| 摘要 |
PURPOSE:To attain the positioning with high precision without using a tracking actuator, by using a driving circuit for stepping motor for both coarse shifting and fine positioning purposes and feeding the track shift back to one of these two purpose driving circuits. CONSTITUTION:A pulse accordant with a shift extent up to a target track is fed to a stepping motor driving circuit 12 for the rough positioning. Then a linear stepping motor 15 is moved to shift a mobile base 7 up to a place near the target track. Then the circuit 12 is switched to a fine driving circuit 20 by means of a switch circuit 21. A optical head detects a shift extent of the target track and then feeds it back to the circuit 20. Thus the whole base 7 can be positioned to the target track with high precision. |
