Tracking error detecting circuit in disc-shaped recording medium reproducing and recording apparatus

摘要

A tracking error detecting circuit including a light receiving unit divided into a plurality of light receiving sensors; a push-pull signal detecting circuit detecting the push-pull signal based on the difference of the amount of the reflected light received by the sensors; a compulsory offset cancellation circuit for removing the input offset signal from the detected push-pull signal; an offset component detecting circuit for detecting an offset component in accordance with the push-pull signal based on an amplitude of the wobbling component of the groove; a cancellation signal detecting circuit for finding an offset cancellation signal with respect to the push-pull signal an offset cancellation circuit for finding a tracking error signal by removing the offset cancellation signal from the push-pull signal; and a parameter determining means for determining the parameter to be referred to at the cancellation signal detecting circuit based on an offset component detected at the offset component detecting circuit by the movement of an optical pick-up and the offset signal input to the compulsory offset cancellation circuit for suitably removing this offset component from the push-pull signal.