GB917728A - Reproduction systems for magnetic records of television signals - Google Patents

Abstract

917,728. Television. TOKYO SHIBAURA ELECTRIC CO. Ltd. Nov. 22, 1960 [Nov. 30, 1959], No. 40165/60. Class 40 (3). Television signals derived from a magnetic tape 1 (Fig. 1), on which complete fields are recorded on each track, such as 2 1 , 2 2 by means of a single rotating transducer head with field synchronizing signals recorded on marginal portions 3, 4 have some of the latter signal periods blanked and during such periods regenerated synchronizing signals are inserted to replace such signals inevitably lost during the period in which the head transfers from the end of one track to the beginning of the next track. As shown in Fig. 2, the signals derived, by known means, from the tape are supplied via terminal 5 to one input of a switch 6, which, during field picture signal portions, supplies such input signals to an output terminal 7 and a synchronizing signal separator 8. The output from the latter is supplied to a pulse generator 9, and to a field pulse separator 10, the output from which controls generator 9 to produce pulses of line period and of half-line period. These pulses are then supplied to a second input of switch 6 which is operated by a gating pulse from a generator 11 controlled by field synchronizing signals from separator 10 to interrupt the signal input from terminal 5 and to supply instead the input signals from generator 9 to output terminal 7. The generator 9 includes an A.F.C. circuit of large time constant so that output signals continue to be supplied in the event that the tape signals are intermittently omitted. The length of the gating signals from generator 11 may be adjusted. U.S.A. Specifications 2,773,120, 2,866,012 and 2,919,314 are referred to.