Projection illumination system with tunnel integrator and field lens

• US 20050140940A1
• Filed: 12/23/2004
• Published: 06/30/2005
• Est. Priority Date: 04/11/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Eckhardt, Stephen K.
• Granted Patent: US 7,152,981 B2
• Time in Patent Office: Days
• US Class Current: 353/102
• 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
• 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
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

A projector illumination system includes a tunnel integrator incorporated with a field lens at its output end. One advantage of using the field lens is to form an image of the entrance end of the tunnel integrator at the secondary stop of the illumination system when combined with other relay and/or imager field lenses in the illumination system. This reduces vignetting, resulting in an increased uniformity of illumination, and increased light throughput.

Claims

1. An optical system, comprising:

a tunnel integrator having an input end and an output end; and

an integrator field lens disposed at the output end of the tunnel integrator, the integrator field lens having a negative optical power.

2. A system as recited in claim 1, further comprising an aperture stop disposed on an optical path from the integrator field lens, the input end of the tunnel integrator being imaged at the aperture stop.

3. A system as recited in claim 2, further comprising a relay lens system disposed on the optical path from the integrator field lens, the relay lens system comprising at least a first lens, the first lens being disposed on the optical path between the integrator field lens and the aperture stop.

4. A system as recited in claim 3, further comprising at least one imaging device on the optical path from the integrator field lens, the output end of the tunnel integrator being imaged by the relay lens system at the at least one imaging device.

5. A system as recited in claim 4, further comprising a projection lens unit disposed to project image light from the at least one imaging device.

6. A system as recited in claim 5, wherein the aperture stop is a stop of the projection lens unit.

7. A system as recited in claim 4, wherein the at least one imaging device comprises at least one of a transmissive liquid crystal imaging device, a reflective liquid crystal imaging device and an array of mirrors.

8. A system as recited in claim 4, wherein the at least one imaging device comprises at least two imaging devices, image light from the at least two imaging devices being combined to form a single image beam.

9. A system as recited in claim 1, further comprising a light source capable of generating illumination light and arranged to direct the illumination light into the input end of the tunnel integrator.

10. An optical system, comprising:

a tunnel integrator having an input end and an output end;

an integrator field lens disposed at the output end of the tunnel integrator;

a relay lens system disposed on an optical path from the integrator field lens, the relay lens system comprising at least a first lens; and

and a first aperture stop on the optical path, the first lens of the relay lens system being disposed on the optical path between the integrator field lens and the aperture stop.

11. A system as recited in claim 10, wherein the input end of the tunnel integrator is imaged at the aperture stop.

12. A system as recited in claim 10, further comprising at least one imaging device on the optical path from the integrator field lens.

13. A system as recited in claim 12, wherein the at least one imaging device comprises at least two imaging devices, image light from the at least two imaging devices being combined to form a single image beam.

14. A system as recited in claim 12, further comprising a projection lens unit disposed to project image light from the at least one imaging device.

15. A system as recited in claim 14, wherein the first aperture stop is a stop of the projection lens unit.

16. A system as recited in claim 10, further comprising a light source capable of generating illumination light directed into the input end of the tunnel integrator.

17. A system as recited in claim 10, wherein the integrator field lens is a negative lens.

18. An optical system, comprising:

a tunnel integrator having an input end and an output end;

an integrator field lens disposed at the output end of the tunnel integrator;

a relay lens system disposed on an optical path from the integrator field lens, the relay lens system comprising at least a first relay lens and forming an image of the output end of the tunnel integrator;

a first aperture stop disposed on an optical path from the integrator field lens, the input end of the tunnel integrator being imaged at the first aperture stop.

19. A system as recited in claim 18, further comprising at least one imager device, the relay lens system forming the image of the output end of the tunnel integrator at the at least one imager device.

20. A system as recited in claim 19, further comprising a projection lens unit disposed to project image light from the at least one imager device.

21. A system as recited in claim 20, wherein the first aperture stop is a stop of the projection lens unit.

22. A system as recited in claim 19, wherein the at least one imager device comprises at least two imager devices, image light from the at least two imager devices being combined to form a single image beam.

23. A system as recited in claim 18, further comprising a light source capable of generating illumination light directed onto the input end of the tunnel integrator.

24. A system as recited in claim 18, wherein the integrator field lens is negative.