CONCAVE PROJECTION SCREEN AND PROCESS OF ITS MANUFACTURE Russian patent published in 1997 - IPC

FIELD: movie and photographic equipment. SUBSTANCE: concave projection screen has layer 1 of material with reflecting surface 2 and assemblage of oblong concave reflecting lenses in the form of part of ellipsoid 3 or cylindrical surface which major axes 5 pass along surface of layer. Depth of layer is 0.5-500.0 $$$. EFFECT: facilitated manufacture, enhanced functional reliability. 3 cl, 5 dwg