Method and apparatus for cooling a lightbulb

• US 7,824,075 B2
• Filed: 06/08/2006
• Issued: 11/02/2010
• Est. Priority Date: 06/08/2006
• Status: Expired due to Fees

• Current Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Original Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Inventors: Maxik, Fredric S.
• Primary Examiner(s): Choi, Jacob Y
• Assistant Examiner(s): Makiya, David J
• Application Number:
  US11/449,148
• Publication Number:
  US 20070285926A1
• Time in Patent Office: 1,608 Days
• Field of Search: 362/294, 362/373, 362/650
• US Class Current: 362/294
• 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: F21V 23/001 the elements being electrical wires or cables
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 29/773 the planes containing the fins or blades having the direction of the light emitting axis
• 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]

Abstract

A device has a plurality of light emitting diodes (LEDs), heat conducting structure that includes a heat pipe and that carries heat from the region of the LEDs to a further location spaced therefrom, and heat dissipating structure that accepts heat from the heat conducting structure at the further location and that discharges the heat externally of the device. In a different embodiment, a device has a radiation generator, a thermal spreader that receives heat emitted by the radiation generator, heat conducting structure that carries heat from the thermal spreader to a location spaced therefrom, and heat dissipating structure that accepts heat at the location from the heat conducting structure and that discharges the heat externally of the device.

Claims

1. An apparatus comprising a device that includes:

a radiation generator that, when energized, produces electromagnetic radiation that is emitted from said device;

a thermal spreader that is larger than said radiation generator and that is disposed near said radiation generator for receiving heat emitted by said radiation generator;

heat conducting structure for carrying heat from said thermal spreader to an end opposite said thermal spreader and said radiation generator, said heat conducting structure having an elongate portion adjacent said end, said heat conducting structure including a heat pipe that has, at all points along the length thereof, a cross-sectional shape with first and second transverse dimensions in respective directions that are orthogonal, said first transverse dimension being substantially greater than said second transverse dimension at all points along the length of said heat pipe; and

heat dissipating structure spaced apart from said thermal spreader for accepting heat from said heat conducting structure at said end and for discharging heat externally of said device, said heat dissipating structure extending substantially radial to a central axis of said apparatus;

wherein said heat dissipating structure includes a first plurality of fins having a first cross-sectional width and a second plurality of fins having a second cross-sectional width, said first cross-sectional width being larger than said second cross-sectional width, wherein said first plurality of fins has at least one hole sized to receive said end of said heat pipe.

2. An apparatus according to claim 1, wherein said thermal spreader has a platelike shape.

3. An apparatus according to claim 1, including a plurality of further radiation generators that each, when energized, produce electromagnetic radiation that is emitted from said device, said further radiation generators each being disposed near said thermal spreader so that said thermal spreader receives heat emitted by each of said further radiation generators.

4. An apparatus according to claim 3, wherein said radiation generators each include a light emitting diode.

5. An apparatus according to claim 3, wherein said electromagnetic radiation emitted by each of said radiation generators includes at least one of visible radiation, infrared radiation and ultraviolet radiation.

6. An apparatus according to claim 3, including a circuit board having each of said radiation generators supported thereon.

7. An apparatus according to claim 6, wherein said thermal spreader is made of an electrically conductive material;

and including a sheet of electrically insulating and thermally conducting material that is disposed between and engages each of said thermal spreader and said circuit board.

8. An apparatus according to claim 7, wherein said thermal spreader has a platelike shape.

9. An apparatus according to claim 1, wherein said heat pipe is configured for orientation-independent operation.

10. An apparatus according to claim 1, wherein said heat pipe has a central portion that is thermally coupled to one of said thermal spreader and said heat dissipating structure, and has end portions that are each thermally coupled to the other of said thermal spreader and said heat dissipating structure.

11. An apparatus according to claim 10, wherein said central portion extends in a first direction and said end portions each extend in a second direction approximately perpendicular to said first direction.

12. An apparatus according to claim 1, wherein said heat conducting structure includes a further heat pipe that has, at all points along the length thereof, a cross-sectional shape with third and fourth transverse dimensions in respective directions that are orthogonal, said third transverse dimension being substantially greater than said fourth transverse dimension at all points along the length of said heat pipe, said heat pipes each having a first end portion that is thermally coupled to said thermal spreader and a second end portion that is thermally coupled to said heat dissipating structure.

13. An apparatus according to claim 12, wherein said first and second end portions of each said heat pipe extend in respective directions that are approximately perpendicular to each other.

14. An apparatus according to claim 1, wherein said heat dissipating structure includes a heat sink having a plurality of fins.

15. An apparatus according to claim 1, wherein said device is a lightbulb.

16. An apparatus according to claim 14, wherein said fins of said heat sink each receive heat from and extend approximately parallel to a portion of said heat pipe in the region of said location;

and

wherein said device is free of a housing surrounding said heat sink.

17. A lighting device comprising:

a plurality of light emitting diodes that each, when energized, produce electromagnetic radiation that is emitted from said device;

a spreader plate thermally coupled to said plurality of light emitting diodes, said spreader plate transferring heat in a plane substantially perpendicular to a central axis of said lighting device;

at least one heat pipe having a first end thermally coupled to said spreader plate and arranged to transfer heat in a direction substantially perpendicular to said plane to a second end; and

, a heat sink, said heat sink being thermally coupled to said at least one heat pipe, said heat sink having a first plurality of fins and a second plurality of fins extending radially from said central axis wherein said lighting device is sized and shaped to conform with an Edison type lightbulb, wherein said spreader plate includes a groove sized to receive a first portion of said at least one heat pipe; and

said at least one heat pipe furthering includes a first curved portion adjacent said first portion and a second portion adjacent said first curved portion, said second portion extending substantially perpendicular to said spreader plate, said first plurality of fins has a larger width than said second plurality of fins and said first plurality of fins includes at least one hole sized to receive said second portion of said heat pipe.

18. The lighting device of claim 17 wherein said at least one heat pipe includes a second curved portion adjacent said first portion opposite said first curved portion and a third portion adjacent said second curved portion, said third portion extending substantially parallel to said second portion, said second portion being coupled to said first plurality of fins and said third portion being coupled to said second plurality of fins.

19. The lighting device of claim 17 wherein said heat sink further includes a plate portion on one end, said plate portion being arranged between said spreader plate and said first plurality of fins, said plate portion having an annular groove extending about an outer diameter.