GB495394A - Improvements in or relating to television or like transmitting installations - Google Patents

Abstract

495,394. Television. TELEFUNKEN GES. FUR DRAHTLOSE TELEGRAPHIE. May 11, 1937, No. 13447. Convention date, May 12, 1936. Addition to 450,303. [Class 40 (iii)] Signals from a main transmitter are received at a local transmitter and the synchronizing impulses separated and utilized to synchronize a television camera whose signals are transmitted to the main transmitter for broadcasting. The synchronizing signals H1 ... H5, Fig. 1, originally transmitted, arrive at the local transmitter with a delay a, Fig. 2. They are further delayed by a period b, Fig. 3, so that the local transmitter radiates a signal as shown in Fig. 4 and the delay produced in transmission to the main transmitter results in the signal of Fig. 5 reaching the main transmitter. The period a+b+a (i.e. the overall delay) should equal one or more whole line periods. The framing impulses V, Fig. 1, are not subjected to the delay b; the main transmitter is so arranged as not to radiate the picture signal following H"3, Fig. 3. The delay b may be produced by applying the impulses to a sawtooth generator arranged to give an impulse only when the saw-tooth has reached a predetermined amplitude ; alternatively, a multivibrator may be used, the impulses H<1>1 ... being applied to one discharge path and the impulses H<11>1 ... occurring on the anode of the other discharge path.