| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk apparatus which does not erroneously record information into an adjacent track and can prevent occurrence of focusing error/tracking crosstalk, even when information is recorded onto a DVD-RAM. <P>SOLUTION: In the optical disk apparatus, since a sub-beam S-Beam (±) is in a defocused state, information is not erroneously recorded. Also, when a focusing error signal is obtained using an astigmatism method based on a result of light reception of the sub-beam S-Beam, since the sub-beam S-Beam (±) is not push-pull modulated, the influence of crosstalk is considerably small. Also, since a push-pull offset component which is caused by spot movement or the tilt of an optical disk 10 occurs in any of a main beam M-Beam and the sub-beam S-Beam, a tracking error offset can be eliminated even when an operation similar to a DPP method is used. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
