GB351002A - Improvements in and relating to reproducing apparatus for talking films - Google Patents

Abstract

351,002. Optical sound reproduction; associated working with kinematographs. MIH‡LY, D. VON, 13B, Hildegardstrasse, Wilmersdorf, Berlin. March 14, 1930, No. 8328. Convention date, Aug. 6, 1929. [Class 40 (ii).] In sound-reproducing apparatus wherein an image of the sound record is projected from a film on to a light-sensitive cell L located behind a gap J in a screen E, the screen E, cell L, and circuits associated therewith are constructively and electrically entirely separate from the appliance G for projecting the sound record and the distance of the screen E from the projector G is so great that electrical reactions from the projector upon the cell and its circuits do not occur. As shown, the projector for the sound film comprises a lamp G and lens H mounted so as to be tiltable about an axis X and movable laterally of the film. The size of the gap J may be varied by adjustable plates 1 .. 4 and the gap may be positioned in the screen for receiving projected pictures, or the sound record may be projected laterally and into a room separate from that containing the projector. The cell L, amplifier M, and condenser lens K, and, if desired, the means for adjusting the position and size of the gap J, may be formed as a unit. If the apparatus is used with an intermittent picture projector the feed roller F, Fig. 2, is driven through a centrifugal governor associated with a flywheel Q. The phase displacement between the sound and pictures may be varied by varying the size of the film loop between the sound and picture projectors and for this purpose extra rollers may be used between the roller F and lens D.