| 摘要 |
<p>PURPOSE:To make a private fixed head unnecessary to simplify the constitution by detecting a variance of period between tracks on a basis of the output of a rotary head at a high-speed reproducing time and controlling the rotation of a reel (motor) with this detection output to make a relative speed between a tape and the rotary head constant. CONSTITUTION:At a high-speed reproducing time, for example, at a rewinding period heads HA and HB scan across plural signal tracks, and a pulse signal S# having a certain period is taken out to the output side of a waveform shaping circuit 5. That is, a variance of period between tracks is detected. The output signal S3 of the waveform shaping circuit 5 is supplied to a trigger pulse generating circuit 10 to generate a narrow-width pulse signal S6. A saw tooth wave signal S7 is sampled on a basis of this signal S6, and a certain output signal S8 is taken out to the output side. After this signal S8 is amplified by a driving circuit 12, servo control is so performed that the period of the signal S3 becomes constant to a reel motor 13.</p> |
