GB297407A - Talking motion picture production - Google Patents

Abstract

297,407. Beatty, W. E., (Bell Telephone Laboratories, Inc.). June 21, 1927. Records, optical; records, combined phonographic and kinematographic.-Relates to the production of combined sound and motion picture records. According to the invention, in recording, the sound and picture records are made photographically at the same time, with the sound record film running at a greater speed than the picturefilm, in order to obtain greater definition of the high frequencies, and the same speed ratio as is maintained in the running of the sound and picture negatives is maintained when they are being simultaneously printed to make a combined positive on a single film. An optical system, including one or more cylindrical lenses, may be used to reduce the width of the sound record on the positive as compared with that on the negative. The Figure shows apparatus for printing upon a sensitized film 12 a motion picture (record 13 and a sound record 20 which have been obtained by recording-apparatus in which the speed of the sound film is twice that off the picture film The sound record, in the form of transverse strice of various densities, is of greater width on the negative than is permissible on the positive, the space available for the sound record on the margin the picture film being small, and the necessary reduction in width in printing is obtained by using an optical system 27 - - 29, a cylindrical lens 29<1> also being used. The disadvantageous effect of the coarse granular structure of the negative film is thus eliminated. The films 12, 18, in contact with each other, pass downward over sprocket wheels 18, 18<1>, the film 12 being driven by a sprocket 24 operated by a shaft 32. This shaft is driven by a wheel 31 which also, through 2 : 1 gearing, moves the film 20 at twice the speed of the films 12, 13. Light, from a source 19, passing through an adjustable apercture 15, prints the pictures upon the film 12, the associated sound record being simultaneously printed at a different position in the length of the film, by light from a source 25 passing through the negative sound film 20, the optical system 27 - - 29<1>, and a slit 17.