Display apparatus and method

• US 6,909,473 B2
• Filed: 01/07/2002
• Issued: 06/21/2005
• Est. Priority Date: 01/07/2002
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Eastman Kodak Company
• Inventors: Kurtz, Andrew F., Kessler, David, Mi, Xiang-Dong
• Primary Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US10/040,663
• Publication Number:
  US 20030128320A1
• Time in Patent Office: 1,261 Days
• Field of Search: 349/5, 349/9, 349/96, 349/113, 349/117, 349/118, 353/8, 353/20, 359/486
• US Class Current: 349/5
• 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
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/3016 involving passive liquid crystal elements optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133548 Wire-grid polarisers
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/133638 Waveplates, i.e. plates with a retardation value of lambda/n
• CPC Class Codes: G02F 2203/02 reflective
• CPC Class Codes: H04N 9/3108 by using a single electronic spatial light modulator
• CPC Class Codes: H04N 9/3167 for polarizing the light beam polarizing optical systems per se G02B27/28
• CPC Class Codes: H04N 9/3191 Testing thereof testing of displays in general G09G3/006

Abstract

A projection display apparatus (10) uses a modulation optical system (200) that includes a liquid crystal device (210) in combination with a wire grid polarization beamsplitter (240), a wire grid polarization analyzer (270) and a projection lens (285) to form an image. In order to achieve high contrast and maintain high brightness levels, a compensator (260) is provided for minimizing leakage light for pixels in the black (OFF) state. A number of configurations are possible, such as with the compensator (260) disposed in the optical path between the liquid crystal device (210) and the wire grid polarization beamsplitter (240) and with a secondary compensator (265) disposed between wire grid polarization analyzer (270) and the wire grid polarization beamsplitter (240).

Claims

1. A display apparatus comprising:

(a) a light source for forming a beam of light;

(b) a pre-polarizer for polarizing said beam of light to provide a polarized beam of light;

(c) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(d) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(e) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, for conditioning the polarization states of oblique and skew rays of said modulated beam to provide a compensated modulated beam;

(f) wherein said wire grid polarization beamsplitter reflects said compensated modulated beam;

(g) a polarization analyzer which removes residual light of an opposite polarization; and

(h) image-forming optics for forming an image from said compensated modulated beam.

2. The apparatus of claim 1 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

3. The A-plate according to claim 2 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization beamsplitter.

4. The A-plate according to claim 2 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization beamsplitter.

5. The apparatus of claim 1 wherein said reflective liquid crystal device has a vertically aligned construction.

6. The compensator of claim 1 which modifies polarization states of the oblique and skew rays relative to said wire grid polarization beamsplitter, or said reflective liquid crystal device, or both.

7. A modulation optical system for providing high contrast modulation of an incident light beam, comprising:

(a) a pre-polarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(c) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(d) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, for conditioning the polarization states of oblique and skew rays of said modulated beam to provide a compensated modulated beam;

(e) a polarization analyzer which removes residual light of the opposite polarization.

8. The system of claim 7 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

9. The A-plate according to claim 8 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization beam splitter.

10. The A-plate according to claim 8 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization beamsplitter.

11. The system of claim 7 wherein said reflective liquid crystal device has a vertically aligned construction.

12. The compensator of claim 7 which modifies polarization states of the oblique and skew rays relative to said wire grid polarization beamsplitter, or said reflective liquid crystal device, or both.

13. A modulation optical system for providing high contrast modulation of an incident light beam, comprising:

(a) a wire grid pre-polarizer for pre-polarizing said beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire and polarization beamsplitter face a reflective liquid crystal device;

(c) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(d) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, for conditioning the polarization states of oblique and skew rays of said modulated beam to provide a compensated modulated beam; and

(e) a wire grid polarization analyzer which removes residual light of the opposite polarization.

14. The system of claim 13 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

15. The A-plate according to claim 14 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization beamsplitter.

16. The A-plate according to claim 14 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization beamsplitter.

17. The system of claim 13 wherein said reflective liquid crystal device has a vertically aligned construction.

18. The compensator of claim 13 which modifies polarization states of the oblique and skew rays relative to said wire grid polarization beamsplitter, or said reflective liquid crystal device, or both.

19. A modulation optical system for providing high contrast modulation of an incident light beam, comprising:

(a) a wire grid pre-polarizer for pre-polarizing said beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(c) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(d) a wire grid polarization analyzer which removes unmodulated first polarization light; and

(e) a compensator which conditions the polarization states of oblique and skew rays relative to said wire-grid polarization analyzer and said wire grid pre-polarizer.

20. The system of claim 19 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

21. The A-plate according to claim 20 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization analyzer.

22. The A-plate according to claim 20 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization analyzer.

23. The system of claim 19 wherein said reflective liquid crystal device has a vertically aligned construction.

24. The system of claim 19 wherein said compensator is located between said wire grid pre-polarizer and said wire grid polarization beamsplitter.

25. The system of claim 19 wherein said compensator is located between said wire grid polarization beamsplitter and said wire grid polarization analyzer.

26. A display apparatus comprising:

(a) a light source for forming a beam of light;

(b) a wire grid pre-polarizer for polarizing said beam of light to provide a polarized beam of light;

(c) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(d) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(e) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, for conditioning the polarization states of oblique and skew rays of said modulated beam to provide a compensated modulated beam;

(f) a wire grid polarization analyzer which removes residual light of the opposite polarization; and

(g) image-forming optics for forming an image from said compensated modulated beam.

27. The system of claim 26 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

28. The A-plate according to claim 27 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization beamsplitter.

29. The A-plate according to claim 27 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization beamsplitter.

30. The system of claim 26 wherein said reflective liquid crystal device has a vertically aligned construction.

31. The compensator of claim 26 which modifies polarization states of the oblique and skew rays relative to said wire grid polarization beamsplitter, or said reflective liquid crystal device, or both.

32. A method for projecting an image generated from image data, the method comprising:

(a) creating a polarized light beam;

(b) directing said polarized light beam to a wire grid polarization beamsplitter, transmitting incident light having a first polarization as a transmitted beam, and reflecting incident light having a second polarization as a reflected beam;

(c) modulating said transmitted beam from said wire grid polarization beamsplitter to encode image data at a reflective liquid crystal device and to provide a modulated beam;

(d) disposing a compensator in the path of said modulated beam to alter polarization states of oblique and skew light rays and thereby enhance the removal of leakage light from said modulated beam; and

(e) projecting said modulated beam to form said image.

33. A display apparatus comprising:

(a) a light source for forming a beam of light;

(b) a wire grid pre-polarizer for polarizing said beam of light to provide a polarized beam of light;

(c) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(d) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(e) a wire grid polarization analyzer which removes residual light of the opposite polarization;

(f) a compensator for conditioning the polarization states of oblique and skew rays from said wire grid pre-polarizer and said wire grid polarization analyzer; and

(g) image-forming optics for forming an image from said modulated beam.

34. The apparatus of claim 33 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

35. The A-plate according to claim 34 wherein the optical axis of said A-plate is substantially parallel to said sub-wavelength wires of said wire grid polarization beamsplitter.

36. The A-plate according to claim 34 wherein the optical axis of said A-plate is substantially perpendicular to said sub-wavelength wires of said wire grid polarization beamsplitter.

37. The apparatus of claim 33 wherein said reflective liquid crystal device has a vertically aligned construction.

38. The apparatus of claim 33 wherein said compensator is located between said wire grid pre-polarizer and said wire grid polarization beamsplitter.

39. The apparatus of claim 33 wherein said compensator is located between said wire grid polarization beamsplitter and said wire grid polarization analyzer.

40. A display apparatus comprising:

(a) a light source for forming a beam of light;

(b) a pre-polarizer for polarizing said beam of light to provide a polarized beam of light;

(c) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire mid polarization beamsplitter face a reflective liquid crystal device;

(d) wherein said reflective liquid crystal device selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(e) a wire grid polarization analyzer which removes residual light of the opposite polarization;

(f) image-forming optics for forming an image from said modulated beam; and

(g) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device for conditioning the polarization states of oblique and skew rays of said modulated beam.

41. A display apparatus comprising:

(a) a light source for forming a beam of light;

(b) a pre-polarizer for polarizing said beam of light to provide a polarized beam of light;

(c) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization, wherein sub-wavelength wires on said wire grid notarization beamsplitter face a reflective spatial light modulator;

(d) wherein said reflective spatial light modulator selectively modulates said polarized beam of light having a first polarization to encode image data thereon in order to form a modulated beam, and then reflects said modulated beam back to said wire grid polarization beamsplitter;

(e) a compensator, located between said wire grid polarization beamsplitter and said reflective spatial light modulator, for conditioning the polarization states of oblique and skew rays of said modulated beam to provide a compensated modulated beam;

(f) wherein said wire grid polarization beamsplitter reflects said compensated modulated beam;

(g) a polarization analyzer which removes residual light of the opposite polarization; and

(h) image-forming optics for forming an image from said compensated modulated beam.

42. A modulation optical system for providing contrast modulation of an incident light beam, comprising:

(a) polarization optics including at least two wire grid polarization devices, where at least one of said wire grid polarization devices is a wire grid polarization beamsplitter, and said incident beam of light interacts with said wired grid polarization beamsplitter with a portion reflected and another portion transmitted;

(b) a reflective liquid crystal device for selectively modulating a beam of light having to encode image data thereon in order to form a modulated beam, where said reflective liquid crystal device alters a polarization state of said beam of light in a controlled manner with said image data and reflects said modulated beam back to said wire grid polarization beamsplitter;

(c) a compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, for conditioning the polarization states of oblique and skew rays of said modulated beam; and

wherein the sub-wavelength wires on said wire grid polarization beamsplitter face said reflective liquid crystal device.

43. The system of claim 42 wherein said compensator comprises one or more birefringent layers, wherein said birefringent layers comprise at least one of the following;

an A-plate film, a C-plate film, or a biaxial film.

44. The A-plate according to claim 43 wherein the optical axis of said A-plate is substantially parallel to the sub-wavelength wires of said wire grid polarization beamsplitter.

45. The A-plate according to claim 43 wherein the optical axis of said A-plate is substantially perpendicular to the sub-wavelength wires of said wire grid polarization beamsplitter.

46. The modulation optical system of claim 42 wherein said reflective liquid crystal device has a vertically aligned construction.

47. The compensator of claim 42 which modifies polarization states of the oblique and skew rays relative to said wire grid polarization beamsplitter, or said reflective liquid crystal device, or both.

48. An electronic projection apparatus for projection of color images onto a display surface, said apparatus comprising:

(a) a light source which produces a beam of light;

(b) an optical system which separates said beam of light into separate color beams of light, and which provides beam shaping and focusing of said color beams of light;

(c) a modulation optical system for each of said color beams of light, said modulation optical system providing an image bearing color light beam, and said modulation optical system comprising;

(1) a prepolarizer for prepolarizing one of said colored beams of light to provide a polarized beam of light

(2) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective liquid crystal device;

(3) wherein said reflective liquid crystal device receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode image data thereon, providing both modulated light and unmodulated light which differ in polarization;

(4) wherein said reflective liquid crystal device reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(5) wherein a polarization compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, is provided for conditioning oblique and skew light rays;

(6) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light;

(7) wherein a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light;

(d) a recombination prism for combining said image bearing color light beams corresponding to each of said color beams of light, into a full color image bearing beam; and

(e) a projection lens system for projecting said full color image bearing beam onto said display surface; and

wherein said pre-polarizer and said polarization analyzer in any of said modulation optical systems corresponding to a given color have different polarization properties from one another.

49. An electronic projection apparatus according to claim 48 wherein said pre-polarizer is a MacNielle type prism and said polarization analyzer is a wire grid polarizer.

50. An electronic projection apparatus according to claim 48 wherein said pre-polarizer and said polarization analyzer are both wire grid polarizers.

51. An electronic projection apparatus as in claim 48 wherein said reflective liquid crystal device receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

52. An electronic projection apparatus as in claim 48 wherein said reflective liquid crystal device receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

53. An electronic projection apparatus for projection of color images onto a display surface, said apparatus comprising:

(a) a light source which produces a beam of light;

(b) an optical system which separates said beam of light into separate color beams of light, and which provides beam shaping and focusing of said color beams of light;

(c) a modulation optical system for each of said color beams of light, said modulation optical system providing an image bearing color light beam, and said modulation optical system comprising;

(1) a prepolarizer for prepolarizing one of said colored beams of light to provide a polarized beam of light

(2) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(3) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode image data thereon, providing both modulated light and unmodulated light which differ in polarization;

(4) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(5) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light;

(6) wherein a compensator, located between said wire grid polarization beamsplitter and said reflective spatial light modulator, is provided for conditioning the polarization states of oblique and skew light rays;

(7) wherein a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light;

(d) a recombination prism for combining said image bearing color light beams corresponding to each of said color beams of light, into a full color image bearing beam;

(e) a projection lens system for projecting said full color image bearing beam onto said display surface; and

wherein said pre-polarizer and said polarization analyzer in any of said modulation optical systems corresponding to a given color have different polarization properties from one another.

54. An electronic projection apparatus according to claim 53 wherein said pre-polarizer is a MacNielle type prism and said polarization analyzer is a wire grid polarizer.

55. An electronic projection apparatus according to claim 53 wherein said pre-polarizer and said polarization analyzer are both wire grid polarizers.

56. An electronic projection apparatus as in claim 53 wherein said reflective spatial light modulator receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

57. An electronic projection apparatus as in claim 53 wherein said reflective spatial light modulator receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

58. A modulation optical system for providing modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(c) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein a polarization compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal device, is provided for conditioning oblique and skew light rays;

(f) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light;

(g) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light; and

wherein said pre-polarizer and said polarization analyzer in said modulation optical system have different polarization properties from one another.

59. A modulation optical system according to claim 58 wherein said pre-polarizer is a MacNielle type prism and said polarization analyzer is a wire grid polarizer.

60. A modulation optical system according to claim 58 wherein said pre-polarizer and said polarization analyzer are both wire grid polarizers.

61. A modulation optical system as in claim 58 wherein said reflective spatial light modulator receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

62. A modulation optical system as in claim 58 wherein said reflective spatial light modulator receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

63. A modulation optical system for providing modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(c) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light;

(f) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light; and

wherein said pre-polarizer and said polarization analyzer in said modulation optical system have different polarization properties from one another.

64. A modulation optical system according to claim 63 wherein said pre-polarizer is a MacNielle type prism and said polarization analyzer is a wire grid polarizer.

65. A modulation optical system according to claim 63 wherein said pre-polarizer and said polarization analyzer are both wire grid polarizers.

66. A modulation optical system as in claim 63 wherein said reflective spatial light modulator receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

67. A modulation optical system as in claim 63 wherein said reflective spatial light modulator receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

68. A modulation optical system for providing modulation of an incident beam of light comprising:

(a) a wire grid polarization beamsplitter for receiving said beam of light and providing a polarized beam of light, by nominally transmitting the portion of said beam of light having a first polarization, and for nominally reflecting the portion of said beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator

(b) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and then selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(c) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(d) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light; and

(e) wherein said modulation optical system further comprises at least a second wire grid polarizer, which is either a pre-polarizer that interacts with said incident beam of light prior to said wire grid polarization beamsplitter, or is a polarization analyzer that follows said wire grid polarization beamsplitter, and receives said modulated light, and further removes any residual unmodulated light from said modulated light.

69. A modulation optical system as in claim 68 wherein said modulator is a liquid crystal display device.

70. A modulation optical system as in claim 68 wherein said liquid crystal display device is comprised of vertically aligned liquid crystal molecules.

71. A modulation optical system as in claim 68 wherein said reflective spatial light modulator receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

72. A modulation optical system as in claim 68 wherein said reflective spatial light modulator receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

73. A modulation optical system for providing high contrast modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(c) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein a polarization compensator, located between said wire grid polarization beamsplitter and said reflective liquid crystal spatial light modulator, is provided for conditioning oblique and skew light rays relative to said wire and polarization beamsplitter, or said reflective spatial light modulator, or both;

(f) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light; and

(g) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light.

74. A modulation optical system as in claim 73 wherein said reflective spatial light modulator is a liquid crystal display device is comprised of vertically aligned liquid crystal molecules.

75. A modulation optical system as in claim 73 wherein said prepolarizer comprises a wire grid polarizer.

76. A modulation optical system as in claim 73 wherein said polarization analyzer comprises a wire grid polarizer.

77. A modulation optical system as in claim 73 wherein said reflective spatial light modulator receives said polarized beam of light having a first polarization, as was transmitted through said wire grid polarization beamsplitter.

78. A modulation optical system as in claim 73 wherein said reflective spatial light modulator receives said polarized beam of light having a second polarization, as was reflected from said wire grid polarization beamsplitter.

79. A modulation optical system for providing contrast modulation of an incident light beam comprising:

(a) a wire grid polarization beamsplitter for receiving said incident beam of light, for transmitting a portion of said incident beam of light having a first polarization, and for reflecting a portion of said incident beam of light having a second polarization nominally orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(b) wherein said reflective spatial light modulator receives a beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(c) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(d) wherein a polarization compensator, located between said wire grid polarization beamsplitter and said reflective spatial light modulator, is provided for conditioning oblique and skew light rays relative to said wire grid polarization beamsplitter, or said reflective spatial light modulator, or both; and

(e) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light.

80. A modulation optical system for providing contrast modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization, wherein subwavelength wires on said wire grid polarization beamsplitter face a reflective spatial light modulator;

(c) wherein said reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein a polarization compensator, provided adjacent to said wire grid polarization beamsplitter, conditions the oblique and skew light rays relative to said wire grid polarization beamsplitter, or said reflective spatial light modulator, or both; and

;

(f) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light; and

(g) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light.

81. A modulation optical system for providing contrast modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization;

(c) a reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein a polarization compensator, located between said wire grid polarization beamsplitter and said reflective spatial light modulator, conditions the oblique and skew light rays relative to said wire grid polarization beamsplitter, or said reflective spatial light modulator, or both; and

;

(f) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light; and

(g) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light.

82. A modulation optical system for providing contrast modulation of an incident light beam comprising:

(a) a prepolarizer for pre-polarizing said beam of light to provide a polarized beam of light;

(b) a wire grid polarization beamsplitter for receiving said polarized beam of light, for transmitting said polarized beam of light having a first polarization, and for reflecting said polarized beam of light having a second polarization orthogonal to said first polarization;

(c) a reflective spatial light modulator receives said polarized beam of light, having either a first polarization or a second polarization, and selectively modulates said polarized beam of light to encode data thereon, providing both modulated light and unmodulated light which differ in polarization;

(d) wherein said reflective spatial light modulator reflects back both said modulated light and said unmodulated light to said wire grid polarization beamsplitter;

(e) wherein a polarization compensator, located in the portion of the optical path that includes said wire grid polarization beamsplitter and said reflective spatial light modulator, conditions the oblique and skew light rays relative to said wire grid polarization beamsplitter, or said reflective spatial light modulator, or both;

(f) wherein said wire grid polarization beamsplitter separates said modulated light from said unmodulated light; and

(g) a polarization analyzer receives said modulated light, and which further removes any residual unmodulated light from said modulated light.