Light emission device and method utilizing multiple emitters and multiple phosphors

• US 7,564,180 B2
• Filed: 01/10/2005
• Issued: 07/21/2009
• Est. Priority Date: 01/10/2005
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Brandes, George R.
• Primary Examiner(s): Guharay; Karabi
• Application Number:
  US11/032,363
• Publication Number:
  US 20060152140A1
• Time in Patent Office: 1,653 Days
• Field of Search: 313501-503, 257/88, 257/89, 257 98-100
• 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: C09K 11/77342 Silicates
• 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: 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: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A light emission device, including at least two LED dies having differing spectral output from one another; and phosphor material including one or more phosphors, arranged to receive spectral output from at least one of the LED dies and to responsively emit a phosphor output, as a component of a spectral output of the light emission device. In a specific arrangement, the multiple LED dies and phosphor material are arranged to produce a white light output having a color temperature selected from among (i) color temperature in a range of from 1350° K to 1550° K, (ii) color temperature in a range of from 2400° K to 3550° K and (iii) color temperature in a range of from 4950° K to 6050° K.

Claims

1. A light emission device, comprising:

a first electrically activated solid state emitter having a first spectral output;

a second electrically activated solid state emitter having a second spectral output that differs from the first spectral output;

a first phosphor material arranged to interact with at least the first emitter and responsively emit a third spectral output; and

a second phosphor material arranged to interact with at least the second emitter, and responsively emit a fourth spectral output that differs from the third spectral output;

wherein at least one of the first phosphor material and the second phosphor material is disposed relative to the emitters in an amount that differs among the first emitter and the second emitter, and wherein each of the first, second, third, and fourth spectral output comprises output in the visible range.

2. The light emission device of claim 1, wherein at least one of the first phosphor material and the second phosphor material is arranged to interact with both the first emitter and the second emitter.

3. The light emission device of claim 1, wherein the first phosphor material is arranged to receive significant spectral output from only the first emitter, and the second phosphor material is arranged to receive significant spectral output from only the second emitter.

4. The light emission device of claim 1, wherein each of the first spectral output, the second spectral output, the third spectral output, and the fourth spectral output differs from the other.

5. The light emission device of claim 1, wherein any of the first phosphor material and the second phosphor material is conformally coated on at least one of the first emitter and the second emitter.

6. The light emission device of claim 1, wherein the first emitter differs substantially in size from the second emitter.

7. The light emission device of claim 1, further comprising a common covering material comprising any of a glass composition and a polymeric composition, wherein said covering material is arranged to transmit each of the first spectral output, second spectral output, third spectral output, and fourth spectral output therethrough.

8. A method of generating light, comprising:

exciting a first electrically activated solid state emitter having a first spectral output; and

exciting a second electrically activated solid state emitter having a second spectral output, said second spectral output differing from said first spectral output;

wherein a first phosphor material is arranged to interact with at least the first emitter to responsively emit a third spectral output from said first phosphor material;

wherein a second phosphor material is arranged to interact with at least the second emitter to responsively emit a fourth spectral output from said second phosphor material, said fourth spectral output differing from said third spectral output; and

wherein at least one of the first phosphor material and the second phosphor material is disposed relative to the emitters in an amount that differs among the first emitter and the second emitter, and wherein each of the first, second, third, and fourth spectral output comprises output in the visible range.

9. A light emission device comprising:

a first electrically activated solid state emitter having a first spectral output including a first color peak in the visible range;

a second electrically activated solid state emitter having a second spectral output including a second color peak in the visible range;

a first phosphor material arranged to interact with at least the first emitter and responsively emit a third spectral output including a third color peak in the visible range; and

a second phosphor material arranged to interact with at least the second emitter and responsively emit a fourth spectral output including a fourth color peak in the visible range;

wherein each of the first color peak, second color peak, third color peak, and fourth color peak differs from the other, and an aggregated spectral output of the device includes the first color peak, second color peak, third color peak, and fourth color peak.

10. The light emission device of claim 9, wherein at least one of the first phosphor material and the second phosphor material is disposed relative to the emitters in an amount that differs among the first emitter and the second emitter.

11. The light emission device of claim 9, wherein at least one of the first phosphor material and the second phosphor material is arranged to interact with both the first emitter and the second emitter.

12. The light emission device of claim 9, wherein the first phosphor material is arranged to receive significant spectral output from only the first emitter, and the second phosphor material is arranged to receive significant spectral output from only the second emitter.

13. The light emission device of claim 9, wherein any of the first phosphor material and the second phosphor material is conformally coated on at least one of the first emitter and the second emitter.

14. The light emission device of claim 9, adapted to provide an aggregated spectral output of white light.

15. The light emission device of claim 9, adapted to provide an aggregated spectral output that substantially matches an illumination spectrum of sunlight, candle light, or incandescent filament light.

16. The light emission device of claim 9, adapted to provide an aggregated spectral output of white light having a color temperature in a range of from 1350°

K to 1550°

K.

17. The light emission device of claim 9, adapted to provide an aggregated spectral output of white light having a color temperature in a range of from 2400°

K to 3550°

K.

18. The light emission device of claim 9, adapted to provide an aggregated spectral output of white light having a color temperature in a range of from 4950°

K to 6050°

K.

19. The light emission device of claim 9, wherein spectral output of each of the first emitter and the second emitter traverses a different thickness of phosphor material.

20. The light emission device of claim 9, further comprising a common covering material comprising any of a glass composition and a polymeric composition, wherein said covering material is arranged to transmit each of the first spectral output, second spectral output, third spectral output, and fourth spectral output therethrough.

21. The light emission device of claim 20, wherein any of the first phosphor material and the second phosphor material is dispersed in the common covering material.

22. The light emission device of claim 9, wherein the first emitter and the second emitter differ substantially in size.

23. The light emission device of claim 9, wherein the first emitter, the second emitter, the first phosphor material, and the second phosphor material are disposed in a unitary package

24. The light emission device of claim 9, wherein the first emitter comprises a first LED die and the second emitter comprises a second LED die.

25. The light emission device of claim 9, wherein at least one of the first emitter, the second emitter, the first phosphor material, and the second phosphor material has a first aging profile including a degradation of light emission over its service life, and at least one other of the first emitter, the second emitter, the first phosphor material, and the second phosphor material has a second aging profile at least partially compensating said degradation of light emission inherent to said first aging profile.

26. The light emission device of claim 9, wherein at least two of said first emitter, second emitter, first phosphor material, and second phosphor material are matched in aging character thereof to provide a predetermined character of spectral output of the light emission device over the operating life of the light emission device.

27. The light emission device of claim 26, wherein said predetermined character of spectral output of the light emission device includes a transition in color of spectral output of the light emission device at a predetermined time during said life of the device.

28. The light emission device of claim 9, further comprising a third electrically activated solid state emitter having a fifth spectral output that differs from each of the first and second spectral output.

29. The light emission device of claim 28, further comprising a third phosphor material having a sixth spectral output that differs from each of the third and fourth spectral output.

30. The light emission device of claim 9, wherein current to each emitter is individually controlled.

31. The light emission device of claim 9, wherein the first emitter and the second emitter are disposed in or on a common reflector.

32. A method of generating light, comprising:

exciting a first electrically activated solid state emitter having a first spectral output including a first color peak in the visible range; and

exciting a second electrically activated solid state emitter having a second spectral output including a second color peak in the visible range;

wherein the first spectral output interacts with a first phosphor material and responsively emits a third spectral output including a third color peak in the visible range;

wherein the second spectral output interacts with a second phosphor material and responsively emits a fourth spectral output including a fourth color peak in the visible range; and

wherein each of the first color peak, second color peak, third color peak, and fourth color peak differs from the other, and an aggregated spectral output of the device includes the first color peak, second color peak, third color peak, and fourth color peak.