JPS5654655A - Tracking control device for magnetic recorder/reproducer - Google Patents

Abstract

PURPOSE: To secure an accurate control of tracking without using any control signal, by giving a phase comparison between the vertical and horizontal synchronous signals synchronizing with the rotational phase of the rotary head and the vertical and horizontal synchronous signals reproduced and isolated.

CONSTITUTION: The rotation of the cylinder 2 which turns in a body with the cylinder motor 4 is detected by the magnet 21 and the tag head 22 and then processed through the PLL comprising the phase comparator 24, the voltage control oscillator 25, the counter 26 and the FF27 each. Thus the reference vertical and horizontal synchronous signals synchronizing with the rotational phase of the rotary head are produced. These signals are compared for the phase with the reproduced vertical and horizontal signals corresponding to the tape velocity and supplied from the isolating circuit 12 and through the comparators 15 and 17. And to secure a constant phase difference, the rotation of the capstan 5 is controlled via the adder circuit 19 to which the velocity detection output is applied, the motor driving circuit 20 and others. Thus an accurate control of tracking is possible without using any control signal. Accordingly, no adjustment is required for the relative position between the rotary head and the control head, thus simplifying the tracking control.

COPYRIGHT: (C)1981,JPO&Japio