LED lighting systems including luminescent layers on remote reflectors

• US 20080198572A1
• Filed: 02/21/2007
• Published: 08/21/2008
• Est. Priority Date: 02/21/2007
• Status: Abandoned Application

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Medendorp, Nicholas W.
• Application Number:
  US11/708,818
• Publication Number:
  US 20080198572A1
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: F21S 8/086 with lighting device attached sideways of the standard, e.g. for roads and highways
• CPC Class Codes: F21V 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21V 9/38 Combination of two or more photoluminescent elements of different materials
• CPC Class Codes: F21W 2131/103 of streets or roads
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lighting system may include a substrate and a light emitting device (LED) on the substrate, and the light emitting device may be configured to transmit light having a first wavelength along a path away from the substrate. A remote reflector may be spaced apart from the light emitting device, and the light emitting device may be between the substrate and the remote reflector. The remote reflector may also be in the path of the light having the first wavelength transmitted by light emitting device. A luminescent layer may be on a surface of the remote reflector, and the luminescent layer may be configured to convert a portion of the light having the first wavelength to light having a second wavelength different than the first wavelength. Moreover, the remote reflector may be configured to reflect light having the first and second wavelengths.

Claims

1. A lighting system comprising:

a light emitting device (LED) configured to transmit light having a first wavelength along a path;

a remote reflector spaced apart from the light emitting device wherein the remote reflector is in the path of the light having the first wavelength transmitted by light emitting device; and

a luminescent layer on a surface of the remote reflector, wherein the luminescent layer is configured to convert a portion of the light having the first wavelength to light having a second wavelength different than the first wavelength, and wherein the remote reflector is configured to reflect light having the first and second wavelengths.

2. A lighting system according to claim 1 further comprising:

a second light emitting device (LED) configured to transmit light having a third wavelength different than the first and second wavelengths along a path, wherein the remote reflector is spaced apart from the first and second light emitting devices, and wherein the remote reflector is in the path of the light having the third wavelength transmitted by the second light emitting device.

3. A lighting system according to claim 2 wherein the remote reflector is configured to reflect light having the first, second, and third wavelengths.

4. A lighting system according to claim 1 wherein the remote reflector includes a reflective surface on an opaque support member.

5. A lighting system according to claim 4 wherein the reflective surface comprises a metallic layer.

6. A lighting system according to claim 5 wherein the metallic layer comprises a layer of silver and/or aluminum.

7. A lighting system according to claim 1 wherein the luminescent layer comprises a phosphor material in a translucent and/or transparent binder agent.

8. A lighting system according to claim 7 wherein the binder agent comprises a silicone, an epoxy, and/or a plastic.

9. A lighting system according to claim 7 wherein the phosphor material comprises a yttrium-aluminum-garnet (YAG) phosphor material, an oxynitride phosphor material, a nitride phosphor material, and/or a zinc oxide phosphor material.

10. A lighting system according to claim 1 wherein the remote reflector comprises a concave reflector surface configured to focus the reflected light having the first and second wavelengths.

11. A lighting system according to claim 1 wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 1 cm.

12. A lighting system according to claim 1 wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 10 cm.

13. A lighting system according to claim 1 further comprising:

a housing reflector surrounding the light emitting device wherein the housing reflector is spaced apart from the remote reflector.

14. A lighting system according to claim 1 further comprising:

a second light emitting device configured to transmit light having the first wavelength along a path toward the luminescent layer and the remote reflector.

15. A lighting system according to claim 1 further comprising:

a substrate wherein the light emitting device (LED) is on the substrate and wherein the light emitting device is between the substrate and the remote reflector.

16. A lighting system comprising:

a light emitting device (LED) configured to transmit light having a first wavelength along a path;

a remote reflector spaced apart from the light emitting device wherein the remote reflector is in the path of the light having the first wavelength transmitted by light emitting device; and

a luminescent layer on a surface of the remote reflector, wherein the luminescent layer is configured to convert a portion of the light having the first wavelength to light having a second wavelength different than the first wavelength, wherein the remote reflector is configured to reflect light having the first and second wavelengths and wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 1 cm.

17. A lighting system according to claim 16 further comprising:

a substrate, wherein the light emitting device is on the substrate such that the light emitting device is between the substrate and the remote reflector.

18. A lighting system according to claim 16 further comprising:

a second light emitting device (LED) configured to transmit light having a third wavelength different than the first and second wavelengths, wherein the remote reflector is spaced apart from the first and second light emitting devices, and wherein the remote reflector is in a path of the light having the third wavelength transmitted by the second light emitting device.

19. A lighting system according to claim 16 wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 10 cm.

20. A lighting system according to claim 16 further comprising:

a housing reflector around the light emitting device and wherein the housing reflector is spaced apart from the remote reflector.

21. A lighting system according to claim 16 further comprising:

a second light emitting device adjacent the first light emitting device wherein the second light emitting device is configured to transmit light having the first wavelength along a path toward the luminescent layer and the remote reflector.

22. A lighting system comprising:

a light emitting device (LED) configured to transmit light having a first wavelength along a path;

a housing reflector adjacent the light emitting device;

a remote reflector spaced apart from the light emitting device and from the housing reflector, wherein the remote reflector is in the path of the light having the first wavelength transmitted by light emitting device; and

a luminescent layer on a surface of the remote reflector, wherein the luminescent layer is between the remote reflector and the housing reflector and between the remote reflector and the light emitting device, wherein the luminescent layer is configured to convert a portion of the light having the first wavelength to light having a second wavelength different than the first wavelength, and wherein the remote reflector is configured to reflect light having the first and second wavelengths.

23. A lighting system according to claim 22 further comprising:

a substrate, wherein the light emitting device and the housing reflector are on the substrate between the substrate and the luminescent layer.

24. A lighting system according to claim 22 wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 1 cm.

25. A lighting system according to claim 22 wherein the light emitting device is spaced apart from the reflector surface and from the luminescent layer by a distance of at least about 10 cm.