Troffer-style lighting fixture with specular reflector

• US 8,905,575 B2
• Filed: 02/09/2012
• Issued: 12/09/2014
• Est. Priority Date: 02/09/2012
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Durkee, John, Pickard, Paul Kenneth
• Primary Examiner(s): Alavi, Ali
• Application Number:
  US13/370,252
• Publication Number:
  US 20130208457A1
• Time in Patent Office: 1,034 Days
• Field of Search: 362/249.01, 362/249.02, 362/294, 362/218, 362/545, 362/547, 362/345
• US Class Current: 362/218
• CPC Class Codes: F21S 8/026 intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling
• CPC Class Codes: F21S 8/04 intended only for mounting on a ceiling or the like overhead structures F21S8/02 takes precedence; details of ceiling bases F21V21/03
• CPC Class Codes: F21S 8/061 with a non-rigid pendant, i.e. a cable, wire or chain
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 25/12 Flameproof or explosion-proof arrangements
• 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 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/0025 Combination of two or more reflectors for a single light source array of reflectors for a cluster of light sources F21V7/0083
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2103/10 comprising a linear 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]

Abstract

An indirect troffer-style lighting fixture that is particularly well-suited for use with solid state light sources. An elongated heat sink with a mount surface for light sources runs longitudinally along the fixture. To facilitate heat dissipation, a portion of the heat sink is exposed to the ambient room environment. An elongated specular reflector also runs along the device proximate to the heat sink. The heat sink and the specular reflector are mounted such that a spatial relationship is maintained. Some of the light from the sources impinges directly on the specular reflector and is redirected towards a back surface. The back surface defines a luminous surface that receives light directly from the sources and redirected light from the specular reflector. The back surface and the heat sink mechanically obscure any images of the light sources in the specular reflector such that they are not visible in a viewing area.

Claims

1. A lighting fixture, comprising:

an elongated heat sink comprising a mount surface;

an elongated specular reflector proximate to said mount surface, said heat sink and said specular reflector configured such that a spatial relationship is maintained between said heat sink and said specular reflector; and

a back surface proximate to said elongated specular reflector.

2. The lighting fixture of claim 1, further comprising at least one cluster of light emitting diodes (LEDs) on said mount surface.

3. The lighting fixture of claim 1, further comprising at least one cluster of LEDs, each of said clusters comprising at least one red LED and at least one blue-shifted yellow (BSY) LED.

4. The lighting fixture of claim 1, said specular reflector comprising at least two parabolic reflective surfaces shaped to redirect light toward said back surface.

5. The lighting fixture of claim 1, said specular reflector comprising a metal-coated surface.

6. The lighting fixture of claim 1, said back surface comprising a diffuse reflective surface.

7. The lighting fixture of claim 1, further comprising at least one light source on said mount surface.

8. The lighting fixture of claim 7, said back surface shaped to receive light redirected from said specular reflector and light emitted directly from said light source such that substantially all light emitted from said light source impinges on said back surface.

9. The lighting fixture of claim 7, further comprising a lens over said at least one light source on said mount surface.

10. The lighting fixture of claim 7, further comprising a flame barrier over said at least one light source on said mount surface.

11. The lighting fixture of claim 1, wherein said back surface is at least partially light transmissive.

12. The lighting fixture of claim 1, said back surface comprising a curved shape.

13. The lighting fixture of claim 1, said back surface comprising a corrugated shape.

14. The lighting fixture of claim 1, said back surface comprising a faceted surface.

16. The lighting fixture of claim 1, further comprising at least one end piece to which the ends of said heat sink and said specular reflector are mounted.

17. The lighting fixture of claim 1, said back surface extending from both lateral sides of said elongated specular reflector.

15. A lighting fixture, comprising:

an elongated heat sink comprising a mount surface;

an elongated specular reflector proximate to said mount surface, said heat sink and said specular reflector configured such that a spatial relationship is maintained between said heat sink and said specular reflector;

a back surface proximate to said elongated specular reflector; and

a lens plate extending from said heat sink to said back surface.

18. A lighting assembly, comprising:

a protective housing comprising at least one end piece and a back surface;

an elongated heat sink mounted to said at least one end piece, said heat sink comprising a mount surface;

an elongated specular reflector on said back surface, such that a spatial relationship is established between said specular reflector and said heat sink;

at least one light source on said mount surface; and

a control circuit for controlling said at least one light source.

19. The lighting assembly of claim 18, said at least one light source comprising at least one cluster of light emitting diodes (LEDs) on said mount surface.

20. The lighting assembly of claim 18, said at least one light source comprising at least one cluster of LEDs, each of said clusters comprising at least one red LED and at least one blue-shifted yellow (BSY) LED.

21. The lighting assembly of claim 18, said specular reflector comprising at least two parabolic reflective surfaces shaped to redirect light toward said back surface.

22. The lighting assembly of claim 18, said specular reflector comprising a metal-coated surface.

23. The lighting assembly of claim 18, said back surface comprising a diffuse reflective surface.

24. The lighting assembly of claim 18, further comprising a lens over said at least one light source on said mount surface.

25. The lighting assembly of claim 18, further comprising a flame barrier over said at least one light source on said mount surface.

26. The lighting assembly of claim 18, wherein said back surface is at least partially light transmissive.

27. The lighting assembly of claim 18, said back surface comprising a curved shape.

28. The lighting assembly of claim 18, said back surface comprising a corrugated shape.

29. The lighting assembly of claim 18, said back surface comprising a faceted surface.

30. The lighting assembly of claim 18, further comprising a lens plate extending from said heat sink to said back surface.

31. A method of lighting a surface:

emitting light from a light source over a range of angles;

redirecting at least a portion of said light with a specular reflector toward a luminous surface;

receiving light directly from said light source and from said specular reflector at said luminous surface; and

mechanically obscuring images of said light source on said specular reflector from a viewing area.