| 摘要 |
PURPOSE:To servo-control stably a pickup position in a wide temperature range by changing servo gains in accordance with the temperature. CONSTITUTION:A positioning error signal of a pickup controlled in terms of position through an actuator from an error signal generator circuit 3 is supplied to a comparator 10 for detecting the gain declining through an HPF8 of a bypass filter and an amplifier 9. When an error signal level drops at a high temperature through the comparator 10, a gain alteration switch 11 is switched, and servo-system gains for controlling a pickup position control actuator are adjusted by a circuit gain setting amplifier 4 in accordance with the temperature, whereby a pickup position is servo-controlled stably in a wide temperature range. |
