| 摘要 |
<p>PURPOSE:To always enable a stable tracking control with high accuracy despite of the difference in the patterns on a recording tape by retrieving the optimum tracking phase with two frames as a reference unit. CONSTITUTION:The FM reproduction output from a video head 2 is inputted to a microcomputer (MP) 7 via a preamplifier 4, amplitude detection circuit 5 and A/D conversion circuit 6. On the other hand the control signal from a control signal head 8 is inputted to a servo circuit 9 and the rotation phase information from a PG head 10 is inputted to the servo circuit 9, which executes the phase alignment of the head 2 and a magnetic tape 3 via circuits 13, 14 based on both input signals by the command from the MP 7. In this case the MP 7 reads the detection output voltage of a reproduction output level synchronously with a sampling pulse on each specified time, the minimum value inside the two frames is detected and a tracking servo is executed by retrieving the optimum tracking value at the position thereof.</p> |
