| 摘要 |
PURPOSE:To obtain an excellent reproduced picture by fixing an absence position at a prescribed position on a reproduction screen at any time by rotating a capstan motor so as to coincide in phase a phase detection output corresponding to the rotary phase of a rotary head with an output obtained by dividing the frequency of a reproduced control signal by (n). CONSTITUTION:A signal with a frequency which corresponds to the rotating speed of a head motor 1 is applied to a speed control circuit 3 to drive the motor 1 at a prescribed speed. A rotary phase detector 5 detects a rotary phase, which is compared with the phase of an output obtained by dividing a vertical synchronizing signal by two and applied to a phase comparator 7 via a changeover switch SW1 in recording to control a circuit 3 with a signal based upon the phase difference. Further, the rotating speed of a capstan motor 8 is detected and applied to a speed control circuit 11 via an amplifier 10 to control the motor 8. In reproduction, a phase comparator 15 compares the phase of the output of a frequency divider 14 with that of the output of the switch SW1, the circuit 11 is controlled by said resulting phase difference to control the rotation of the motor 8. |
