Integrating chamber LED lighting with modulation to set color and/or intensity of output

• US 20070235639A1
• Filed: 09/23/2005
• Published: 10/11/2007
• Est. Priority Date: 06/23/2003
• Status: Abandoned Application

• Current Assignee: Advanced Optical Technologies, LLC
• Original Assignee: Advanced Optical Technologies, LLC
• Inventors: Rains, Jack
• Application Number:
  US11/233,036
• Publication Number:
  US 20070235639A1
• Time in Patent Office: Days
• US Class Current: 250/228
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21V 7/24 characterised by the material
• CPC Class Codes: F21V 7/30 the coatings comprising photoluminescent substances
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: H05B 47/175 by remote control

Abstract

A system to provide visible lighting of a selectable spectral characteristic (e.g. a selectable color combination of light) uses an optical integrating cavity to combine light of different wavelengths from different sources. Sources of light of different wavelengths, typically different color LEDs, supply light into the interior of the cavity. The cavity has a diffusely reflective interior surface and an aperture for allowing emission of combined light. Modulation of the light sources, e.g. pulse width modulation of LED drive currents, controls the amount of each light wavelength supplied to the cavity and thus the amount included in the combined output through the aperture and any associated optical processing element. Examples are also disclosed that utilize phosphor doping of one or more of the system'"'"'s reflective elements, to add desired wavelengths of light to the combined output.

Claims

1. A lighting method, for emitting visible light of a set color characteristic so as to be humanly perceptible, the lighting method comprising:

receiving an input specifying a light color setting;

based on the light color setting;

(a) modulating operation of a first source of light, to produce a modulated amount of light of a first wavelength; and

(b) modulating operation of a second source of light, to produce a modulated amount of light of a second wavelength, wherein the second wavelength is different from the first wavelength;

diffusely reflecting the light of the first wavelength and the light of the second wavelength within an optical cavity so as to optically combine the light of the first wavelength with the light of the second wavelength to form combined light having a humanly visible color characteristic at least substantially corresponding to the light color setting; and

emitting the combined light from the optical cavity so that it may be perceived by a person.

2. The method of claim 1, wherein:

the modulating of operation of the first source of light comprises pulse width modulating a drive signal for driving the first source of light; and

the modulating of operation of the second source of light comprises pulse width modulating a drive signal for driving the second source of light.

3. The method of claim 2, further comprising adjusting an intensity of light output from at least one of the sources.

4. The method of claim 1, wherein the receiving of the input comprises receiving a data communication signal containing light color setting data from a remote device.

5. The method of claim 1, wherein the receiving of the input comprises receiving a signal representing a manual input regarding the light color setting.

6. The method of claim 1, wherein the sources comprise light emitting diodes for emitting light of two different visible colors.

7. The method of claim 1, wherein:

the first source comprises a light emitting diode for emitting visible light of the first wavelength; and

the second source comprises a source of radiant excitation energy, and a phosphor doped in a surface of the cavity, for emitting visible light including at least the second wavelength, in response to the radiant energy.

8. The method of claim 1, wherein the combined light emitted from the optical cavity provides substantially white light of a selected color temperature having a difference in chromaticity from the selected temperature on the black body curve.

9. The method of claim 1, further comprising:

sensing color of the combined light; and

adjusting operation in relation to at least one of the sources responsive to the sensed color, so that the combined light exhibits the color characteristic at least substantially corresponding to the light color setting.

10. The method of claim 9, wherein the adjusting includes activating at least one initially inactive source of light of one of the first and second wavelengths in response to the sensed color.

11. A lighting system, for emitting visible light of a set color characteristic so as to be humanly perceptible, comprising:

a first source of light, for producing light of a first wavelength, in an amount responsive to a first drive signal;

a second source of light, for producing light of a second wavelength, in an amount responsive to a second drive signal;

control circuitry responsive to an input specifying a light color setting, for modulating the first and second drive signals to control the first source to output a modulated amount of light of the first wavelength and to control the second source to output a modulated amount of light of the second wavelength;

an optical integrating cavity having a diffusely reflective interior surface and coupled to receive light of the first and second wavelength from the first and second sources, for optically combining the light of the first wavelength with the light of the second wavelength to form combined light having a humanly visible color characteristic at least substantially corresponding to the light color setting; and

an aperture of the cavity, for allowing emission of the combined light from the optical cavity so that it may be perceived by a person.

12. The system of claim 11, further comprising a data communication interface, for receiving a data communication signal containing setting data from a remote device and supplying the setting data to the control circuitry for use as said light color setting.

13. The system of claim 11, wherein the control circuitry is responsive to a manual input relating to the light color setting.

14. The system of claim 11, further comprising an optical processing element coupled to the aperture of the optical cavity.

15. The system of claim 14, wherein the optical processing element comprises a deflector having a reflective inner surface coupled to the aperture to deflect at least some of the combined light.

16. The system of claim 14, 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.

17. The system of any of claims 14, wherein the optical processing element comprises a variable focusing lens system and a variable opening iris located between the cavity and the variable focusing lens system.

18. The system of any of claims 14, wherein the optical processing element comprises a transmissive diffuser, selected from the group consisting of a diffusing lens, a curved transmissive cover over the aperture of the optical cavity and a holographic diffuser.

19. The system of claim 11, 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 5 second visible color, wherein the second color is different from the first color.

20. The system of claim 19, 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.

21. The system of claim 11, further comprising a third source of light, for producing light different from the light of the first and second wavelengths.

22. The system of claim 21, wherein the third source is for producing light of a third wavelength different from the first and second wavelengths.

23. The system of claim 21, wherein the third source is for producing substantially white light.

24. The system of claim 23, wherein the third source comprises one or more white light emitting diodes or one or more incandescent or fluorescent light bulbs.

25. The system of claim 11 wherein the combined light provides substantially white light of a selected color temperature with a difference in chromaticity from the selected temperature on the black body curve.

26. The system of claim 11, wherein the first source comprises:

a source of radiant excitation energy; and

at least one phosphor doped within a wall of the optical cavity, such that the radiant excitation energy excites the at least one phosphor to emit light including at least the light of the first wavelength.