Light source including reflective wavelength-converting layer

• US 7,810,956 B2
• Filed: 08/23/2007
• Issued: 10/12/2010
• Est. Priority Date: 08/23/2007
• Status: Active Grant

• Current Assignee: Signify North America Corporation (Signify N.V.)
• Original Assignee: Philips Lumileds Lighting (Apollo Global Management, Inc.), Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Harbers, Gerard, Bierhuizen, Serge J.
• Primary Examiner(s): Choi; Jacob Y
• Application Number:
  US11/844,176
• Publication Number:
  US 20090052158A1
• Time in Patent Office: 1,146 Days
• Field of Search: 362/231, 362/293, 362/297, 362/304, 362/346, 362/296, 362/307, 362/308, 362/310, 362/311, 362/255, 362/296.01, 362/294, 362/311.02, 313/111, 313/112, 313/512
• US Class Current: 362/294
• 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 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/644 in intimate contact or integrated with parts of the device other than the semiconductor body

Abstract

A light source configured to emit first light is combined with a wavelength-converting layer. The wavelength-converting layer is disposed in a path of first light, is spaced apart from the light source, and includes at least one wavelength-converting material such as a phosphor configured to absorb first light and emit second light. The wavelength-converting layer is disposed between a reflective layer and the light source. In some embodiments, the wavelength-converting layer is a thick layer.

Claims

1. A structure comprising:

a light source configured to emit a first light along a forward optical axis;

a wavelength-converting layer, wherein the wavelength-converting layer is disposed in a path of the first light, is spaced apart from the light source, and comprises a first wavelength-converting material configured to absorb the first light and emit a second light; and

a reflective layer configured to be reflective of the first light and the second light, wherein the wavelength-converting layer is disposed between the reflective layer and the light source, and wherein the reflective layer is a surface of a heat sink having a plurality of fins.

2. The structure of claim 1 wherein the light source comprises at least one semiconductor light emitting diode.

3. The structure of claim 1 wherein the wavelength-converting layer further comprises a non-wavelength converting material.

4. The structure of claim 1 wherein the wavelength-converting layer further comprises a second wavelength-converting material.

5. The structure of claim 4 wherein the first wavelength-converting material is disposed in a first portion of the wavelength-converting layer and the second wavelength-converting material is disposed in a second portion of the wavelength-converting layer.

6. The structure of claim 4 wherein the first and second wavelength-converting materials are phosphors.

7. The structure of claim 1 wherein the wavelength-converting layer has a thickness between 5 and 500 microns.

8. The structure of claim 1 wherein the reflective layer is in direct contact with the wavelength-converting layer.

9. The structure of claim 1 further comprising an adhesive layer disposed between the reflective layer and the wavelength-converting layer.

10. The structure of claim 1 wherein the reflective layer has a lateral extent approximately equal to a lateral extent of the wavelength-converting layer.

11. The structure of claim 1 wherein the reflective layer has a lateral extent larger than a lateral extent of the wavelength-converting layer.

12. The structure of claim 1 further comprising a transparent member disposed between the light source and the wavelength-converting layer.

13. The structure of claim 12 further comprising a mirror proximate a bottom surface of the transparent member.

14. The structure of claim 13 wherein the mirror comprises a reflective coating disposed on a portion of a bottom surface of the transparent member.

15. The structure of claim 1 wherein the wavelength-converting layer is positioned in a collimating optic comprising reflective sidewalls.

16. The structure of claim 1 further comprising a lens disposed over the reflective layer.

17. The structure of claim 1 wherein the wavelength converting layer and the light source are spaced at least 0.5 mm apart.

18. The structure of claim 1 wherein the reflective layer is one of a metal, a reflective coating, and a dielectric stack.

19. The structure of claim 1, wherein the wavelength converting layer and the light source are spaced by a distance of a length of a side of the light source.

20. The structure of claim 1, wherein the wavelength converting layer has a thickness between 100 and 250 microns.