LED LAMP INCORPORATING REMOTE PHOSPHOR WITH HEAT DISSIPATION FEATURES

• US 20110215701A1
• Filed: 02/16/2011
• 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: KELLER, BERND, LETOQUIN, RONAN, TARSA, ERIC, TONG, TAO
• Granted Patent: US 9,500,325 B2
• Time in Patent Office: Days
• US Class Current: 313/46
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• 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 29/502 characterised by the adaptation for cooling of specific components
• CPC Class Codes: F21V 29/506 of globes, bowls or cover glasses
• CPC Class Codes: F21V 29/75 with fins or blades having different shapes, thicknesses or spacing
• CPC Class Codes: F21V 29/76 with essentially identical parallel planar fins or blades, e.g. with comb-like cross-section
• CPC Class Codes: F21V 29/767 the planes containing the fins or blades having directions perpendicular to the light emitting axis
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• 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]
• 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 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 33/644 in intimate contact or integrated with parts of the device other than the semiconductor body

Abstract

An LED lamp or bulb is disclosed that comprises a light source, a heat sink structure and a remote planar 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 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 phosphor arranged according to the present invention can operate at lower temperature to thereby operate at greater phosphor conversion efficiency and with reduced heat related damage to the phosphor.

Claims

1. A lamp, comprising:

a light source;

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

an LED light source;

a 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.

12. The lamp of claim 11, further comprising a heat sink, said thermally conductive path at least partially comprising said heat sink.

13. The lamp of claim 12, wherein said phosphor is arranged in a phosphor carrier.

14. The lamp of claim 13, wherein said phosphor carrier comprises a phosphor layer and a carrier layer.

15. The lamp of claim 13, wherein said phosphor carrier layer comprises a thermally conductive transparent material.

16. The lamp of claim 13, wherein said phosphor carrier comprises a surface that is roughened or shaped.

17. The lamp of claim 11, further comprising scattering particles.

18. The lamp of claim 11, 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.

19. The lamp of claim 11, 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.

20. The lamp of claim 19, wherein said optical cavity comprises reflective surfaces.

21. 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; and

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

22. The lamp of claim 21, 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.

23. The lamp of claim 22, 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.

24. The lamp of claim 22, wherein said optical cavity comprises reflective surfaces.

25. The lamp of claim 21, wherein heat from said first light source is conducted away from said light source through a second thermally conductive path.

26. The lamp of claim 25, wherein said first and second thermally conductive paths are coupled.

27. The lamp of claim 25, wherein said first and second conductive paths are de-coupled.

28. A lamp, comprising:

a light source;

an optical cavity comprising a 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.

29. The lamp of claim 28, 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.

30. The lamp of claim 28, wherein said phosphor carrier is planar.