| 摘要 |
PURPOSE:To always allow the execution of an exact and stable tracking control by specifying the mesial axis of pits for information with respect to a pit depth and the distance of the pits for information to the center of tracks to a specific relation and specifying the mesial axis. CONSTITUTION:The pits IP for information are formed at the center O (track center 2) of the tracks 2 formed on the surface of an optical disk 1. Wobbling pits WPa, WPb as the pits for detecting track positions are formed in the positions deviated by l to the right and left in the radial direction of the track center 2 from the track center. These pits have a trapezoidal shape and the depth of the pits is designated as D and the mesial axis thereof as W. Equation I is satisfied in this case and the mesial axis W thereof at this time is set in the range of equation II. The pits IP can, therefore, be formed by having some tolerance in the shape and forming position thereof. The generation of an off-tracking is substantially prevented in this way and the reliability of the tracking is enhanced. |
