Journal of the Society of Motion Picture Engineers (1930-1949)

July, 1931] PATENT ABSTRACTS 141 produce that contrasting light effect which will relieve optical strain upon t heobservers. 1,802,595. Multiple Sound Tracks for Obtaining Long Records on Normal Length Film. LEE DEFOREST. Assignor to DeForest Phonofilm Corporation. April 28, 1931. A mechanism for reproducing sound from film where the film has a plurality of longitudinally extending sound records thereon. A light slit is provided in a block which is shif table laterally of the film. The film is driven past the slit block successively in opposite directions and the slit block moved to align the same successively with each sound record on the film upon each reversal in direction of the film. In this way a sound program of extended length is obtained from a film record of normal length. 1,802,747. Kerr Cell Employing a Plurality of Elements and Electrostatic Fields. V. K. ZWORYKIN. Assigned to Westinghouse Electric & Manufacturing Company. April 28, 1931. A Kerr cell comprising a plurality of linear electrodes, interpositioned between the light source and a light-sensitive film. A sound modulating circuit has the output thereof connected to the electrodes of the Kerr cell and controls the operation of the Kerr cell for analyzing polarized light directed through the cell upon a light-sensitive film. The invention consists in subdividing each electrode of a Kerr cell into a plurality of electrode elements, and in so intercalating these elements that the incident light is subjected to a plurality of electrostatic fields during its travel therebetween in of being subjected to but a single field as in Kerr cells that were known to the prior art. In addition, a linear source of light is so related with the Kerr cell that each portion of the light beam is subjected to a separate electrostatic field. 1,802,530. Method and Device for Producing Color Films. OTTO PILNY AND ALEX PILNY. April 28, 1931. Color film which is produced from two series of component color pictures arranged in close proximity on one film projected by means of a single source of light utilizing a mechanical separation of the beams, while avoiding any crossings of the path of the beams, to the front and back of a second film sensitized on both sides so that the two pictures coincide with each other. The first film carries closely adjacent pairs of correlated pictures through which parallel rays are projected, and separately and simultaneously focused to different optical reflecting systems and reflected upon opposite sensitized surfaces of a second film in registering positions of the same height as the pictures on the first film. Both films are then moved step by step the same distance in the same direction for the normal picture height. The second film is thus prepared from the two pictures carried by the first film. 1.802.802. Gyroscopic Scanning Device for Vertical and Horizontal Scanning. F. E. BEST. April 28, 1931. Scanning means which includes a high-speed rotary reflector having a relatively great gyroscopic action. The apparatus while in operation can be moved freely in any plane that does not involve a tilting of the axis of rotation of the rapidly rotating part, thereby permitting scanning operations in both vertical and horizontal planes. 1.802.803. Device for Transmitting Vision Electrically. F. E. BEST. 28, 1931. Television system in which two rotatable disks are each provided with a plurality of slots which are adapted to reverse as the disks are rotated to progressively permit the passage of contiguous lines of light. One of the disks is illuminated in proportion to received electromagnetic impulses in close