looking for a lead in circuit to an optical disk.

摘要

A track search circuit includes a command decoder (4) which decodes command data sent by a microcomputer and stored in a command register (1) and outputs signals commanding a track jump and commanding count of a counter (5) which counts a tracking error signal. Time difference between a present A-time and a target A-time is calculated such that an optical pick-up can be moved toward a target position by utilizing the track jump of 4n. When a counted value of the counter reaches a predetermined value, the A-time is renewed such that the time difference can be reduced by addition or subtraction suitable time data to or from the A-time. If the renewed A-time becomes within 1 minutes with respect to the target A-time in repeating such a track jump in accordance with the renewed A-time, the optical pick-up is stopped to move, and the A-time is read to jump the optical pick-up again to catch the target position.