Troffer-style optical assembly

• US 9,494,293 B2
• Filed: 12/06/2010
• Issued: 11/15/2016
• Est. Priority Date: 12/06/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Pickard, Paul Kenneth
• Primary Examiner(s): Husar, Stephen F
• Assistant Examiner(s): ALLEN, DANIELLE NICOLE
• Application Number:
  US12/961,385
• Publication Number:
  US 20120140461A1
• Time in Patent Office: 2,171 Days
• Field of Search: 362/225, 362/222, 362/223, 362/224, 362/217.01, 362/219, 362/221, 362/217.02, 362/217.04, 362/217.05, 362/217.1, 362/217.11, 362/217.12, 362/230, 362/231, 362/249.01, 362/249.02, 362/310, 362/334, 362/335
• US Class Current: 1/1
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 15/013 the housing being an extrusion
• CPC Class Codes: F21V 29/505 of reflectors
• CPC Class Codes: F21V 29/745 the fins or blades being planar and inclined with respect to the joining surface from which the fins or blades extend
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/777 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers

Abstract

A troffer-style fixture. The fixture is particularly well-suited for use with solid state light sources. The troffer comprises a light engine unit surrounded by a reflective pan. An elongated heat sink comprises a mount surface for light sources. An elongated lens is mounted on or above the heat sink. The mount surface is designed to accommodate the light emitters which may come on prefabricated a light strip. One or more reflectors extend out away from the heat sink on the mount surface side. A lens plate is mounted to proximate to the heat sink and extends out to the edge of the reflector(s). An interior cavity is at least partially defined by the reflector(s), the lens plates, and the heat sink. One or more light sources disposed along the heat sink mount surface emit light into the interior cavity where it can be mixed and/or shaped before it is emitted.

Claims

1. A light engine unit, comprising:

an elongated heat sink comprising a mount surface;

an elongated lens on said heat sink and over said mount surface;

reflectors extending from both sides of said heat sink away from said elongated lens; and

a light transmissive lens plate proximate to said heat sink, said light transmissive lens plate spaced apart from said heat sink and proximate to said reflectors, such that said heat sink, said reflectors, and said light transmissive lens plate at least partially define an interior cavity, wherein said elongated lens is at least partially within said interior cavity;

wherein said elongated lens is at least partially between said heat sink and said light transmissive lens plate.

2. The light engine unit of claim 1, further comprising at least one light source on said mount surface such that said at least one light source is at least partially surrounded by said elongated lens.

3. The light engine unit of claim 2, said at least one source comprising at least one cluster of light emitting diodes (LEDs).

4. The light engine unit of claim 2, said at least one source comprising at least one cluster of LEDs comprising two blue-shifted yellow LEDs and a red LED.

5. The light engine unit of claim 2, said at least one source comprising at least one cluster of LEDs comprising three blue-shifted yellow LEDs and a red LED.

6. The light engine unit of claim 2, said at least one source comprising at least one cluster of LEDs comprising a blue-shifted yellow LED and a red LED.

7. The light engine unit of claim 2, said at least one source comprising at least one cluster of LEDs comprising two blue-shifted yellow LEDs and two red LEDs.

8. The light engine unit of claim 1, further comprising at least one light strip on said mount surface such that said at least one light strip faces said elongated lens.

9. The light engine unit of claim 8, wherein said light strip comprises a printed circuit board (PCB) and a plurality of LEDs thereon.

10. The light engine unit of claim 1, said elongated lens shaped to accept light from the side facing said heat sink and redirect at least some of said light out of either side of said elongated lens.

11. The light engine unit of claim 1, said reflectors comprising a diffuse white reflector.

12. The light engine unit of claim 1, said reflectors comprising a microcellular polyethylene terephthalate (MCPET) material.

13. The light engine unit of claim 1, said reflectors comprising a specular reflective material.

14. The light engine unit of claim 1, wherein said reflectors are partially specular reflective and partially diffuse reflective.

15. The light engine unit of claim 1, wherein said reflectors are greater than 97% reflective.

16. The light engine unit of claim 1, wherein said reflectors are greater than 95% reflective.

17. The light engine unit of claim 1, wherein said reflectors are greater than 93% reflective.

18. The light engine unit of claim 1, said light transmissive lens plate comprising an elongated center region and two side regions, said center region running along the same direction as said elongated heat sink.

19. The light engine unit of claim 18, said center region comprising a convex shape defined from a reference point outside said interior cavity, said side regions comprising a concave shape.

20. The light engine unit of claim 1, said light transmissive lens plate comprising a diffusive film inlay.

21. The light engine unit of claim 1, said light transmissive lens plate comprising a diffusive film integral to said light transmissive lens plates.

22. The light engine unit of claim 1, said light transmissive lens plate comprising a diffractive pattern.

23. The light engine unit of claim 1, said light transmissive lens plate comprising a random or regular geometric pattern.

24. The light engine unit of claim 1, said light transmissive lens plate comprising a diffusive volumetric material.

25. The light engine unit of claim 1, said light transmissive lens plate comprising beam-shaping features.

26. The light engine unit of claim 1, said light transmissive lens plate comprising microlens structures.

27. The light engine unit of claim 1, further comprising transmissive end caps at both longitudinal ends of said light engine unit.

28. The light engine unit of claim 1, said heat sink comprising notches and said elongated lens comprising flanges shaped to mate with said notches such that said elongated lens may be held in place over said mount surface.

29. The light engine unit of claim 1, wherein said elongated lens is mounted to said heat sink with a snap-fit structure.

30. The light engine unit of claim 1, wherein said heat sink and said elongated lens define an interior space over said mount surface wherein a light strip can be inserted.

74. The light engine unit of claim 2, wherein emission from said at least one light source is substantially in the same direction as the intended emission of the light engine unit.

75. The light engine unit of claim 2, wherein said at least one light source is positioned to emit at least some light in an initial direction toward an exit surface of said light engine unit.

31. A lighting troffer, comprising:

an elongated heat sink comprising a mount surface;

an elongated lens on said heat sink and over said mount surface, said elongated lens and said heat sink defining an interior space;

a plurality of light emitting diodes (LEDs) on said mount surface within said interior space;

reflectors extending from both sides of said heat sink away from said elongated lens;

a lens plate proximate to said heat sink, said lens plate spaced apart from said heat sink and proximate to said reflectors, such that said heat sink, said reflectors, and said lens plate at least partially define an interior cavity, wherein said elongated lens is at least partially within said interior cavity, wherein at least some light from said plurality of LEDs is transmitted through said lens plate when said LEDs are operational; and

a pan structure comprising an inner reflective surface, said inner reflective surface around the perimeter of said lens plate and extending away from said heat sink.

32. The lighting troffer of claim 31, wherein said plurality of LEDs are on a printed circuit board (PCB) that is on said mount surface.

33. The lighting troffer of claim 31, wherein said plurality of LEDs is in at least one cluster along said mount surface.

34. The lighting troffer of claim 31, wherein light emitted from said LEDs is mixed such that the light emitting from said lighting troffer appears white.

35. The lighting troffer of claim 31, said elongated lens shaped to accept light from the side facing said heat sink and redirect at least some of said light out of either side of said elongated lens.

36. The lighting troffer of claim 31, said reflectors comprising a diffuse white reflector.

37. The lighting troffer of claim 31, said reflectors comprising a specular reflective material.

38. The lighting troffer of claim 31, wherein said reflectors are partially specular reflective and partially diffuse reflective.

39. The lighting troffer of claim 31, said lens plate comprising an elongated center region and two side regions with said center region running along the same direction as said elongated heat sink.

40. The lighting troffer of claim 39, said center region comprising a convex shape defined from a reference point outside said interior cavity, said side regions comprising a concave shape.

41. The lighting troffer of claim 31, said lens plate comprising a diffusive film inlay.

42. The lighting troffer of claim 31, said lens plate comprising a diffusive film integral to said lens plates.

43. The lighting troffer of claim 31, said lens plate comprising a diffractive pattern.

44. The lighting troffer of claim 31, said lens plate comprising a random or regular geometric pattern.

45. The lighting troffer of claim 31, said lens plate comprising a diffusive volumetric material.

46. The lighting troffer of claim 31, said lens plate comprising beam-shaping features.

47. The lighting troffer of claim 31, said lens plate comprising microlens structures.

48. The lighting troffer of claim 31, further comprising transmissive end caps at both longitudinal ends of said light engine unit.

49. The lighting troffer of claim 31, said heat sink comprising notches and said elongated lens comprising flanges shaped to mate with said notches such that said elongated lens may be held in place over said mount surface.

50. The lighting troffer of claim 31, wherein said elongated lens is mounted to said heat sink with a snap-fit structure.

51. The lighting troffer of claim 31, wherein said heat sink and said elongated lens define an interior space over said mount surface wherein a light strip can be inserted.

52. A light engine unit, comprising:

an elongated heat sink comprising a mount surface;

an elongated lens on said heat sink and over said mount surface;

at least one reflector extending from a side of said heat sink away from said elongated lens; and

a lens plate proximate to said heat sink, said lens plate spaced apart from said heat sink and proximate to said at least one reflector, such that said heat sink, said at least one reflector, and said lens plate at least partially define an interior cavity, wherein said elongated lens is at least partially within said interior cavity, wherein at least some light emitted within said interior cavity is emitted out through said lens plate.

53. The light engine unit of claim 52, wherein said mount surface of said heat sink faces at an angle toward the intersection of said at least one reflector and said lens plate.

54. The light engine unit of claim 52, said reflector comprising a diffuse white reflector.

55. The light engine unit of claim 52, wherein said light engine unit is asymmetrical about a longitudinal axis running through said heat sink.

56. A lens, comprising:

an elongated body, said body comprising at least one light entry surface, at least one front exit surface, and at least one side exit surface,

wherein said body is shaped to internally reflect at least some light, such that said at least some light exits out of said at least one side exit surface over a range of different exit angles.

57. The lens of claim 56, wherein said body is shaped to redirect at least 70% of light entering said light entry surface out of said at least one side exit surface and at least a portion of the remaining light out of said at least one front exit surface.

58. The lens of claim 56, wherein said body is shaped to redirect at least 80% of light entering said light entry surface out of said at least one side exit surface and at least a portion of the remaining light out of said at least one front exit surface.

59. The lens of claim 56, wherein said body is shaped to redirect at least 90% of light entering said light entry surface out of said at least one side exit surface and at least a portion of the remaining light out of said at least one front exit surface.

60. The lens of claim 56, further comprising a mount mechanism.

61. The lens of claim 56, further comprising flanges shaped to provide a mount mechanism.

62. The lens of claim 56, said lens comprising an aspect ratio (length to width) of no less than approximately 10:

1.

63. The lens of claim 56, said lens comprising an aspect ratio (length to width) of no more than approximately 80:

1.

64. An elongated lighting unit, comprising:

a mount body comprising a mount surface;

a plurality of light sources on said mount surface, at least one of said light sources comprising a phosphor material;

a lens on said mount body; and

a lens plate proximate to said mount body, wherein at least some light from said plurality of light sources passes through said lens plate;

wherein said light sources are in a plurality of clusters along the length of said mount body;

wherein each of said light sources within one of said clusters is separated by at least a first longitudinal distance;

wherein each of said clusters is separated by at least a second longitudinal distance larger than said first distance.

65. The elongated lighting unit of claim 64, said mount body comprising a printed circuit board (PCB).

66. The elongated lighting unit of claim 64, at least one of said clusters comprising two blue-shifted yellow light emitting diodes (LEDs) and a red LED.

67. The elongated lighting unit of claim 64, at least one of said clusters comprising three blue-shifted yellow LEDs and a red LED.

68. The elongated lighting unit of claim 64, at least one of said clusters comprising a blue-shifted yellow LED and a red LED.

69. The elongated lighting unit of claim 64, at least one of said clusters comprising two blue-shifted yellow LEDs and two red LEDs.

70. The elongated lighting unit of claim 64, said mount body further comprising electronic components and interconnections for operating said plurality of light emitters.

71. The elongated lighting unit of claim 64, wherein each of said clusters comprises at least one phosphor-based light emitter.

72. The elongated lighting unit of claim 64, wherein a longitudinal distance between consecutive sources within each of said clusters is uniform.

73. The elongated lighting unit of claim 64, wherein said longitudinal distance between consecutive light clusters is not more than approximately 8 mm.