GB405289A - Method of and system for producing copies of an original such as a talking picture record - Google Patents

Abstract

405,289. Duplicating sound films. RADIO CORPORATION OF AMERICA, 570, Lexington Avenue, New York, U.S.A. July 29, 1932, No. 21489. Convention date, Jan. 13. [Class 40 (ii).] Copies of two sets of impressions disposed on a common carrier or on separate carriers are produced on a common carrier by simultaneously copying one set photographically with magnification other than unity, and the other set electro-optically. As shown, the combined sound and picture film 1 is fed through the picture gate 4 by an intermittent sprocket 5, and through the sound gate 7 at a uniform speed by a sprocket 8. The film 11 on which the copies are to be made is fed intermittently through the picture gate 14 by a sprocket 15 and through the sound gate 17 by a sprocket 18. The lamp 21, condenser 22, and projection lens 23 produce a reduced copy of the picture frame in the gate 4 on the film 11. The lamp 24, condenser 25, slit 26 and projection lens 25a produce a beam of light which is modulated by the sound record and which actuates a photoelectric cell 27 connected to an amplifier 28 provided with a gain control 31 and monitoring loud speaker 32. The amplified current actuates the vibrating mirror 29 of a recording galvanometer 30. Light from a lamp 33 passes through a condenser 34, a stop 35, and a lens 36, and is reflected by the mirror 29 through the lens 36 and the projection system 37 to form an image of the sound record on the film 1 upon the film 11 in the sound gate 17. The shaft 41 of the motor 40 carries bevel gears 42, 43 meshing respectively with bevel gears 44, 45 fixed to the shafts 46, 47. Fixed to the shaft 46 are the bevel gears 48, 50, and 52 meshing with bevel gears 54, 56 and 58, the latter being mechanically coupled to the sprocket 3, the intermittent movement 5 and the sprocket 8. Fixed to the shaft 47 are bevel gears 49, 51 and 53 meshing with gears 55, 57 and 59 mechanically coupled to the sprocket 13, the intermittent movement 15, and the sprocket 18. By adjusting the throw of the galvanometer mirror 29 the amplitude of the re-recorded sound on the film 11 may be adjusted to any desired extent.