Optical integrating chamber lighting using multiple color sources to adjust white light

• US 20060268544A1
• Filed: 04/25/2005
• Published: 11/30/2006
• 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.
• Granted Patent: US 7,625,098 B2
• Time in Patent Office: Days
• 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, 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 cavity having a diffusely reflective interior surface for receiving and combining light of the first and second wavelengths and the substantially white light, from the sources of light, 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.

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

3. The apparatus of claim 2, 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.

4. The apparatus of claim 3, wherein at least a substantial portion of the reflective inner surface of the deflector exhibits a diffuse reflective characteristic with respect to the combined light.

5. The apparatus of claim 3, wherein:

a first portion of the reflective inner surface of the deflector exhibits a diffuse reflective characteristic; and

a second portion of the reflective inner surface of the deflector exhibits a specular reflective characteristic.

6. The apparatus of any of claims 1, 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.

7. The apparatus of any of claims 1, 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.

8. The apparatus of any of claims 1, 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.

9. The apparatus of any of claims 1-8, 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.

10. The apparatus of any of claims 1-8, 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.

11. The apparatus of claim 10, 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.

12. The apparatus of any of claim 10, wherein the third source comprises one or more white light emitting diodes or one or more incandescent or fluorescent light bulbs.

13. The apparatus of any of claims 1-8, 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.

14. The apparatus of claim 13, 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.

15. The apparatus of claim 14, wherein the first, second and third colors are red, green and blue, respectively.

16. A system comprising:

a plurality of apparatuses for emitting light, each as specified in claim 1;

and

a master controller coupled to control each of the apparatuses, for providing a common control of all light emissions by the apparatuses.

17. A lighting system, for providing variable white lighting for studio or theater applications, the lighting system comprising:

a first of 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, for supplying a substantially white light;

an optical cavity having a diffusely reflective interior surface for receiving and combining light of the first and second wavelengths and the substantially white light from the sources, 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;

a variable opening iris optically coupled to the aperture of the optical cavity, for controlling an amount of the light of the desired spectral characteristic emitted toward a subject to be illuminated; and

control circuitry coupled to at least the first and second sources for establishing intensity of light from the first and second sources, so as to set the desired spectral characteristic of the light directed toward the subject to be illuminated in the studio or theater.

18. The lighting system of claim 17, further comprising a variable focusing lens system, for adjustably focusing the light emitted through the iris toward the subject to be illuminated.

19. The lighting system of claim 17 or claim 18, 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.

20. The lighting system of claim 19, wherein the control circuitry comprises:

a color sensor responsive to the combined light; and

logic circuitry responsive to color detected by the sensor to control output intensity of the one or more first color light emitting diodes and intensity of the one or more second color light emitting diodes.

21. The lighting 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 diode for emitting light of the first color on an as needed basis; and

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

22. The lighting system of claim 21, wherein the control circuitry comprises:

a color sensor responsive to the combined light; and

logic circuitry responsive to color detected by the sensor to control output intensity of the one or more first color light emitting diodes and intensity of the one or more second color light emitting diodes, and

wherein the logic circuitry is responsive to the detected color to selectively activate the inactive light emitting diodes, as needed to maintain a desired color distribution in the emitted light.

23. The lighting system of claim 22, wherein the third source comprises one or more light emitting diodes for supplying substantially white light into the optical cavity for combination with the light of the first and second wavelengths.

24. The lighting system of claim 17, wherein the third source comprises one or more incandescent or fluorescent light bulbs.

25. A lighting network comprising:

a plurality of lighting systems, each as specified in claim 17;

and

a master controller communicatively networked to the control circuitry of each of the lighting systems, for providing a common control of all light emissions by the lighting systems.