Additive color mixing system with variable hue and saturation light sources

• US 5,031,078 A
• Filed: 08/28/1989
• Issued: 07/09/1991
• Est. Priority Date: 08/28/1989
• Status: Expired due to Fees

• Current Assignee: Vari-Lite, Inc. (Signify N.V.)
• Original Assignee: Vari-Lite, Inc. (Signify N.V.)
• Inventors: Bornhorst, James M.
• Primary Examiner(s): Husar, Stephen F.
• Application Number:
  US07/399,827
• Time in Patent Office: 680 Days
• Field of Search: 362/321, 362/230, 362/231, 362/237, 362/241, 362/268, 362/293, 362/298, 362/300, 362/301, 362/302, 362/304
• US Class Current: 362/552
• CPC Class Codes: F21S 10/00 Lighting devices or systems producing a varying lighting effect
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21W 2131/406 for theatres, stages or film studios
• CPC Class Codes: F21Y 2113/10 of different colours
• CPC Class Codes: G02B 26/023 comprising movable attenuating elements, e.g. neutral density filters
• CPC Class Codes: G02B 27/102 for generating a colour image from monochromatic image signal sources
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

Abstract

A high performance color mixing system combines colored light beams from three primary color sources into a composite light beam. Each light source assembly can be individually dimmed to control the color of the composite beam. Each primary color beam can be varied in hue and saturation by the use of pivoting dichroic filters, thereby providing improved performance and increased capability. This system is capable of producing deeply saturated colors in all hues, and does not comprise performance in white, provides good color balance and sufficient intensity when the dichroic filters are pivoted to a position parallel to the light rays of the beam.

Claims

1. An additive color mixing system for a light projector, comprising:

at least two light source assemblies, each including;

a light for generating light rays defining a beam of light,

an intensity control for varying the intensity of said beam of light,

color changing apparatus for varying a hue and saturation of said beam of light, including at least one dichroic filter movably positioned in said beam of light and operable to move from a first position to a second position and thereby change a centerline wavelength of light transmitted therethrough to produce a desired colored light; and

a combiner for receiving colored light generated by said light source assemblies and for combining the beams of colored light into a composite beam.

2. The additive color mixing system of claim 1, wherein said dichroic filters are movable by said color changer to intermediate positions between said first position substantially parallel to said light rays to said second position substantially perpendicular to said light rays.

3. The additive color mixing system of claim 1, further including a bundle of optical fibers for coupling the colored light from each said color changer to said combiner.

4. The additive color mixing system of claim 1, further including a mirror arrangement for coupling the colored light from said each color changer to said combiner.

5. The additive color mixing system of claim 1, wherein said combiner comprises an arrangement of interwoven optical fibers.

6. The additive color mixing system of claim 1, wherein said combiner comprises an arrangement of mirrors and dichroic filters.

7. The additive color mixing system of claim 1, wherein each said intensity control is adapted for independently varying the intensity of the light emitted by each said light source assembly.

8. The additive color mixing system of claim 1, wherein said dichroic filters are pivotally movable to desired angular orientations with respect to respective said light rays.

9. The additive color mixing system of claim 1, wherein each color changer includes multiple dichroic filters which are mechanically interconnected to provide for rotation to substantially the same angles of incidence.

10. The additive color mixing system of claim 9, wherein said dichroic filters are pivotal to positions so that light from a respective said beam can pass therearound and change the saturation of the color produced by the respective said color changer.

11. The additive color mixing system of claim 1, wherein each said intensity control comprises a mechanical control disposed in the path of the respective light beam for restricting the amount of light transmitted therethrough.

12. An additive color mixing system for a light projector, comprising:

a light source assembly comprising;

a light for generating rays defining a beam of light,

means for dividing said beam into at least two beams of light;

at least two color filters mechanisms, each adapted to accept one said light beam, each color filter mechanism including

means for varying the hue and saturation of one said beam of light, including at least one dichroic filter rotatably movable in a path of the divided beam of light and operable to rotate from a first position substantially parallel to the light rays to a second position substantially perpendicular to the light rays to produce colored light;

means for carrying said colored beams of light along respective paths;

an intensity control for varying the intensity of said divided beams of light; and

a combiner for combining the two colored beams of light from the respective paths into a composite beam.

13. The additive color mixing system of claim 12 wherein a plurality of said dichroic filters are movable by said color changer to intermediate positions between said first and second positions.

15. The additive color mixing system of claim 12, further including a mirror arrangement for coupling the colored light from said color filter mechanism to said combiner.

16. The additive color mixing system of claim 12, wherein said combiner comprises an arrangement of interwoven optical fibers.

17. The additive color mixing system of claim 12, wherein said combiner comprises an arrangement of mirrors and dichroic filters.

18. The additive color mixing system of claim 12, wherein said intensity control is adapted for independently varying the intensity of the divided light beams.

19. The additive color mixing system of claim 12, wherein said dichroic filter is pivotally movable to desired angular orientations with respect to said light rays.

20. The additive color mixing system of claim 12, wherein each color filter mechanism includes multiple dichroic filters which are mechanically interconnected to provide for rotation to the same angles of incidence.

14. The additive color mixing system 12, further including a bundle of optical fibers for coupling the colored light from said color filter mechanisms to said combiner.

21. An additive color mixing system for a light projector, comprising:

a plurality of light sources each for generating a beam of light,

a color changer associated with each said light source for coloring the respective light beam with desired hues, at least one said color changer being adapted for selecting a centerline wavelength hue of an associated light beam from a continuum of centerline wavelength hues so that the selected centerline wavelength and centerline wavelength hues with respect to other colored light beams can be brought together to provide a desired enhanced saturated hue from a range of saturated hues,

an intensity control for varying the intensity of the light beams produced by said light sources; and

a light mixer for mixing the colored light produced by each said color changer to provide a composite colored light beam.

22. The additive color mixing system of claim 21, further including a dichroic color changer having a dichroic filter which is movable with respect to the associated light beam to vary the centerline wavelength thereof.

23. The additive color mixing system of claim 21, further including means for varying the intensity of each light beam to vary the saturation of the color produced by the respective color changer, and for varying the position of a dichroic filter to change the hue of the color produced by the respective color changer beams.

24. The additive color mixing system of claim 22, wherein said color changer includes means for pivoting the dichroic filter to change the angle of incidence with respect to the light rays striking the dichroic filter.

25. A method for generating and mixing colored light, comprising the steps of:

producing a plurality of light beams;

changing the intensity of at least one of the light beams to produce a change in the saturation of a respective resultant colored light beam;

changing the hue of the light beams to alter respective centerline wavelengths thereof by pivoting dichroic filters to alter the incidence angle by which light beams strike the respective filters; and

mixing the colored light beams together to provide a composite light beam having the combined color characteristics of the individual colored light beams.

26. The method of claim 25, further including moving a centerline wavelength characteristic of at least two colored light beams closer together to provide a highly saturated hue of the composite light beam.