| 摘要 |
PURPOSE:To ensure a decision for a VTR output of the varying speed reproduction mode, by deciding whether a cycle of the separated vertical synchronizing signal is the standard vertical cycle and then limiting a selecting circuit with the output of decision. CONSTITUTION:The composite synchronzing signal COMP.S separated from the VTR output or the TV broadcast wave supplied to the terminal 5 is supplied to a separating circuit 6 for separation of the vertical synchronizing signal PV1 (containing the pseudo vertical synchronizing signal VD). This external vertical synchronizing signal PV1 is supplied to the two reset pulse producing circuits 7 and 8. In case the standard synchronizing form is secured like the TV broadcast wave or the VTR output of the normal reproduction mode, the 1st reset pulse PR1 obtained from the circuit 7 is selected by the selecting circuit 9 that is limited by the output of the deciding circuit 10 to be supplied to the counter 2. While in the case of the synchronizing from like the VTR output in the varying speed reproduction mode, the 2nd reset pulse PR2 obtained by the circuit 8 is supplied to the counter 2. |
