LED lamp incorporating remote phosphor and diffuser with heat dissipation features

• US 8,632,196 B2
• Filed: 02/16/2011
• Issued: 01/21/2014
• Est. Priority Date: 03/03/2010
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated), Ideal Industries, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Tong, Tao, Letoquin, Ronan, Keller, Bernd, Tarsa, Eric
• Primary Examiner(s): DZIERZYNSKI, EVAN P
• Application Number:
  US13/029,005
• Publication Number:
  US 20110215700A1
• Time in Patent Office: 1,070 Days
• Field of Search: 362/84, 362/235, 362/294, 313/46
• US Class Current: 362/84
• 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 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• 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]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and a remote phosphor carrier having at least one conversion material. The phosphor carrier can be remote to the light sources and mounted to the heat sink so that heat from the phosphor carrier spreads into the heat sink. The phosphor carrier can have a three-dimensional shape, and can comprise a thermally conductive transparent material and a phosphor layer, with an LED based light source mounted to the heat sink such that light from the light source passes through the phosphor carrier. At least some of the LED light is converted by the phosphor carrier, with some lamp embodiments emitting a white light combination of LED and phosphor light. The phosphors in the phosphor carriers can be arranged to operate at a lower temperature to thereby operate at greater phosphor conversion efficiency and with reduced heat related damage to the phosphor. The lamps or bulbs can also comprise a diffuser over the phosphor carrier to distribute light and to conceal the phosphor carrier.

Claims

1. A lamp, comprising:

a light source;

a three-dimensional non-planar phosphor carrier remote to said light source and comprising a thermally conductive material at least partially transparent to light from said light source, and a conversion material that absorbs light from said light source and emits different wavelengths of light; and

a heat sink structure, said phosphor carrier thermally coupled to said heat sink structure.

2. The lamp of claim 1, wherein said phosphor carrier comprises a carrier layer and a phosphor layer.

3. The lamp of claim 1, wherein said phosphor carrier comprises scattering particles.

4. The lamp of claim 1, wherein said phosphor carrier comprises a separate layer containing scattering particles.

5. The lamp of claim 1, wherein said phosphor carrier comprises a surface that is roughened or shaped.

6. The lamp of claim 1, wherein heat from said phosphor carrier layer conducts into said heat sink structure through a thermal coupling.

7. The lamp of claim 1, wherein said light source comprises an LED based light source.

8. The lamp of claim 1, wherein said light source comprises a blue emitting LED and said phosphor carrier comprises a phosphor that absorbs blue light and re-emits a different wavelength of light, said lamp emitting a perceived white light combination of blue LED light and conversion material light.

9. The lamp of claim 1, further comprising an optical cavity, said phosphor carrier mounted over an opening in said cavity, said light source mounted within said cavity with light from said light source passing through said phosphor carrier.

10. The lamp of claim 9, wherein said optical cavity comprises reflective surfaces.

11. The lamp of claim 1, further comprising a diffuser element over said phosphor carrier.

12. The lamp of claim 11, wherein said diffuser element disperses light from a narrow or Lambertian emission pattern to a more omnidirectional emission pattern.

13. The lamp of claim 1, wherein said phosphor carrier has a shape from the group comprising hemispheric, bullet shaped, conic, tubular and rectangular.

14. The lamp of claim 1, emitting light with an emission pattern that is Energy Star compliant.

15. The lamp of claim 1, sized to fit an A19 size profile.

16. A light emitting diode (LED) based lamp, comprising:

an LED light source;

a three-dimensional non-planar phosphor arranged remote to said light source such that light emitted from said light source passes through said phosphor and is converted by said phosphor; and

a thermally conductive path to conduct phosphor conversion heat away from said phosphor and to dissipate said heat.

17. The lamp of claim 16, further comprising a heat sink, said thermally conductive path at least partially comprising said heat sink.

18. The lamp of claim 16, wherein said phosphor is arranged in a phosphor carrier.

19. The lamp of claim 18, wherein said phosphor carrier comprises a phosphor layer and a carrier layer.

20. The lamp of claim 18, wherein said phosphor carrier layer comprises a thermally conductive transparent material.

21. The lamp of claim 18, wherein said phosphor carrier comprises a surface that is roughened or shaped.

22. The lamp of claim 16, further comprising scattering particles.

23. The lamp of claim 16, wherein said light source comprises a blue emitting LED and said phosphor absorbs blue light and re-emits a different wavelength of light, said lamp emitting a perceived white light combination of blue LED light and phosphor light.

24. The lamp of claim 16, further comprising an optical cavity, said phosphor arranged over an opening in said cavity, said light source mounted within said cavity with light from said light source passing through said phosphor.

25. The lamp of claim 24, wherein said optical cavity comprises reflective surfaces.

26. The lamp of claim 16, further comprising a diffuser element over said phosphor.

27. The lamp of claim 16, wherein said phosphor has a shape from the group comprising hemispheric, bullet shaped, conic, tubular and rectangular.

28. The lamp of claim 16, emitting light with an emission pattern that is Energy Star compliant.

29. The lamp of claim 16, sized to fit an A19 size profile.

30. A lamp, comprising:

a heat sink structure;

a light emitting diode (LED) based light source;

a phosphor carrier remote to said light source and arranged to absorb light from said light source and re-emit light in different wavelengths, said phosphor carrier comprising a carrier layer and a phosphor layer;

a first thermally conductive path to conduct conversion generated heat away from said conversion material to said heat sink; and

a diffuser over said conversion material.

31. The lamp of claim 30, further comprising an optical cavity, said conversion material arranged on an optical cavity opening and said LED based light source arranged in said cavity with light from light source passing through said conversion material.

32. The lamp of claim 31, further comprising a platform within said optical cavity, said light source mounted on said cavity with heat dissipating from said light source through said platform.

33. The lamp of claim 31, wherein said optical cavity comprises reflective surfaces.

34. The lamp of claim 30, wherein heat from said first light source is conducted away from said light source through a second thermally conductive path.

35. The lamp of claim 34, wherein said first and second thermally conductive paths are coupled.

36. The lamp of claim 34, wherein said first and second conductive paths are de-coupled.

37. A lamp, comprising:

a light source;

a heat sink structure;

an optical cavity comprising an phosphor carrier over an opening to said cavity and thermally coupled to said heat sink structure, said light source mounted in said optical cavity remote to said phosphor carrier with light from said light source passing through said phosphor carrier; and

a diffuser element over said optical cavity, with light from said optical cavity passing through said diffuser element;

wherein said diffuser element comprises an enlarged portion at an end opposite said heat sink structure.

38. The lamp of claim 37, wherein said phosphor carrier comprises a thermally conductive material at least partially transparent to light from said light source, and a conversion material that absorbs light from said light source and emits a different wavelength of light.

39. The lamp of claim 37, wherein said diffuser element disperses light from optical cavity to a predominantly omnidirectional emission pattern.

40. The lamp of claim 37, wherein said diffuser element comprises scattering particles.

41. The lamp of claim 37, wherein said diffuser element masks the color of said phosphor carrier.

42. The lamp of claim 37, wherein said phosphor carrier is hemispheric.

43. The lamp of claim 37, wherein said phosphor carrier is bullet shaped.

44. The lamp of claim 37, wherein said light source comprises a blue emitting LED and said phosphor carrier absorbs blue light and re-emits a different wavelength of light, said lamp emitting a white light combination of blue LED light and phosphor carrier light.

45. A lamp, comprising:

a light source;

an optical cavity comprising a three-dimensional non-planar phosphor carrier over an opening to said cavity, said light source mounted in said optical cavity remote to said phosphor carrier with light from said light source passing through said phosphor carrier, said optical cavity further comprising reflective surfaces to reflect light from said light source and said phosphor carrier; and

a thermally conductive path to conduct phosphor conversion heat away from said phosphor and to dissipate said heat.

46. The lamp of claim 45, further comprising a diffuser element over said optical cavity, with light from said optical cavity passing through said diffuser element.

47. The lamp of claim 45, further comprising a heat sink, wherein said optical cavity is integral to said heat sink and said thermally conductive path is through said heat sink.

48. The lamp of claim 45, wherein said phosphor carrier is planar.

49. The lamp of claim 45, wherein said phosphor carrier has a three-dimensional shape.

50. A lamp, comprising:

a heat sink structure;

a light emitting diode (LED) based light source;

a conversion material remote to said light source and arranged to absorb light from said light source and re-emit light in different wavelengths;

a first thermally conductive path to conduct conversion generated heat away from said conversion material to said heat sink structure;

a shaped diffuser dome comprising an enlarged portion at an end opposite said heat sink structure;

wherein said lamp emits light with an emission pattern that is Energy Star compliant.

51. A lamp, comprising:

a heat sink structure;

a light emitting diode (LED) based light source;

a three-dimensional non-planar phosphor carrier comprising a conversion material remote to said light source and arranged to absorb light from said light source and re-emit light in different wavelengths; and

a first thermally conductive path to conduct conversion generated heat away from said conversion material to said heat sink, wherein said lamp is sized to fit an A19 profile.