Light Engine

• US 20080094835A1
• Filed: 08/02/2005
• Published: 04/24/2008
• Est. Priority Date: 08/06/2004
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Van Sprang, Hans, Marra, Johan
• Granted Patent: US 7,722,211 B2
• Time in Patent Office: Days
• US Class Current: 362/247
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• 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: F21S 41/24 Light guides
• CPC Class Codes: F21S 41/37 characterised by their material, surface treatment or coatings
• CPC Class Codes: F21V 2200/17 characterised by the admission of light into the guide
• CPC Class Codes: F21V 29/58 characterised by the coolants
• CPC Class Codes: F21V 31/04 Provision of filling media
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The invention describes a Light engine (1,2,3,4,5) comprising a chamber (6) with at least one aperture (7) and a number of LED elements (13) positioned inside this chamber, where effectively all inner surfaces of the chamber (6) are realized as high-reflective surfaces (20) which are essentially non-absorbing towards light within a desired wavelength region

Claims

1. Light engine (1, 2, 3, 4, 5) comprising a chamber (6) with at least one aperture (7) and a number of LED elements (13) positioned inside this chamber, where effectively all inner surfaces of the chamber (6) are realized as high-reflective surfaces (20) which are essentially non-absorbing towards light within a desired wavelength region.

2. A light engine according to claim 1, comprising outcoupling means (15, 15′

, 16, 17, 19) for enhancing outcoupling of the light emitted by the LED elements (13) into the chamber (6).

3. A light engine according to claim 1, where the high-reflective surfaces (20) are realized by a diffuse-reflective material (12, 18) distributed over the inside surface of the chamber walls (10, 10′

).

4. A light engine according to claim 3, where the diffuse-reflective material (12) is enclosed between a transparent covering plate (11, 11′

) and the inside surface of the chamber walls (10, 10′

).

5. A light engine according to claim 3, where the diffuse-reflective material (12) comprises a reflective dry powder (12).

6. A light engine according to claim 4, where the transparent covering plate (11) covers the LED elements (13), and the outcoupling means (15, 15′

) comprise a number of transparent outcoupling elements (15, 15′

) each of which extends from a light emitting surface of an associated LED element (13) to the transparent covering plate (11).

7. A light engine according to claim 6, where the transparent outcoupling elements (15) have a cross section which is wider at an interface between the outcoupling element (15) and the transparent covering plate (11) than at an interface between the outcoupling element (15) and the associated LED element (13).

8. A light engine according to claim 1, where the outcoupling means (19) comprise transparent domes (19) each of which is optically connected to a light emitting surface of an associated LED element.

9. A light engine according to claim 8, where the domes (19) protrude through holes (22) in a covering plate (11′

, 21) covering the chamber wall (10) on which the LED elements are mounted.

10. A light engine according to claim 3, where the reflective material (12) distributed over the inside surface of the chamber walls (10, 10′

) comprises a light converting substance.

11. A light engine according to claim 1 where LED elements of different wavelength characteristics are positioned inside the chamber.

12. A light engine according to claim 1 comprising a light collimating element (8) positioned at the aperture (7) of the chamber (6).

13. A light engine according to claim 1, where the chamber (6) is filled with a material (22) which has a refractive index that approaches or, preferably, matches the refractive index of the transparent covering plate (11, 11′

) and/or of the outcoupling means (15, 15′

, 19) and/or of the collimating element (8) and/or of the LED elements (13).

14. A light engine according to claim 13, where the material (22) is a liquid material that is also used for the front-end cooling of the LED elements (13).

15. A light engine according to claim 1, where an aperture fraction (f) defined by the ratio of a surface area (A_exit) of the aperture (7) to a total interior surface area (A_engine) of the light engine ((1, 2, 3, 4, 5), which includes the surface area (A_exit) of the aperture (7), is preferably ≦

0.15, more preferably ≦

0.1.

16. Automotive light system enclosing a light engine (1, 2, 3, 4, 5) according to claim 1.