LIGHTING DEVICE, HEAT TRANSFER STRUCTURE AND HEAT TRANSFER ELEMENT

• US 20100103678A1
• Filed: 05/21/2009
• Published: 04/29/2010
• Est. Priority Date: 10/24/2008
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: Cree LED Lighting Solutions Inc (Wolfspeed, Inc.)
• Inventors: Negley, Gerald H., VAN DE VEN, Antony Paul
• Granted Patent: US 8,858,032 B2
• Time in Patent Office: Days
• 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: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 23/06 the elements being coupling devices , e.g. connectors
• CPC Class Codes: F21V 29/51 using condensation or evaporation of a fluid, e.g. heat pipes
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence

Abstract

A heat pipe configured to transfer heat from a central portion of a lighting device to an edge portion of the lighting device, the heat pipe comprising one region which extends along a portion of a diameter of a substantially circular, substantially annular shape and another region that extends along a diameter of the shape. Also, a lighting device comprising a housing, a reflector, a light emitter and a heat pipe as described above. Also, a self ballasted lamp comprising a solid state light source, an electrical connector, an AC power supply, a reflector configured to receive light from the source and emit reflected light from an aperture, and a thermal management system. Also, a lighting device, comprising a housing, a reflector, a light emitter comprising an array of solid state light emitters, a heat pipe and a sensor.

Claims

1. A lighting device, comprising:

a housing having a substantially circular, substantially annular portion;

a reflector disposed within the housing;

a light emitter;

a heat pipe in thermal communication with the light emitter and the housing, the heat pipe having a thermal transfer region and at least a first thermal exchange region, at least a portion of the first thermal exchange region extending in a shape which follows at least a first portion of the substantially circular, substantially annular portion of the housing and the thermal transfer region extends in a shape which comprises at least a portion of a diameter of the substantially circular, substantially annular portion of the housing.

2. A lighting device as recited in claim 1, wherein the portion of the first thermal exchange region extends at least 10 degrees along the first portion of the substantially circular substantially annular shape.

3. A lighting device as recited in claim 1, wherein the thermal transfer region extends substantially radially relative to said substantially circular, substantially annular portion of the housing.

4. A lighting device as recited in claim 1, wherein:

the heat pipe further comprises a second thermal exchange region; and

at least a portion of the second thermal exchange region follows at least a second portion of the substantially circular, substantially annular portion of the housing.

5. A lighting device as recited in claim 4, wherein the portion of the first thermal exchange region which follows the substantially circular, substantially annular portion of the housing extends at least 10 degrees along the first portion of the substantially circular, substantially annular portion of the housing, and the portion of the second thermal exchange region which follows the substantially circular, substantially annular portion of the housing extends at least 10 degrees along the second portion of the substantially circular, substantially annular portion of the housing.

6. A lighting device as recited in claim 4, wherein the portion of the first thermal exchange region extends in a first circumferential direction relative to the substantially circular, substantially annular portion of the housing, and the portion of the second thermal exchange region also extends in the first circumferential direction.

7. A lighting device as recited in claim 1, further comprising a heat plate, the light emitter being mounted on the heat plate and the heat plate being in thermal communication with the thermal transfer region of the heat pipe.

8. A lighting device as recited in claim 7, wherein the heat plate comprises a heat plate groove, and a portion of the thermal transfer region extends along at least a portion of the heat plate groove.

9. A lighting device as recited in claim 7, wherein the heat plate comprises copper.

10. A lighting device as recited in claim 1, wherein the light emitter comprises a packaged light emitting diode.

11. A heat transfer element for a solid state lighting device, comprising:

a heat pipe, the heat pipe configured to transfer heat from a central portion of a substantially circular, substantially annular shaped portion of the lighting device to an edge portion of the lighting device, remote from the central portion of the lighting device, the heat pipe comprising;

a thermal transfer region, at least a portion of which extends in a shape that comprises at least a portion of a diameter of the substantially circular, substantially annular shape; and

a first thermal exchange region that extends in a shape that comprises at least a first portion of the substantially circular, substantially annular shape.

12. A heat transfer element as recited in claim 11, wherein the portion of the first thermal exchange region extends at least 10 degrees along the first portion of the substantially circular, substantially annular shape.

13. A heat transfer element as recited in claim 11, wherein the thermal transfer region extends substantially radially relative to the substantially circular, substantially annular shape.

14. A heat transfer element as recited in claim 11, wherein:

the heat pipe further comprises a second thermal exchange region; and

at least a portion of the second thermal exchange region extends in a shape which comprises a second portion of the substantially circular, substantially annular shape.

15. A heat transfer element as recited in claim 14, wherein the portion of the first thermal exchange region extends at least 10 degrees along the first portion of the substantially circular substantially annular shape, and the portion of the second thermal exchange region extends at least 10 degrees along the second portion of the substantially circular substantially annular shape.

16. A heat transfer element as recited in claim 14, wherein the portion of the first thermal exchange region extends in a first circumferential direction relative to the substantially circular substantially annular shape, and the portion of the second thermal exchange region also extends in the first circumferential direction.

17. A heat transfer element as recited in claim 11, wherein:

the heat transfer element further comprises a heat plate; and

the heat plate is in thermal contact with the thermal transfer region of the heat pipe.

18. A heat transfer element as recited in claim 17, wherein the heat plate comprises a heat plate groove, and a portion of the thermal transfer region extends along at least a portion of the heat plate groove.

19. A heat transfer element as recited in claim 11, wherein the substantially circular, substantially annular shaped portion of the lighting device comprises a heat rim and wherein the first thermal exchange region is in thermal contact with the heat rim.

20. A solid state self ballasted lamp for operation on alternating current (AC) line voltage, the self ballasted lamp comprising:

a solid state light source wherein the light emitted by the solid state light source has a Correlated Color Temperature (CCT) of 4000K or less and a Color Rendering Index (CRI) of at least 90;

an electrical connector for connecting to a light socket;

an AC power supply electrically coupled to the electrical connection and configured to receive the AC line voltage and provide current to the solid state light source;

a reflector configured to receive light from the solid state light source and emit reflected light from an aperture of about 4 inches or less, the reflected light having a beam angle of 30 degrees or less; and

a thermal management system configured to extract heat from the solid state light source and transfer the extracted heat to a surrounding environment and maintain a junction temperature of the solid state light source at or below a 25,000 hour rated lifetime junction temperature for the solid state light source in a 25°

C. surrounding environment,

wherein the self ballasted lamp has a wall plug efficiency of at least about 40 delivered lumens per watt.

21. The solid state self ballasted lamp of claim 20, wherein the thermal management system maintains the junction temperature of the solid state light source at or below a 35,000 hour rated lifetime junction temperature.

22. The solid state self ballasted lamp of claim 20, wherein the thermal management system maintains the junction temperature of the solid state light source below a 50,000 hour rated lifetime junction temperature.

23. The solid state self ballasted lamp of claim 20, wherein the thermal management system maintains the junction temperature of the solid state light source below a 50,000 hour rated lifetime junction temperature in a 35°

C. surrounding environment.

24. The solid state self ballasted lamp of claim 20, wherein the reflector provides a beam angle of 20 degrees or less.

25. The solid state self ballasted lamp of claim 20, wherein the reflector provides a beam angle of 15 degrees or less.

26. The solid state self ballasted lamp of claim 20, wherein the reflector provides a beam angle of 10 degrees or less.

27. The solid state self ballasted lamp of claim 20, wherein the wall plug efficiency is at least about 50 lumens per watt.

28. The solid state self ballasted lamp of claim 20, wherein the wall plug efficiency is at least about 60 lumens per watt.

29. The solid state self ballasted lamp of claim 20, wherein the lamp is configured to have external dimensions of a PAR-38 lamp.

30. The solid state self ballasted lamp of claim 20, wherein the lamp is configured to have external dimensions of a PAR-30 lamp.

31. The solid state self ballasted lamp of claim 20, wherein the thermal management system comprises a heat pipe having an “

S”

shaped configuration.

32. The solid state self ballasted lamp of claim 20, wherein the solid state light source comprises a plurality of non-white, non-saturated light emitting diodes and a plurality of red or red-orange light emitting diodes.

33. The solid state self ballasted lamp of claim 20, wherein the light emitted by the reflector is perceived as white light in the near field.

34. The solid state self ballasted lamp of claim 20, wherein the solid state light source and the reflector are oriented in a back-reflector configuration.

35. The solid state self ballasted lamp of claim 20, further comprising a sensor configured to receive light from the solid state light source and the sensor being operably associated with the power supply so as to control at least one characteristic of the light output by the solid state light source responsive to a characteristic of the light detected by the sensor.

36. The solid state self ballasted lamp of claim 20, wherein the solid state light source comprises:

an array of one or more strings of light emitting diodes; and

a lens on the array of light emitting diodes.

37. The solid state self ballasted lamp of claim 36, further comprising a diffuser associated with the solid state light source to mix light from the array of light emitting diodes in the near field.

38. A lighting device, comprising:

a housing;

a reflector disposed within the housing;

a light emitter comprising an array of solid state light emitters;

a heat pipe in thermal communication with the light emitter and the housing; and

at least one sensor, the sensor being positioned within a region which receives direct light from the light emitter when the light emitter is emitting light.

39. A lighting device as recited in claim 38, wherein the housing comprises a substantially circular, substantially annular portion.

40. A lighting device as recited in claim 39, wherein:

the heat pipe has a thermal transfer region and at least a first thermal exchange region,

at least a portion of the first thermal exchange region extends in a shape which follows at least a first portion of the substantially circular, substantially annular portion of the housing, and

the thermal transfer region extends in a shape which comprises at least a portion of a diameter of the substantially circular, substantially annular portion of the housing.

41. A lighting device as recited in claim 38, wherein the sensor is positioned within a conical region bounded by lines which each define an angle of ten degrees or less relative to an axis of direct light emitted by the light emitter when the light emitter is emitting light.

42. A lighting device as recited in claim 38, wherein the sensor is sensitive to only some wavelengths of visible light.

43. A lighting device as recited in claim 38, wherein the lighting device is self-ballasted.

44. A lighting device as recited in claim 38, wherein the array has groups of first and second LED chips with the first group of LED chips arranged so that no two of the first group LED chips are directly next to one another in the array.

45. A lighting device as recited in claim 38, wherein the array comprises a first group of LED chips and one or more additional groups of LED chips, the first group of LEDs being arranged so that at least three LED chips from the one or more additional groups is adjacent each of the LED chips in the first group.

46. A lighting device as recited in claim 38, wherein:

the array is mounted on a submount,

the array comprises a first group of LED chips and one or more additional groups of LED chips, and

the array is arranged so that less than fifty percent of the LED chips in the first group of LED chips are on a perimeter of the array.

47. A lighting device as recited in claim 38, wherein:

the array comprises a first group of LED chips and one or more additional groups of LED chips, and

the first group of LED ships is arranged so that no two LED chips from the first group are directly next to one another in the array, and so that at least three LED chips from the one or more additional groups is adjacent each of the LED chips in the first group.

48. A lighting device as recited in claim 38, wherein the array is arranged so that (a) no two LED chips from the first group are directly next to one another in the array, (b) fewer than fifty percent of the LED chips in the first group of LEDs are on a perimeter of the array, and (c)at least three LED chips from the one or more additional groups is adjacent each of the LED chips in the first group.