| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a recording pitch in a recording layer from depending upon a track pitch of a reference surface and to make the stability of a tracking servo surer at that time in an optical recording medium having the reference surface with a position guide member formed and the recording layer formed at depth different from the reference surface. <P>SOLUTION: In an optical recording medium, a pit string in which an interval of a pit formable position in one orbiting is limited in a first interval is formed spirally or concentrically in a reference surface, and the interval of the pit formable position in a pit formation direction is set to a position shifted by a prescribed second interval at a time in a pit string arranged in a radial direction so as to have a plurality of pit string phases. By sequentially switching pit strings and the intermediate position thereof as a servo target, a higher linearity part of a tracking error signal can be used, and the stability of servo control can be improved. <P>COPYRIGHT: (C)2012,JPO&INPIT |
