| 摘要 |
<p>PURPOSE: To precisely detect fluctuation in an average height position of a track by comparing the measuring value of this time with the measuring value of the last time and discriminating the fluctuation in the average height position of the track by the comparison result. CONSTITUTION: A relative speed between a drum motor 8 and a capstan motor 7 is adjusted so that when the measuring value Ts(u) is obtained, it is compared with a reference value To, and an error amount becomes error information, and the rotational speed of the capstan motor 7 is adjusted by that the error information is reflected to a drive current for the capstan motor 7, and an excellent tracking state is obtained. In such a timing ATF system servo operation, when the average height position of the track is fluctuated, normal operation becomes impossible. Thus, a motor servo circuit 12 continues the normal operation corresponding to the fluctuation in the average height position of the track also.</p> |
