| 摘要 |
Apparatus for controlling the speed of advancement of a magnetic tape in a video tape recordor (VTR) of the type including a rotary magnetic head assembly for recording and reproducing an information signal with respect to a plurality of record tracks extending obliquely on a magnetic tape, comprises a recording section including a control signal generator which generates a control signal, a pilot signal generator which generates a pilot signal having a predetermined frequency, an AM modulator which amplitude modulates the pilot signal by the control signal to produce a superimposed or amplitude-modulated signal which is recorded in a control track on the magnetic tape by a fixed magnetic head; and a reproducing section including the fixed magnetic head for reproducing the superimposed signal recorded in the control track on the magnetic tape, a limiter circuit for detecting the pilot signal from the reproduced superimposed signal, an FM detector for detecting a frequency fluctuated component of the detected pilot signal, an envelope detector for reproducing or detecting the control signal from the reporduced superimposed signal, and a servo circuit for controlling a drive motor for the magnetic tape in response to the detected control signal and the detected frequency fluctuated component of the pilot signal so that wow and flutter in the detected control signal are eliminated or substantially reduced by the detected frequency fluctuated component of the pilot signal, and a constant speed of advancement of the magnetic tape is achieved. |
