| 摘要 |
PURPOSE:To apply immediately the stable and assured tracking servo even when a searching action is over by providing a DC voltage converting circuit and correcting the DC offset voltage value of a tracking error signal in response to the output signal of said voltage converting circuit. CONSTITUTION:The track jump signal K delivered from a tracking servo circuit 23 in a search mode is supplied to a DC voltage convering circuit 24 via an actuator coil 15. The current flowing to the coil 15 is converted into a voltage signal by a resistance R1 and supplied to an integration circuit to produce a mean DC voltage signal Vc. Then the signal Vc is supplied to an adder 26 via a reverse amplifier 25 in the form of a tracking error correcting signal DELTAT. This signal DELTAT is added to a tracking error signal T, and these added signals are delivered to the circuit 23. When an objective 12 is deflected toward the plus side, the correcting signal DELTAT of negative voltage is added to the signal T. Thus the offset voltage +VT1 is corrected. |
