STEREOSCOPIC 3D PROJECTION SYSTEM WITH HIGH LEVEL OF OPTICAL LIGHT EFFICIENCY Russian patent published in 2019 - IPC G02B27/26 

FIELD: physics.

SUBSTANCE: invention relates to stereoscopic projection systems. System for stereoscopic 3D projection with time multiplexing includes a beam division element for dividing an arbitrarily polarized image forming beam generated by the projector with one lens, on one primary image forming beam, having a first linear polarization state, and two secondary image formation beams, both having a second state of linear polarization. Polarization states are orthogonal to each other. Primary and secondary image formation beams are recombined to form a full image on the surface of the projection screen which preserves polarization. System includes polarization modulators which modulate the first and second linear polarization states between the left and right circular polarization states. Contrast enhancement film is placed on the optical path of the primary or secondary image formation beam between the polarization modulator and a projection screen and comprises a stack of at least three uniaxial stretched delay films which disrupt the circular polarization state of said image formation beams and have a delay value in the plane substantially equal to 140 nm, 270 nm or 540 nm.

EFFECT: invention provides high level of optical light efficiency.

26 cl, 4 dwg