Apparatus and method of using light sources of differing wavelengths in an unitized beam

• US 20050047135A1
• Filed: 07/30/2004
• Published: 03/03/2005
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Illumination Management Solutions Incorporated (Eaton Corporation PLC.)
• Inventors: Holder, Ronald G., Rhoads, Greg
• Granted Patent: US 7,083,304 B2
• Time in Patent Office: Days
• US Class Current: 362/240
• 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: F21W 2131/107 of the exterior of buildings
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios
• CPC Class Codes: H04N 9/315 Modulator illumination systems general applications of lighting devices F21V; general optical systems G02B; lamp houses for projectors not peculiar to the presence of an electronic spatial light modulator G03B21/20

Abstract

A plurality of light sources, each radiating a color of light; a corresponding plurality of reflectors are arranged and configured so that the reflector reflects light from a predetermined one of the plurality of light sources. The reflected light from the plurality of reflectors is mixed to generate a composite light from the plurality of light sources. A sequenced or stacked array of the light sources and dichroic reflectors mixes the reflected light from the reflectors. Each reflector is positioned on a common optical axis with an aligned corresponding one of the plurality of light sources to provide a light source and reflector pair. Each reflector is coated with a dichroic filter material which reflects the color of light radiated by the corresponding light source of the pair, and which transmits light radiated by all preceding light sources in the sequenced array.

Claims

1. An apparatus for generating a selected color of light comprising:

a housing;

a plurality of light sources disposed in the housing, each radiating a color of light into an aperture of defined radial size; and

a corresponding plurality of reflectors disposed in the housing, each reflector arranged and configured to reflect light from a predetermined one of the plurality of light sources into the aperture, where the plurality of light sources and reflectors are arranged and configured with respect to each other to mix reflected light from the reflectors into a composite beam from the plurality of light sources into the aperture, the housing having a radial size comparable to the radial size of the aperture.

2. The apparatus of claim 1 where the plurality of light sources generate a full color spectrum of visible light.

3. The apparatus of claim 1 where the plurality of light sources generate green, blue and red light in selected amounts.

4. The apparatus of claim 1 where at least some of the plurality of reflectors are coated with a dichroic filter material.

5. The apparatus of claim 1 where the means for mixing reflected light from the reflectors comprises a sequenced array of the plurality of light sources and reflectors in an alternating pairs, each reflector being positioned on a common optical axis with an aligned corresponding one of the plurality of light sources to provide a light source and reflector pair, each reflector with the possible exception of the first reflector of the sequenced array having a dichroic filter material which reflects the color of light radiated by the corresponding light source of the pair, and which transmits light radiated by all preceding light sources in the sequenced array.

6. The apparatus of claim 1 further comprising a corresponding plurality of heat sinks, each heat sink thermally coupled to one of the plurality of light sources.

7. The apparatus of claim 6 where each heat sink comprises a fixture for mounting each corresponding light source relative to the corresponding reflector.

8. The apparatus of claim 6 where each heat sink comprises a thermally conductive, transparent substrate disposed in the housing to which the light source is mounted and thermally coupled.

9. The apparatus of claim 8 where the housing is thermally coupled to each of the heat sinks.

10. The apparatus of claim 1 wherein the plurality of light sources, and reflectors comprise a color pixel unit and further comprising a plurality of color pixel units arranged and configured into a compound system.

11. The apparatus of claim 10 where the compound system comprises a large format LED display screen, a backlight for an LCD screen, a light source for a digital light projection system, a digital cinema projector, a color video projector, a color changing light source for a display, an architectural light, a theater and stage light, or a light source for a color corrected display system.

12. The apparatus of claim 10 where in each unit time-multiplexes the generation of colored light from the unit by cycling individual light sources to generate corresponding color images.

13. The apparatus of claim 10 where in each unit mixes the generation of colored light from the unit by selectively controlling the intensity of individual light sources to generate corresponding color images.

14. A method for generating a selected color of light comprising:

radiating light from selected ones of a plurality of colored light sources contained within a housing with a maximum radial size comparable to an aperture of defined size;

reflecting light from each of the light sources into a common light beam into the aperture; and

mixing reflected light in a common beam to generate a composite light of a selected composite color from the plurality of light sources.

15. The method of claim 14 where radiating light from selected ones of a plurality of colored light sources comprises generating a full color spectrum of visible light.

16. The method of claim 14 where radiating light from selected ones of a plurality of colored light sources comprises generating green, blue and red light in selected amounts.

17. The method of claim 16 where radiating light from selected ones of a plurality of colored light sources comprises generating a full color spectrum of visible light.

18. The method of claim 17 where radiating light from selected ones of a plurality of colored light sources comprises generating green, blue and red light in selected amounts.

19. The method of claim 14 where reflecting light from each of the light sources into a common beam comprising reflecting at least some of the radiated light from reflectors coated with a dichroic filter material.

20. The method of claim 14 where mixing reflected light from the reflectors comprises providing a sequenced longitudinal array of the plurality of light sources and reflectors in an alternating pairs of light sources and reflectors, and where reflecting light from each of the light sources into a common light beam comprises reflecting light radiated from a light source by the corresponding reflector of the pair along a common optical axis while transmitting light from other ones of the plurality of light sources corresponding to other reflectors along the common optical axis with the possible exception of the first reflector of the sequenced array.

21. The method of claim 14 further comprising thermally controlling each of the light sources by means of a corresponding plurality of heat sinks, each heat sink thermally coupled to one of the plurality of light sources.

22. The method of claim 21 further comprising positioning each corresponding light source relative to the corresponding reflector by means of the heat sink.

23. The method of claim 22 further comprising thermally coupling each of the heat sinks to a common housing.

24. The method of claim 14 further comprising combining the plurality of light sources, reflectors into a unit and arranging and configuring a plurality of units into a compound system.

25. The method of claim 24 where arranging and configuring a plurality of units into a compound system comprises arranging and configuring a plurality of units into a large format LED display screen, a backlight for an LCD screen, a light source for a digital light projection system, a digital cinema projector, a color video projector, a color changing light source for a display, an architectural light, a theater and stage light, or a light source for a color corrected display system.

26. The method of claim 24 where mixing reflected light in the common beam to generate a composite light beam of a selected composite color from the plurality of light sources in each unit comprises time-multiplexing the generation of colored light from the unit by cycling individual light sources to generate corresponding color images.

27. The method of claim 24 where mixing reflected light in the common beam to generate a composite light beam of a selected composite color from the plurality of light sources in each unit comprises color-multiplexing the generation of colored light from the unit to generate corresponding color images.