Optical tracking control apparatus for controlling a tracking of a light beam which scans an information recording disc using pre- formatted guide tracks having an interrupted signal format

摘要

An optical tracking control apparatus comprises a differential amplifier for differentially amplifying signals respectively reproduced from two mutually adjacent track turns of a guide track on both sides of an intermediate part in which an information signal is recorded and reproduced on and from a disc, a zero crossing detector for detecting a zero crossing of an output signal of the differential amplifier and for producing a switching pulse signal, and a polarity inverting circuit responsive to the switching pulse signal for alternately inverting the polarity of a crosstalk component reproduced from the two mutually adjacent track turns of the guide track as crosstalk for every one-half period of the switching pulse signal. An output signal of the polarity inverting circuit is used as a tracking error signal for controlling the tracking of the light beam.