Light guide for low profile luminaire

Patent metadata

Field	Value
Publication number	US-2016370535-A1
Application number	US-201615248769-A
Country	US
Kind code	A1
Filing date	Aug 26, 2016
Priority date	Oct 5, 2009
Publication date	Dec 22, 2016
Grant date	—

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.

First claim

That which is claimed is:

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 wherein 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 a 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 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.

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 light source 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

Assignees

• Lighting Science Group Corp

Inventors

• Boomgaarden Mark Penley
• Romeu Ricardo
• Kelley Ryan
• Holland Eric

Classifications

• G02B6/0041 Primary

  provided in the bulk of the light guide · CPC title

• F21K9/61

  using light guides · CPC title

• G02B6/0031

  Reflecting element, sheet or layer · CPC title

• F21K9/23

  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 title

• G02B6/0073 Primary

  Light emitting diode [LED] · CPC title