| 摘要 |
<p>PURPOSE:To shorten the access time by detecting an output voltage correspond ing to relative positions of a head and a track from a 4-frequency pilot signal and controlling a capstan motor by the obtained head position error voltage and the output voltage of a comparator when the 4-frequency pilot signal is used to trace the track. CONSTITUTION:In an 8mm VTR having two heads, videos and the 4-frequency pilot signal recorded on a magnetic tape 120 are detected by a magnetic heads 101 and 102 and are inputted to a regenerative amplifier 104 through an analog SW 103, and an obtained reproduced signal is filtered by an LPF 1 constituting a low-pass filter circuit and is sent to a tracking detector 106. A reference byte signal has beat eliminated to generate a head position error signal, and a frequency signal proportional to the number of revolutions from a capstan motor 117 is inputted to a speed comparator 119 and a phase comparator 120. A signal obtained by them is sent to a motor driver 5 to control the speed of the motor 117.</p> |
