GB672012A - Improvements in and relating to stereoscopic kinematography and photography - Google Patents

Abstract

672,012. Stereoscopic apparatus. DUDLEY, L. P. C. J. Oct. 14, 1948 [Oct. 14, 1947], No. 650/51. Divided out of 671,916. Class 97 (i). Apparatus for projecting superposed images from a stereoscopic pair of pictures disposed in vertical or horizontal alignment, comprises a projector having a single objective, optical means for causing the projected images of said pictures to be superposed on a projection screen, said optical means being disposed sufficiently far in advance of the projection lens to prevent the formation on said screen of objectionable side images, and filters disposed in the film gate or adjacent to the optical means for imparting to the light rays from the respective pictures of each stereoscopic pair characteristics which enable the superposed images to be resolved upon being viewed through appropriate resolving spectacles. As shown in Fig. 6, a film having left and right-eye images L1, R1 disposed thereon as in Fig. 3 is fed through the film gate of a projector and light therefrom passes through the projection lens 7, polarizers 8, 10 and a bi-prism 9, 11 on to a screen 12. Adjacent the latter is a mask (not shown) for obscuring the light from that part of the film 3 which does not bear the pictures. Polarizers 8, 10 may be replaced by complementary colour filters and instead of passing through a bi-prism, the light may be reflected vertically by a plane mirror on to two plane mirrors which are hinged together so that the angle therebetween may be varied and which reflect the light in a direction substantially parallel to that in which it leaves the lens 7. A bi-prism and filters 8. 10 may be carried by a support pivoted between brackets secured to the base of the projector so that they can be lowered out of the light path when it is desired to project non-stereoscopic pictures. Specifications 505,800 and 671,916 are referred to.