| 摘要 |
PURPOSE:To surely operate a radial servo, by providing a means to hold an offset part at a naught by a radial-on signal, and a means to perform the pull-in of the radial servo after setting an offset voltage at the naught. CONSTITUTION:An offset voltage RE1 that is the output of a low-pass filter 12 is supplied to an amplifier 11, and a radial error signal RE2 from which the voltage RE1 of the offset part is generated, and it is supplied to the driver 13 of the actuator of an objective lens in an optical system through a switch SW2, and the actuator 14 of the optical system is driven, then a requested radial servo is performed. Also, a radial servo system generates a signal RLC ON, that is a servo on signal, and operates a switch SW1, and also, through a delay circuit 15 of 0.1sec, operates the switch SW2. Therefore, the switch SW1 is opened by the signal RLO ON, and afterwards, the switch SW2 is closed by a delay signal RLC' after a time of 0.1sec, then the pull-in of the radial servo is performed. In such a way, the servo system can be surely operated.
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