| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for performing recording and reproduction of a phase change type media in a DVD drive. <P>SOLUTION: Lands and grooves are formed in a substrate and each groove has 0.74 μm track pitch as an information track. When tracking control is performed to the phase change type media by a DPD (Differential Phase Detection) system, a DPD signal can be obtained by phase difference between a recorded mark and a crystallized state showing reflection characteristics higher than that of the recorded mark and when tracking control is performed to the phase change type media by a push-pull system, a push-pull value specified by a mirror part is formed so as to be ≥0.2 and dummy data for one cycle are recorded adjacently to an outermost peripheral track in which recording data are recorded. When information is recorded in the groove, tracking control is performed by obtaining a tracking error signal from a push-pull signal and when information recorded in the groove is reproduced, tracking control is performed by obtaining the tracking error signal from the DPD signal. <P>COPYRIGHT: (C)2008,JPO&INPIT |
