Projector with camcorder defeat

• US 20040150794A1
• Filed: 01/30/2003
• Published: 08/05/2004
• Est. Priority Date: 01/30/2003
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Tredwell, Timothy J., Kurtz, Andrew F., Silverstein, Barry D., Nelson, David J., Cobb, Joshua M., Ehrne, Franklin D.
• Application Number:
  US10/354,424
• Publication Number:
  US 20040150794A1
• Time in Patent Office: Days
• US Class Current: 353/31
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto

Abstract

A copy protection illumination system (1) comprises a polychromatic light source (20); uniformizing optics (22) for homogenizing light from the polychromatic light source to provide a uniform illumination field; condenser relay optics; dichroic optics; illumination relay optics (82); a spatial light modulator (30); and a modulation element located at a plane in an optical path located between the polychromatic light source and the spatial light modulator.

Claims

1. A copy protection illumination system for illuminating a spatial light modulator comprising:

(a) a polychromatic light source;

(b) uniformizing optics for homogenizing light from said polychromatic light source to provide a uniform illumination field;

(c) relay optics;

(d) dichroic optics; and

(e) an interference modulation element located at a plane in an optical path located between said polychromatic light source and said spatial light modulator.

2. A copy protection illumination system as in claim 1 wherein the polychromatic light source is a lamp.

3. A copy protection illumination system as in claim 1 wherein the relay optics consists of one or more of the following:

(a) condenser relay optics for directing said uniform illumination field toward a dichroic separator

(b) illumination relay optics for imaging and directing said light in colored light modulation channel towards said spatial light modulator.

4. A copy protection illumination system as in claim 1 wherein the relay optics provides both an aperture stop or a plane conjugate to an aperture stop plane and an intermediate image plane conjugate to said spatial light modulator.

5. A copy protection illumination system as in claim 1 wherein said spatial light modulator is a transmissive liquid crystal device (LCD).

6. A copy protection illumination system as in claim 1 wherein said spatial light modulator is a reflective liquid crystal device (LCD).

7. A copy protection illumination system as in claim 1 wherein said spatial light modulator is a digital micromirror device (DMD).

8. A copy protection illumination system as in claim 1 wherein said interference modulation element is located at an intermediate image plane conjugate to said spatial light modulator.

9. A copy protection illumination system as in claim 8 wherein said interference modulation element is modulated in such a way that the interference modulation element, when averaged over time, modulates the light equally over the field.

10. A copy protection illumination system as in claim 1 wherein said interference modulation element is located at an aperture stop plane or a plane conjugate to an aperture stop plane.

11. A copy protection illumination system as in claim 1 wherein said interference modulation element is located between a conjugate image plane and an aperture stop or between a conjugate image plane and a conjugate aperture stop.

12. A copy protection illumination system as in claim 1 wherein said interference modulation element is a mechanical interference element.

13. A copy protection illumination system as in claim 12 wherein said interference modulation element is a shutter.

14. A copy protection illumination system as in claim 1 wherein said interference modulation element is an electro optical interference element.

15. A copy protection illumination system as in claim 1 wherein said interference modulation element is located in a single color channel.

16. A copy protection illumination system as in claim 1 wherein said interference modulation element operates at a frequency greater than 30 Hz.

17. A copy protection illumination system as in claim 16 wherein said frequency varies.

18. A copy protection illumination system as in claim 1 wherein said interference modulation element comprises a watermark.

19. A projector with camcorder defeat capability including a copy protection illumination system for illuminating a spatial light modulator comprising:

(a) a polychromatic light source;

(b) uniformizing optics for homogenizing light from said polychromatic light source to provide a uniform illumination field;

(c) relay optics;

(d) dichroic optics; and

(e) an interference modulation element located at a plane in an optical path located between said polychromatic light source and said spatial light modulator.

20. A copy protection imaging system comprising:

(a) a spatial light modulator;

(b) image relay optics;

(c) a dichroic combiner;

(d) a projection lens; and

(e) an interference modulation element located at a plane in an optical path located between said spatial light modulator and said projection lens.

21. A copy protection imaging system as in claim 20 wherein said spatial light modulator is a transmissive liquid crystal device (LCD).

22. A copy protection imaging system as in claim 20 wherein said spatial light modulator is a reflective liquid crystal device (LCD).

23. A copy protection imaging system as in claim 20 wherein said spatial light modulator is a digital micromirror device (DMD).

24. A copy protection imaging system as in claim 20 wherein said interference modulation element is located at an intermediate image plane conjugate to said spatial light modulator.

25. A copy protection imaging system as in claim 24 wherein said interference modulation element is modulated in such a way that the interference modulation element, when averaged over time, modulates the light equally over the field.

26. A copy protection imaging system as in claim 20 wherein said interference modulation element is located at an aperture stop plane or a plane conjugate to an aperture stop plane.

27. A copy protection imaging system as in claim 20 wherein said interference modulation element is located between a conjugate image plane and an aperture stop or between a conjugate image plane and a conjugate aperture stop.

28. A copy protection imaging system as in claim 20 wherein said interference modulation element is a mechanical interference elements.

29. A copy protection imaging system as in claim 28 wherein said interference modulation element is a shutter.

30. A copy protection imaging system as in claim 29 wherein said interference modulation element is an electro optical interference element.

31. A copy protection imaging system as in claim 20 wherein said interference modulation element is located in a single color channel.

32. A copy protection imaging system as in claim 20 wherein said interference modulation element operates at a frequency greater than 30 Hz.

33. A copy protection imaging system as in claim 32 wherein said frequency varies.

34. A copy protection imaging system as in claim 20 wherein said interference modulation element comprises a watermark.

35. A copy protection imaging system as in claim 20 wherein correction means is applied to said spatial light modulators to correct for color non-uniformity across the field generated by spatially non uniform modulation by said spatial modulation interference elements.

36. A projector with camcorder defeat including a copy protection imaging system comprising:

(a) a spatial light modulator;

(b) image relay optics;

(c) a dichroic combiner;

(d) a projection lens; and

(e) an interference modulation element located at a plane in an optical path located between said spatial light modulator and said projection lens.

37. A projector with camcorder defeat for projecting a multicolor image onto a display surface comprising:

(a) a polychromatic light source;

(b) uniformizing means for homogenizing light from said polychromatic light source to provide a uniform illumination field;

(c) condenser relay optics for directing said uniform illumination field toward a dichroic separator, said dichroic separator providing colored light for a first, second, and third colored channel;

(d) wherein each colored channel is similarly constructed and comprises;

(i) an illumination relay lens for imaging and directing said colored light in said colored channel towards;

(ii) a spatial light modulator for forming a first image thereon; and

(iii) an image relay lens for focusing and relaying a real image of said first image towards a dichroic combiner;

(e) said dichroic combiner forming a multicolor image by combining said real image from said first colored channel, said real image from said second colored channel, and said real image from said third colored channel;

,

(f) a projection lens for projecting said multicolor image toward said display surface; and

(g) an interference modulation element located at a plane in an optical path located between said polychromatic light source and said projection lens.

38. A projector as in claim 37 wherein at least one of said spatial light modulators is a transmissive liquid crystal device (LCD).

39. A projector as in claim 37 wherein at least one of said spatial light modulators is a reflective liquid crystal device (LCD).

40. A projector as in claim 37 wherein at least one of said spatial light modulators is a digital micromirror device (DMD).

41. A projector as in claim 37 wherein said interference modulation element is located at an intermediate image plane conjugate to said spatial light modulator.

43. A projector as in claim 37 wherein said interference modulation element is located at an aperture stop plane or a plane conjugate to an aperture stop plane.

44. A projector as in claim 37 wherein said interference modulation element is located between a conjugate image plane and an aperture stop or between a conjugate image plane and a conjugate aperture stop.

45. A projector as in claim 37 wherein said interference modulation element is a mechanical interference element.

46. A projector as in claim 45 wherein said mechanical interference element provides a watermark.

47. A projector as in claim 45 wherein said interference modulation element is a shutter.

48. A projector as in claim 37 wherein said interference modulation element is an electro optical interference element.

49. A projector as in claim 48 wherein said electro optical interference element provides a watermark.

50. A projector as in claim 37 wherein said interference modulation element is located in a single color channel.

52. A projector as in claim 37 wherein said interference modulation element operates at a frequency greater than 30 Hz.

53. A projector as in claim 52 wherein said frequency varies.

54. A projector as in claim 37 wherein said interference modulation element comprises a watermark.

55. A projector as in claim 37 wherein a first modulation interference element is located in the first of said color channels and a second modulation interference element is located in a second of said color channels.

56. A projector as in claim 55 wherein the first and second modulation interference elements are modulated sequentially.

57. A projector as in claim 56 where the modulation of said first and second modulation interference elements is performed randomly.

58. A projector as in claim 55 wherein the first and second modulation interference elements are modulated at different frequencies.

59. A projector as in claim 55 wherein the first and second modulation interference elements are modulated such that they are out of phase with each other.

60. A projector as in claim 37 wherein a first modulation interference element is located in one of said color channels and a second modulation interference element is located before said dichroic separator or after said dichroic combiner.

61. A projector as in claim 37 wherein correction means is applied to said spatial light modulators to correct for color non-uniformity generated by spatially non uniform modulation by said spatial modulation interference elements.

42. A projector as in 41 wherein said interference modulation element is modulated in such a way that the interference modulation element, when averaged over time, modulates the light equally over the field.

51. A projector as in claim to 50 wherein said single color channel is a channel which has excess light for a desired white light color temperature when displayed.

62. A method of creating temporal and spatial interference using an interference modulation element at a plane conjugate to a spatial light modulator in a digital projection system.

63. A method as in claim 62 wherein said interference modulation element is modulated in such a way that the interference modulation element, when averaged over time, modulates the light equally over the field.

64. A method as in claim 62 wherein correction means is applied to said spatial light modulators to correct for color non-uniformity generated by spatially non uniform modulation by said spatial modulation interference elements.

65. A method as in claim 62 wherein said interference modulation element is a mechanical interference element.

66. A method as in claim 65 wherein said mechanical interference element provides a watermark.

67. A method as in claim 65 wherein said mechanical interference element is a shutter.

68. A method as in claim 62 wherein said interference modulation element an electro optical interference element.

69. A method as in claim 68 wherein said electro optical interference element provides a watermark.

70. A method of creating temporal interference using an interference modulation element at an aperture stop plane or a plane conjugate to an aperture stop plane in a digital projection system.

71. A method as in claim 70 wherein said interference modulation element is a mechanical interference element.

72. A method as in claim 71 wherein said mechanical interference element provides a watermark.

73. A method as in claim 71 wherein said mechanical interference element is a shutter.

74. A method as in claim 70 wherein said interference modulation element an electro optical interference element.

75. A method as in claim 74 wherein said electro optical interference element provides a watermark.

76. A method of creating temporal and spatial interference using an interference modulation element at a plane in convergent or divergent space outside the depth of focus of the image plane or conjugate image plane in a digital projection system.

77. A method as in claim 76 wherein said interference modulation element is modulated in such a way that the interference modulation element, when averaged over time, modulates the light equally over the field.

78. A method as in claim 76 wherein correction means is applied to said spatial light modulators to correct for color non-uniformity generated by spatially non uniform modulation by said spatial modulation interference elements.

79. A method as in claim 76 wherein said interference modulation element is a mechanical interference element.

80. A method as in claim 79 wherein said mechanical interference element provides a watermark.

81. A method as in claim 79 wherein said mechanical interference element is a shutter.

82. A method as in claim 76 wherein said interference modulation element an electro optical interference element.

83. A method as in claim 82 wherein said electro optical interference element provides a watermark.