Abstract: A time-multiplexed stereoscopic 3d projection system including a beam-splitting element to split the randomly polarized image-beam generated by a single-lens projector into one primary image-beam, possessing a first state of linear polarization, and two secondary image-beams, both possessing a second state of linear polarization. The polarization states are mutually orthogonal. The primary and secondary image-beams recombine to form a complete image on the surface of a polarization-preserving projection-screen. There are polarization modulators that modulate the first and second states of linear polarization between a left and right circular polarization state. There is a contrast enhancement film in the optical-path of the primary or secondary image-beams located between the polarization modulator and the projection-screen.

Abstract: A 3-d projection system including first and second projectors generates left and right eye image beams. There is a first beam-splitting element to split the left-eye image beam into a primary left-eye image beam and two secondary left-eye image-beams and a second beam-splitting element to split the right-eye image beam into a primary right-eye image beam and two secondary right-eye image beams. The primary and secondary image beams have first and second linear polarization states, respectively. There is a first optical quarter waveplate device configured to receive the primary left-eye image beam and two secondary left-eye image beams and to convert their linear polarization states to a first circular polarization orientation. There is a second optical quarter waveplate device configured to convert the primary right-eye image beam and two secondary right-eye image beams to a second circular polarization orientation. The first and second circular polarization orientations are mutually orthogonal.