LED lamp with active cooling element

Patent metadata

Field	Value
Publication number	US-9625105-B2
Application number	US-98527511-A
Country	US
Kind code	B2
Filing date	Jan 5, 2011
Priority date	Mar 3, 2010
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

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 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 fan's 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.

First claim

We claim:

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;
an integral fan configured to reduce the convective thermal resistance of at least some lamp elements;
at least one electrical contact configured to pass through said integral fan so that an electrical signal applied to said at least one electrical contact is supplied to said LED;
a diffuser dome on said heat sink and over said LED; and
a phosphor carrier on said heat sink and over said LED, said phosphor carrier separate from and at least partially within said diffuser dome;
said heat sink shaped to define at least two inlets, at least one of which opens adjacent to said LED and inside said phosphor carrier, such that said fan flows cool air from outside said light source into said phosphor carrier via said at least one inlet adjacent to said LED.

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

3. The light source of claim 1 , wherein said fan flows air over one or more surfaces of said heat sink.

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

5. The light source of claim 1 , wherein said fan is internal to one of said lamp components and draws ambient air internal to said lamp.

6. The light source of claim 1 , wherein said fan is internal to said heat sink and draws air into said heat sink and flows air into said diffuser dome.

7. The light source of claim 1 , wherein said phosphor carrier is configured so that at least some light from said LED passes through said phosphor carrier.

8. The light source of claim 7 , wherein said phosphor carrier is a three-dimensional structure.

9. The light source of claim 1 , wherein said fan is modular.

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

11. The light source of claim 10 , further comprising drive electronics integral to said base.

12. The light source of claim 10 , wherein said fan is between said base and said heat sink.

13. The light source of claim 1 , wherein said diffuser dome disperses light from said LED.

14. A solid state light source, comprising:
a light emitting diode (LED);
a heat sink with said LED in thermal contact with said heat sink;
an integral active air agitation mechanism configured to reduce the convective thermal resistance of at least some lamp elements, said air agitation mechanism comprising at least one electrical contact configured to pass through said air agitation mechanism so that an electrical signal applied to said at least one electrical contact is supplied to said LED;
a diffuser dome on said heat sink and over said LED; and
a phosphor carrier between said heat sink and said diffuser dome; said phosphor carrier on said heat sink and separate from said diffuser dome
said heat sink shaped to define at least two inlets, at least one of which opens adjacent to said LED and inside said phosphor carrier, such that said active air agitation mechanism flows cool air from outside said light source into said heat sink and then into said phosphor carrier via said at least one inlet opening adjacent to said LED.

15. A solid state light source, comprising:
a plurality of light emitting diodes (LEDs);
a heat sink comprising fins, said heat sink configured in relation to said LEDs so that said LEDs are in thermal contact with said heat sink;
an integral fan configured to flow air over the surfaces of said heat sink to reduce the convective thermal resistance of said heat sink;
at least one electrical contact configured to pass through said fan so that an electrical signal applied to said at least one electrical contact is supplied to said plurality of LEDs; and
a phosphor carrier in thermal contact with said heat sink; and
a diffuser dome on said heat sink and over said LEDs, said phosphor carrier between said heat sink and said diffuser dome, wherein said integral fan flows cool air through said heat sink and then into said phosphor carrier;
wherein at least a portion of said fins are outside the footprint of the base of said diffuser dome.

16. The light source of claim 15 , further comprising a base, wherein said fan is adjacent to said heat sink between said base and said heat sink.

17. The light source of claim 15 , wherein said phosphor carrier is configured so that at least some light from said LEDs passes through said phosphor carrier.

18. The light source of claim 17 , wherein said phosphor carrier is a three-dimensional structure or planar.

19. The light source of claim 15 , wherein said fan is modular.

20. The light source of claim 16 , wherein said base further comprises drive electronics.

21. The light source of claim 20 , wherein said drive electronics provide electrical inputs to said fan and said LEDs.

22. The light source of claim 15 , wherein said diffuser dome disperses light from said LEDs.

23. A solid state light source, comprising:
a plurality of light emitting diodes (LEDs);
a heat sink comprising fins and a mount surface, said heat sink configured in relation to said LEDs so that said LEDs are in thermal contact with said heat sink;
a fan internal to said solid state light source and configured to flow air over surfaces of said solid state light source to reduce the convective thermal resistance at said surfaces;
at least one electrical contact configured to pass through said fan so that an electrical signal applied to said at least one electrical contact is supplied to said plurality of LEDs; and
a diffuser cavity over said LEDs; and
a phosphor carrier between said heat sink and said diffuser cavity; said phosphor carrier on said heat sink and separate from said diffuser cavity
said heat sink shaped to define at least two inlets, at least one of which is through said mount surface and adjacent to said LEDs and inside said phosphor carrier, such that said fan flows cool air from outside said light source into said heat sink and then into said phosphor carrier via said at least one inlet adjacent to said LEDs;
wherein at least a portion of said fins are outside the footprint of the base of said diffuser dome.

24. The light source of claim 23 , wherein said fan is internal to said heat sink.

25. The light source of claim 23 , wherein said fan draws air from external to the internal of said heat sink.

26. The light source of claim 23 , wherein said fan is configured to flow air into said diffuser cavity.

27. The light source of claim 23 , said fan moving air over and between said heat sink fins.

28. The light source of claim 26 , further comprising an outlet to allow air to exit from said diffuser cavity.

29. The light source of claim 23 , wherein said phosphor carrier is three-dimensional.

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

31. The light source of claim 30 , wherein said base is at least partially internal to said heat sink.

32. The light source of claim 31 , wherein said fan flows air over said base.

33. A solid state light source, comprising:
a plurality of light emitting diodes (LEDs);
a heat sink comprising fins,

Assignees

• Tong Tao
• Youmans Mark
• He Yejin
• Cree Inc

Inventors

• Tong Tao
• Youmans Mark
• He Yejin

Classifications

• F21V29/67 Primary

  characterised by the arrangement of fans · CPC title

• F21K9/232

  specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb · CPC title

• F21V3/02 Primary

  characterised by the shape · CPC title

• F21V29/505

  of reflectors · CPC title

• F21K9/64

  using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer · CPC title