Apparatus for converting motion picture projectors for stereo display

Claim 1

Apparatus for producing stereo motion picture displays comprising in combination with a single film motion picture projector, a projection lens for said projector, a single film strip having a series of image frames with a pair of corresponding stereo images in each frame, an opaque band extending across the center of each frame for separating the images of the stereo pair along their abutting margins, said opaque hand having a width of 10 to 12 percent of the image frame, a hollow housing, means to secure one end of the housing to the projection lens, a prism assembly carried by the opposite end of the housing, said prism assembly comprising a first and a second angularly adjustable prism, said first and second prisms abutting each other at their inner edges, a light polarizer laminated to each of said prisms, the plane of polarization of the polarizer of the first prism being disposed normal to the plane of polarization of the polarizer of the second prism, said prism abutment being parallel to and in optical alignment with but spaced from the opaque band between the stereo pairs when they are being projected, said prisms each receiving one of the images of the stereo pair in each of the image frames and directing them in overlapped relationship together with the opaque band upon a screen with the plane of polarization of the two images of a stero pair being normal to each other and the opaque band at opposite edges of the screen.