GB556320A - Improvements in television system - Google Patents

Abstract

556,320. Television. HOWELLS, J. N. M. March 27, 1942, No. 4085. [Classes 39 (i) and 40 (iii)] A television transmitter comprises a plurality of photo-responsive elements P, Fig. 1, disposed along a line SS, each element connected to a circuit 28, Fig. 4, tuned to an individual characteristic frequency modulated by the illumination of the element, and all the circuits 28 being connected to an oscillator 42, Fig. 7, leading to the signal transmitter. The individual circuits each comprise a coil 28 connected to a condenser 25 and the element P. These parts are in laminar formation and are packed side by side in a casing 20 with a reaction coil 35 common to all the circuits and forming part of the circuit of the oscillator 42. The scanning operation may be performed by three such sets 20 mounted on a rotating disc 52, Fig. 8, associated with a lens 51 for the picture 50 and with a commutator 53 for connecting the three sets in succession. The line of elements of the three sets may be covered by light filters for colour transmission. The receiver comprises a similar arrangement of circuits connected to elements in a line and mounted on a synchronously rotating disc, but the elements are lightemissive elements L, Fig. 14. These elements may each comprise a pair of terminals 71, 72 behind a window 62' in a space containing a suitable gas emitting white light when an alternating voltage is applied to the terminals. Or, the window 62' may be coated with a layer which becomes fluorescent when voltages are applied to the terminals.