DISK SUBSTRATE AND OPTICAL DISK

摘要

A disk substrate comprises a data zone for recording and/or reproducing data and an eccentricity measurement zone (14) in which groove regions provided with spiral grooves and planar mirror regions are spatially alternated. The widths of the groove regions and those of the mirror regions formed in the eccentricity measurement zone and the distances between the grooves in the groove regions are selected so that a conventional mechanical property measuring apparatus can track a plurality of grooves formed in the groove regions as if they were a single groove.