Sequential cross-fading color filters and system

• US 5,969,868 A
• Filed: 05/05/1998
• Issued: 10/19/1999
• Est. Priority Date: 09/11/1997
• 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., Hutton, Richard W.
• Primary Examiner(s): HENRY, JON W
• Application Number:
  US09/072,703
• Time in Patent Office: 532 Days
• Field of Search: 359/589, 359/578, 359/577, 359/590, 359/889, 359/890, 359/891, 359/892, 362/268, 362/293
• US Class Current: 359/589
• 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: 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: G02B 26/008 in the form of devices for effecting sequential colour changes, e.g. colour wheels
• CPC Class Codes: G02B 26/023 comprising movable attenuating elements, e.g. neutral density filters
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A color filter plate includes a continuously-variable dichroic filter coating constituting a variable band-pass or variable band-reject filter having a spatially-modulated variable-density pattern formed in the coating, and provides continuously-variable hue and saturation characteristics along separate gradient axes. A color filter mechanism includes a sequential arrangement of rectangular or circular color filters, having continuously-variable band-pass or band-reject filter coatings, mounted in motorized carriages. One mechanism provides two-axis translation of the rectangular color filters while another mechanism provides translation and rotation of the circular color filters. A light projection system comprising a lamp with a reflector and a lens includes a color filter mechanism having sequential, continuously-variable band-pass and band-reject filters supported by motorized carriages mounted in a region where the beam diameter is small.

Claims

1. A color filter mechanism comprising:

a first color filter plate comprising a transparent substrate supporting a first spatially-modulated, continuously-variable interference filter coating on a surface thereof, said coating exhibiting a continuously-variable band pass hue characteristic along a first gradient axis thereof, said first coating exhibiting a continuously-variable saturation characteristic along a second gradient axis thereof;

a first carriage supporting said first color filter plate, said first carriage being movable in two directions relative to said surface;

a second color filter plate comprising a transparent substrate supporting a second spatially-modulated, continuously-variable interference filter coating on a surface thereof, said second coating exhibiting a continuously-variable band reject hue characteristic along a first gradient axis thereof, said coating exhibiting a continuously-variable saturation characteristic along a second gradient axis thereof; and

a second carriage supporting said second color filter plate in a sequential arrangement relative to said first color filter plate, said second carriage being movable in two directions relative to said surface.

2. A color filter mechanism according to claim 1, wherein said first and second coatings comprise multi-layer, thin-film dielectric interference filters, the various layers thereof having a continuously-varied thickness along said first gradient axes.

3. A color filter mechanism according to claim 1, wherein said first and second coatings having a pattern formed therein, said pattern having a continuously-varied density along said second gradient axes.

4. A color filter mechanism according to claim 3, wherein said pattern comprises a stochastic pattern of randomly sized dots.

5. A color filter mechanism according to claim 3, wherein said pattern comprises a stochastic pattern of randomly arranged dots.

6. A color filter mechanism according to claim 3, wherein said pattern comprises a stochastic pattern of randomly sized polygons.

7. A color filter mechanism according to claim 3, wherein said pattern comprises a stochastic pattern of randomly arranged polygons.

8. A color filter mechanism according to claim 1, wherein said first and second color plates are generally rectangular.

9. A color filter mechanism according to claim 5, wherein both of said two directions are linear.

10. A color filter mechanism according to claim 1, wherein said first and second color filter plates are generally circular.

11. A color filter mechanism according to claim 10, wherein one of said directions is linear and the other of said directions is arcuate.

12. A light projection system comprising:

a lamp coupled with a reflector such that when said lamp is energized, said lamp and reflector form a visible light beam focused upon a focal point;

a first color filter plate mounted near said focal point, said first color filter plate comprising a transparent substrate supporting a first spatially-modulated, continuously-variable interference filter coating on a surface thereof, said first coating exhibiting a band pass hue characteristic that varies along a first gradient axis thereof, said coating exhibiting a saturation characteristic that varies along a second gradient axis thereof;

a first carriage supporting said first color filter plate, said first carriage being movable in two directions relative to said surface;

a second color filter plate mounted near said focal point, said color filter plate comprising a transparent substrate supporting a second spatially-modulated, continuously-variable interference filter coating on a surface thereof, said second coating exhibiting a band reject hue characteristic that varies along a first gradient axis thereof, said second coating exhibiting a continuously-variable saturation characteristic along a second gradient axis thereof;

a second carriage supporting said second color filter plate in a sequentially arrangement relative to said first color filter plate, said second carriage being moveable in two directions relative to said surface; and

a lens disposed downstream of said color filter plates.

13. A light projection system according to claim 12, wherein said color filter plates are generally rectangular.

14. A light projection system according to claim 13, wherein said carriages are movable in two linear directions.

15. A light projection system according to claim 12, wherein said color filter plates are generally circular.

16. A light projection system according to claim 15, wherein said color filter plates are movable in a linear direction and an arcuate direction.

17. A light projection system according to claim 12, further comprising a motor drive coupled to each said carriage.