Color correction filter for displays

• US 6,231,190 B1
• Filed: 06/22/1999
• Issued: 05/15/2001
• Est. Priority Date: 06/22/1998
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Dewald, D. Scott
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US09/338,166
• Time in Patent Office: 693 Days
• Field of Search: 353/84, 353/81, 353/31, 353/33, 353/34, 353/37, 359/589, 359/590, 359/634, 359/885, 349/5, 349/8, 349/9
• US Class Current: 353/31
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

A method of and system for improving the saturation of the primary colors in a display system. A color correction filter (218) removes unwanted wavelengths from a beam of light. A color splitter (228) separates the beam of light into at least three primary color beams of light. The primary color beams of light are selectively modulated by spatial light modulators (220, 222, 224) before passing through a projection lens (104) which focuses the beams of light onto an image plane.

Claims

1. A display system comprising:

a light source for providing a beam of light along a white light path;

a color splitter on said white light path for separating said beam of light into at least three primary color light beams, each of said at least three primary color light beams comprised of light in a band of wavelengths and traveling along a separate light path;

three light modulators, each of said three light modulators disposed on one of said separate light paths for said three primary color light beams; and

at least one color correction filter on said white light path, said color correction filter for removing a portion of light having a wavelength between said three bands of wavelengths.

2. The display system of claim 1, wherein said color splitter is a color splitting prism assembly.

3. The display system of claim 1, wherein said color splitter is a series of dichroic mirrors.

4. The display system of claim 1, wherein said color splitter separates incident light into red, green, and blue primary color light beams.

5. The display system of claim 1, wherein said at least one color correction filter blocks yellow and blue-green light.

6. The display system of claim 1, wherein said at least one color correction filter is angle-tuned to reduce the effect of manufacturing tolerances.

7. The display system of claim 1, wherein said at least one color correction filter is angle-tuned to alter the pass-band characteristics of the filter.

9. The method of claim 1, said separating step further comprising using a color splitting prism assembly to separate said beam of light.

8. A method of creating an image, said method comprising:

providing a beam of light;

separating said beam of light into at least three primary color light beams each comprised of light in a band of wavelengths and traveling along a separate light path;

filtering said beam of light to remove portions of said beam having wavelengths between said bands of wavelengths comprising said at least three primary color light beams;

selectively modulating each of said at least three primary color light beams; and

focusing said at least three selectively modulated primary color light beams onto an image plane.

10. The method of claim 8, said separating step further comprising using a series of dichroic mirrors to separate said beam of light.

11. The method of claim 8, said separating step comprising the step of separating said beam of light into red, green, and blue primary color light beams.

12. The method of claim 8, said filtering step comprising removing at least some of the yellow and blue-green light from said beam of light.

13. A display system comprising:

a light source for providing a beam of light along a white light path;

a color splitter on said white light path for separating said beam of light into at least three primary color light beams, each of said at least three primary color light beams comprised of light in a band of wavelengths and traveling along a separate light path;

three light modulators, each of said three light modulators disposed on one of said separate light paths for said three primary color light beams; and

at least one color correction filter on said white light path, said color correction filter for removing a portion of light having a wavelength between said three bands of wavelengths, said at least one color correction filter angle-tuned to reduce the effect of manufacturing tolerances.

14. The display system of claim 13, wherein said color splitter is a color splitting prism assembly.

15. The display system of claim 13, wherein said color splitter is a series of dichroic mirrors.

16. The display system of claim 13, wherein said color splitter separates incident light into red, green, and blue primary color light beams.

17. The display system of claim 13, wherein said at least one color correction filter blocks yellow and blue-green light.

18. A display system comprising:

a light source for providing a beam of light along a white light path;

a color splitter on said white light path for separating said beam of light into at least three primary color light beams, each of said at least three primary color light beams comprised of light in a band of wavelengths and traveling along a separate light path;

three light modulators, each of said three light modulators disposed on one of said separate light paths for said three primary color light beams; and

at least one color correction filter on said white light path, said color correction filter for removing a portion of light having a wavelength between said three bands of wavelengths, said at least one color correction filter angle-tuned to alter the pass-band characteristics of the filter.

19. The display system of claim 18, wherein said color splitter is a color splitting prism assembly.

20. The display system of claim 18, wherein said color splitter is a series of dichroic mirrors.

21. The display system of claim 18, wherein said color splitter separates incident light into red, green, and blue primary color light beams.

22. The display system of claim 18, wherein said at least one color correction filter blocks yellow and blue-green light.