| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize a stable constant tracking servo with high accuracy by detecting the rotational error information of a rotary drum and generating a servo control signal based on a corrected tracking detection period. SOLUTION: A servo circuit 30 obtains rotation error information by detecting the speed of revolution of a rotary head drum 50 and by comparing the result with a reference speed of revolution. Then, the circuit 30 monitors reference phase position timings of the drum 50 detectable from switching pulses and timing detection pulses TTP to be supplied from a timing detection pulse generating circuit 27 and measurement is implemented for the period as a tracking detection period. The circuit 30 obtains tracking error information by comparing the measured value with the reference value for the tracking detection period and generates a capstan servo signal Scp based on the tracking error information. Then, a tracking servo is performed by increasing or decreasing the rotation speed of a capstan 28.</p> |
