REPRODUCING DEVICE

摘要

PURPOSE:To eliminate the influence of temperature fluctuations and a secular change by using the 1st tracking control loop which responds fast to tracking error detection by a differential means and the 2nd tracking control on a wobbling system in combination. CONSTITUTION:Error signals detected differentially by detectors 301a-301b are amplified by a differential amplifier 302 to drive a tracking drive part 306 by Y. A periodic fine signal generated by an oscillator 303 is added by an adder 304 to wobble a signal detector 307 periodically. A detection signal is demodulated by an AM demodulator 308 and detected synchronously by a synchronous detector 309 to detect a tracking error E accurately. This is added to a tracking control signal to nearly eliminate a DC offset.