Light enhancing structures with three or more arrays of elongate features

• US 20070086086A1
• Filed: 11/08/2006
• Published: 04/19/2007
• Est. Priority Date: 01/13/2006
• Status: Active Grant

• Current Assignee: Avery Dennison Corporation, Synopsys Incorporated
• Original Assignee: Avery Dennison Corporation, Optical Research Associates (Synopsys Incorporated)
• Inventors: Chapman, Steven, Cassarly, William
• Granted Patent: US 7,366,393 B2
• Time in Patent Office: Days
• US Class Current: 359/362
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer

Abstract

Various embodiments comprise light recycling films comprising an array of parallel ridges and grooves that form prisms that selectively reflect or transmit light. In some embodiments, the light recycling film may be used in displays that include spatial light modulators comprising a plurality of pixels. The light recycling film can limit the field-of-view of the display and enhance the luminance within that field-of-view. Various embodiments comprising multiple arrays of ridges and/or grooves can enhance uniformity of illumination of the pixels in the spatial light modulator and reduce Moiré effects.

Claims

1. An optical member. comprising an array of total internal reflection structures, said optical member comprising:

an optically transmissive material having a surface;

a first plurality of non-intersecting elongate features formed in said surface, said first plurality of non-intersecting elongate features oriented at an angle α

;

a second plurality of non-intersecting elongate features formed in said surface, said second plurality of non-intersecting elongate features oriented at an angle α

′

, said first plurality of non-intersecting elongate features being oriented at an angle |α

-α

′

| with respect to said second plurality of non-intersecting elongate features, said angle |α

-α

′

| being less than 30°

; and

a third plurality of non-intersecting elongate features formed in said surface, said third plurality of non-intersecting elongate features oriented at an angle ξ

, said second plurality of non-intersecting elongate features being oriented at an angle |α

′

-ξ

| with respect to said third plurality of non-intersecting elongate features, said angle |α

′

-ξ

| being less than 30°

, said first plurality of non-intersecting elongate features being oriented at an angle |α

-ξ

| with respect to said third plurality of non-intersecting elongate features, said angle |α

-ξ

| being less than 30°

,

wherein each of said non-intersecting elongate features in said first plurality extends across said non-intersecting elongate features in said second plurality and said non-intersecting elongate features in said third plurality and each of said non-intersecting elongate features in said second plurality extends across said non-intersecting elongate features in third plurality thereby defining said total internal reflection structures.

2. The optical member of claim 1, wherein at least two of said non-intersecting elongate features comprise substantially parallel linear features.

3. The optical member of claim 1, wherein at least one of said non-intersecting elongate features varies in height or depth along said its length.

4. The optical member of claim 1, wherein at least one of said non-intersecting elongate features comprises a non-linear feature.

5. The optical member of claim 4, wherein said non-linear feature undulates laterally.

6. The optical member of claim 1, wherein said non-intersecting elongate features comprise grooves.

7. The optical member of claim 1, wherein said non-intersecting elongate features comprise ridgelines.

8. The optical member of claim 1, wherein at least one of said total internal reflection structures comprises a prism having planar facets.

9. The optical member of claim 8, wherein said prism comprises a pyramid.

10. The optical member of claim 8, wherein said planar facets have rounded edges.

11. The optical member of claim 8, wherein each of said facets in said prism has substantially the same projected area.

12. The optical member of claim 1, wherein at least two of said total internal reflection structures have different heights.

13. The optical member of claim 1, wherein at least one of said total internal reflection structures comprises curved surfaces that totally internally reflect light.

14. The optical member of claim 1, wherein said optically transmissive material comprises a polymer.

15. The optical member of claim 1, wherein said optically transmissive material comprises a sheet or film.

16. The optical member of claim 1, wherein a first elongate feature in said first plurality of non-intersecting elongate features, a second elongate feature in said second plurality of non-intersecting elongate features, and a third elongate feature in said third plurality of non-intersecting elongate features intersect at a point.

17. The optical member of claim 1, wherein a first elongate feature in said first plurality of non-intersecting elongate features and a second elongate feature in said second plurality of non-intersecting elongate features intersect at a point, and said third plurality does not intersect with said point.

18. The optical member of claim 1, wherein a first pair of adjacent non-intersecting elongate features in said first plurality of non-intersecting elongate features is spaced apart by a first amount and a second pair of adjacent non-intersecting elongate features in said first plurality of non-intersecting elongate features is spaced apart by a second different amount.

19. The optical member of claim 1, wherein first and second non-intersecting elongate features in said first plurality of non-intersecting elongate features have different depths or heights.

20. The optical member of claim 1, wherein at least one of said first plurality and second plurality of non-intersecting elongate features has a vertex angle of about 90°

.

21. The optical member of claim 1, further comprising a diffuser on either side of said surface.

22. The optical member of claim 1, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the first pitch is not equal to the second pitch.

23. The optical member of claim 1, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the pitch of at least one of the first and second plurality of non-intersecting elongate features varies.

24. The optical member of claim 1, wherein at least one of said non-intersecting elongate features is linear.

25. The optical member of claim 1, wherein said optically transmissive material comprises a film.

26. The optical member of claim 1, wherein said optically transmissive material has a thickness of 0.2 mm or less.

27. An optical apparatus comprising the optical member of claim 1, 30, 57, or 81 and an illumination apparatus that backlights said optical member.

28. The optical member of claim 1, wherein each of said non-intersecting elongate features in said first plurality intersect each of said non-intersecting elongate features in said second plurality only once.

29. The optical member of claim 1, wherein the first plurality of non-intersecting elongate features has a first pitch and said first pitch increases and decreases along at least one direction.

102. An optical apparatus comprising the optical member of claim 1, 30, 57, or 81 and an illumination apparatus that backlights said optical member.

30. An optical member comprising an array of total internal reflection structures, said optical member comprising:

an optically transmissive material having a surface, said surface having a surface normal;

a first plurality of non-intersecting elongate features in said surface;

a second plurality of non-intersecting elongate features in said surface, said first plurality of non-intersecting elongate features angled with respect to said second plurality of non-intersecting elongate features; and

a third plurality of non-intersecting elongate features in said optically transmissive material, said second plurality of non-intersecting elongate features being angled with respect to said first plurality of non-intersecting elongate features and said third plurality of non-intersecting elongate features,

wherein each of said non-intersecting elongate features in said first plurality extends across said non-intersecting elongate features in said second plurality and said non-intersecting elongate features in said third plurality and each of said non-intersecting elongate features in said second plurality extends across said non-intersecting elongate features in third plurality thereby defining said total internal reflection structures, said total internal reflection structures being configured such that a first portion of light incident on said surface is total internally reflected back from said surface and a second portion of said light incident on said surface is transmitted through said surface, a substantial portion of said second portion of light that is transmitted being refracted by said total internal reflection structures into a limited to a range of angles, Φ

.

31. The optical member of claim 30, wherein at least two of said non-intersecting elongate features comprise substantially parallel linear features.

32. The optical member of claim 30, wherein at least one of said non-intersecting elongate features varies in height or depth along its length.

33. The optical member of claim 30, wherein at least one of said non-intersecting elongate features comprises a non-linear feature.

34. The optical member of claim 33, wherein said non-linear feature undulates laterally.

35. The optical member of claim 30, wherein said non-intersecting elongate features comprise grooves.

36. The optical member of claim 30, wherein said non-intersecting elongate features comprise ridgelines.

37. The optical member of claim 30, wherein at least one of said total internal reflection structures comprise a prism having planar facets.

38. The optical member of claim 37, wherein said prism comprises a pyramid.

39. The optical member of claim 37, wherein said planar facets have rounded edges.

40. The optical member of claim 37, wherein each of said facets in said prism has substantially the same projected area.

41. The optical member of claim 30, wherein at least two of said total internal reflection structures have different heights.

42. The optical member of claim 30, wherein at least one of said total internal reflection structures comprises curved surfaces that totally internally reflect light.

43. The optical member of claim 30, wherein said optically transmissive material comprises a sheet or a film.

44. The optical member of claim 30, wherein said range of angles, Φ

, is centered about the normal to said surface.

45. The optical member of claim 30, wherein said substantial portion of said second portion of light that is transmitted comprises at least about 30% of said light.

46. The optical member of claim 45, wherein said range of angles, Φ

, is no more than about ±

45°

.

47. The optical member of claim 45, wherein said substantial portion of said second portion of light that is transmitted comprises at least about 50% of said light and said range of angles, Φ

, is no more than about ±

45°

.

48. The optical member of claim 30, further comprising a diffuser on either side of said surface.

49. The optical member of claim 30, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the first pitch is not equal to the second pitch.

50. The optical member of claim 30, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the pitch of at least one of the first and second plurality of non-intersecting elongate features varies.

51. The optical member of claim 30, wherein at least one of said non-intersecting elongate features is linear.

52. The optical member of claim 30, wherein said optically transmissive material comprises a film.

53. The optical member of claim 30, wherein said optically transmissive material has a thickness of 0.2 mm or less.

54. An optical apparatus comprising the optical member of claim 30 and an illumination apparatus that backlights said optical member.

55. The optical member of claim 30, wherein each of said non-intersecting elongate features in said first plurality intersect each of said non-intersecting elongate features in said second plurality only once.

56. The optical member of claim 30, wherein the first plurality of non-intersecting elongate features has a first pitch and said first pitch increases and decreases along at least one direction.

57. An optical member comprising an array of total internal reflection structures, said optical member comprising:

an optically transmissive material having a surface;

a first plurality of non-intersecting elongate features in said surface;

a second plurality of non-intersecting elongate features in said surface, said first plurality of non-intersecting elongate features being angled with respect to said second plurality of non-intersecting elongate features;

a third plurality of non-intersecting elongate features in said surface, said second plurality of non-intersecting elongate features being angled with respect to said first plurality of non-intersecting elongate features and said third plurality of non-intersecting elongate features; and

a fourth plurality of non-intersecting elongate features in said surface, each of said third plurality of non-intersecting elongate features being angled with respect to said first plurality of non-intersecting elongate features, said second plurality of non-intersecting elongate features, and said third plurality of non-intersecting elongate features,

wherein each of said non-intersecting elongate features in said first plurality extends across said non-intersecting elongate features in said second, third, and fourth pluralities of non-intersecting elongate features, each of said non-intersecting elongate features in said second plurality extends across said non-intersecting elongate features in said third, and fourth pluralities of non-intersecting elongate features, and each of said non-intersecting elongate features in said third plurality extends across said non-intersecting elongate features in said fourth plurality, thereby defining said total internal reflection structures.

58. The optical member of claim 57, wherein at least two of said non-intersecting elongate features comprise substantially parallel linear features.

59. The optical member of claim 57, wherein at least one of said non-intersecting elongate features varies in height or depth along its length.

60. The optical member of claim 57, wherein at least one of said non-intersecting elongate features comprises a non-linear feature.

61. The optical member of claim 60, wherein said non-linear feature undulates laterally.

62. The optical member of claim 57, wherein said non-intersecting elongate features comprises grooves.

63. The optical member of claim 57, wherein said non-intersecting elongate features comprise ridgelines.

64. The optical member of claim 57, wherein at least one of said total internal reflection structures comprises a prism having planar facets.

65. The optical member of claim 64, wherein said prism comprises pyramids.

66. The optical member of claim 64, wherein said planar facets have rounded edges.

67. The optical member of claim 64, wherein each of said facets in said prisms has substantially the same projected area.

68. The optical member of claim 57, wherein at least two of said total internal reflection structures have different heights.

69. The optical member of claim 57, wherein at least one of said total internal reflection structures comprises curved surfaces that totally internally reflect light.

70. The optical member of claim 57, wherein said optically transmissive material comprises a sheet or a film.

71. The optical member of claim 57, further comprising a fifth plurality of non-intersecting elongate features in said surface, said fifth plurality of non-intersecting elongate features being angled with respect to each of said first plurality of non-intersecting elongate features, said second plurality of non-intersecting elongate features, said third plurality of non-intersecting elongate features, and said fourth plurality of non-intersecting elongate features.

72. The optical member of claim 57, further comprising a diffuser on either side of said surface.

73. The optical member of claim 57, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the first pitch is not equal to the second pitch.

74. The optical member of claim 57, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the pitch of at least one of the first and second plurality of non-intersecting elongate features varies.

75. The optical member of claim 57, wherein at least one of said non-intersecting elongate features is linear.

76. The optical member of claim 57, wherein said optically transmissive material comprises a film.

77. The optical member of claim 57, wherein said optically transmissive material has a thickness of 0.2 mm or less.

78. An optical apparatus comprising the optical member of claim 57 and an illumination apparatus that backlights said optical member.

79. The optical member of claim 57, wherein each of said non-intersecting elongate features in said first plurality intersect each of said non-intersecting elongate features in said second plurality only once.

80. The optical member of claim 57, wherein the first plurality of non-intersecting elongate features has a first pitch and said first pitch increases and decreases along at least one direction.

81. An optical member comprising a plurality of total internal reflection structures, said optical member comprising:

an optically transmissive material having a surface;

a first plurality of non-intersecting elongate features in said surface, said first plurality of non-intersecting elongate features oriented at an angle α

;

a second plurality of non-intersecting elongate features in said surface, said second plurality of non-intersecting elongate features oriented at an angle α

′

; and

a third plurality of non-intersecting elongate features in said surface, said third plurality of non-intersecting elongate features oriented at an angle ξ

,

wherein each of said non-intersecting elongate features in said first plurality extends across said non-intersecting elongate features in said second and third pluralities of non-intersecting elongate features and each of said non-intersecting elongate features in said second plurality extends across said non-intersecting elongate features in said third pluralities of non-intersecting elongate features thereby forming said plurality of total internal reflection structures, and said first and second plurality of non-intersecting elongate features are arranged non-symmetrically about said third plurality of non-intersecting elongate features such that |α

+α

′

|≠

ξ

|.

82. The optical member of claim 81, wherein at least two of said non-intersecting elongate features comprise substantially parallel linear features.

83. The optical member of claim 82, wherein at least one of said non-intersecting elongate features varies in height or depth along its length.

84. The optical member of claim 81, wherein at least one of said non-intersecting elongate features comprise a non-linear feature.

85. The optical member of claim 84, wherein said non-linear feature undulates laterally.

86. The optical member of claim 81, wherein said non-intersecting elongate features comprise grooves.

87. The optical member of claim 81, wherein said non-intersecting elongate features comprise ridgelines.

88. The optical member of claim 81, wherein at least one of said total internal reflection structures comprise a prism having planar facets.

89. The optical member of claim 88, wherein said prism comprises a pyramid.

90. The optical member of claim 88, wherein said planar facets have rounded edges.

91. The optical member of claim 88, wherein each of said facets has substantially the same projected area.

92. The optical member of claim 81, wherein at least one of said total internal reflection structures comprises curved surfaces that totally internally reflect light.

93. The optical member of claim 81, wherein at least two of said total internal reflection structures have different heights.

94. The optical member of claim 81, wherein said optically transmissive material comprises a sheet or a film.

95. The optical member of claim 81, wherein the height of at least one of the first, second, and third plurality of non-intersecting elongate features are different.

96. The optical member of claim 81, further comprising a diffuser on either side of said surface.

97. The optical member of claim 81, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the first pitch is not equal to the second pitch.

98. The optical member of claim 81, wherein the first plurality of non-intersecting elongate features has a first pitch, the second plurality of non-intersecting elongate features has a second pitch, and wherein the pitch of at least one of the first and second plurality of non-intersecting elongate features varies.

99. The optical member of claim 81, wherein at least one of said non-intersecting elongate features is linear.

100. The optical member of claim 81, wherein said optically transmissive material comprises a film.

101. The optical member of claim 81, wherein said optically transmissive material has a thickness of 0.2 mm or less.

103. The optical member of claim 81, wherein each of said non-intersecting elongate features in said first plurality intersect each of said non-intersecting elongate features in said second plurality only once.

104. The optical member of claim 81 wherein the first plurality of non-intersecting elongate features has a first pitch and said first pitch increases and decreases along at least one direction.