GB300235A - Improvements in methods and means for the screen projection of acoustic cinematographic films with continuous travel - Google Patents

Abstract

300,235. Soc. des Etablissements Gaumont. Nov. 9, 1927, [Convention date]. Optical records and apparatus. - Talking- picture films are'constructed with a sound record which is reproduced by radiations, such as ultraviolet. outside, the range of the visible radiations which reproduce the picture, a beam from a single source emitting both the visible and the special radiations being employed for picture projection and sound reproduction. The sound record may be superposed on the picture record, which moves continuously during projection. Fig. 1 shows a reproducing apparatus for the talking- picture film, employing as a single source of radiations carbons with a mineral core. Radiations frorn this source A pass through a condenser C, through the image i of the superposed records on the film F, and through a lens O<1> and inclined glass plate R on to the picture screen E. A small portion of the radiations falling on the plate R is reflected through a lens O<2> and a selecting screen E<1> on to a photo-electric cell. The screen E' may be a Wood screen, consisting of a nickel oxide glass, which arrests all radiations below 3650‹ A. but permits the cell to be affected by radiations above this wave length, which have been influenced by the sound record on the film F. In a modification, the glass plate R is replaced by a quartz plate silvered on the side adjacent the film. This plate reflects the greater part of the radiations through a lens on to a picture screen but permits the passage of ultra-violet radiations which, influenced by the sound record, pass through the plate and a lens and slit on to a photo electric cell. The Specification as open to inspection under Sect. 91 (3) (a) states that the two classes of radiations may be provided by different sources arranged on the same optical axis, and refers to Specification 297,733 for the preparation of the record. This subject-matter does not appear in the Specification as accepted.