Color-tunable lighting devices and methods of use

• US 9,562,671 B2
• Filed: 08/19/2011
• Issued: 02/07/2017
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: Research Triangle Institute International
• Original Assignee: Research Triangle Institute
• Inventors: Davis, James Lynn
• Primary Examiner(s): Sawhney, Hargobind S
• Application Number:
  US13/817,887
• Publication Number:
  US 20130215597A1
• Time in Patent Office: 1,999 Days
• US Class Current: 1/1
• CPC Class Codes: F21V 13/08 the elements being filters or photoluminescent elements and reflectors
• CPC Class Codes: F21V 14/08 by movement of the screens or filters
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/28 characterised by coatings
• 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: 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 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21V 9/45 by adjustment of photoluminescent elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01J 1/63 characterised by the luminescent material
• 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 33/507 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 33/60 Reflective elements

Abstract

A lighting device (100) includes a housing (104) enclosing a housing interior (108), a light source (132), a light converter (136), and a color tuning device. The light source is configured for emitting a primary light beam of a primary wavelength (140) through the housing interior. The light converter includes a luminescent material (144) facing the housing interior and configured for emitting secondary light (156, 158) of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beam. The housing includes a light exit (124) for outputting a combination of primary light and secondary light. The color tuning device is configured for adjusting a position of the primary light beam relative to the luminescent material.

Claims

1. A lighting device, comprising:

a housing enclosing a housing interior and comprising a light exit for outputting a combination of primary light and secondary light;

a light source configured for emitting a primary light beam of a primary wavelength through the housing interior;

a light converter comprising a luminescent material facing the housing interior and configured for emitting secondary light of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beam;

a color tuning device configured for adjusting a position of the primary light beam relative to the luminescent material; and

an optical element disposed in the housing interior and interposed in at least a portion of the primary light beam between the light source and the luminescent material, wherein the color tuning device is configured for moving the optical element, and

the optical element is selected from the group consisting of;

an optical waveguide comprising an input surface configured to receive the portion of the primary light beam at an incident direction and an output surface configured to output the portion of the primary light beam transmitted through the optical waveguide at an angle relative to the incident direction; and

an optical waveguide comprising an input end optically coupled to the light source and an output end facing the housing interior at an angle to the luminescent material, and the optical waveguide is configured for directing the primary light beam from the light source, through the housing interior and toward the luminescent material.

2. The lighting device of claim 1, wherein the luminescent material comprises a pattern of two or more luminescent components configured for emitting secondary light components of two or more different wavelengths, and the color tuning device is configured for adjusting a ratio of respective amounts of the primary light beam directly incident on respective areas of the two or more luminescent components.

3. The lighting device of claim 1, comprising a reflective surface facing the housing interior, wherein the color tuning device is configured for adjusting a ratio of an amount of the primary light beam directly incident on the luminescent material to an amount of the primary light beam directly incident on the reflective surface.

4. The lighting device of claim 1, wherein the color tuning device is configured for moving the luminescent material relative to the light source or for moving the light source relative to the luminescent material.

5. The lighting device of claim 4, wherein the color tuning device is configured for moving the luminescent material according to a mode selected from the group consisting of linearly translating the luminescent material in a plane orthogonal to a nominal output axis of the light source, linearly translating the luminescent material toward or away from the light source, rotating the luminescent material, and combinations of two of more of the foregoing.

6. The lighting device of claim 4, wherein the color tuning device comprises an actuator configured for actuating movement of the luminescent material or the light source, and a support structure configured for supporting the actuator or the luminescent material during movement.

7. The lighting device of claim 1, wherein the color tuning device comprises an actuator configured for actuating movement of the optical element, and a support structure configured for supporting the actuator or the optical element during movement.

8. The lighting device of claim 1, wherein the luminescent material comprises at least a first luminescent component and a second luminescent component configured for respectively emitting secondary light of a first wavelength and a second wavelength, and the first luminescent component and the second luminescent component are arranged in an alternating pattern.

9. The lighting device of claim 8, wherein the alternating pattern is selected from the group consisting of a plurality of polygons, a plurality of ellipses, a plurality of circular sectors, a spiral pattern, a dot or circular pattern, and combinations of two or more of the foregoing.

10. The lighting device of claim 1, wherein the housing comprises an inside surface coaxial with an axis of the housing interior, the light exit is disposed at an axial end of the housing interior, and the luminescent material is disposed at an opposite axial end of the housing interior.

11. The lighting device of claim 1, wherein the housing comprises an inside surface, the inside surface comprises at least two opposing curved sections, and the luminescent material is interposed between the at least two curved sections.

12. The lighting device of claim 1, comprising a reflective surface facing the housing interior.

13. The lighting device of claim 12, wherein the housing comprises an inside surface and the reflective surface is disposed on the inside surface.

14. The lighting device of claim 1, wherein the light converter comprises a reflective substrate and the luminescent material is supported by the substrate.

15. The lighting device of claim 14, wherein the substrate comprises a nonwoven material.

16. The lighting device of claim 14, wherein the substrate comprises a plurality of nanofibers.

17. The lighting device of claim 1, wherein the luminescent material is selected from the group consisting of quantum dots, phosphors, nano-phosphors, organic dyes, and combinations of two or more of the foregoing.

18. The lighting device of claim 1, wherein the light source is one of a plurality of light sources configured for emitting respective primary light beams, and further comprising a plurality of optical waveguides comprising respective input ends optically coupled to the respective light sources and respective output ends positioned at respective angles to the luminescent material, wherein the optical waveguides are configured for directing the respective primary light beams from the respective light sources, through the housing interior and toward the luminescent material.

19. The lighting device of claim 18, wherein the light converter comprises a reflective section facing the housing interior, at least one of the light sources or optical waveguides is configured to direct a corresponding primary light beam to the reflective section, and at least one of the other light sources or optical waveguides is configured to direct a corresponding primary light beam to the luminescent material.

20. The lighting device of claim 18, wherein the luminescent material comprises a first luminescent section configured for emitting secondary light of a first wavelength, and a second luminescent section configured for emitting secondary light of a second wavelength different from the first wavelength, and at least one of the light sources or optical waveguides is configured to direct a corresponding primary light beam to the first luminescent section, and at least one of the other light sources or optical waveguides is configured to direct a corresponding primary light beam to the second luminescent section.

21. A method for tuning a color of light outputted from a lighting device, the method comprising:

emitting a primary light beam of a primary wavelength through a housing interior of a housing of the lighting device such that at least a portion of the primary light beam is incident on a luminescent material, by transmitting the primary light beam from a light source into an optical waveguide, and emitting the primary light beam from the optical waveguide along a nominal output axis oriented at an angle to the luminescent material;

emitting secondary light from the luminescent material through the housing interior, in response to excitation by the primary light beam, wherein the secondary light is emitted at one or more wavelengths different from the primary wavelength;

outputting an output light from a light exit of the housing, wherein the output light comprises a combination of primary light and emitted secondary light; and

adjusting a position of the primary light beam relative to the luminescent material to tune the output light to a desired color.

22. The method of claim 21, wherein outputting the output light comprises outputting primary light selected from the group consisting of primary light reflected from a reflective surface in the housing interior, unconverted primary light reflected from the luminescent material, primary light reflected from a substrate supporting the luminescent material, primary light transmitted through a substrate supporting the luminescent material, and combinations of two or more of the foregoing.

23. The method of claim 21, wherein the luminescent material comprises a pattern of two or more luminescent components configured for emitting secondary light of two or more different wavelengths, and adjusting the position of the primary light beam relative to the luminescent material comprises adjusting a ratio of respective amounts of the primary light beam directly incident on respective areas of the two or more luminescent components.

24. The method of claim 21, wherein adjusting the position of the primary light beam relative to the luminescent material comprises adjusting a ratio of an amount of the primary light beam directly incident on the luminescent material to an amount of the primary light beam directly incident on a reflective surface in the housing interior.

25. The method of claim 21, wherein adjusting the position of the primary light beam relative to the luminescent material comprises adjusting a size of an area of the primary light beam incident on the luminescent material.

26. The method of claim 21, wherein adjusting the position of the primary light beam relative to the luminescent material comprises making an adjustment selected from the group consisting of moving the luminescent material relative to the light source, moving the light source relative to the luminescent material, moving an optical element disposed in the housing interior and interposed in at least a portion of the primary light beam between the light source and the luminescent material, and combinations of two or more of the foregoing.

27. The method of claim 21, wherein:

(a) the light converter comprises a plurality of sections facing the housing interior and having a configuration selected from the group consisting of;

(i) a section of reflective material and a section of luminescent material;

(ii) a section of a first luminescent material configured for emitting secondary light of a first wavelength, and a section of a second luminescent material configured for emitting secondary light of a second wavelength different from the first wavelength; and

(iii) a section of reflective material, a section of a first luminescent material configured for emitting secondary light of a first wavelength, and a section of a second luminescent material configured for emitting secondary light of a second wavelength different from the first wavelength;

(b) the primary light beam is incident on one or more of the plurality of sections; and

(c) further comprising adjusting a color of the output light by adjusting a position of the light converter relative to the light source, adjusting a position of the light source relative to the light converter, adjusting a position of an optical waveguide relative to the light converter, modifying an optical path of the primary light beam between the light source and the light converter, or two or more of the foregoing.

28. A lighting device, comprising:

a housing enclosing a housing interior and comprising a light exit for outputting a combination of primary light and secondary light;

a plurality of light sources configured for emitting respective primary light beams of a primary wavelength through the housing interior;

a light converter comprising a luminescent material facing the housing interior and configured for emitting secondary light of one or more wavelengths different from the primary wavelength, in response to excitation by the primary light beams;

a color tuning device configured for adjusting a position of the primary light beam relative to the luminescent material; and

a plurality of optical waveguides comprising respective input ends optically coupled to the respective light sources and respective output ends positioned at respective angles to the luminescent material, wherein the optical waveguides are configured for directing the respective primary light beams from the respective light sources, through the housing interior and toward the luminescent material.

29. The lighting device of claim 28, wherein the light converter comprises a reflective section facing the housing interior, at least one of the light sources or optical waveguides is configured to direct a corresponding primary light beam to the reflective section, and at least one of the other light sources or optical waveguides is configured to direct a corresponding primary light beam to the luminescent material.

30. The lighting device of claim 28, wherein the luminescent material comprises a first luminescent section configured for emitting secondary light of a first wavelength, and a second luminescent section configured for emitting secondary light of a second wavelength different from the first wavelength, and at least one of the light sources or optical waveguides is configured to direct a corresponding primary light beam to the first luminescent section, and at least one of the other light sources or optical waveguides is configured to direct a corresponding primary light beam to the second luminescent section.