Low-profile LED heat management system

• US 9,004,722 B2
• Filed: 07/31/2012
• Issued: 04/14/2015
• Est. Priority Date: 07/31/2012
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Sampsell, Matthew B., Holman, Robert L.
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US13/562,923
• Publication Number:
  US 20140036516A1
• Time in Patent Office: 987 Days
• Field of Search: 362/249.02, 362/294, 362/373, 362/555, 362/612
• US Class Current: 362/294
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21K 9/61 using light guides
• 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: F21V 2200/20 of light guides of a generally planar shape
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/77 with essentially identical diverging planar fins or blades, e.g. with fan-like or star-like cross-section
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• CPC Class Codes: F21V 29/80 with pins or wires
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• 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 6/003 Lens or lenticular sheet or layer
• 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 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• 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
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

This disclosure provides systems, methods and apparatus for low-profile lighting systems. In one aspect, an LED-based light engine, which may be thinner and/or lighter than conventional light engines, may be retained in both conventionally-dimensioned and low-profile light fixtures. In another aspect, a light engine can include both convective and conductive heat transfer components, the efficacy of which will vary based on the dimensions of a light fixture in which the light engine is installed.

Claims

1. A light engine, comprising:

a light-emitting diode (LED);

a light guide in optical communication with the LED and having an output surface, wherein the light guide is configured to direct light from the LED through the output surface;

a convective heat transfer component configured to provide a convective thermal path away from the LED;

a transfer surface configured to provide a conductive heat path away from the LED when the light engine is installed within a light fixture such that the transfer surface is configured to abut a portion of the light fixture; and

one or more contacts extending from a surface of the light engine, the contacts configured to provide electrical and mechanical connection with a light fixture.

2. The light engine of claim 1, wherein the light engine additionally includes a thermal pad, wherein the transfer surface is a surface of the thermal pad.

3. The light engine of claim 2, wherein the thermal pad includes a deformable material.

4. The light engine of claim 1, wherein the one or more contacts are disposed radially outward of at least a portion of the transfer surface.

5. The light engine of claim 1, wherein an upper portion of the one or more contacts does not extend beyond an upper portion of the transfer surface.

6. The light engine of claim 1, wherein the one or more contacts are disposed radially inward of at least a portion of the transfer surface.

7. The light engine of claim 6, wherein the transfer surface includes an annular surface.

8. The light engine of claim 1, wherein the convective heat transfer component includes a plurality of thermal fins, rods, and/or pins disposed radially outward of at least a portion of the transfer surface.

9. The light engine of claim 1, wherein the convective heat transfer component includes a movable component configured to increase airflow adjacent the light fixture.

10. The light engine of claim 9, wherein the movable component includes one of a fan or a piezoelectric element.

11. A light engine, comprising:

a light guide in optical communication with a light-emitting diode (LED) and having an output surface, wherein the light guide is configured to direct light from the LED through the output surface;

a convective heat transfer component configured to provide a convective thermal path away from the LED;

a transfer surface configured to provide a conductive thermal path away from the LED; and

a plurality of contacts which provide electrical and mechanical connection with a light fixture, wherein the contacts further enable a conductive thermal connection by securing the transfer surface of the light engine against a complimentary transfer surface of the light fixture when the light engine is installed within the light fixture.

12. The light engine of claim 11, wherein the transfer surface comprises a surface of a deformable thermal pad, wherein the contacts maintain the thermal pad in a partially deformed state when the transfer surface of the light engine is secured against the transfer surface of the light fixture.

13. The light engine of claim 11, wherein the contacts are disposed within a recessed portion of the light engine.

14. The light engine of claim 11, wherein an upper portion of the contacts do not extend beyond an upper portion of the transfer surface.

15. The light engine of claim 11, wherein the contacts are disposed radially outward of at least a portion of the transfer surface.

16. A light engine, comprising:

a light guide in optical communication with a light-emitting diode (LED) and having an output surface, wherein the light guide is configured to direct light from the LED through the output surface;

a plurality of thermal fins disposed around a periphery of the light engine for providing a convective thermal path away from the LED; and

means for providing a conductive thermal path away from the LED when the light engine is disposed within a light fixture such that the means for providing a conductive thermal path is configured to abut a portion of the light fixture.

17. A light engine, comprising:

a light guide in optical communication with a light-emitting diode (LED) and having an output surface, wherein the light guide is configured to direct light from the LED through the output surface;

a transfer surface configured to abut a complimentary transfer surface of the light fixture for providing a convective thermal path away from the LED; and

means for providing a conductive thermal path away from the LED when the light engine is disposed within a light fixture such that the means for providing a conductive thermal path is configured to abut a portion of the light fixture.

18. The light engine of claim 17, wherein the transfer surface comprises a surface of a thermal pad.

19. A method of installing a light engine into a light fixture, comprising:

providing an LED-based light engine, the light engine comprising;

a convective heat transfer component configured to provide a convective thermal path away from the light engine;

a transfer surface; and

a plurality of contacts extending from the light engine;

engaging the plurality of contacts with a corresponding connection portion of a light fixture; and

translating the light engine relative to the light fixture to form an electrical and mechanical connection with the light fixture, wherein translation of the light engine brings the transfer surface of the light engine into contact with a complementary transfer surface of the light fixture to form a thermal connection therebetween.

20. The method of claim 19, wherein translating the light engine relative to the light fixture includes rotating the light engine relative to the light fixture.

21. A light fixture, comprising:

a housing defining a receiving space dimensioned to retain a light engine therein;

a transfer surface including a thermally conductive material, wherein the transfer surface is exposed to the receiving space;

a connector portion configured to provide electrical and mechanical connection with the light engine, wherein the connector portion is configured to mechanically bias a portion of the light engine against the transfer surface to provide a conductive heat path from the light engine to the transfer surface.

22. The light fixture of claim 21, wherein the receiving space of the housing has a depth of less than two inches, and wherein a minimum height to width ratio of the light fixture is less than or equal to 1:

2.

23. The light fixture of claim 21, wherein the receiving space of the housing has a depth of less than one inch, and wherein the minimum height to width ratio of the light fixture is less than or equal to 1:

4.

24. The light fixture of claim 21, wherein the light fixture additionally comprises at least one convective heat transfer component disposed on an outer surface of the housing.

25. A method of fabricating a light engine, comprising:

providing a light-emitting diode (LED) in optical communication with a light guide;

providing a convective heat transfer component in thermal communication with the LED; and

providing a transfer surface in thermal communication with the LED and configured to provide a conductive heat path away from the LED when the light engine is installed within a light fixture such that the transfer surface is configured to abut a portion of the light fixture; and

providing at least one connector in electrical communication with the LED, wherein the connector is configured to provide mechanical and electrical connections between the LED and the light fixture.

26. The method of claim 25, wherein providing a convective heat transfer component in thermal communication with the LED comprises providing a plurality of thermal fins, pins, or rods extending outward from a surface of the light engine.