Angled illumination for a single order light modulator based projection system

• US 6,707,591 B2
• Filed: 08/15/2001
• Issued: 03/16/2004
• Est. Priority Date: 04/10/2001
• Status: Expired due to Term

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Amm, David T.
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): THOMPSON, TIMOTHY J
• Application Number:
  US09/930,831
• Publication Number:
  US 20020186448A1
• Time in Patent Office: 944 Days
• Field of Search: 359/224, 359/291, 359/290, 359/833, 359/618, 359/627, 359/629, 359/638, 359/639, 359/640, 348/742, 348/744, 348/748
• US Class Current: 359/290
• CPC Class Codes: G02B 27/18 for optical projection, e.g. combination of mirror and condenser and objective photographic, cine and overhead projectors G03B21/00; photographic projection printing G03B27/32; photolithographic projectors G03F7/20; projection television H04N5/74; colour projection television H04N9/31

Abstract

A display apparatus projects a two dimensional image onto a display screen and includes illumination optics, a light modulator, separating optics and scanning optics. The light modulator is optically coupled to the illumination optics such that in operation the illumination optics illuminate the light modulator with an off-axis illumination and further such that the light modulator directs light onto an optic axis for a bright pixel, thereby forming on-axis light, and away from the optic axis for a dark pixel, thereby forming off-axis light. The separating optics are coupled to the light modulator and separate the off-axis and on-axis light where the on-axis light produces a real and virtual image that is displayed by the projection and scanning optics.

Claims

1. A display apparatus comprising:

a. illumination optics;

b. a light modulator optically coupled to the illumination optics such that in operation the illumination optics illuminate the light modulator with an off-axis illumination and the light modulator selectively directs the off-axis illumination onto an optic axis, thereby forming on-axis light;

c. separating optics optically coupled to the light modulator; and

d. projecting and scanning optics optically coupled to the separating optics.

2. The display apparatus as claimed in claim 1 wherein the light modulator is further coupled to the illumination optics such that in operation the light modulator directs light onto the optic axis for a bright pixel, thereby forming the on-axis light.

3. The display apparatus as claimed in claim 1 wherein the light modulator is further coupled to the illumination optics such that in operation the light modulator directs the light away from the optic axis for a dark pixel, thereby forming off-axis light.

4. The display apparatus as claimed in claim 1 wherein the separating optics are coupled to the light modulator such that in operation the separating optics separate the off-axis light from the on-axis light.

5. The display apparatus as claimed in claim 1 wherein the separating optics are further coupled to the light modulator such that in operation the on-axis light produces a two dimensional image.

6. The display apparatus as claimed in claim 5 wherein the two dimensional image is a real image.

7. The display apparatus as claimed in claim 5 wherein the two dimensional image is a virtual image.

8. A method of providing angled illumination for a single order grating light valve projection system comprising:

a. illuminating a light modulator with illuminating optics such that in operation the illumination optics illuminate the light modulator with an off-axis illumination and the light modulator selectively directs the off-axis illumination onto an optic axis, thereby forming on-axis light;

b. coupling separating optics to the light modulator optically; and

c. coupling projection and scanning optics to the separating optics optically.

9. The method as claimed in claim 8 further comprising coupling the light modulator to the illumination optics such that in operation the light modulator directs light onto the optic axis for a bright pixel, thereby forming the on-axis light.

10. The method as claimed in claim 8 further comprising coupling the light modulator to the illumination optics such that in operation the light modulator directs the light away from the optics axis for a dark pixel, thereby forming off-axis light.

11. The method as claimed in claim 8 further comprising coupling the separating optics to the light modulator such that in operation the separating optics separate the off-axis light from the on-axis light.

12. The method as claimed in claim 8 further comprising coupling the separating optics to the light modulator such that in operation the on axis light produces a two dimensional image.

13. The method as claimed in claim 12 further comprising the two dimensional image being a real image.

14. The method as claimed in claim 12 further comprising the two dimensional image being a virtual image.

15. A display system comprising:

a. means for illuminating;

b. means for modulating light optically coupled to the means for illuminating such that in operation the means for illuminating illuminates the means for modulating with an off-axis illumination and the means for modulating selectively directs the off-axis illumination onto an optic axis, thereby forming on-axis light;

c. means for separating optically coupled to the means for modulating; and

d. means for projecting and scanning optically coupled to the means for separating.

16. The display apparatus as claimed in claim 15 wherein the means for modulating is further coupled to the means for illuminating such that in operation the means for modulating directs light onto the optic axis for a bright pixel, thereby forming the on-axis light.

17. The display apparatus as claimed in claim 15 wherein the means for modulating is further coupled to the means for illuminating such that in operation the means for modulating directs the light away from the optic axis for a dark pixel, thereby forming off-axis light.

18. The display apparatus as claimed in claim 15 wherein the means for separating is coupled to the means for modulating such that in operation the means for separating separates the off-axis light from the on-axis light.

19. The display apparatus as claimed in claim 15 wherein the means for separating is further coupled to the means for modulating such that in operation the on-axis light produces a two dimensional image.

20. The display apparatus as claimed in claim 19 wherein the two dimensional image is a real image.

21. The display apparatus as claimed in claim 19 wherein the two dimensional image is a virtual image.

22. A display apparatus for providing angled illumination for a single order grating light valve projection system comprising:

a. a light modulator configured to receive off-axis illumination and to direct light onto an optic axis for a bright pixel, thereby forming on-axis light, and the light modulator directs the light away from the optic axis for a dark pixel, thereby forming off-axis light;

b. separating optics optically coupled to the light modulator such that in operation the separating optics separate the off-axis light from the on-axis light and further such that in operation the on-axis light produces a two dimensional image; and

c. projection and scanning optics optically coupled to receive the on-axis light from the separating optics.

23. The display apparatus as claimed in claim 22 wherein the two dimensional image is a real image.

24. The display apparatus as claimed in claim 22 wherein the two dimensional image is a virtual image.

25. A display apparatus comprising:

a. a light modulator configured to receive illumination from an off-axis illumination; and

b. separating optics optically coupled to the light modulator for receiving an on-axis diffraction from the light modulator.

26. The display apparatus as claimed in claim 25 wherein the light modulator is further coupled to illumination optics such that in operation the light modulator directs light onto an optic axis for a bright pixel, thereby forming on-axis light.

27. The display apparatus as claimed in claim 25 wherein the light modulator is further coupled to the illumination optics such that in operation the light modulator directs the light away from the optic axis for a dark pixel, thereby forming off-axis light.

28. The display apparatus as claimed in claim 25 wherein the separating optics are coupled to the light modulator such that in operation the separating optics separate the off-axis light from the on-axis light.

29. The display apparatus as claimed in claim 25 wherein the separating optics are further coupled to the light modulator such that in operation the on-axis light produces a two dimensional image.

30. The display apparatus as claimed in claim 29 wherein the two dimensional image is a real image.

31. The display apparatus as claimed in claim 29 wherein the two dimensional image is a virtual image.

32. A light valve comprising:

a. illumination optics;

b. a light modulator optically coupled to the illumination optics such that in operation the illumination optics illuminate the light modulator with an off-axis illumination and the light modulator selectively directs the off-axis illumination onto an optic axis, thereby forming on-axis light; and

c. separating optics optically coupled to the light modulator.

33. The light valve as claimed in claim 32 wherein the light modulator is further coupled to the illumination optics such that in operation the light modulator directs light onto the optic axis for a bright pixel, thereby forming the on-axis light.

34. The light valve as claimed in claim 32 wherein the light modulator is further coupled to the illumination optics such that in operation the light modulator directs the light away from the optic axis for a dark pixel, thereby forming off-axis light.

35. The light valve as claimed in claim 32 wherein the separating optics are coupled to the light modulator such that in operation the separating optics separate the off-axis light from the on-axis light.

36. The light valve as claimed in claim 32 wherein the separating optics are further coupled to the light modulator such that in operation the on-axis light produces a two dimensional image.

37. The light valve as claimed in claim 36 wherein the two dimensional image is a real image.

38. The light valve as claimed in claim 36 wherein the two dimensional image is a virtual image.