| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent degradation of recording/reproducing quality caused by variation in layer thickness between inner and outer circumferences when a spherical aberration is corrected in a radial direction only at one place, since there is a difference in layer thickness between the inner and the outer circumferences in an optical disk. <P>SOLUTION: An optimal spherical aberration correction amount is calculated at a recording position by providing an adjustment area for spherical aberration correction to the arbitrary radial position of a disk irrespective of inner and outer circumferences. The adjusting area is provided in the arbitrary position. There is a need to determine whether the area is a user data area or the adjustment area. Management information to determine the use status as the adjustment area is held in the fixed position of the disk. <P>COPYRIGHT: (C)2011,JPO&INPIT |
