LED LAMP WITH ACTIVE COOLING ELEMENT

• US 20110215698A1
• Filed: 02/07/2011
• Published: 09/08/2011
• Est. Priority Date: 03/03/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: HE, YEJIN, YOUMANS, MARK, TONG, TAO
• Granted Patent: US 8,931,933 B2
• Time in Patent Office: Days
• US Class Current: 313/46
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 29/63 using electrically-powered vibrating means; using ionic wind
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 29/673 the fans being used for intake
• CPC Class Codes: F21V 29/677 the fans being used for discharging
• 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 3/02 characterised by the shape
• CPC Class Codes: F21V 3/12 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

Solid state lamp or bulb structures are disclosed that can provide an essentially omnidirectional emission pattern from directional emitting light sources, such as forward emitting light sources. The present invention is also directed to lamp structures using active elements to assist in thermal management of the lamp structures and in some embodiments to reduce the convective thermal resistance around certain of the lamp elements to increase the natural heat convection away from the lamp. Some embodiments include integral fans or other active elements such as diaphragm-pump type active cooling elements, that move air over the surfaces of a heat sink, while other embodiments comprise internal fans or other active elements that can draw air internal to the lamp. The movement of the air over these surfaces can agitate otherwise stagnant air to decrease the convective thermal resistance and increasing the ability of the lamp to dissipate heat generated during operation.

Claims

1. A solid state light source, comprising:

a light emitting diode (LED);

a heat sink with said LED in thermal contact with said heat sink; and

an integral diaphragm pump type cooling element arranged to reduce the convective thermal resistance of at least some of the light source elements.

2. The light source of claim 1, wherein said diaphragm cooling element is adjacent to said heat sink.

3. The light source of claim 1, wherein said diaphragm cooling element flows air over one or more surface of said heat sink.

4. The light source of claim 1, wherein said diaphragm cooling element reduces convective thermal resistance by agitating the air over at least some of said lamp elements.

5. The light source of claim 1, further comprising a diffuser dome over on said heat sink and over said LED.

6. The light source of claim 1, wherein said diaphragm cooling element is internal to one of said lamp components and draws ambient air internal to said lamp.

7. The light source of claim 5, wherein said diaphragm cooling element is internal to said heat sink and draws air into said heat sink and flows air into said diffuser dome.

8. The light source of claim 1, further comprising a phosphor carrier arranged so that at least some of light from said LED passes through said phosphor carrier.

9. The light source of claim 8, wherein said phosphor carrier is a three-dimensional structure.

10. The light source of claim 1, wherein said diaphragm cooling element is modular.

11. The light source of claim 1, further comprising a base for connecting to a source of electrical power.

12. The light source of claim 11, further comprising drive electronics integral to said base.

13. The light source of claim 11, wherein said diaphragm cooling element is between said base and said heat sink.

14. The light source of claim 5, wherein said diffuser dome disperses light from said LED.

15. A solid state lamp, comprising:

a plurality of light emitting diodes (LEDs);

a heat sink arranged in relation to said LEDs so that said LEDs are in thermal contact with said heat sink; and

a diaphragm positive displacement pump cooling element integral to said lamp and arranged to flow air over surfaces of said lamp to reduce the convective thermal resistance at said surfaces.

16. The lamp of claim 15, wherein said diaphragm cooling element is internal to said heat sink.

17. The lamp of claim 15, wherein said diaphragm cooling element draws air from external to the internal of said heat sink.

18. The lamp of claim 15, further comprising a diffuser cavity over said LEDs, said diaphragm cooling element arranged to flow air into said diffuser cavity.

19. The lamp of claim 15, wherein said heat sink comprises heat sink fins, said diaphragm cooling element moving air over and between said heat sink fins.

20. The lamp of claim 18, further comprising an outlet to allow air to exit from said diffuser cavity.

21. The lamp of claim 18, further comprising a phosphor carrier arranged in said diffuser cavity over said LEDs.

22. The lamp of claim 21, wherein said phosphor carrier is three-dimensional and said diaphragm cooling element flows air into said phosphor carrier.

23. The lamp of claim 15, further comprising a base for connecting to a source of electrical power.

24. The lamp of claim 23, wherein said base is at least partially internal to said heat sink.

25. The lamp of claim 24, wherein said diaphragm cooling element flows air over said base.

26. A diaphragm-pump type of active cooling element, comprising:

a housing with a housing opening;

a membrane over said housing opening and capable of vibrating; and

passage holes to allow air to flow through said housing in preferred direction in response to said membrane vibrating.

27. The cooling element of claim 26, comprising a means for causing vibration of said membrane.

28. The cooling element of claim 26, further comprising a piezoelectric material for causing vibration of said membrane.

29. The cooling element of claim 26, further comprising a piezoelectric film on said membrane for actuating vibration of said membrane.

30. The cooling element of claim 26, further comprising a film on said membrane for electrostatic actuation to cause vibration of said membrane.

31. The cooling element of claim 26, further comprising air flow holes to allow air to flow in and out of said housing in response to vibration of said membrane.

32. The cooling element of claim 30, further comprising one way valve features or asymmetric geometries over said holes.

33. The cooling element of claim 30, wherein air flows through said housing in substantially one direction.

34. The cooling element of claim 26, comprising a positive displacement pump.

35. A solid state lamp, comprising:

a light emitting diode (LED);

a heat sink arranged in relation to said LED so that said LED is in thermal contact with said heat sink; and

an active cooling element integral to said lamp and arranged to flow air over surfaces of said lamp to reduce the convective thermal resistance at said surfaces, wherein said lamp fits within the A19 size envelope.

36. The lamp of claim 35, wherein active cooling element comprises a diaphragm positive displacement pump cooling element.

37. The lamp of claim 35, wherein active cooling element comprises a fan.

38. The lamp of claim 35, wherein said active cooling element draws air from external to the internal of said heat sink.

39. The lamp of claim 35, further comprising a diffuser cavity over said LEDs, said active cooling element arranged to flow air into said diffuser cavity.

40. The lamp of claim 35, further comprising an outlet to allow air to exit from said diffuser cavity.

41. The lamp of claim 35, wherein said heat sink comprises heat sink fins, said active cooling element moving air over and between said heat sink fins.

42. The lamp of claim 39, further comprising a phosphor carrier arranged in said diffuser cavity over said LEDs.

43. The lamp of claim 42, wherein said phosphor carrier is three-dimensional and said diaphragm cooling element flows air into said phosphor carrier.

44. A solid state lamp, comprising:

a light emitting diode (LED);

a heat sink arranged in relation to said LED so that said LED is in thermal contact with said heat sink; and

an active cooling element integral to said lamp and arranged flow air over surfaces of said lamp to reduce the convective thermal resistance at said surfaces, wherein said lamp emits light with a substantially omnidirectional emission pattern.

45. The lamp of claim 44, wherein said emission pattern is in compliance with Energy Star defined omnidirectional emission criteria.

46. The lamp of claim 44, sized to fit within the A19 size envelope.

47. A solid state lamp, comprising:

a plurality of light emitting diodes (LEDs); and

an active cooling element integral to said lamp and arranged flow air over surfaces of said lamp comprising an emission pattern that complies with Energy Star defined omnidirectional emission criteria, and wherein said lamp is sized to fit the A19 size envelope.