| 摘要 |
PURPOSE:To achieve stable auto tracking by dividing tracking information synchronizing with the revolving period of a disk, by reading them synchronizing with the revolving period of the disk, and by mixing them with the tracking information. CONSTITUTION:Voltages 71, 72- charged in capacitors 26, 27- are developed at connection points 35 between a resistor 22 and FETs in time series according to gate pulses 50, 51-. This time-series signal is amplified by a voltage amplifier 36 and a current amplifier 37 and supplied to the other supply terminal of a mixer 13 to be mixed with a tracking error voltage obtained by wobbling. Therefore, even if the tracking error voltage is absent, a tracking error signal stored in a memory capacitor is mixed, so that no erroneous tracking occurs. This constitution enables stable auto tracking. |
