| 摘要 |
PURPOSE:To prevent track jumps by providing a sample and holde circuit which is controlled, based on the output from the disc-error detecting circuit, to become on/off, and maintains the output value at the time of disc-error detecting of the tracking-error signal to be of the value immediately before the detecting, to the output side of the differential amplifier circuit. CONSTITUTION:The sample and holiding circuit 29 is provided on the output side of the differential amplifier circuit 21. The disc-error detecting circuit 33 outputs a disc-error detection signal to the base of a switching transistor 31 via a resistor 34 when there is defect in the information recording surface of the compact disc. The switching transistor 31 is controlled to be on, based on this disc-error detection signal. When it is on, a terminal of a capacitor 30 is grounded, and the output value of the tracking-error detection signal outputted from the differential amplifier circuit 21 is maintained at the value immediately before detecting the disc error. Accordingly, a track jump based on the offset adjustment is prevented.
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