Tracking method and apparatus for optical recording medium

Abstract From the Canadian patent

A tracking method for reading/writing data with respect to an optical recording medium having clock tracks each formed of clock bits of optical patterns and data tracks. The present invention features by: irradiating a pair of light beams onto a pair of clock tracks between, which a data track to be written/read is positioned from an, optical head side, with the beams so deviated from each other in a direction of a relative movement of the optical head with respect to the medium that beam detection signals may have a phasial difference therebetween; detecting reflections of the respective light beams from the clock tracks; obtaining a difference signal between said reflections from the …