Light guide for low profile luminaire

• US 9,581,756 B2
• Filed: 08/26/2016
• Issued: 02/28/2017
• Est. Priority Date: 10/05/2009
• Status: Active Grant

• Current Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Original Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Inventors: Boomgaarden, Mark Penley, Romeu, Ricardo, Kelley, Ryan, Holland, Eric
• Primary Examiner(s): Breval, Elmito
• Application Number:
  US15/248,769
• Publication Number:
  US 20160370535A1
• Time in Patent Office: 186 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• 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: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21S 8/026 intended to be recessed in a ceiling or like overhead structure, e.g. suspended ceiling
• CPC Class Codes: F21V 21/20 operated by weights
• CPC Class Codes: F21V 2200/20 of light guides of a generally planar shape
• CPC Class Codes: F21V 23/02 the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• CPC Class Codes: F21V 23/0471 the sensor detecting the proximity, the presence or the movement of an object or a person
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 29/83 the elements having apertures, ducts or channels, e.g. heat radiation holes
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2103/33 annular
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
• 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 6/0041 : provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0065 : Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0068 : Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 : Light emitting diode [LED]
• CPC Class Codes: G02B 6/0085 : Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64

Abstract

A luminaire comprising a heat sink, a light source to emit a source light, a heat spreader having inner and outer surfaces, and LEDs carried by a circuit board and disposed generally along a periphery of the inner surface and positioned in thermal communication therewith. The luminaire comprises a reflector disposed coextensively with the LEDs and comprising an aperture. An outer edge of the aperture defines an inner rim of the reflector. A light guide positioned between the reflector and the light source exhibits a height defined as the distance between the inner surface of the heat spreader and a plane defined by the inner rim of the reflector. The light guide comprises deformations and/or lens portions configured to change the source light into a shaped light that is directed through the aperture. The deformations are characterized by a common shape positioned about a center of the light guide.

Claims

1. A luminaire comprising:

a heat sink;

a light source carried by the heat sink and configured to emit a source light, the light source comprising

a heat spreader having an inner surface and an outer surface, and

a plurality of light-emitting diodes (LEDs) carried by a circuit board and disposed generally along an outer peripheral perimeter portion of the inner surface of the heat spreader, and positioned in thermal communication with the heat spreader;

a reflector disposed generally coextensive with the plurality of LEDs and comprising an aperture formed in a medial region thereof, an outer edge of the aperture defining an inner rim of the reflector; and

a light guide positioned between the reflector and the light source, the light guide including a light spreader, defined as at least one of a plurality of deformations and a plurality of lens portions, configured to change the source light into a first shaped light;

wherein the source light is emitted from the light source incident upon the reflector, and is changed by the light spreader of the light guide into the first shaped light that is directed by the light guide through the aperture.

2. The luminaire according to claim 1 wherein the light guide is configured to change the source light into the first shaped light using at least one of collimation, concentration, refraction, reflection, conversion, and diffusion.

3. The luminaire according to claim 2 wherein the source light is within a first wavelength range and wherein the first shaped light is within a second wavelength range.

4. The luminaire according to claim 2 wherein the light guide comprises a material selected from the group consisting of phosphors, quantum dots, luminescent materials, fluorescent materials, and dyes.

5. The luminaire according to claim 1 wherein the light guide is integrally formed with the reflector.

6. The luminaire according to claim 1 wherein the first shaped light is characterized by a substantially uniform emission from a projection surface of the light guide.

7. The luminaire according to claim 1 wherein the plurality of deformations comprises grooves in the light guide each characterized by a common shape positioned about a center of the light guide.

8. The luminaire according to claim 7 wherein the common shape is at least one of round, ellipsoidal, and polygonal.

9. The luminaire according to claim 7 wherein each of the grooves are characterized by a width, a depth, and a radius;

and wherein the grooves, in combination, are configured to redirect the first shaped light at angles that produce a substantially uniform emission from a projection surface of the light guide.

10. The luminaire according to claim 7 wherein the grooves are characterized by a density that increases nearer the center of the light guide.

11. The luminaire according to claim 1 wherein the light source, the heat sink, and the reflector, in combination, has an overall outside height H and an overall outside dimension D such that the ratio of H/D is equal to or less than 0.25.

12. The luminaire according to claim 1 wherein a combination of the light source, the heat sink, and the reflector is so dimensioned as to cover an opening defined by a nominally sized four-inch can light fixture, and to cover an opening defined by a nominally sized four-inch electrical junction box.

13. The luminaire according to claim 1 further comprising an outer optic retained relative to at least one of the light source and the light guide.

14. The luminaire according to claim 13 whenein the outer optic is configured to change the first shaped light into a second shaped light using at least one of collimation, concentration, refraction, reflection, conversion, and diffusion of the first shaped light;

and wherein the outer optic comprises a material selected from the group consisting of phosphors, quantum dots, luminescent materials, fluorescent materials, and dyes.

15. The luminaire according to claim 14 further comprising a mounting ring;

and wherein the outer optic is carried by at least one of the reflector and the mounting ring.

16. A luminaire comprising:

a heat sink comprising a sidewall and a base that, in combination, define a recess;

a light source carried by the heat sink and configured to emit a source light, the light source comprising

a heat spreader that is fittedly disposed in the recess of the heat sink and has an inner surface and an outer surface, the heat spreader comprising a printed circuit board, and

a plurality of light-emitting diodes (LEDs) disposed generally along an outer peripheral perimeter portion of the inner surface of the heat spreader, and positioned in thermal communication with the heat spreader;

a reflector disposed generally coextensive with the plurality of LEDs and comprising an aperture formed in a medial region thereof, an outer edge of the aperture defining an inner rim of the reflector; and

light guide positioned between the reflector and the light source, the light guide comprising a propagation region and light spreader, defined as at least one of a plurality of deformations and a plurality of lens portions, wherein the light spreader and the propagation region, in combination, are configured to change the source light into a first shaped light;

wherein the source light is emitted from the light source incident upon the reflector, and is changed by the light spreader and the propagation region of the light guide into the first shaped light that is directed by the light guide through the aperture; and

wherein a combination of the light source, the heat sink, and the reflector has a overall outside height H and an overall outside dimension D such that the ratio of H/D is equal to or less than 0.25.

17. The luminaire according to claim 16 wherein the light guide is configured to change the source light into the first shaped light using at least one of collimation, concentration, refraction, reflection, conversion, and diffusion;

wherein the source light is within a first wavelength range and wherein the first shaped light is within a second wavelength range; and

wherein the light guide comprises a material selected from the group consisting of phosphors, quantum dots, luminescent materials, fluorescent materials, and dyes.

18. The luminaire according to claim 16 wherein the plurality of deformations comprises grooves in the light guide each characterized by a common shape positioned about a center of the light guide.

19. The luminaire according to claim 18 wherein the common shape is at least one of round, ellipsoidal, and polygonal.

20. The luminaire according to claim 18 wherein each of the grooves are characterized by a width, a depth, and a radius;

and wherein the grooves, in combination, are configured to redirect the first shaped light at angles that produce a substantially uniform emission from a projection surface of the light guide.

21. The luminaire according to claim 18 wherein the grooves are characterized by a density that increases nearer the center of the light guide.

22. A luminaire comprising:

a heat sink;

a light source carried by the heat sink and configured to emit a source light, the source light comprising

a heat spreader comprising a circuit board having an inner surface and an outer surface, and

a plurality of light-emitting diodes (LEDs) carried by and disposed generally along the inner surface of the heat spreader, and positioned in thermal communication with the heat spreader;

a reflector disposed generally coextensive with the plurality of LEDs; and

a light guide positioned between the reflector and the light source, wherein the light guide includes a light spreader, defined as at least one of a plurality of deformations and a plurality of lens portions, configured to change the source light into a first shaped light;

wherein the source light is emitted from the light source incident upon the reflector, and is changed by the light spreader of the light guide into the first shaped light.