GB445834A - Improvements in or relating to television systems - Google Patents

Abstract

445,834. Television. COSSOR, Ltd., A. C., Highbury Grove, London.-(Assignees of Ardenne, Baron M. von; 19, Jungfernstieg, Lichterfelde, Berlin) July 3, 1934, No. 19605. Void [Abridged as open to inspection under Sect 91 of the Acts, Jan. 18, 1935]. [Class 40 (iii)] In a television system employing velocitymodulated scanning the output from the photo-cell amplifier at the transmitter is utilized as the television signal and is transmitted to the receiver where it is used to modulate the deflecting potentials applied to a scanning device for the purpose of reproducing at the receiver the movements of the scanning spot at the transmitter. The scanning spot on the screen of the tube 1 is focused on a picture 3 which is to be transmitted and behind which is placed a photo-electric cell and amplifier 4 the output of which is fed to the transmitter 10 and to the circuits 5, 7 where the deflecting potentials are modulated by the picture signals. At the receiver the deflecting potentials produced by the timing circuits 13, 14 are modulated by the picture signals and are applied to the pairs of plates 12, 15 to reproduce on the screen of the cathode-ray tube 17 the varying velocity of the beam at the transmitter. The timing circuits 13, 14 are maintained in synchronism with the corresponding circuits 5, 7 at the transmitter by impulses transmitted at the end of each line and picture. The receiving apparatus may be utilized in a system with intensity modulation of the cathode beam by moving a switch 19 to its upper position in which the picture signals are applied to the control grid 16 of the tube 17, the timing circuits 13, 14 controlled by the synchronizing impulses effecting the movement of the beam.