GB441030A - Improvements in or relating to films bearing photographic sound records - Google Patents

Abstract

441,030. Duplicating photographic sound-records. FILM OZAPHANE, 5, Avenue Percier, Paris. Sept. 22, 1934, No. 27263. Convention date, Oct. 14, 1933. [Class 40 (ii)] [See also Group XX] A number of sound-films are obtained from a single film bearing one or more variable density photographic records by dividing the latter up longitudinally in such a manner that the single sound track portion or each such portion on the film which is divided is cut into strips, each of which constitutes a separate sound film. The film so divided is preferably a regenerated cellulose film, sensitized by a mixture of a diazo compound and a phenol and developed in an ammoniacal atmosphere after being printed photographically from a record on a film bearing a wide track ; alternatively, the printing of the original wide record may be effected photo-mechanically. The whole process is preferably carried out as follows. Starting with a 35 mm. sensitized celluloid film, a single sound track of 24 mm. width is recorded thereon either by a direct electro-optical process or by photographic copying with enlargement from a record of normal width. The wide record thus obtained is printed on to a sensitized regenerated cellulose film, and the print is then divided longitudinally into narrow bands bearing identical records, e.g. twelve 2 mm. bands or twenty-four 1 mm. bands. The Figure shows an apparatus suitable for reproducing sound from a narrow film obtained as described. The film G passes over two flanged rollers A, B over which it is drawn under slight tension by a uniformly-driven rubbered drum F. Between the rollers A, B, the reproducing light beam, acting on a photoelectric cell K, is transmitted through the film by suitable means, such as the optical system E ; or light illuminating a part of the film may be projected on to a slit arranged in front of the cell. The Specification as open to inspection under Sect. 91 states also that "instead of a single variable density record of large width, there might also be reproduced on the celluloid film serving as a matrix, a very large number of very narrow and adjacent identical records of variable or fixed density. Each elementary phonofilm when cut up would then carry a certain number of these elementary recordings." This subject-matter does not appear in the Specification as accepted.