LIGHTING SOURCE USING SOLID STATE EMITTER AND PHOSPHOR MATERIALS

• US 20110063830A1
• Filed: 11/17/2010
• Published: 03/17/2011
• 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 8,764,225 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 light source for emitting a first light in a forward direction. A wavelength-converting layer is spaced apart from the light source and disposed in a path of the first light. The wavelength-converting layer is configured to absorb at least a portion of the first light and emit a second light. A reflective layer is configured to be reflective of at least the second light, and the wavelength-converting layer is disposed between the reflective layer and the light source.

Claims

1. A light emitting apparatus comprising:

a light source for emitting a first light in a forward direction;

a wavelength-converting layer spaced apart from the light source and disposed in a path of the first light, the wavelength-converting layer configured to absorb at least a portion of the first light and emit a second light; and

a reflective layer configured to be reflective of at least the second light, wherein the wavelength-converting layer is disposed between the reflective layer and the light source.

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

3. The light emitting apparatus of claim 1, wherein the source of light is a semiconductor light emitting diode, including one of a light emitting diode (LED), a laser diode (LD), or a resonant cavity light emitting diode (RCLED).

4. The light emitting apparatus of claim 1, wherein the wavelength-converting layer further comprises a second wavelength-converting material.

5. The light emitting apparatus 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 light emitting apparatus of claim 4, wherein the first and second wavelength-converting materials are selected form the group consisting of phosphors, quantum dots, quantum dot crystals, and quantum dot nano crystals.

7. The light emitting apparatus of claim 1, wherein the reflective layer has a lateral extent larger than a lateral extent of the wavelength-converting layer.

8. The light emitting apparatus of claim 1, further comprising a transparent member disposed between the light source and the wavelength-converting layer.

9. The light emitting apparatus of claim 8, the transparent member is an optic device.

10. The light emitting apparatus of claim 9, wherein the optic device includes at least one of a lens or a light guide having a light transmissive property.

11. The light emitting apparatus of claim 9, wherein the reflector surrounds at least a portion of the optic device.

12. The light emitting apparatus of claim 11, further comprising at least one of a lens and light diffuser deposited on top of at least a portion of the reflective layer.

13. The light emitting apparatus of claim 1, wherein the reflective layer and the down conversion material each have a curved shape.

14. The light emitting apparatus of claim 1, wherein the light source includes a plurality of semiconductor light emitters.

15. The light emitting apparatus of claim 1, wherein the wavelength-converting layer is positioned in an optic comprising reflective sidewalls.

16. A light emitting apparatus, comprising:

a light-emitting diode emitting short-wavelength light;

a phosphor layer longitudinally spaced apart from the light-emitting diode, the phosphor layer absorbing short-wavelength light and emitting wavelength-converted light; and

a reflector circumferentially surrounding the phosphor layer,

wherein the wavelength-converted light emitted from the phosphor layer either exits the apparatus directly or exits the apparatus after a reflection off the reflector.

17. The light emitting apparatus of claim 16, wherein the reflector has a concave shape

18. The light emitting apparatus of claim 16, wherein the phosphor comprises a generally planar transparent layer parallel and longitudinally adjacent the phosphor layer and facing the light-emitting diode.

19. The light emitting apparatus of claim 16, further comprises a transparent optic adjacent the phosphor layer and facing away from the light-emitting diode.

20. The light emitting apparatus of claim 16, further comprising a reflective layer adjacent the phosphor layer and facing away from the light-emitting diode module.

21. A light emitting apparatus, comprising:

a light source for emitting a first light having a first wavelength;

a phosphor layer longitudinally spaced apart from the light-emitting diode, the phosphor layer absorbing at least a portion of the first light and emitting a second light having a second wavelength different from the first wavelength;

an optic device disposed between the light source at the phosphor layer; and

a reflector adjacent opposite side faces of the optic device,

wherein the optic device and the reflector each have an elongated width in comparison with their respective heights.

22. The light emitting apparatus according to claim 21, wherein the light source is a plurality of light sources spaced apart from one another and adjacent a bottom portion of the optic device.

23. The light emitting apparatus according to claim 22, wherein the plurality of light sources emit light having the first wavelength.

24. The light emitting apparatus according to claim 22, wherein a first portion of the plurality of light sources emit light the first wavelength and a second portion of the plurality of light source emit light having a wavelength different from the first wavelength.

25. The light emitting apparatus according to claim 21, wherein the respective widths of the optic device and reflector are substantially the same.

26. The light emitting apparatus according to claim 21, further comprising a diffuser either adjacent to the phosphor layer or as part of the phosphor layer.