Stereoscopic projection systems and methods for employing spatial multiplexing at an intermediate image plane
View Patent ↗Proposed are various embodiments of projection systems that generally provide stereoscopic images. The projection systems act to split a spatially separated image in a stereoscopic image frame and superimpose the left- and right-eye images on a projection screen with orthogonal polarization states. The embodiments are generally well suited to liquid crystal polarization based projection systems and may use advanced polarization control.
1. A stereoscopic projection system, comprising:
an anamorphic relay lens subsystem operable to receive a stereoscopic image frame from an input light path and convey the stereoscopic image frame to an intermediate image plane, the stereoscopic image frame having first image area light and second image area light;
a light splitting subsystem operable to receive the stereoscopic image frame at the intermediate image plane and split the first and second image area light, to direct the first image area light on a first image light path, and to direct the second image area light on a second image light path; and
a projection lens subsystem operable to direct the first and second image area light toward a screen.
2. The stereoscopic projection system of claim 1 , wherein the anamorphic relay lens subsystem comprises an anamorphic relay lens.
3. The stereoscopic projection system of claim 1 , wherein the anamorphic relay lens subsystem comprises a relay lens and an anamorphic component.
4. The stereoscopic projection system of claim 3 , wherein the anamorphic component comprises a Bravais system.
5. The stereoscopic projection system of claim 1 , wherein the projection lens subsystem comprises a first and a second lens;
wherein the first lens is operable to focus the first image area light on a first output image path toward a screen;
wherein the second lens is operable to focus the second image area light on a second output image path toward the screen; and
wherein the first and second image area light substantially overlap on the screen.
6. The stereoscopic projection system of claim 1 , further comprising a liquid crystal (LC) projector.
7. The stereoscopic projection system of claim 6 , further comprising a matched waveplate located on the input light path before the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within the LC projector.
8. The stereoscopic projection system of claim 6 , further comprising a matched waveplate located on the intermediate light path after the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within the LC projector.
9. The stereoscopic projection system of claim 1 , further comprising:
a wavelength selective polarization filter located on one of the input light path and intermediate light path;
a first linear polarizer and a first quarter wave plate located on the first output light path; and
a second linear polarizer and a second quarter wave plate located on the second output light path,
wherein the first quarter wave plate is oriented at +45 degrees to the first linear polarizer, wherein the second quarter wave plate is oriented at −45 degrees to the second linear polarizer such that the first and second quarter wave plates are orthogonal.
10. The stereoscopic projection system of claim 1 , further comprising an achromatic rotator located on one of the first and the second output light paths.
11. The stereoscopic projection system of claim 1 , wherein the light splitting subsystem comprises a first and a second pair of mirrors.
12. The stereoscopic projection system of claim 1 , wherein the light splitting subsystem comprises a first and a second total internal reflection prism.
13. The stereoscopic projection system of claim 12 , wherein the light splitting subsystem further comprises a first and a second polarization transformer.
14. The stereoscopic projection system of claim 1 , wherein the light splitting subsystem comprises a polarization transformer and a polarization beam splitter (PBS),
wherein the polarization transformer is operable to transform the polarization state of first image area light at the intermediate image plane prior to entering the PBS,
wherein the polarization state of the second image area light is not transformed.
15. The stereoscopic projection system of claim 1 , wherein the first area image light and the second area image light comprise one of a video game stereoscopic image and a motion picture stereoscopic image.
16. The stereoscopic projection system of claim 1 , wherein the projection lens subsystem comprises a polarization beam splitter (PBS) and a single projection lens;
wherein the PBS is operable to combine the first and second image area light;
wherein the single projection lens is operable to project the combined first and second image area light toward the screen; and
wherein the first and second image area light substantially overlap on the screen.
17. A stereoscopic projection system, comprising:
a relay lens subsystem operable to receive a stereoscopic image frame from an input light path and convey the stereoscopic image frame to an intermediate image plane, the stereoscopic image frame having first image area light and second image area light;
a light splitting subsystem operable to receive the stereoscopic image frame at the intermediate image plane and split the first and second image area light, to direct the first image area light on a first image light path, and to direct the second image area light on a second image light path;
a first lens operable to direct the first image area light on a first output image path toward a screen;
a second lens operable to direct the second image area light on a second output image path toward the screen;
a first anamorphic afocal converter located on the first output image path; and
a second anamorphic afocal converter located on the second output image path.
18. The stereoscopic projection system of claim 17 , further comprising a matched waveplate located on the input light path before the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within a projector.
19. The stereoscopic projection system of claim 17 , further comprising a matched waveplate located on the intermediate light path after the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within a projector.
20. The stereoscopic projection system of claim 17 , further comprising:
a first quarter wave plate positioned adjacent to the first lens; and
a second quarter wave plate positioned adjacent to the second lens.
21. A stereoscopic projection system, comprising:
a relay lens subsystem operable to receive a stereoscopic image frame from an input light path and convey the stereoscopic image frame to an intermediate image plane, the stereoscopic image frame having first image area light and second image area light;
a light splitting subsystem operable to receive the stereoscopic image frame at the intermediate image plane and split the first and second image area light, to direct the first image area light on a first image light path, and to direct the second image area light on a second image light path; and
an anamorphic projection lens subsystem operable to direct the first and second image area light toward a screen.
22. The stereoscopic projection system of claim 21 , wherein the anamorphic projection lens subsystem comprises an anamorphic projection lens.
23. The stereoscopic projection system of claim 21 , wherein the anamorphic projection lens subsystem comprises a projection lens and an anamorphic converter.
24. The stereoscopic projection system of claim 23 , wherein the anamorphic converter comprises an anamorphic converter attachment to the projection lens.
25. The stereoscopic projection system of claim 23 , wherein the anamorphic converter comprises an anamorphic afocal converter.
26. The stereoscopic projection system of claim 21 , wherein the anamorphic projection lens subsystem comprises a projection lens and Bravais system.
27. The stereoscopic projection system of claim 21 , wherein the anamorphic projection lens subsystem comprises a first and a second anamorphic projection lens subsystem;
wherein the first anamorphic projection lens subsystem is operable to focus the first image area light on a first output image path toward a screen;
wherein the second anamorphic projection lens subsystem is operable to focus the second image area light on a second output image path toward the screen; and
wherein the first and second image area light substantially overlap on the screen.
28. The stereoscopic projection system of claim 27 , wherein the first and second anamorphic projection lens subsystems each comprise an anamorphic projection lens.
29. The stereoscopic projection system of claim 27 , wherein the first and second anamorphic projection lens subsystems each comprise a projection lens and an anamorphic converter.