Lighting system using multiple colored light emitting sources and diffuser element

• US 20080094829A1
• Filed: 12/20/2006
• Published: 04/24/2008
• Est. Priority Date: 05/05/2004
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Gu, Yimin, Narendran, Nadarajah
• Granted Patent: US 7,837,348 B2
• Time in Patent Office: Days
• US Class Current: 362/231
• CPC Class Codes: F21K 2/00 Non-electric light sources using luminescence using excitation by radioactivity G21H3/02, H01J65/06, H01J65/08; using excitation by an external electromagnetic field or by external corpuscular radiation H01J65/04; Light sources using electrochemiluminescence
• 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 13/14 the elements being filters or photoluminescent elements, reflectors and refractors
• CPC Class Codes: F21V 3/02 characterised by the shape
• CPC Class Codes: F21V 5/004 using microlenses
• CPC Class Codes: F21V 7/06 with parabolic curvature
• 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: F21V 9/45 by adjustment of photoluminescent elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/30 Semiconductor lasers
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• 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 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

A light emitting apparatus has a radiation source for emitting multi-colored radiation. A diffuser material receives at least a portion of the multi-colored radiation emitted by the radiation source and converts the multi-colored radiation into forward transferred radiation and back transferred radiation. An optic device is coupled to the diffuser material and is adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device.

Claims

1. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

a diffuser material for receiving at least a portion of the multi-colored radiation emitted by the radiation source and converting the multi-colored radiation into forward transferred radiation and back transferred radiation; and

an optic device coupled to the diffuser material adapted to receive the back transferred radiation and extract at least a portion of the back transferred radiation from the optic device.

2. The light emitting apparatus of claim 1, wherein the radiation source comprises a plurality of light emitting sources, each of the light emitting sources exhibiting a spectrum different than a spectrum of at least one of the other light emitting sources.

3. The light emitting apparatus of claim 2, wherein the plurality of light sources comprises at least one of one of light emitting diodes (LEDs), laser diodes (LDs), and resonant cavity light emitting diodes (RCLEDs).

4. The light emitting apparatus of claim 2, wherein a first plurality of light emitting sources are disposed adjacent a first side of the diffuser material and a second plurality of light emitting sources are disposed adjacent a second side of the diffuser material.

5. The light emitting apparatus of claim 2, wherein the plurality of light emitting sources are disposed at a predetermined distance from the diffuser material.

6. The light emitting device of claim 2, wherein the plurality of light emitting sources is disposed adjacent a first portion of the optic device.

7. The light emitting device of claim 6, wherein the diffuser material is disposed adjacent a second portion of the optic device.

8. The light emitting device of claim 7, wherein the diffuser material is disposed over one of a portion of a second end of the optic device or over substantially all of the second end of the optic device.

9. The light emitting apparatus of claim 2, further comprising a light pipe, wherein the plurality of light emitting sources are disposed about at least a portion of a circumference of the light pipe for directing the light into the light pipe.

10. The light emitting apparatus of claim 9, further comprising a microlens layer disposed on a side of the light pipe.

11. The light emitting apparatus of claim 1, wherein the diffuser material for receiving the multi-colored radiation is at least one of a diffuser, a down conversion material, and a microlens.

12. The light emitting apparatus of claim 11, wherein the down conversion material includes at least one material for absorbing radiation of a first wavelength in a spectral region and emitting radiation of a second wavelength longer than the first wavelength in the spectral region.

13. The light emitting apparatus of claim 11, wherein the down conversion material comprises one of a layer having substantially uniformly dispersed material, a layer having a plurality of materials each of the plurality of materials exhibiting a respective density, or material dispersed within the optic device.

14. The light emitting apparatus of claim 11, wherein the diffuser material comprises at least one layer of down conversion material adjacent the diffuser.

15. The light emitting apparatus of claim 11, wherein the diffuser material comprises at least one layer of down conversion material positioned away from the diffuser.

16. The light emitting apparatus of claim 1, wherein the diffuser material for receiving the multi-colored radiation comprises a plurality of down conversion materials for absorbing radiation of a first wavelength in a spectral region and emitting radiation of at least a second wavelength in the spectral region longer than the first wavelength.

17. The light emitting apparatus of claim 1, wherein the diffuser material for receiving the multi-colored radiation comprises at least one of i) a plurality of diffuser layers and ii) a plurality of down conversion material layers.

18. The light emitting apparatus of claim 1, further comprising a collecting device for collecting at least a portion of the back transferred radiation leaving the optic device.

19. The light emitting apparatus of claim 18, wherein the collecting device includes a reflector disposed around at least a portion of the optic device.

20. The light emitting apparatus of claim 19, wherein a shape of the reflector is one of a cone, sphere, hyperbola, parabola, ellipse, pyramid, and box.

21. The light emitting apparatus of claim 18, wherein the optic device is disposed one of on the collecting device or at a distance away from the collecting device.

22. The light emitting apparatus of claim 21, wherein the collecting device is disposed adjacent at least two sides of the optic device.

23. The light emitting apparatus of claim 18, wherein the light source is disposed between the collecting device and the diffuser material.

24. The light emitting apparatus of claim 1, wherein the diffuser material is dispersed within the optic device.

25. The light emitting apparatus of claim 1, further comprising a heat dissipation device coupled to the radiation source.

26. A light emitting apparatus comprising:

a radiation source for emitting multi-colored radiation;

an optic device configured to receive radiation emitted from the radiation source;

a diffuser material disposed on a portion of the optic device receiving at least a portion of the multi-colored radiation received by the optic device and converting the portion of the multi-colored radiation into forward transferred light and back transferred light,

wherein the optic device is configured to extract a portion of the back transferred light.

27. The light emitting apparatus of claim 26, wherein the radiation source comprises a plurality of light emitting sources, each of the light emitting sources exhibiting a spectrum different than a spectrum of at least one other of the other light emitting sources.