Patent ID: 6272105
Filing Date: 2001-08-07
Classification: G11B

Abstract:
An optical disc on which a plurality of data pits whose edge positions are shifted according to a multi-level pit edge recording method are recorded, the optical disc comprising:a substrate member; anda plurality of tracks formed on the substrate member,wherein a plurality of data areas and a plurality of reference areas are formed on the substrate member such that each of the data areas and the reference areas is formed continuously over the plurality of tracks, the data pits corresponding to digital data are recorded on the tracks in each of the data areas according to the multi-level pit edge recording method, tilt reference pits which are used as a reference for detecting a tilt of the optical disc relative to a direction of a light beam which is emitted to the optical disc to record or reproduce the digital data are recorded on the tracks in each of the reference areas.