JPS5775076A - High-speed picture retrieving device - Google Patents

Abstract

PURPOSE:To prevent the step-out even for continuous change of a tape speed, by extracting a synchronizing signal from the repoduced signal of a rotary head type VTR and by controlling the rotation number of a drum motor by a signal corresponding to the deviation between the frequency of this synchronizing signal and a prescribed frequency. CONSTITUTION:A drum motor 1 is controlled by a speed servo loop consisting of a frequency generator 2, a speed detecting circuit 3, an amplifier 5, etc. and a phase control loop which compares a reference signal A and the phase from a phase generator 7 with each other at an ordinary reproducing and recording time to transfer the comparison result to the drum motor 1. At a picture retrieval time, a switch 6 is connected to a contact (b), and a DC voltage is generated which corresponds to a degree of deviation between the frequency of a synchronizing signal B, which is separated and extracted from a reproduced video signal, and the center value, and this voltage is added to the drum control loop. Thus, the drum speed is controlled to eliminate the deviation of the frequency of the synchronizing signal, thereby retrieving a position to be reproduced rapidly without the step-out of the synchronism of the monitor televison even for stepless change of the tape speed in still, fast- forwarding, and rewindng modes.