GB368764A - Improvements in or relating to combined sound reproducing and picture projecting apparatus - Google Patents

Abstract

368,764. Kinematograph projectors. ELECTRICAL RESEARCH PRODUCTS, Inc., 195, Broadway, New York, U.S.A.- (Assignees of Glunt, O. M. ; 384, Park Avenue, Rutherford, and Gent, E. W. ; 251, Speedwell Avenue, Morristown, both in New Jersey, U.S.A.) Dec. 10, 1930, No. 37256. Convention date, Dec. 10, 1929. [Class 97 (i).] In continuous-feed apparatus the film 11 bearing the picture and sound records is drawn by a sprocket 29 over rollers 45 .. 49, Fig. 2, and passes through a combined sound and picture gate comprising a pressure foot 16 and film guides 17, 17<1>, Fig. 1. The projection beam from a lamp housing 12 passes through a picture framing aperture 19, and is reflected by a lens prism 20 and a prism 33 on opposite sides of the film. Optical compensation is effected by a refracting system consisting of four plane glass plates 38 .. 41 clamped between spiders 42, 43 mounted on the shaft of the sprocket 2. The optical sound-reproducing means comprises a light source 54 mounted in a housing 55, and a lens tube 56 within which is an optical slit 56 and through which light passes to the sound record track on the film from whence it is reflected by a prism 65 to fall on a photo-electric cell 64 located within a housing 57. The optical axis of the lens tube 56 is placed in line with that of the picture framing aperture 19 and in juxtaposition with the picture lens prism 20. To prevent the diffusing of light irregularly refracted through the prism 20, its rear face is opaque.