Stereoscopic projection systems 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:
a relay lens subsystem operable to receive a stereoscopic image frame from a projection subsystem along 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 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.
3. The stereoscopic projection system of claim 1 , further comprising a liquid crystal (LC) projector.
4. The stereoscopic projection system of claim 3 , 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.
5. The stereoscopic projection system of claim 3 , further comprising a matched waveplate located on an intermediate light path after the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within the LC projector.
6. 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 a first output light path; and
a second linear polarizer and a second quarter wave plate located on a 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.
7. The stereoscopic projection system of claim 1 , further comprising an achromatic rotator located on one of a first and a second output light paths.
8. The stereoscopic projection system of claim 1 , wherein the light splitting subsystem comprises a first and a second pair of mirrors.
9. The stereoscopic projection system of claim 1 , wherein the light splitting subsystem comprises a first and a second total internal reflection prism.
10. The stereoscopic projection system of claim 9 , wherein the light splitting subsystem further comprises a first and a second polarization transformer.
11. 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.
12. 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.
13. 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.
14. The stereoscopic projection system of claim 2 , further comprising an achromatic rotator located on one of the first and the second output light paths, wherein the light splitting subsystem comprises a first and a second pair of mirrors.
15. The stereoscopic projection system of claim 2 , further comprising:
an achromatic rotator located on one of the first and the second output light paths; and
a matched waveplate located on one of the input light path and an intermediate light path;
wherein the light splitting subsystem comprises a first and a second total internal reflection prism.
16. The stereoscopic projection system of claim 2 , further comprising:
a matched waveplate located on one of the input light path and an intermediate light path;
a wavelength selective polarization filter located on one of the input light path and the 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.
17. A method of stereoscopic projection, comprising:
optically receiving a stereoscopic image frame from a projector, the stereoscopic image frame having first image area light and second image area light;
splitting the first image area light from the second image area light;
directing the first image area light on a first light path;
directing the second image area light on a second light path; and
focusing the first and second light path light toward a screen, wherein the first image area light substantially overlaps with the second image area light.
18. The method of claim 17 , wherein the first image area comprises a left eye image and the second image area comprises a right eye image.
19. The method of claim 17 , wherein the left eye image and the right eye image comprises a motion picture stereoscopic image;
wherein the stereoscopic image frame comprises polarized light; and
wherein the projector is a liquid crystal projector.
20. A stereoscopic projection system, comprising:
a relay lens subsystem operable to receive a stereoscopic image frame from a projection subsystem along 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; and
a second lens operable to direct the second image area light on a second output image path toward the screen.
21. The stereoscopic projection system of claim 20 , further comprising:
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.
22. The stereoscopic projection system of claim 21 , 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.
23. The stereoscopic projection system of claim 21 , further comprising a matched waveplate located on an intermediate light path after the relay lens subsystem, the matched waveplate being substantially dispersion matched to a waveplate within a projector.
24. The stereoscopic projection system of claim 21 , 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.
25. 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 wavelength selective polarization filter located on one of the input light path and intermediate light path;
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 projection lens subsystem operable to direct the first and second image area light toward a screen;
a first linear polarizer and a first quarter wave plate located on a first output light path; and
a second linear polarizer and a second quarter wave plate located on a second output light path,
wherein the first quarter wave plate is oriented at +45 degrees to the first linear polarizer and 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.
26. 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 matched waveplate located on one of the input light path and an intermediate light path;
a wavelength selective polarization filter located on one of the input light path and the intermediate light path;
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 projection lens subsystem operable to direct the first and second image area light along a first output light path and a second output image path, respectively, toward a screen;
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 projection lens subsystem comprises a first and a second lens;
wherein the first lens is operable to focus the first image area light on the first output image path toward the screen;
wherein the second lens is operable to focus the second image area light on the second output image path toward the screen;
wherein the first and second image area light substantially overlap on the screen; and
wherein the first quarter wave plate is oriented at +45 degrees to the first linear polarizer and 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.