Optical reproducing method for optical medium with aligned prepit portion

摘要

A reproduction apparatus for reproducing information recorded on an optical medium having an aligned prepit portion straddled on a plurality of tracks in a radial direction, the prepit portion including first and second prepit portions divided in a track direction, the respective first and second prepit portion being arranged on a boundary of the respective tracks. The first and second prepit portions include a synchronous information prepit arranged at every two-track pitch in the radial direction. The synchronous information prepit of the first and second prepit portions are arranged at opposite boundaries of the same track, and a trailing end of the first prepit portion is aligned with the radial direction in arrangement. The apparatus includes an irradiation source for irradiating a light spot on the medium, a detector for detecting a reflected light from the medium, and a reproducer for reproducing information by using a signal from the detector.