Optical recording/reproducing apparatus using three count control signals for counting a number of tracks crossed by a light beam

摘要

An optical head irradiates a light beam on an optical recording medium having a plurality of tracks on which data is recorded and a plurality of guide tracks for separating the plurality of tracks, and receives a response light beam from the optical recording medium. A count control signal generation circuit performs predetermined calculation of an output from the optical head, thereby generating three binary count control signals having different phases, which represent the position of the light beam on the tracks and the guide tracks along a direction of the light beam crossing the tracks. A count pulse generation circuit generates a count pulse on the basis of a transition path for positioning the light beam, which is defined by the three count control signals from the count control signal generation circuit. A track count circuit counts the count pulse output from the count pulse generation circuit while recognizing the moving direction of the light beam.