JPS57159185A - Variable speed reproduction controller for magnetic video recorder and reproducer - Google Patents

Abstract

PURPOSE:To enable vari-speed reproduction and to achieve accurate tracking control with a simple constitution, by picking up only a prescribed index signal among index signals reproduced from a magnetic tape and making tracking control. CONSTITUTION:A rotating phase of a disc of a VTR is detected at a track head 7, a detected DTF is frequency-divided at a counter 22, the dropout of a reproduced RF signal is detected at a dropout detection circuit 21, the counter 22 is reset with a detected pulse d, and a gate pulse e is outputted from the counter 22. Only when the pulse e is at high level, a signal from an index separating circuit 23 passes through and an index signal f appeared at the same phase as the standard reproduction is applied to a phase comparison circuit 15, where the phase comparison between the signal f and the DTF from a pulse shaping circuit 11 is made and a phase error signal is outputted. At the reproduction, a capstan motor 17 is controlled with an error signal from the circuit 15, allowing to achieve accurate tracking control with a simple constitution.