Polarization conversion systems for stereoscopic projection

A polarization conversion system;

• comprising:
• a polarization beam splitter operable to direct light on first and second light paths;
• a polarization rotation element located on the second light path;
• a reflector element located on the second light path;
• a polarization switch located on the first light path and on the second light path after the reflector element, wherein the reflector element is operable to direct the second light path toward substantially similar locations on a projection screen as the first light path, and wherein the polarization switch comprises first and second polarization switch panels, the first polarization switch panel receiving light from the first light path, and the second polarization switch panel receiving light from the second light path;
• and
• a telephoto lens pair located on the first light path.

A projection system utilizing polarized light for encoding stereoscopic images, comprising:

• a projector comprising a projection lens operable to output randomly-polarized light;
• a polarization conversion system optically coupled to the projection lens, comprising:
• a polarization beam splitter operable to direct light on first and second light paths;
• a polarization rotation element located on the second light path;
• a reflector element located on the second light path;
• a polarization switch located on the first light path and on the second light path, wherein the first light path forms an image on a projection screen, and wherein the reflector element directs light on the second light path toward the projection screen, and further wherein the polarization switch comprises first and second polarization switch panels, the first polarization switch panel receiving light from the first light path, and the second polarization switch panel receiving light from the second light path;
• and
• a telephoto lens pair located on the first light path.

A method for stereoscopic image projection, comprising:

• receiving randomly-polarized light from a projector;
• directing first state of polarization (SOP) light on a first light path;
• directing second SOP light on a second light path;
• transforming the second SOP light on the second light path to first SOP light;
• selectively translating the first SOP light on both light paths to one of a first output SOP and a second output SOP;
• and
• wherein the first SOP light passes through a telephoto lens pair located on the first light path.