An improvement in screens for focussing and viewing the images projected by photographic, lantern, cinema, and other lenses

摘要

378,270. Focusing devices ; projection screens. STEVENS, F. H., 9, Osborne Villas, St. Michels, Bristol. Nov. 3, 1931, No. 30393. [Classes 97 (i) and 98 (i).] A screen for focusing and viewing the images projected by photographic lantern, kinema and other projecting lenses comprises a converging lens having one side rendered matt or translucent. In place of a single element, two parts may be employed, one being a converging lens and the other having a matt surface. The lens may be plano-convex, meniscus, double convex, cylindrical, piano-cylindrical or crossed cylindrical and may be a single lens or an achromatic or other corrected combination. The screen is made of glass, celluloid or othertransparent material.