LED flashlight and heat sink arrangement

• US 7,883,243 B2
• Filed: 07/17/2007
• Issued: 02/08/2011
• Est. Priority Date: 07/20/2006
• Status: Active Grant

• Current Assignee: Streamlight, Inc.
• Original Assignee: Streamlight, Inc.
• Inventors: Snyder, Mark W.
• Primary Examiner(s): Sember; Thomas M
• Application Number:
  US11/779,038
• Publication Number:
  US 20080018256A1
• Time in Patent Office: 1,302 Days
• Field of Search: 362/294, 362/373, 362/545, 362/547, 362202-208, 362/646, 362/631, 362/249.02, 362/218, 362/345, 362/196, 362/200
• US Class Current: 362/294
• CPC Class Codes: F21L 4/027 the light sources being a LED
• 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 29/74 with fins or blades
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/30 Driver circuits

Abstract

An LED light may comprise a light emitting diode selectively energizable for producing light; an electronic circuit for selectively energizing the light emitting diode; and a heat sink of a thermally conductive material, wherein the light emitting diode is thermally bonded to the heat sink; and wherein the electronic circuit is attached to the heat sink. The light may have a pair of contact springs extending from the heat sink and the electronic circuit may include thermal conductivity enhancing features.

Claims

1. A light comprising:

a heat sink of a thermally conductive material comprising a first generally rectangular planar member, and a second generally rectangular member integrally joined to the first generally rectangular member;

a light emitting diode attached to a broad surface of the first generally rectangular planar member of said heat sink;

an electronic circuit board comprising circuitry for controlling the energizing of said light emitting diode, wherein said electronic circuit board is attached to the second generally rectangular planar member; and

a case for receiving said heat sink, said light emitting diode, said electronic circuit board, and a source of electrical power.

2. The light of claim 1 wherein said light emitting diode is bonded to a central region of the broad surface of the first generally rectangular member of said heat sink by a thermally conductive adhesive.

3. The light of claim 1 further comprising a second electronic circuit board for receiving said light emitting diode and having conductive areas thereon, wherein said light emitting diode is bonded to the central region of the broad surface of the first generally rectangular member of said heat sink through said second electronic circuit board and wherein the electrical contacts of said light emitting diode are electrically connected to the conductive areas of said second electronic circuit board.

4. The light of claim 1 wherein the first generally rectangular member of said heat sink has at least two spaced apart alignment features for positioning said light emitting diode on a central region of a broad surface of the first generally rectangular member of said heat sink for bonding said light emitting diode to said heat sink.

5. The light of claim 1 wherein said electronic circuit board is supported at one end by a fastener engaging the second generally rectangular member of said heat sink.

6. The light of claim 5 further comprising an electronic component for controlling the energization of said light emitting diode, wherein said electronic component is disposed on said electronic circuit board proximate said fastener.

7. The light of claim 6 wherein said electronic circuit board includes a substantial electrical conductor area, a thicker electrical conductor, one or more conductive vias, or any combination thereof, proximate said fastener for reducing thermal resistance between said electronic component and the fastener.

8. The light of claim 1 wherein said electronic circuit board is attached to said heat sink without thermally conductive bonding material.

9. The light of claim 1 wherein said heat sink is fabricated from a single piece of a thermally conductive material.

10. The light of claim 9 wherein said heat sink is fabricated by machining, by casting, by die casting, by molding, or by forging the single piece of a thermally conductive material.

11. The light of claim 1 wherein the first generally rectangular planar member and the second generally rectangular member are fabricated separately from thermally conductive material, and wherein the first and second generally rectangular planar members are integrally joined by welding, by brazing, by soldering, by a permanent adhesive, by a permanent thermally conductive adhesive, or by any combination thereof.

12. The light of claim 11 wherein each of the first generally rectangular planar member and the second generally rectangular member of said heat sink is fabricated by machining, by casting, by die casting, by molding, by forging, or by any combination thereof.

13. The light of claim 1 wherein said circuitry for energizing said light emitting diode receives a voltage from the source of electrical power and provides a predetermined current to said light emitting diode, and increases the voltage from the source of electrical power if necessary to provide the predetermined current.

14. The light of claim 1 further comprising a pair of contact springs extending away from said heat sink for electrically connecting said electronic circuit board to the source of electrical power.

15. The light of claim 1 further comprising a second electronic circuit board including terminals for making electrical connection to a battery, wherein said second electronic circuit board is attached to said heat sink juxtaposed from said electronic circuit board and proximate an edge of the first generally rectangular member.

16. The light of claim 1 wherein said heat sink maintains said light emitting diode and the energizing circuitry of said electronic circuit board at a temperature less than 200°

C. in normal operation and under a fault condition.

17. The light of claim 1 wherein the first generally rectangular member of said heat sink is thicker in a central region whereat said light emitting diode is attached thereto than in a surrounding region.

18. A light comprising:

a heat sink of a thermally conductive material, said heat sink comprising a first generally rectangular planar member defining four edges and two opposing broad surfaces, two opposing elongated members each integrally joined to the first rectangular planar member proximate two opposing edges thereof, and a second generally rectangular member integrally joined at opposing ends thereof to the two elongated members and integrally joined to the first generally rectangular member;

a light emitting diode attached to a broad surface of the first generally rectangular planar member of said heat sink between the two elongated members thereof;

an electronic circuit board comprising circuitry for energizing said light emitting diode, wherein said electronic circuit board is attached to the second generally rectangular planar member between the two opposing elongated members; and

a case for receiving said heat sink, said light emitting diode, said electronic circuit board, and a source of electrical power.

19. The light of claim 18 wherein said light emitting diode is bonded to a central region of the broad surface of the first generally rectangular member of said heat sink by a thermally conductive adhesive.

20. The light of claim 18 further comprising a second electronic circuit board for receiving said light emitting diode and having conductive areas thereon, wherein said light emitting diode is bonded to the central region of the broad surface of the first generally rectangular member of said heat sink through said second electronic circuit board and wherein the electrical contacts of said light emitting diode are electrically connected to the conductive areas of said second electronic circuit board.

21. The light of claim 18 wherein the first generally rectangular member of said heat sink has at least two spaced apart alignment features for positioning said light emitting diode on a central region of a broad surface of the first generally rectangular member of said heat sink for bonding said light emitting diode to said heat sink.

22. The light of claim 18 wherein said electronic circuit board is supported at one end by a groove in a first one of the two elongated members of said heat sink and at an opposite end by a fastener engaging the second generally rectangular member of said heat sink.

23. The light of claim 22 further comprising an electronic component for controlling the energization of said light emitting diode, wherein said electronic component is disposed on said electronic circuit board proximate said fastener.

24. The light of claim 23 wherein said electronic circuit board includes a substantial electrical conductor area, a thicker electrical conductor, one or more conductive vias, or any combination thereof, proximate said fastener for reducing thermal resistance between said electronic component and said fastener.

25. The light of claim 18 wherein said electronic circuit board is attached to said heat sink without thermally conductive bonding material.

26. The light of claim 18 wherein said heat sink is fabricated from a single piece of a thermally conductive material.

27. The light of claim 26 wherein said heat sink is fabricated by machining, by casting, by die casting, by molding, or by forging the single piece of a thermally conductive material.

28. The light of claim 18 wherein the first generally rectangular planar member, the two opposing elongated members and the second generally rectangular member are fabricated separately from thermally conductive material, and wherein the first and second generally rectangular planar members and the two elongated members are integrally joined by welding, by brazing, by soldering, by a permanent adhesive, by a permanent thermally conductive adhesive, or by any combination thereof.

29. The light of claim 28 wherein each of the first generally rectangular planar member, the two opposing elongated members and the second generally rectangular member of said heat sink is fabricated by machining, by casting, by die casting, by molding, by forging, or by any combination thereof.

30. The light of claim 18 wherein said circuitry for energizing said light emitting diode receives a voltage from the source of electrical power and provides a predetermined current to said light emitting diode, and increases the voltage from the source of electrical power if necessary to provide the predetermined current.

31. The light of claim 18 further comprising a pair of contact springs extending away from said heat sink for electrically connecting said electronic circuit board to a source of electrical power.

32. The light of claim 18 further comprising a second electronic circuit board including terminals for making electrical connection to a battery, wherein said second electronic circuit board is attached to said heat sink between the two elongated members thereof juxtaposed from said electronic circuit board and proximate an edge of the first generally rectangular member.

33. The light of claim 18 wherein said heat sink maintains said light emitting diode and the energizing circuitry of said electronic circuit board at a temperature less than 200°

C. in normal operation and under a fault condition.

34. The light of claim 18 wherein the first generally rectangular member of said heat sink is thicker in a central region whereat said light emitting diode is attached thereto than in a surrounding region.

35. A light comprising:

a heat sink of a thermally conductive material;

a light emitting diode selectively energizable for producing light, wherein said light emitting diode is thermally coupled to said heat sink;

an electronic circuit for selectively energizing said light emitting diode, wherein said electronic circuit includes an electronic circuit board having an attachment location at which it is attached to said heat sink,

said electronic circuit including an electronic component for selectively controlling the energizing of said light emitting diode, wherein said electronic component generates heat and is disposed on said electronic circuit board proximate the location at which said electronic circuit board is attached to said heat sink,

said electronic circuit board further including a conductive element that reduces the thermal resistance between the heat generating component and the attachment location thereof; and

a case for receiving said heat sink, said light emitting diode, said electronic circuit, and a source of electrical power.

36. The light of claim 35 wherein said electronic circuit board includes vias and/or a conductor for increasing a thermal conductivity of said electronic circuit board proximate the location at which said electronic circuit board is attached to said heat sink.

37. The light of claim 35 wherein said electronic circuit board is attached to said heat sink without thermally conductive bonding material.

38. The light of claim 35 wherein said said conductive element that reduces the thermal resistance between the heat generating component and the attachment location includes a substantial electrical conductor area, a thicker electrical conductor, one or more conductive vias, or any combination thereof, proximate to the attachment location of said electronic circuit.

39. The light of claim 35 wherein said heat sink maintains said light emitting diode and said electronic circuit at a temperature less than 200°

C. in an ambient 40°

C. environment under normal operation and under a fault condition.

40. The light of claim 35 wherein said electronic circuit includes a pair of contact springs extending away from said heat sink for making electrical contact with the source of electrical power.

41. The light of claim 35 wherein said heat sink of a thermally conductive material comprises:

a first generally rectangular planar member for supporting said light emitting diode, and a second generally rectangular member integrally joined to the first generally rectangular member and for supporting said electronic circuit.

42. The light of claim 35 wherein said heat sink has at least two spaced apart alignment features for positioning said light emitting diode on a predetermined region of said heat sink for bonding said light emitting diode thereto.

43. The light of claim 35 wherein said electronic circuit for selectively energizing said light emitting diode receives a voltage from the source of electrical power and provides a predetermined current to said light emitting diode.

44. The light of claim 43 wherein said electronic circuit for selectively energizing said light emitting diode increases the voltage from the source of electrical power if necessary to provide the predetermined current.

45. A light comprising:

a heat sink of a thermally conductive material;

a light emitting diode selectively energizable for producing light, wherein said light emitting diode is thermally coupled to said heat sink;

an electronic circuit for selectively energizing said light emitting diode, wherein said electronic circuit includes an electronic circuit board having an attachment location at which it is attached to said heat sink,

said electronic circuit further including a pair of contact springs extending away from said heat sink in the same direction for contacting a source of electrical power; and

a case for receiving said heat sink, said light emitting diode, said electronic circuit, and the source of electrical power.

46. The light of claim 45 wherein said electronic circuit board includes vias and/or a conductor for increasing a thermal conductivity of said electronic circuit board proximate a location at which said electronic circuit board is attached to said heat sink.

47. The light of claim 45 wherein said electronic circuit includes an electronic component for selectively controlling the energizing of said light emitting diode, wherein said electronic component is disposed on said electronic circuit board proximate the location at which said electronic circuit board is attached to said heat sink.

48. The light of claim 45 wherein said electronic circuit board is attached to said heat sink without thermally conductive bonding material.

49. The light of claim 45 wherein said electronic circuit includes a substantial electrical conductor area, a thicker electrical conductor, one or more conductive vias, or any combination thereof, proximate to an attachment location of said electronic circuit for reducing the thermal resistance between a heat generating component thereof and the attachment location thereof.

50. The light of claim 45 wherein said heat sink maintains said light emitting diode and said electronic circuit at a temperature less than 200°

C. in an ambient 40°

C. environment under normal operation and under a fault condition.

51. The light of claim 45 wherein said pair of contact springs include coiled spring-like structures of electrically conductive wire extending away from said heat sink for making electrical contact with terminals of the source of electrical power.

52. The light of claim 45 wherein said heat sink of a thermally conductive material comprises:

a first generally rectangular planar member for supporting said light emitting diode, and a second generally rectangular member integrally joined to the first generally rectangular member and for supporting said electronic circuit.

53. The light of claim 45 wherein said heat sink has at least two spaced apart alignment features for positioning said light emitting diode on a predetermined region of said heat sink for bonding said light emitting diode thereto.

54. The light of claim 45 wherein said electronic circuit for selectively energizing said light emitting diode receives a voltage from the source of electrical power and provides a predetermined current to said light emitting diode.

55. The light of claim 54 wherein said electronic circuit for selectively energizing said light emitting diode increases the voltage from the source of electrical power if necessary to provide the predetermined current.

56. A light comprising:

a heat sink of a thermally conductive material, said heat sink comprising a first generally rectangular planar member defining four edges and two opposing broad surfaces, two opposing elongated members each integrally joined to the first rectangular planar member proximate two opposing edges thereof, and a second generally rectangular member integrally joined at opposing ends thereof to the two elongated members and integrally joined to the first generally rectangular member;

a light emitting diode bonded by a thermally conductive adhesive to a central region of a broad surface of the first generally rectangular planar member of said heat sink between the two elongated members thereof;

wherein said heat sink has at least two spaced apart alignment features for positioning said light emitting diode on the central region of the broad surface of the first generally rectangular member of said heat sink for the bonding of said light emitting diode thereto;

a first electronic circuit board adjacent the second generally rectangular member of said heat sink comprising circuitry for energizing said light emitting diode, wherein said first electronic circuit board is supported at one end by a fastener engaging the second generally rectangular member of said heat sink;

a second electronic circuit board supporting said light emitting diode, wherein electrical contacts of said light emitting diode are electrically connected to respective conductive areas of said second electronic circuit board and to said first electronic circuit board; and

a case for receiving said heat sink, said light emitting diode, said first and second electronic circuit boards, and a source of electrical power.

57. The light of claim 56 wherein an electronic component for controlling the energization of said light emitting diode is disposed on said first electronic circuit board proximate said fastener.

58. The light of claim 56 wherein said first electronic circuit board includes a substantial electrical conductor area, a thicker electrical conductor, one or more conductive vias, or any combination thereof, proximate to said fastener for reducing thermal resistance between the circuitry for energizing said light emitting diode and said fastener.

59. The light of claim 56 wherein said first electronic circuit board is attached to said heat sink without thermally conductive bonding material.

60. The light of claim 56 wherein said heat sink is fabricated from a single piece of a thermally conductive material.

61. The light of claim 60 wherein said heat sink is fabricated by machining, by casting, by die casting, by molding, or by forging the single piece of a thermally conductive material.

62. The light of claim 56 wherein the first generally rectangular planar member, the two opposing elongated members and the second generally rectangular member are fabricated separately from thermally conductive material, and wherein the first and second generally rectangular planar members and the two elongated members are integrally joined by welding, by brazing, by soldering, by a permanent adhesive, by a permanent thermally conductive adhesive, or by any combination thereof.

63. The light of claim 62 wherein each of the first generally rectangular planar member, the two opposing elongated members and the second generally rectangular member of said heat sink is fabricated by machining, by casting, by die casting, by molding, by forging, or by any combination thereof.

64. The light of claim 56 wherein said circuitry for energizing said light emitting diode receives a voltage from the source of electrical power and provides a predetermined current to said light emitting diode, and provides a voltage greater than the voltage from the source of electrical power when necessary to provide the predetermined current.

65. The light of claim 56 further comprising a pair of contact springs extending away from said heat sink for electrically connecting said first electronic circuit board to a source of electrical power.

66. The light of claim 56 further comprising a third electronic circuit board including terminals for making electrical connection to a battery, wherein said third electronic circuit board is attached to said heat sink between the two elongated members thereof juxtaposed from said first electronic circuit board and proximate an edge of the first generally rectangular member.

67. The light of claim 56 wherein said heat sink maintains said light emitting diode and the energizing circuitry of said electronic circuit board at a temperature less than 200°

C. in normal operation and under a fault condition.

68. The light of claim 56 wherein said second electronic circuit board supporting said light emitting diode comprises:

said second circuit board having an opening therethrough in which said light emitting diode is disposed;

or

said second circuit board having a contact area thereon to which said light emitting diode is attached;

or

said second circuit board having a contact area thereon to which said light emitting diode is attached, wherein the contact area includes a plurality of openings, of holes, of conductive vias, of plated-through holes, of plated full plated-through holes, and/or of solder filled holes, in said second circuit board.