| 摘要 |
PURPOSE:To avoid a so-called locked loop phenomenon that produces repetitively the information of a rotary disk-shaped recording medium at the same position, by applying the bias voltage to a tracking coil and obtaining apparently a state where a housing precedes a stylus. CONSTITUTION:It is supposed that the signal fed from a phase compensating circuit 2 has voltage VA while a housing 8 is moving toward a reference mark 10. In such a case, the signal supplied from a processing circuit 12 consisting of a microcomputer, etc. applies the bias voltage VB to a feed motor driving circuit 5a through a control circuit 13. The voltage VB is larger than the output voltage VA of the circuit 12 (VB>VA). Therefore, the circuit 5a drives a feed motor 6 with the electric power equivalent to the voltage (VA+VB). As a result, the housing 8 moves toward the mark 10 and apparently ahead of a stylus 9. |
