Data recording/reproducing method and apparatus using a recording medium having clock marks recorded in a wobbled track for read/write synchronization

摘要

A data recording/reproduction method and apparatus uses an optical disk equipped with wobbling track guide grooves disposed in a track scanning direction and minutely wobbled. The apparatus uses a circuit for detecting and correcting displacement of an optical spot position from the wobbling track, and a system for allowing data to correspond to front and rear edges of recording pits as a recording system, and includes a circuit for independently handling reproduction pulses obtained from reproduction signals of the recording pits on the front and rear edge sides and for generating reproduction clocks. A circuit resynthesizes the two series of reproduction pulse trains by a specific pattern portion in the data. Another optical disk apparatus divides each track into zones, and switches a rate of revolution each zone to attain a substantially equal linear velocity. A servo signal reproduction clock generation circuit and a data signal recording/reproduction clock generation circuit are disposed separately. The latter changes a frequency division ratio in accordance with the zones so that a clock having a predetermined frequency can be generated even when the rate of revolution changes.