Lighting device with low glare and high light level uniformity

• US 8,967,821 B2
• Filed: 03/21/2012
• Issued: 03/03/2015
• Est. Priority Date: 09/25/2009
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Pickard, Paul Kenneth
• Primary Examiner(s): HINES, ANNE M
• Application Number:
  US13/425,702
• Publication Number:
  US 20120236537A1
• Time in Patent Office: 1,077 Days
• Field of Search: 362/84, 362/336, 362/338, 362/237, 362/240, 362242-243, 362/245, 362255-256, 362/327, 362/328, 362330-332, 362/335, 362/800
• US Class Current: 362/84
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21S 8/02 of recess-mounted type, e.g. downlighters specially adapted for vehicle exteriors F21S41/00-F21S45/00
• CPC Class Codes: F21V 11/06 using crossed laminae or strips , e.g. grid-shaped louvers; using lattices or honeycombs
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/041 with conical or pyramidal surface
• 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: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lighting device, comprising at least a first light control element, at least a first light source positioned so that at least a portion of light emitted by the first light source passes through at least a portion of the first light control element and at least a first luminescent material, at least a portion of the first luminescent material being spaced from the first light source, the first luminescent material being positioned so that at least a portion of light emitted by the first light source excites at least a portion of the first luminescent material.

Claims

1. A lighting device, comprising:

at least a first light control element comprising light control structures;

at least a first light source positioned so that at least a portion of light emitted by the first light source passes through at least a portion of the first light control element;

at least a first luminescent material, at least a portion of the first luminescent material spaced from the first light source, the first luminescent material positioned so that at least a portion of light emitted by the first light source excites at least a portion of the first luminescent material, wherein

each light control structure causes light that is incident on the light control structure to be at least one of (1) collimated, in which at least 50% of incident light is caused to travel in a first direction or substantially parallel to the first direction, and (2) distributed, in which comparatively less light incident on the light control structure is directed to a location directly below the light control structure and comparatively more light is directed to one or more locations spaced from directly below the light control structure.

2. A lighting device as recited in claim 1, wherein the light control element comprises a film comprising at least one region that comprises volumetric light control structures.

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

the film comprises a first surface and a second surface,

at least a portion of the first luminescent material is on the first surface of the film, and

the first surface of the film is closer to the first light source than the second surface of the film.

4. A lighting device as recited in claim 1, wherein the light control element comprises a film comprising at least one region that comprises surface light control features.

5. A lighting device as recited in claim 4, wherein:

the film comprises a first surface and a second surface,

at least a portion of the first luminescent material is on the first surface of the film,

the first surface of the film is closer to the first light source than the second surface of the film, and

the at least one region that comprises surface light control features is on the second surface of the film.

6. A lighting device as recited in claim 1, wherein the light control element comprises a lens comprising at least one region that comprises volumetric light control structures.

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

the lens comprises a first surface and a second surface,

at least a portion of the first luminescent material is on the first surface of the lens, and

the first surface of the lens is closer to the first light source than the second surface of the lens.

8. A lighting device as recited in claim 6, wherein the lens is injection molded or extruded.

9. A lighting device as recited in claim 1, wherein the light control element comprises a lens comprising at least one region that comprises surface light control features.

10. A lighting device as recited in claim 9, wherein:

the lens comprises a first surface and a second surface,

at least a portion of the first luminescent material is on the first surface of the lens,

the first surface of the lens is closer to the first light source than the second surface of the lens, and

the at least one region that comprises surface light control features is on the second surface of the lens.

11. A lighting device as recited in claim 9, wherein the lens is injection molded or extruded.

12. A lighting device as recited in claim 1, wherein the lighting device comprises a plurality of light sources including the first light source, the plurality of light sources mounted on a support, each of the plurality of light sources spaced from the light control element by substantially the same distance.

13. A lighting device as recited in claim 1, wherein the lighting device further comprises a baffle system and a side reflector, the baffle system comprising a plurality of baffle elements.

14. A lighting device as recited in claim 1, wherein the lighting device further comprises a side reflector, and light exiting the lighting device passes through an aperture defined by the side reflector.

15. A lighting device as recited in claim 14, wherein the aperture is of a shape selected from among substantially square, substantially rectangular and substantially circular.

16. A lighting device as recited in claim 1, wherein first and second major dimensions of the lighting device extend in a first plane, and an emission plane of the first light source is substantially parallel to the first plane.

17. A lighting device as recited in claim 1, wherein the first light source comprises at least one solid state light emitter.

18. A lighting device as recited in claim 1, wherein the first light source comprises at least one light emitting diode.

19. A lighting device as recited in claim 1, wherein the first direction is substantially perpendicular to a surface of the light control element.