MICROMIRROR-BASED PROJECTION SYSTEM WITH OPTICS HAVING SHORT FOCAL LENGHTS

Abstract

Disclosed herein is a projection system that comprises an illumination system providing incident light, a projection lens for directing the incident light onto one or more spatial light modulator from where the incident light is modulated in accordance with a stream of image data derived from the desired image, and a projection lens for projecting the modulated light onto a screen.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary micromirror-based rear projection system;

FIG. 2 a illustrates a cross-sectional view of the incident light and the spatial light modulator in FIG. 1;

FIG. 2 b demonstrates the geometric relations of the spatial light modulator, the incident light and the modulate light;

FIG. 3 illustrates an exemplary illumination system for use in the projection system of FIG. 1;

FIG. 4 illustrates another exemplary illumination system for use in the projection system of FIG. 1;

FIG. 5 illustrates another exemplary micromirror-based rear-projection system;

FIG. 6 illustrates a cross-sectional view of an exemplary spatial light modulator for use in the projection system of FIG. 1 and FIG. 2;

FIG. 7 is a cross-sectional view of an exemplary micromirror device for use in the spatial light modulator of FIG. 6;

FIG. 8 is a perspective view of an exemplary micromirror device of FIG. 7;

FIG. 9 is a perspective view of an exemplary micromirror device of FIG. 7;

FIG. 10 is a perspective view of an exemplary spatial light modulator having an array of micromirror devices in FIG. 9 for use in the projection systems of FIG. 1 and FIG. 5;

FIG. 11 is a top view of another exemplary spatial light modulator having an array of micromirror devices of FIG. 9 for use in the projection systems of FIG. 1 and FIG. 5;

FIG. 12 is a top view of yet another exemplary spatial light modulator having an array of micromirror devices of FIG. 9 for use in the projection systems of FIG. 1 and FIG. 5;

FIG. 13 is a top view of yet another exemplary spatial light modulator having an array of micromirror devices of FIG. 9 for use in the projection systems of FIG. 1 and FIG. 5;

FIG. 14 a to FIG. 14c illustrate a top view of yet another exemplary spatial light modulator; and

FIG. 15 is a top view of yet another exemplary spatial light modulator having an array of micromirror devices of FIG. 9 for use in the projection systems of FIG. 1 and FIG. 5.

Claims

1. A projection system, comprising: an illumination system providing light;an array of reflective and deflectable mirror plates for modulating the incident light in accordance with a stream of image data;a projection lens for projecting the modulated light onto a translucent screen;wherein each mirror plate is capable of being rotated to an ON state angle from a natural resting state with the ON state angle being 14° degrees or higher; andwherein the projection lens has a back-focal length of 20.7 mm or less.

2. (canceled)

3. The system of claim 1, wherein the back-focal length is 17 mm or less.

4. The system of claim 1, wherein the distance between the projection lens and the mirror plate at the natural resting state is 20.7 mm or less

5. (canceled)

6. The system of claim 1, wherein the distance between the projection lens and the mirror plate at the natural resting state is 17 mm or less

7. The system of claim 1, further comprising: a relay lens for directing light from the illumination system to the array of mirror plates.

8. The system of claim 1, wherein the f-number of the projection lens is from f/1.8 to f/4.

9. The system of claim 1, wherein the f-number of the projection lens is around f/2.4.

10-12. (canceled)

13. The system of claim 1, wherein the difference between the ON and OFF state angles is 14° degrees or more.

14-30. (canceled)

31. The system of claim 1, wherein the illumination system comprises an arc lamp, a lightpipe, and a color wheel, and wherein the color wheel is positioned after the lightpipe and the light source at a propagation path of the light from the light source.

32-37. (canceled)

38. A projection system, comprising: an illumination system providing light;an array of reflective and deflectable mirror plates for modulating the incident light in accordance with a stream of image data;a projection lens for projecting the modulated light onto a translucent screen;wherein each mirror plate is capable of being rotated to an ON state angle from a natural resting state with the ON state angle being 14° degrees or higher; anda relay lens positioned at a propagation path of the illumination light onto the mirror plate array.

39. The system of claim 38, wherein the projection lens has a back-focal length of 20.7 mm or less.

40. (canceled)

41. The system of claim 39, wherein the back-focal length is 17 mm or less.

42. The system of claim 39, wherein the distance between the projection lens and the mirror plate at the natural resting state is 20.7 mm or less

43-45. (canceled)

46. The system of claim 39, wherein the f-number of the projection lens is from f/1.8 to f/4.

47. The system of claim 39, wherein the f-number of the projection lens is around f/2.4.

48. A projection system, comprising: an illumination system providing light;an array of reflective and deflectable mirror plates for modulating the incident light in accordance with a stream of image data derived from a desired image;a projection lens for projecting the modulated light onto a translucent screen such that the desired image projected thereon can be viewed from the opposite side of the screen by a viewer; anda relay lens displaced at a propagation path of the illumination light onto the micromirror array.

49. The system of claim 48, wherein the projection lens has a back-focal length of 20.7 mm or less.

50. (canceled)

51. The system of claim 49, wherein the back-focal length is 17 mm or less.

52. The system of claim 49, wherein the distance between the projection lens and the mirror plate at the natural resting state is 20.7 mm or less

53. (canceled)

54. The system of claim 49, wherein the distance between the projection lens and the mirror plate at the natural resting state is 17 mm or less

55. (canceled)

56. The system of claim 49, wherein the f-number of the projection lens is from f/1.8 to f/4.

57. The system of claim 49, wherein each mirror plate is capable of being rotated to an ON state angle from a natural resting state with the ON state angle being 14° degrees or higher; and

58. (canceled)

59. The system of claim 56, wherein the f-number is around f/2.4.