LIGHTING DEVICE

• US 20130070442A1
• Filed: 10/25/2012
• Published: 03/21/2013
• Est. Priority Date: 12/22/2005
• Status: Active Grant

• Current Assignee: Creeled Incorporated
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: NEGLEY, Gerald H.
• Granted Patent: US 8,858,004 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• 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 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• 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 33/505 characterised by the shape, e.g. plate or foil
• 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

Abstract

A lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface of the luminescent element being at least twice as large as the illumination surface of the light emitter. Also, a lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface of the luminescent element surface being at least twice as large as and substantially parallel to the illumination surface of the light emitter. Also, a lighting device comprising at least one solid state light emitter and at least one luminescent element spaced from the light emitter, a surface area of a projection of the luminescent element being at least twice as large as a surface area of a projection of the light emitter.

Claims

1. A lighting device comprising:

at least one solid state light emitter; and

at least one luminescent element,

the luminescent element comprising particles of at least a first luminescent material,

the luminescent element spaced from the solid state light emitter,

a content of luminescent material in the luminescent element not greater than about 15% by volume,

the particles of the first luminescent material having an average particle size of not greater than 50 microns, and

a thickness of the luminescent element not greater than 1 cm.

2. A lighting device as recited in claim 1, wherein:

the solid state light emitter has an illumination surface,

the luminescent element has a luminescent element surface,

the luminescent element surface is at least twice as large as the illumination surface.

3. A lighting device as recited in claim 1, wherein:

the solid state light emitter has an illumination surface,

the luminescent element is spaced from the solid state light emitter by a distance which is at least equal to a largest dimension of the illumination surface.

4. A lighting device as recited in claim 1, wherein the solid state light emitter is a light emitting diode chip.

5. A lighting device as recited in claim 1, wherein:

the solid state light emitter has an illumination surface,

the luminescent element has a luminescent element surface,

the luminescent element surface is at least five times as large as the illumination surface.

6. A lighting device as recited in claim 1, wherein:

the solid state light emitter has an illumination surface,

the luminescent element has a luminescent element surface,

the luminescent element surface is at least ten times as large as the illumination surface.

7. A lighting device as recited in claim 1, wherein:

the solid state light emitter has an illumination surface,

the luminescent element has a luminescent element surface,

the illumination surface is substantially planar, and

the luminescent element surface is substantially planar.

8. A lighting device as recited in claim 1, further comprising at least one scattering layer.

9. A lighting device as recited in claim 1, further comprising at least one brightness enhancing film.

10. A lighting device as recited in claim 1, wherein the luminescent element is also a scattering layer.

11. A lighting device as recited in claim 1, wherein the luminescent element is spaced from the solid state light emitter by a distance in the range of from about 100 micrometers to about 750 micrometers.

12. A lighting device as recited in claim 1, wherein the luminescent element is spaced from the solid state light emitter by a distance in the range of from about 500 micrometers to about 750 micrometers.

13. A lighting device as recited in claim 1, wherein the luminescent element comprises a matrix in which a luminescent material is contained.

14. A lighting device as recited in claim 13, wherein the matrix comprises a polymeric material.

15. A lighting device as recited in claim 14, wherein the polymeric material has been cured.

16. A lighting device comprising:

at least one solid state light emitter; and

at least one luminescent element,

the luminescent element comprising at least one luminescent material, a content of the luminescent material in the luminescent element not greater than about 15% by volume,

the luminescent element spaced from the solid state light emitter,

the solid state light emitter having an illumination surface, and

the luminescent element having a luminescent element surface, and

the luminescent element surface at least twice as large as the illumination surface.

17. A lighting device as recited in claim 16, wherein the luminescent element is spaced from the solid state light emitter by a distance which is at least equal to a largest dimension of the illumination surface.

18. A lighting device as recited in claim 16, wherein:

the illumination surface is substantially planar, and

the luminescent element surface is substantially planar.

19. A lighting device as recited in claim 16, wherein the luminescent element comprises a matrix in which a luminescent material is contained.

20. A lighting device as recited in claim 16, wherein the luminescent element surface is at least five times as large as the illumination surface.