Optical waveguide and lamp including same

• US 9,581,751 B2
• Filed: 03/15/2013
• Issued: 02/28/2017
• Est. Priority Date: 01/30/2013
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Yuan, Zongjie, Wilcox, Kurt S., Tarsa, Eric J., Rol, Fabian Jean-Daniel, Ibbetson, James, Keller, Bernd P.
• Primary Examiner(s): Neils, Peggy
• Assistant Examiner(s): GARLEN, ALEXANDER K
• Application Number:
  US13/839,949
• Publication Number:
  US 20140211476A1
• Time in Patent Office: 1,446 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0058 varying in density, size, shape or depth along the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0088 of the light guide or other optical sheets in the package
• CPC Class Codes: G02B 6/009 of the light source in the package G02B6/0021 takes precedence

Abstract

An optical waveguide includes a body of optically transmissive material having a width substantially greater than an overall thickness thereof and including a first side, a second side opposite the first side, a central bore extending between the first and second sides and adapted to receive a light emitting diode, and extraction features on the second side. A light diverter extends into the central bore for diverting light into and generally along the width of the body of material. The extraction features direct light out of the first side and wherein at least one extraction feature has an extraction surface dimension transverse to the thickness that is between about 5% and about 75% the overall thickness of the body of material.

Claims

1. An optical waveguide, comprising

a body of optically transmissive material comprising a width substantially greater than a thickness thereof and comprising a first side, a second side opposite the first side, an interior coupling cavity extending between the first and second sides and adapted to receive a light emitting diode, and a plurality of extraction features on the second side;

wherein the extraction features direct light out of at least the first side and wherein the plurality of extraction features is spaced from an outside edge of the body and each of the plurality of extraction features comprises an extraction surface dimension extending between the first and second sides that is between about 5% and about 75% of the overall thickness of the body of material; and

wherein an extraction surface dimension of at least one of the plurality of extraction features is different than a corresponding extraction surface dimension of each of a first group of the plurality of extraction features, and a corresponding extraction surface dimension of each of a second group of the plurality of extraction features is different than the extraction surface dimension of the at least one extraction feature and the corresponding extraction surface dimension of each of the first group of the plurality of extraction features;

wherein the first group of the plurality of extraction features is disposed farther from the interior coupling cavity than the at least one of the plurality of extraction features;

wherein the second group of the plurality of extraction features is disposed farther from the interior coupling cavity than the first group and the at least one extraction feature of the plurality of extraction features; and

wherein the thickness of the body tapers overall from a center to an outside edge thereof as a result of the extraction surface dimensions of the second group of the plurality of extraction features.

2. The optical waveguide of claim 1, further comprising a light diverter extending into the interior coupling cavity for diverting light into and generally along the width of the body of material.

3. The optical waveguide of claim 2, wherein the light diverter comprises a reflective conical plug member.

4. The optical waveguide of claim 3, wherein the reflective conical plug member is integral with the body of material.

5. The optical waveguide of claim 3, wherein the reflective conical plug member is circular in a dimension transverse to the width and thickness of the body of material.

6. The optical waveguide of claim 3, wherein the reflective conical plug member is separate from the LED.

7. The optical waveguide of claim 1, wherein the extraction features extend fully about the interior coupling cavity.

8. The optical waveguide of claim 1, wherein the extraction features comprise discrete elements disposed about the interior coupling cavity.

9. The optical waveguide of claim 1, wherein the first side is substantially planar.

10. The optical waveguide of claim 1, wherein the at least one extraction feature comprises an inverted V-shape.

11. The optical waveguide of claim 1, wherein the extraction features are symmetric about the interior coupling cavity.

12. The optical waveguide of claim 1, wherein the body of material comprises a substantially circular shape in a dimension transverse to the width and thickness of the body of material and comprises an outer surface coaxial with the interior coupling cavity.

13. The optical waveguide of claim 1, wherein the extraction features are substantially circular and coaxial with the interior coupling cavity in a dimension transverse to the width and thickness of the body of material.

14. The optical waveguide of claim 1, wherein the body of material comprises a substantially rectangular shape in a dimension transverse to the width and thickness of the body of material.

15. The optical waveguide of claim 1, wherein the extraction features are substantially rectangular in a dimension transverse to the width and thickness of the body of material.

16. The optical waveguide of claim 1, wherein the interior coupling cavity comprises a central bore that extends fully through the body of material.

17. The optical waveguide of claim 16, wherein walls defining the central bore are substantially normal to the first and second sides of the body.

18. The optical waveguide of claim 2, wherein the light diverter comprises a member that is star-shaped in a dimension transverse to the width and thickness of the body of material.

19. The optical waveguide of claim 1, wherein the extraction features are chevron-shaped in a dimension transverse to the width and thickness of the body of material.

20. The optical waveguide of claim 1, wherein the body of material comprises an outer surface transverse to the first and second sides.

21. The optical waveguide of claim 20, wherein the outer surface is substantially normal to the first and second sides.

22. The optical waveguide of claim 20, wherein the outer surface is disposed at an acute angle with respect to one of the first and second sides and is disposed at an obtuse angle with respect to another of the first and second sides.

23. The optical waveguide of claim 1, wherein the body of material comprises an outer surface that is curved and extends between the first and second sides;

and wherein the outer surface is arcuate transverse to the first and second sides.

24. The optical waveguide of claim 1, wherein the first side is substantially frusto-conically shaped.

25. The optical waveguide of claim 1, wherein the first side is substantially inverted frusto-conically shaped.

26. The optical waveguide of claim 1, wherein the first side is convex at least in part.

27. The optical waveguide of claim 1, wherein the first side is concave at least in part.

28. The optical waveguide of claim 1, wherein a first extraction feature comprises a first tapered extraction surface and a second extraction feature comprises a second tapered extraction surface and wherein the first tapered extraction surface and the second tapered extraction surface are disposed at different angles with respect to the first side.

29. The optical waveguide of claim 1, wherein a first extraction feature comprises a first tapered extraction surface and a second extraction feature comprises a second tapered extraction surface and wherein the first tapered extraction surface and the second tapered extraction surface are disposed at substantially equal angles with respect to the first side.

30. The optical waveguide of claim 1, wherein a first extraction feature comprises a first tapered extraction surface and a second extraction feature comprises a second tapered extraction surface and wherein the first tapered extraction surface and the second tapered extraction surface terminate at the second side and extend to first and second different distances, respectively, from the first side.

31. The optical waveguide of claim 1, wherein a first extraction feature comprises a first tapered extraction surface and a second extraction feature comprises a second tapered extraction surface and wherein the first tapered extraction surface and the second tapered extraction surface terminate at the second side and extend to substantially equal distances, respectively, from the first side.

32. The optical waveguide of claim 1, wherein a first extraction feature comprises a first pitch and a second extraction feature comprises a second pitch different than the first pitch.

33. The optical waveguide of claim 1, wherein a first extraction feature comprises a first pitch and a second extraction feature comprises a second pitch substantially equal to the first pitch.

34. The optical waveguide of claim 1, wherein a first extraction feature comprises a first width and a second extraction feature comprises a second width different than the first width.

35. The optical waveguide of claim 1, wherein a first extraction feature comprises a first width and a second extraction feature comprises a second width substantially equal to the first width.

36. The optical waveguide of claim 2, wherein the light diverter comprises an optical element integral with the body of material.

37. The optical waveguide of claim 36, in combination with a luminaire and an LED light source disposed in the central bore that directs incident light toward the optical element.

38. The optical waveguide of claim 37, wherein the optical element is adapted to direct a first portion of incident light therethrough and to divert a second portion of incident light into the body of material.

39. The optical waveguide of claim 38, wherein the luminaire comprises a trim ring comprising an aperture and wherein the waveguide comprises a cross sectional size and wherein a cross sectional size of the aperture is less than or equal to the cross sectional size of the waveguide.

40. The optical waveguide of claim 39, wherein the cross sectional size of the aperture relative to the cross sectional size of the waveguide is between about 1:

2 and about 1;

4.

41. The optical waveguide of claim 16, wherein walls defining the central bore are tapered with respect to the first and second sides of the body.

42. The optical waveguide of claim 41, wherein the walls defining the central bore comprise equally-sized facets.

43. The optical waveguide of claim 42, wherein a V-shaped groove extends into the waveguide from the first side.

44. The optical waveguide of claim 42, further comprising lenslets disposed on the first side.

45. The optical waveguide of claim 44, wherein the lenslets comprise an aspect ratio between about 5:

1 to about 60;

1.

46. The optical waveguide of claim 44, wherein the lenslets are convex in shape.

47. The optical waveguide of claim 44, wherein the lenslets are concave in shape.

48. The optical waveguide of claim 42, further comprising additional extraction features disposed on the first side.

49. The optical waveguide of claim 42, wherein the additional extraction features comprise ribs.

50. The optical waveguide of claim 1, wherein the extraction features are asymmetric.

51. The optical waveguide of claim 1, wherein the extraction features are discontinuous.

52. The optical waveguide of claim 1, wherein the waveguide is racetrack-shaped and the extraction features are racetrack-shaped.

53. The optical waveguide of claim 1, further comprising at least one LED disposed in the interior coupling cavity.

54. The optical waveguide of claim 53, wherein the at least one LED directs light outwardly through the body of material.

55. The optical waveguide and LED combination of claim 54, wherein the at least one LED is disposed on a cylindrical carrier.

56. The optical waveguide and LED combination of claim 55, wherein the interior coupling cavity comprises a blind bore and the cylindrical carrier is disposed in the blind bore.

57. The optical waveguide of claim 1, in combination with a plurality of LEDs disposed on a cylindrical carrier, and wherein the interior coupling cavity comprises a blind bore within which the cylindrical carrier and the LEDs are disposed.

58. The optical waveguide of claim 2, in combination with a luminaire and an LED light source disposed in the central bore that directs incident light toward the light diverter.

59. The optical waveguide of claim 1, wherein each extraction feature comprises an aspect ratio of between about 0.25 and about 20.

60. The optical waveguide of claim 1, wherein each extraction feature comprises an aspect ratio of between about 0.5 and about 10.

61. The optical waveguide of claim 1, wherein each extraction feature comprises an aspect ratio of between about 0.75 and about 7.5.

62. The optical waveguide of claim 1, wherein the waveguide creates a beam angle between less than 5 degrees to greater than 60 degrees.

63. The optical waveguide of claim 1, wherein the waveguide creates a beam angle between about 5 degrees and about 50 degrees.

64. The optical waveguide of claim 1, wherein the waveguide creates a beam angle between about 6 degrees and about 40 degrees.

65. The optical waveguide of claim 1, wherein the body of optically transmissive material is of a material selected from the group comprising acrylic, polycarbonate, molded silicone, and glass.

66. The optical waveguide of claim 2, wherein the light diverter is of a material selected from the group comprising polycarbonate, acrylic, molded silicone polytetrafluoroethylene, acetal resin, or a metal.

67. The optical waveguide of claim 66, wherein the light diverter is coated with a reflective material.

68. The optical waveguide of claim 67, wherein the reflective material is one of a specular material and a white material.

69. The optical waveguide of claim 1, further comprising a backplane adjacent the waveguide.

70. The optical waveguide of claim 69, wherein the backplane comprises a tapered surface and a base surface.

71. The optical waveguide of claim 70, wherein at least one of the tapered surface and the base surface is reflective.

72. The optical waveguide of claim 70, wherein at least one of the tapered surface and the base surface is coated or covered with one of a specular and white material.

73. The optical waveguide of claim 1, wherein the waveguide is flower-shaped.

74. The optical waveguide of claim 73, further comprising a carrier comprising a plurality of facets wherein a number of LEDs are disposed on each facet and adapted to direct light outwardly through the waveguide and wherein the at least one extraction feature comprises a plurality of extraction features each comprising a plurality of sections of extraction features each associated with one of the facets.

75. The optical waveguide of claim 74, wherein each section of extraction features comprises nested curved extraction subsections each coaxial with the LEDs disposed on the associated facet.

76. The optical waveguide of claim 75, wherein each extraction subsection meets adjacent extraction subsections at inflection regions.

77. The optical waveguide of claim 73, wherein the extraction features are disposed on an inner surface and further comprising a planar outer surface opposite the inner surface.

78. The optical waveguide of claim 73, wherein the extraction features are disposed on an inner surface and further comprising a curved outer surface opposite the inner surface;

the inner surface comprising the interior coupling cavity.

79. The optical waveguide of claim 1, wherein the waveguide is adapted to produce a beam peak centered at a nadir.

80. The optical waveguide of claim 1, wherein the waveguide is adapted to produce an off-center beam peak.

81. The optical waveguide of claim 1, wherein the at least one extraction feature comprises a plurality of extraction features.

82. The optical waveguide of claim 81, wherein a depth of the extraction features increases with distance from a center line of the waveguide body.

83. The optical waveguide of claim 81, wherein a spacing between extraction features increases overall with distance from a center line of the waveguide body.

84. The optical waveguide of claim 83, wherein the spacing between extraction features is between about 0.7 mm and about 9 mm.

85. The optical waveguide of claim 3, wherein the reflective plug member is symmetric.

86. The optical waveguide of claim 3, wherein the reflective plug member is asymmetric.

87. The optical waveguide of claim 1 wherein the at least one extraction feature comprises a plurality of prisms.

88. The optical waveguide of claim 87, wherein the prisms are identical to one another and face the coupling cavity.

89. The optical waveguide of claim 87, wherein the prisms are not identical to one another.

90. The optical waveguide of claim 1, wherein the at least one extraction feature comprises extraction features that are substantially identical to one another.

91. The optical waveguide of claim 1, wherein the at least one extraction feature comprises extraction features that are not substantially identical to one another.

92. The optical waveguide of claim 1, wherein the interior coupling cavity is polished and optically smooth.

93. The optical waveguide of claim 2 wherein the light diverter is asymmetric.

94. The lamp of claim 93, wherein the lamp is adapted to create multiple light beams.

95. The lamp of claim 94, wherein the light beams comprise substantially identical beam widths.

96. The lamp of claim 94, wherein the light beams comprise different beam widths.

97. The lamp of claim 94, wherein the light beams comprise substantially identical beam intensities.

98. The lamp of claim 94, wherein the light beams comprise different beam intensities.