opposite to the scanning direction of the vertical scanning means associated with the image of the second light valve.

30. A projection-type display device in which light produced by a light source is directed towards a first liquid crystal light valve associated with a first primary color for producing a first image, a second liquid crystal light valve associated with a second primary color for producing a second image and a third liquid crystal light valve associated with a third primary color for producing a third image, the liquid crystal light valves including a plurality of picture element electrodes arranged in an active matrix array, comprising:

integrating means for combining the three images by reflecting the first image twice, by first reflecting the second image and then transmitting the reflected image, and by transmitting the third image twice to produce a synthesized image; and

driving means for driving the image produced by the first and third light valves in a first direction and driving the second image in a second direction, the driving means for the second light valve being invertedly by assembled with respect to the driving means for the first and third light valves, each driving means including horizontal scanning means for horizontally scanning the image to be produced by the associated light valve;

wherein the horizontal scanning directions of the horizontal scanning means associated with the image of the second light valve transmits an image opposite to the scanning direction of the horizontal scanning means associated with the first and third light valves.