Combining P and S rays for bright stereoscopic projection

• US 20110096295A1
• Filed: 12/27/2010
• Published: 04/28/2011
• Est. Priority Date: 10/18/2006
• Status: Active Grant

• Current Assignee: RealD Incorporated
• Original Assignee: RealD Incorporated
• Inventors: Cowan, Matt, Carollo, Jerry, Lipton, Lenny
• Granted Patent: US 7,959,296 B2
• Time in Patent Office: Days
• US Class Current: 353/8
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G03B 21/28 Reflectors in projection beam in illumination beam G03B21/2066
• CPC Class Codes: G03B 35/26 using polarised or coloured light separating different viewpoint images

Abstract

A multiple path stereoscopic projection system is disclosed. The system comprises a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path and a secondary path, a reflector in the secondary path, and a polarization modulator or polarization modulator arrangement positioned in the primary path and configured to modulate the primary path of light energy. A polarization modulator may be included within the secondary path, a retarder may be used, and optional devices that may be successfully employed in the system include elements to substantially optically superimpose light energy transmission between paths and cleanup polarizers. The projection system can enhance the brightness of stereoscopic images perceived by a viewer. Static polarizer dual projection implementations free of polarization modulators are also provided.

Claims

1. An apparatus for projecting stereoscopic images, comprising:

a polarizing splitting element configured to receive image light energy and split the image light energy received into a primary path of light energy transmitted along a primary path and a secondary path of light energy transmitted along a secondary path;

a reflector configured to receive path light energy from one of primary path energy and secondary path light energy and said path light energy toward a surface; and

a first polarization modulator positioned in the primary path and configured to receive the primary path of light energy, modulate the primary path of light energy into primary path modulated light energy, and transmit primary path modulated light energy toward the surface.

2. The apparatus of claim 1, further comprising a retarder configured to receive the secondary path of light energy and transmit retarded secondary path light energy.

3. The apparatus of claim 1, wherein the surface comprises a projection screen.

4. The apparatus of claim 1, wherein reflected secondary path light energy passes is directed through a portion of the first polarization modulator.

5. The apparatus of claim 1, further comprising a second polarization modulator configured to receive secondary path light energy, modulate the secondary path light energy, and transmit modulated secondary path light energy toward the reflector

6. The apparatus of claim 1, wherein the reflector comprises a deformable mirror configured to substantially optically superimpose light energy transmission between the second path and the first path.

7. The apparatus of claim 1, further comprising a cleanup polarizer positioned in the secondary path.

8. The apparatus of claim 7, further comprising a cleanup polarizer positioned in the primary path.

9. The apparatus of claim 1, wherein the polarization modulator comprises a push-pull modulator.

10. The apparatus of claim 1, wherein the polarizing splitting element comprises one from a group comprising:

a polarizing beamsplitter;

a wire grid polarizer; and

a MacNeille prism.

11. The apparatus of claim 1, further comprising a primary path element arrangement configured to substantially optically superimpose light energy transmission between the second path and the first path.

12. The apparatus of claim 11, wherein the primary path element arrangement comprises:

a plurality of reflective surfaces; and

a retarder.

13. The apparatus of claim 2, wherein the retarder is a half wave retarder.

14. The apparatus of claim 1, further comprising a projection lens receiving light energy from an imaging surface and transmitting the image light energy toward the splitting element.

15. The apparatus of claim 9, wherein the push pull modulator comprises an arrangement of two pi-cells having axes crossed and driven out of phase.

16. A method of projecting stereoscopic images, comprising:

receiving image light energy;

splitting the image light energy received into a primary path of light energy transmitted along a primary path and a secondary path of light energy transmitted along a secondary path;

receiving secondary path light energy and directing reflected secondary path light energy toward a surface; and

modulating the primary path of light energy into primary path modulated light energy, and transmitting primary path modulated light energy toward the surface.

17. An apparatus for projecting stereoscopic images, comprising:

a splitter configured to split the image received into a primary path and a secondary path;

a reflector positioned in the secondary path configured to reflect secondary path light energy; and

a polarization modulator arrangement comprising at least one polarization modulator positioned in the primary path and configured to modulate the primary path of light energy;

wherein the polarization modulator arrangement additionally modulates secondary path light energy.

18. The apparatus of claim 17, further comprising a retarder positioned in one of the primary path and the secondary path and configured to rotate light energy received.

19. The apparatus of claim 17, wherein the polarization modulator arrangement comprises two polarization modulators, one in the primary path and one in the secondary path.

20. The apparatus of claim 17, wherein the polarization modulator arrangement comprises a single polarization modulator that modulates light energy in the primary path and the secondary path.