Optical information accessing system capable of reliable jump- back control

摘要

In an optical information accessing system for an optical disc including a plurality of tracks forming one helix, a counter counts sectors, and a comparator compares a value of the counter with a predetermined value. When the value of the counter reaches the predetermined value, a coincidence signal is generated from the comparator. A gate circuit passes the coincidence signal as a jump-back signal. When data processing upon the optical disc is abnormally interrupted and the coincidence signal is generated, the predetermined value is switched from a first value to a second value larger than the first value.