Polarization compensated stereoscopic projection
View Patent ↗Disclosed embodiments include stereoscopic systems having at least one compensator operable to reduce the sensitivity of polarization control over incidence angle of image source optics and analyzer optics. In an exemplary embodiment, the disclosed compensator is operable to compensate polarization changes induced by optics at either or both the image source subsystem and the analyzer subsystem, in which the polarization changes would be operable to cause leakage at the analyzer subsystem if uncompensated. As such, the disclosed compensators and compensation techniques are operable to reduce leakage at the analyzer subsystem even if the disclosed compensator may be located at the analyzer subsystem.
1. A stereoscopic imaging system, comprising:
an image source subsystem operable to output light of first and second states of polarization (SOP);
an analyzer subsystem operable to substantially block light of the first SOP from traveling along a first path, and to substantially block light of the second SOP from traveling along a second path;
wherein the image source subsystem comprises a first optical element operable to cause a first polarization change on light passing therethrough, and the analyzer subsystem comprises a second optical element operable to cause a second polarization change on light passing therethrough;
wherein the first and second polarization changes, if not compensated, would at least partially cause at least one of a leakage of light of the first SOP along the first path or a leakage of light of the second SOP along the second path; and
wherein the image source subsystem or the analyzer subsystem comprises a compensator configured to at least reduce both the first and second polarization changes.
2. The stereoscopic imaging system of claim 1 , wherein the image source subsystem comprises at least one projector, and the compensator is disposed in the image source subsystem optically following the at least one projector.
3. The stereoscopic imaging system of claim 1 , wherein the first and second polarization changes each comprise a geometric rotation, and the compensator comprises a biaxially stretched retarder operable to substantially correct the geometric rotation.
4. The stereoscopic imaging system of claim 1 , wherein the first and second polarization changes each comprise a geometric rotation, and the compensator comprises a +A-plate and a +C-plate operable to cooperate to substantially correct a combined geometric rotation of the first and second polarization changes.
5. The stereoscopic imaging system of claim 1 , wherein the first and second polarization changes each comprise a −C-plate type retardation, and the compensator comprises at least one +C-plate operable to substantially correct a combined −C-plate type retardation of the first and second polarization changes.
6. The stereoscopic imaging system of claim 1 , wherein the compensator is optimized for performance measurements for an ideal viewer centered horizontally with respect to screen center.
7. The stereoscopic imaging system of claim 6 , wherein the compensator is optimized for baseline acceptable performance measurements for viewers in extreme locations of a viewing space with respect to the location of the ideal viewer.
8. The stereoscopic imaging system of claim 6 , wherein the compensator is optimized for maximizing performance measurements for as large a population surrounding the ideal viewer as possible.
9. The stereoscopic imaging system of claim 1 , wherein the image source subsystem comprises a sequentially or spatially modulated LCD panel operable to output light of the first and second states of polarization.