Light emitting diode light source

Abstract

A light source that utilizes light emitting diodes that emit white light is disclosed. The diodes are mounted on an elongate member having at least two surfaces upon which the light emitting diodes are mounted. The elongate member is thermally conductive and is utilized to cool the light emitting diodes. In the illustrative embodiment, the elongate member is a tubular member through which a heat transfer medium flows.

Description

FIG. 7 is a cross-sectional view of a portion of an elongate heat sink with fins on an outer surface of the heat sink in accordance with some embodiments.108 may be added to the exterior surface of tubular heat sink 101 (see, e.g., FIG. 7). In addition, apertures may be added to the tubular heat sink to enhance heat flow.

Light source 100 is mounted into a fixture and retained in position by mounting clips 121, 123 as most clearly seen in FIGS. 3, 4, and 5. Each of the clips is shaped so as to engage and retain light source 100. Each clip is affixed on one surface 122, 124 to a light fixture.

Although light source 100 is shown as comprising an elongate tubular heat sink, other extruded elongate members may be used such as channels.

In the illustrative embodiment shown, convection cooling by flow of air through tubular heat sink 101 is utilized such that cool or unheated air enters tubular heat sink 101 at its lower end and exits from the upper end as heated air. In higher wattage light sources, rather than utilizing air as the cooling medium, other fluids may be utilized. In particular, convective heat pumping may be used to remove heat from the interior of the heat sink.

In one particularly advantageous embodiment of the invention, the light source of the invention is configured to replace compact fluorescent lighting in decorative applications.

As will be appreciated by those skilled in the art, the principles of the invention are not limited to the use of light emitting diodes that emit white light. Different colored light emitting diodes may be used to produce monochromatic light or to produce light that is the combination of different colors.

Although the invention has been described in terms of illustrative embodiments, it is not intended that the invention be limited to the illustrative embodiments shown and described. It will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments shown and described without departing from the spirit or scope of the invention. It is intended that the invention be limited only by the claims appended hereto.

Claims

1. A light source comprising:

an elongate thermally conductive member having an outer surface, a first end, and a second end;

at least one a plurality of light emitting diodes carried on said elongate member outer surface;

one or more electrical conductors carried by said elongate thermally conductive member and connected to said at least one plurality of light emitting diodes to supply electrical power thereto; and

said elongate thermally conductive member being configured to conduct heat away from said at least one light emitting diode plurality of light emitting diodes to fluid contained by said elongate thermally conductive member;

wherein a back of each of said plurality of light emitting diodes is in thermal contact with a corresponding underlying portion of said elongate member outer surface;

wherein said elongate thermally conductive member comprises:

at least one opening at the first end that facilitates entry of fluid into said elongate thermally conductive member; and

at least one opening at the second end that facilitates convective movement of heated fluid out of said elongate thermally conductive member; and

a plurality of exterior fins added to said elongate member outer surface to conduct heat to fluid surrounding said plurality of exterior fins thereby facilitating convective heat dissipation.

2. A light source comprising:

an elongate thermally conductive member having an outer surface, a first end, and a second end;

a plurality of light emitting diodes carried on said elongate member outer surface, at least some of said light emitting diodes being disposed in a first plane and others of said light emitting diodes being disposed in a second plane not coextensive with said first plane;

electrical conductors carried by said elongate thermally conductive member and connected to said plurality of light emitting diodes to supply electrical power thereto; and

said elongate thermally conductive member being configured to conduct heat away from said plurality of light emitting diodes to fluid contained by said elongate thermally conductive member;

wherein a back of each of said plurality of light emitting diodes is in thermal contact with a corresponding underlying portion of said elongate member outer surface;

wherein said elongate thermally conductive member comprises:

at least one opening at the first end that facilitates entry of fluid into said elongate thermally conductive member; and

at least one opening at the second end that facilitates convective movement of heated fluid out of said elongate thermally conductive member; and

a plurality of exterior fins added to said elongate member outer surface to conduct heat to fluid surrounding said plurality of exterior fins thereby facilitating convective heat dissipation.

3. A light source in accordance with claim 2, wherein: each of said plurality of light emitting diodes emits white light.

4. A light source in accordance with claim 2, wherein:

said fluid comprises air.

5. A light source in accordance with claim 4, wherein:

said elongate thermally conductive member comprises one or more heat dissipation protrusions.

6. A light source in accordance with claim 2, wherein:

said elongate thermally conductive member comprises a tube.

7. A light source in accordance with claim 6, wherein:

said tube has a cross-section in the shape of a polygon.

8. A light source in accordance with claim 6, wherein:

said tube has a cross-section having flat portions.

9. A light source in accordance with claim 2, wherein:

said elongate thermally conductive member comprises a channel.

10. A light source in accordance with claim 2, wherein:

said elongate thermally conductive member comprises an extrusion.

11. A light source in accordance with claim 10, wherein:

said extrusion is an aluminum extrusion.

12. A light source in accordance with claim 11, wherein:

said elongate thermally conductive member is a tubular member.

13. A light source in accordance with claim 12, wherein:

said tubular member has a polygon cross-section.

14. A light source in accordance with claim 12, wherein:

said tubular member has a triangular cross-section.

15. A light source in accordance with claim 2, further comprising: a flexible circuit carried on a surface of said elongate thermally conductive member, said flexible circuit comprising said electrical conductors.

16. A light source in accordance with claim 15, wherein:

said flexible circuit comprises a plurality of apertures for receiving said plurality of light emitting diodes.

17. A light source in accordance with claim 16, wherein:

each of said light emitting diodes is disposed in a corresponding one of said apertures and affixed in thermally conductive contact with said elongate thermally conductive member.

18. A light source in accordance with claim 2, wherein:

a thermal transfer media disposed therein.

19. A light source in accordance with claim 18 2, wherein: said elongate thermally conductive member comprises a flow channel for said thermal transfer media fluid.

20. A light source in accordance with claim 2, further comprising: at least one clip for mounting said elongate thermally conductive member in a fixture.

21. A light source in accordance with claim 2, further comprising: an electrically insulating layer disposed on said elongate thermally conductive member outer surface and carrying said electrical conductors thereon.

22. A light source in accordance with claim 21, wherein: said electrically insulating layer comprises a plurality of apertures, each aperture receiving one of said light emitting diodes; and each light emitting diode of said plurality of light emitting diodes being mounted in a corresponding one of said apertures and in thermally conductive contact with said elongate thermally conductive member.

23. A light source in accordance with claim 22, wherein: each of said plurality of light emitting diodes emits white light.

24. A light source in accordance with claim 2, wherein a longitudinal axis of each of said plurality of exterior fins is substantially aligned with a longitudinal axis of said elongate thermally conductive member.

25. A light source in accordance with claim 2, wherein the elongate thermally conductive member defines an interior cavity, and wherein the elongate thermally conductive member further comprises a plurality of interior fins extending into the interior cavity.

26. The light source in accordance with claim 25, wherein the plurality of interior fins comprises integral fins.

27. A light source in accordance with claim 25, wherein each of said plurality of interior fins has a longitudinal axis substantially aligned with a longitudinal axis of said elongate thermally conductive member.

28. A light source in accordance with claim 2, wherein said elongate thermally conductive member further comprises one or more apertures between the first end and the second end enhancing fluid flow through said elongate thermally conductive member.

29. A light source in accordance with claim 2, wherein said plurality of light emitting diodes further comprises a first plurality of light emitting diodes disposed in a third plane not coextensive with said first plane or said second plane.

30. A light source in accordance with claim 2, wherein said plurality of light emitting diodes are evenly distributed along a length of said elongate thermally conductive member for efficient heat dissipation.

31. A light source in accordance with claim 15, wherein said back of each of said plurality of light emitting diodes maintains said thermal contact with said elongate member outer surface through said flexible circuit.

32. A light source in accordance with claim 2, wherein said back of each of said plurality of light emitting diodes maintains said thermal contact with said elongate member outer surface through a printed circuit.

33. A light source in accordance with claim 2, wherein said plurality of light emitting diodes are mounted in orientations spanning a range of 180 degrees to 360 degrees.

34. A light source in accordance with claim 1, wherein each of said plurality of exterior fins has a longitudinal axis substantially aligned with a longitudinal axis of said elongate thermally conductive member.

35. A light source in accordance with claim 1, wherein the elongate thermally conductive member defines an interior cavity, and wherein the elongate thermally conductive member further comprises a plurality of interior fins extending into the interior cavity.

36. The light source in accordance with claim 35, wherein the plurality of interior fins comprises integral fins.

37. A light source in accordance with claim 35, wherein each of said plurality of interior fins has a longitudinal axis substantially aligned with a longitudinal axis said elongate thermally conductive member.

38. A light source in accordance with claim 1, wherein: said elongate thermally conductive member comprises a flow channel for said fluid.

39. A light source in accordance with claim 1, wherein said elongate thermally conductive member further comprises one or more apertures between the first end and the second end enhancing fluid flow through said elongate thermally conductive member.

40. A light source in accordance with claim 1, wherein: each of said plurality of light emitting diodes emits white light.

41. A light source in accordance with claim 1, wherein said plurality of light emitting diodes comprise a plurality of light emitting diodes disposed in a single plane.

42. A light source in accordance with claim 1, wherein said plurality of light emitting diodes are mounted in orientations spanning a range of 180 degrees to 360 degrees.

43. A light source in accordance with claim 1, wherein said plurality of light emitting diodes are evenly distributed along a length of said elongate thermally conductive member for efficient heat dissipation.

44. A light source in accordance with claim 1, wherein a cross-section of said elongate thermally conductive member comprises flat portions.

45. A light source in accordance with claim 1, wherein said back of each of said plurality of light emitting diodes maintains said thermally conductive contact with said elongate member outer surface through a printed circuit.

46. A light source in accordance with claim 1, further comprising: an electrically insulating layer disposed on said elongate thermally conductive member outer surface and carrying said electrical conductors thereon.

47. A light source in accordance with claim 1, wherein said plurality of light emitting diodes emits colored light.

48. A light source in accordance with claim 47, wherein said light source produces white light.

49. A light source in accordance with claim 1, wherein said light source is configured for general illumination.

50. A light source in accordance with claim 1, wherein said elongate thermally conductive member is a single integral piece.

51. A light source in accordance with claim 2, wherein said plurality of light emitting diodes emits colored light.

52. A light source in accordance with claim 51, wherein said light source produces white light.

53. A light source in accordance with claim 2, wherein said elongate thermally conductive member is a single integral piece.