Multi-chip light emitting device lamps for providing high-CRI warm white light and light fixtures including the same

• US 8,125,137 B2
• Filed: 05/02/2007
• Issued: 02/28/2012
• Est. Priority Date: 01/10/2005
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Medendorp, Nicholas W. Jr., McClear, Mark, Keller, Bernd P., Brandes, George R., LeToquin, Ronan P.
• Primary Examiner(s): Guharay, Karabi
• Application Number:
  US11/743,324
• Publication Number:
  US 20070223219A1
• Time in Patent Office: 1,763 Days
• Field of Search: 313501-503, 257/89, 362/800
• US Class Current: 313/501
• CPC Class Codes: C09K 11/586 with alkaline earth metals
• CPC Class Codes: C09K 11/623 with zinc or cadmium
• CPC Class Codes: C09K 11/7421 with alkaline earth metals
• CPC Class Codes: C09K 11/7702 with zinc or cadmium
• 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 23/005 the substrate is supporting also the light source
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2113/17 forming a single encapsulated light source
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A multi-chip lighting emitting device (LED) lamp for providing white light includes a submount including first and second die mounting regions thereon. A first LED chip is mounted on the first die mounting region, and a second LED chip is mounted on the second die mounting region. The LED lamp is configured to emit light having a spectral distribution including at least four different color peaks to provide the white light. For example, a first conversion material may at least partially cover the first LED chip, and may be configured to absorb at least some of the light of the first color and re-emit light of a third color. In addition, a second conversion material may at least partially cover the first and/or second LED chips, and may be configured to absorb at least some of the light of the first and/or second colors and re-emit light of a fourth color. Related light fixtures and methods are also discussed.

Claims

1. A solid state lamp configured to emit light having spectral distribution including at least four different color peaks, the lamp comprising:

a first solid state emitter adapted to emit light including a first color peak of said at least four different color peaks;

a second solid state emitter adapted to emit light including a second color peak of said at least four different color peaks;

a first conversion material at least partially covering the first solid state emitter but not covering the second solid state emitter, wherein the first conversion material is adapted to absorb light emitted by the first emitter and responsively re-emit light including a third color peak of said at least four different color peaks;

a second conversion material at least partially covering each of the first solid state emitter and the second solid state emitter, wherein the second conversion material is adapted to absorb light emitted by any of the first emitter and the second emitter and responsively re-emit light including a fourth color peak of said at least four different color peaks.

2. The solid state lamp of claim 1, wherein the first conversion material only partially covers the first solid state emitter.

3. The solid state lamp of claim 1, wherein the second conversion material only partially covers at least one of the first solid state emitter and the second solid state emitter.

4. The solid state lamp of claim 1, further comprising a third solid state emitter adapted to emit light, wherein the second conversion material at least partially covers each of the first solid state emitter, second solid state emitter, and third solid state emitter.

5. The solid state lamp of claim 4, wherein the third solid state emitter is adapted to emit light including a color peak that is different from at least three of the at least four different color peaks.

6. The solid state lamp of claim 1, further comprising:

a third solid state emitter adapted to emit light including a fifth color peak that is different from any of said four different color peaks; and

a third conversion material at least partially covering the third solid state emitter but not covering the first or the second solid state emitters, wherein the third conversion material is adapted to absorb light emitted by the third emitter and responsively re-emit light including a color peak that is different from at least three of the at least four different color peaks;

wherein the second conversion material at least partially covers each of the first solid state emitter, second solid state emitter, and third solid state emitter.

7. The solid state lamp of claim 1, wherein each of the first and the second conversion material is non-contacting relative to the other.

8. The solid state lamp of claim 1, wherein any of the first and second conversion material comprises a phosphor.

9. The solid state lamp of claim 1, wherein any of the first and second conversion material comprises a semiconductor phosphor.

10. The solid state lamp of claim 1, wherein each of the first solid state emitter and the second solid state emitter is mounted to a common mounting element.

11. The solid state lamp of claim 1, having light output of at least about 60 lumens per watt with a color rendering index of at least 90.

12. The solid state lamp of claim 1, having light output of at least about 85 lumens per watt with a color rendering index of at least 90.

13. A light fixture comprising:

a first solid state lamp according to claim 1;

a second solid state lamp according to claim 1; and

a control circuit electrically coupled to the first and the second solid state lamps.

14. The light fixture of claim 13, wherein the control circuit is configured to independently apply drive current to each of the first solid state multi-chip emitter lamp and the second solid state multi-chip emitter lamp.

15. The light fixture of claim 14, wherein said control circuit is adapted to control intensity of light output from the light fixture.

16. The light fixture of claim 14, wherein said control circuit is adapted to control any of color and chromaticity of light output from the light fixture.

17. The light fixture of claim 13, wherein the control circuit is configured to independently apply drive current to first solid state emitter and each second solid state emitter.

18. The light fixture of claim 17, wherein the control circuit is adapted to provide independent pulse width modulation control for each emitter of the first solid state lamp and each emitter of the second solid state lamp.

19. The light fixture of claim 13, wherein the control circuit is adapted to adjust a ratio of drive currents to different solid state emitters to control any of intensity, color, and chromaticity of light output from the fixture.

20. The light fixture of claim 13, further comprising a solid state single-chip emitter lamp, wherein each of the first solid state emitter lamp, the second solid state emitter lamp, and the solid state single-chip emitter lamp is attached to a common mounting element.

21. The light fixture of claim 13, having light output of at least about 60 lumens per watt with a color rendering index of at least 90.

22. The light fixture of claim 13, having light output of at least about 85 lumens per watt with a color rendering index of at least 90.

23. The solid state lamp of claim 1, further comprising a control circuit arranged to independently energize and/or drive the first solid state emitter and the second solid state emitter.

24. The solid state lamp of claim 1, wherein at least one of the first conversion material and the second conversion material is spatially segregated from each of the first solid state emitter and the second solid state emitter.

25. A solid state lamp configured to emit light having spectral distribution including a plurality of different spectral peaks, the lamp comprising:

a first solid state emitter adapted to emit light having a first spectral peak;

a second solid state emitter adapted to emit light including a second spectral peak;

a first semiconductor phosphor arranged to receive light emissions from the first solid state emitter, wherein the first semiconductor phosphor is adapted to absorb at least a portion of said light emissions from the first solid state emitter and responsively re-emit light having a third spectral peak; and

a second semiconductor phosphor arranged to receive light emissions from the second solid state emitter, wherein the second semiconductor phosphor is adapted to absorb at least a portion of said light emissions from the second solid state emitter and responsively re-emit light having a fourth spectral peak;

wherein at least one of (a) the first spectral peak of the first solid state emitter and (b) the second spectral peak of the second solid state emitter, as well as said light emissions absorbed by at least one of the first semiconductor phosphor and the second semiconductor phosphor, is in a wavelength range of from about 440 nm to about 490 nm; and

wherein each of the first, second, third, and fourth spectral peak differs from the other.

26. The solid state lamp of claim 25, wherein each of the first spectral peak, second spectral peak, third spectral peak, and fourth spectral peak is in the visible range.

27. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor comprises a direct bandgap semiconductor phosphor.

28. The solid state lamp of claim 25, wherein at least a portion of any of the first semiconductor phosphor and the second semiconductor phosphor comprises a conductive semiconductor serving as an electrical contact for the solid state lamp.

29. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor comprises a quantum well structure.

30. The solid state lamp of claim 25, including at least one of the following features (a) and (b):

(a) the first semiconductor phosphor is deposited on the first solid state emitter, and (b) the second semiconductor phosphor is deposited on the second solid state emitter.

31. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor is deposited under a lens disposed over the first solid state emitter and the second solid state emitter.

32. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor is deposited on a substrate supporting any of the first solid state emitter and the second solid state emitter.

33. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor serves as a substrate to support any of the first solid state emitter and the second solid state emitter.

34. The solid state lamp of claim 25, wherein any of the first semiconductor phosphor and the second semiconductor phosphor partially overlaps any of the first solid state emitter and the second solid state emitter.

35. The solid state lamp of claim 25, further comprising a control circuit arranged to independently energize and/or drive the first solid state emitter and the second solid state emitter.

36. The solid state lamp of claim 25, wherein at least one of the first semiconductor phosphor and the second semiconductor phosphor is spatially segregated from each of the first solid state emitter and the second solid state emitter.

37. A light fixture comprising:

a first solid state lamp according to claim 25;

a second solid state lamp according to claim 25; and

a control circuit electrically coupled to the first and the second solid state lamps.