Patent ID: 6845081
Filing Date: 2005-01-18
Classification: G11B

Abstract:
1. An optical reproducing method using an optical medium having an aligned prepit portion straddled on a plurality of tracks in a radius direction, the prepit portion including a first and second prepit portion divided in a track direction, a synchronous information prepit of the respective first and second prepit portion being arranged on a boundary of the respective tracks, the first prepit portion including the synchronous information prepit arranged at every two-track pitch in the radius direction, the second prepit portion including the synchronous information prepit arranged at every two-track pitch in the radius direction, the first prepit portion and the second prepit portion being arranged at opposite boundaries of the same track, and the prepit portion including a gap between the first and second prepit portions, the optical reproducing method comprising the steps of: irradiating an optical spot on said optical medium; detecting a reflected beam from the optical medium; and reproducing information on the optical medium by using a signal obtained by the reflected beam.