Tracking error correction for optical head in different modes of operation

摘要

An offset pulse having a polarity opposite to that of a large tracking error pulse that occurs in response to an operation mode changeover is added to a tracking error signal. The offset pulse has a duration starting immediately before the operation mode changeover and partially overlaps with the tracking error pulse. The offset pulse is generated so as to rise at a timing that is determined based on a wobble signal extracted from the tracking error signal.