Optical integrating chamber lighting using one or more additional color sources to adjust white light

• US 7,604,375 B2
• Filed: 04/30/2008
• Issued: 10/20/2009
• Est. Priority Date: 04/27/2004
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Advanced Optical Technologies, LLC
• Inventors: Brown, Matthew, Rains, Jack C. Jr.
• Primary Examiner(s): Truong; Bao Q
• Application Number:
  US12/149,315
• Publication Number:
  US 20080205053A1
• Time in Patent Office: 538 Days
• Field of Search: 362/227, 362/228, 362/229, 362/230, 362/231, 362/240, 362/243, 362/246, 362/247, 362/281, 362/800, 362612-614, 362543-545
• US Class Current: 362/231
• CPC Class Codes: F21S 10/02 changing colors F21S10/002 - F21S10/007, F21S10/04 take precedence
• CPC Class Codes: F21S 2/00 Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
• CPC Class Codes: F21S 8/00 Lighting devices intended for fixed installation F21S9/00, F21S10/00 take precedence; using a string or strip of light sources F21S4/00
• CPC Class Codes: F21V 11/10 of iris type
• CPC Class Codes: F21V 14/06 by movement of refractors in vehicle head lamps F21S41/635
• CPC Class Codes: F21V 2200/13 the light being emitted at the end of the guide
• CPC Class Codes: F21V 5/002 using microoptical elements for redirecting or diffusing light
• CPC Class Codes: F21V 5/008 Combination of two or more successive refractors along an optical axis
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/28 characterised by coatings
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios
• CPC Class Codes: F21Y 2113/00 Combination of light sources
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2113/20 of different form
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G01J 1/08 Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• CPC Class Codes: G01J 3/0254 Spectrometers, other than colorimeters, making use of an integrating sphere
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/501 Colorimeters using spectrally-selective light sources, e.g. LEDs
• CPC Class Codes: G02B 5/0252 : using holographic or diffractive means
• CPC Class Codes: G02B 5/0278 : used in transmission
• CPC Class Codes: G02B 5/0284 : used in reflection
• CPC Class Codes: G02B 6/0008 : the light being emitted at the end of the fibre
• CPC Class Codes: G03B 15/06 : Special arrangements of screening, diffusing, or reflecting devices, e.g. in studio
• CPC Class Codes: G09F 13/0404 : the light source being enclosed in a box forming the character of the sign
• CPC Class Codes: G09F 13/06 : using individual cut-out symbols or cut-out silhouettes, e.g. perforated signs
• CPC Class Codes: G09F 13/14 : Arrangements of reflectors therein
• CPC Class Codes: G09F 13/22 : electroluminescent electroluminescent light sources per se H05B33/00
• CPC Class Codes: H05B 35/00 : Electric light sources using a combination of different types of light generation
• CPC Class Codes: H05B 45/00 : Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 : Controlling the colour of the light
• CPC Class Codes: H05B 45/22 : using optical feedback
• CPC Class Codes: H05B 45/28 : using temperature feedback
• CPC Class Codes: H05B 45/395 : Linear regulators
• CPC Class Codes: Y02B 20/30 : Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y10S 362/80 : Light emitting diode
• CPC Class Codes: Y10S 362/812 : Signs

Abstract

A system provides white light having a selectable spectral characteristic (e.g. a selectable color temperature) using an optical integrating cavity to combine energy of different wavelengths from different sources with white light. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined light. Control of the intensity of emission of the sources sets the amount of primary color light of each wavelength added to the substantially white input light output and thus determines a spectral characteristic of the white light output through the aperture. A variety of different elements may optically process the combined light output, such a deflector, a variable iris, a lens, a variable focusing lens system, a collimator, a holographic diffuser and combinations thereof.

Claims

1. A lighting apparatus, for a visible illuminating type lighting application, to illuminate or to provide task or object illumination in a region or area intended to be occupied by a person, the apparatus comprising:

a first source of light of a first wavelength;

a second source of light of a second wavelength, the second wavelength being different from the first wavelength;

a third source of light, wherein the third source produces substantially white light; and

an optical integrating cavity having a diffusely reflective interior surface for receiving and integrating light of the first and second wavelengths and the substantially white light, from the sources of light, via multiple diffuse reflections from the reflective interior surface, to form white light of a desired spectral characteristic, and having an aperture for allowing emission of the white light of the desired spectral characteristic in a direction to facilitate said visible illuminating type lighting application.

2. The apparatus of claim 1, further comprising an optical processing element coupled to the aperture of the optical cavity.

3. The apparatus of any of claim 2, wherein the optical processing element comprises at least one element selected from the group consisting of:

a variable opening iris, a variable focusing lens system, a light collimator, and a transmissive diffuser.

4. The apparatus of claim 1, further comprising adjustable control circuitry coupled to the first and second sources for establishing intensity of light from each of the sources, so as to adjust the spectral characteristic of white light emitted through the aperture.

5. The apparatus of claim 1, wherein:

the first source comprises one or more light emitting diodes for emitting light of a first visible color; and

the second source comprises one or more light emitting diodes for emitting light of a second visible color, wherein the second color is different from the first color.

6. The apparatus of claim 5, wherein:

the one or more first color light emitting diodes comprise an initially active light emitting diode for emitting light of the first color and an initially inactive light emitting diode for emitting light of the first color on an as needed basis; and

the one or more second color light emitting diodes comprises an initially active light emitting diode for emitting light of the second color and an initially inactive light emitting diode for emitting light of the second color on an as needed basis.

7. The apparatus of any of claim 5, wherein the third source comprises one or more white light emitting diodes or one or more incandescent or fluorescent light bulbs.

8. The apparatus of claim 1, further comprising a fourth source for supplying light of a third wavelength into the optical cavity for combination with the light of the first and second wavelengths and with the substantially white light, the third wavelength being different from the first wavelength and from the second wavelength.

9. The apparatus of claim 8, wherein:

the first source comprises one or more light emitting diodes for emitting light of a first visible color;

the second source comprises one or more light emitting diodes for emitting light of a second visible color, wherein the second color is different from the first color; and

the fourth source comprises one or more light emitting diodes for emitting light of a third visible color, wherein the third color is different from the first color and from the second color.

10. The apparatus of claim 9, wherein the first, second and third colors are red, green and blue, respectively.

11. A lighting apparatus, for a white light illuminating type application, to illuminate or to provide task or object illumination in a region or area intended to be occupied by a person, the apparatus comprising:

a chamber having at least one diffusely reflective interior surface for combining at least some light by diffuse reflection within the chamber and having an optical passage for allowing emission of combined light from the chamber in a direction to facilitate said white light illuminating type application;

a first source for producing substantially white light, the first source being coupled to supply the substantially white light to the interior of the chamber;

a second source for producing light of a defined wavelength, the second source being coupled to supply the light of the defined wavelength to the interior of the chamber, so that the emission of combined light from the chamber is white light of a spectral characteristic determined by a combination of the substantially white light and the light of the defined wavelength; and

a control circuit coupled to the sources for establishing output intensity of light of each of the sources to set contributions of the substantially white light and the light of the defined wavelength to the combined light and thus set the spectral characteristic of the combined white light emitted through the optical passage of the chamber.

12. The lighting apparatus of claim 11, wherein the first source comprises one or more white light emitting diodes, for emitting the substantially white light.

13. The lighting apparatus of claim 11, wherein the diffusely reflective interior surface and the optical passage are configured so that the chamber acts as an optical integrating cavity such that the combined white light emitted through the optical passage of the chamber is highly uniform.

14. The lighting apparatus of claim 11, wherein the optical passage of the chamber includes a transmissive diffuser.

15. The lighting apparatus of claim 11, wherein the optical passage of the chamber comprises an aperture through a wall of the chamber.

16. The lighting apparatus of claim 11, wherein each of the sources comprises one or more light emitting diodes.

17. The lighting apparatus of claim 11, further comprising:

a third source for producing light of another defined wavelength,

wherein the third source is coupled to supply the light of the other defined wavelength to the interior of the chamber, so that the emission of combined light from the chamber is white light of a spectral characteristic determined by a combination of the substantially white light, the light of the defined wavelength and the light of the other defined wavelength.

18. The lighting apparatus of claim 17, wherein each of the sources comprises one or more light emitting diodes.

19. The lighting apparatus of claim 11, further comprising:

a user interface for receiving a user input relating to a desired characteristic of the combined white light output of the apparatus,

wherein the control circuit establishes the output intensity of light of at least one of the sources in response to the user input.

20. The lighting apparatus of claim 11, further comprising:

a sensor responsive to the combined light,

wherein the control circuit maintains the spectral characteristic of the combined white light responsive to an output from the sensor.

21. The lighting apparatus of claim 20, wherein the sensor comprises a color sensor for sensing a color characteristic of the combined white light in the chamber.

22. The lighting apparatus of claim 20, wherein the sensor comprises a light intensity sensor for sensing intensity of at least some of the combined light in the chamber.

23. The lighting apparatus of claim 20, wherein the sensor comprises a temperature sensor.

24. The lighting apparatus of claim 11, wherein the chamber is configured so that the apparatus functions as a downlight.

25. The lighting apparatus of claim 24, wherein the first and second sources provide sufficient light energy for the combined light emitted through the optical passage to have a level sufficient for a task lighting application.

26. The lighting apparatus of claim 11, wherein the at least one interior surface of the chamber is white and is highly diffusely reflective, at least with respect to light from the sources.

27. The lighting apparatus of claim 26, wherein the at least one interior surface of the chamber exhibits reflectivity over 90%.

28. The lighting apparatus of claim 27, wherein the at least one surface of the chamber exhibits reflectivity of at least 98%.

29. The lighting apparatus of claim 26, wherein the at least one interior surface of the chamber has a shape corresponding to a substantial portion of a sphere.

30. The lighting apparatus of claim 26, wherein the at least one interior surface of the chamber has a shape corresponding to a substantial portion of a cylinder.

31. The lighting apparatus of claim 26, wherein the at least one interior surface of the chamber has a substantially rectangular cross-section.

32. A downlight for a white lighting application, the downlight comprising:

a chamber having at least one diffusely reflective interior surface for combining at least some light by diffuse reflection within the chamber and having an optical passage for allowing emission of combined light from the chamber in a downward direction to facilitate said white light application for the downlight;

at least one white light emitting diode (LED) coupled directly to the chamber, for producing substantially white light;

at least one single-colored light emitting diode (LED) coupled directly to the chamber, for producing a single color of light, so that the emission of combined light from the optical passage of the chamber is white light of a spectral characteristic determined by a combination of the substantially white light and the single color of light; and

a control circuit coupled to the LEDs for establishing output intensity of light of each of the LEDs to set contributions of the substantially white light and the light of the single color to the combined light and thus set the spectral characteristic of the combined white light emitted through the optical passage of the chamber for said white lighting application for the downlight.

33. The downlight of claim 32, wherein the diffusely reflective interior surface and the optical passage are configured so that the chamber acts as an optical integrating cavity such that the combined white light emitted through the optical passage of the chamber is highly uniform.

34. The downlight of claim 33, wherein the optical passage of the chamber includes a transmissive diffuser.

35. The downlight of claim 33, wherein the optical passage of the chamber comprises an aperture through a wall of the chamber.

36. The downlight of claim 33, wherein the at least one interior surface of the chamber is white and is highly diffusely reflective, at least with respect to light from the sources.

37. The downlight of claim 36, wherein the at least one interior surface of the chamber exhibits reflectivity over 90%.

38. The downlight of claim 37, wherein the at least one interior surface of the chamber exhibits reflectivity of at least 98%.

39. The downlight of claim 33, wherein the at least one interior surface of the chamber has a shape corresponding to a substantial portion of a sphere.

40. The downlight of claim 33, wherein the at least one interior surface of the chamber has a shape corresponding to a substantial portion of a cylinder.

41. The downlight of claim 33, wherein the at least one interior surface of the chamber has a substantially rectangular cross-section.

42. The downlight of claim 32, wherein the LEDs provide sufficient light energy for the combined light emitted through the optical passage to have a level sufficient for a task lighting application.

43. The downlight of claim 32, further comprising:

at least one additional single-colored light emitting diode (LED) coupled directly to the chamber, for producing another single color of light,

wherein the at least one additional single-colored LED is coupled to supply the light of the additional color to the interior of the chamber, so that the emission of combined light from the chamber is white light of a spectral characteristic determined by a combination of the substantially white light as well as the single colors of.

44. The downlight of claim 32, further comprising:

a user interface for receiving a user input relating to a desired characteristic of the combined white light output of the apparatus,

wherein the control circuit establishes the output intensity of light of at least one of the sources in response to the user input.

45. The downlight of claim 32, further comprising:

a sensor responsive to the combined light,

wherein the control circuit maintains the spectral characteristic of the combined white light responsive to an output from the sensor.

46. The downlight of claim 45, wherein the sensor comprises a color sensor for sensing a color characteristic of the combined white light in the chamber.

47. The downlight of claim 45, wherein the sensor comprises a light intensity sensor for sensing intensity of at least some of the combined light in the chamber.

48. The downlight of claim 45, wherein the sensor comprises a temperature sensor.