Disk apparatus and disk recording method, and data reproduction method

A data recording method comprising:

• specifying a plurality of regions with different radial positions on a disk, and detecting tilt amounts of the respective regions with respect to an optical axis of a light beam on the basis of a focus control signal used to just-focus the light beam on a recording surface of the disk;
• calculating tilt correction amounts for the respective regions in accordance with the tilt amounts of the respective regions;
• correcting a tilt of the optical axis with respect to a predetermined region on the basis of the tilt correction amount corresponding to the predetermined region;
• and
• recording data on the predetermined region while the tilt of the optical axis with respect to the predetermined region is corrected.

A data reproduction method comprising:

• specifying a plurality of regions with different radial positions on a disk, and detecting tilt amounts of the respective regions with respect to an optical axis of a light beam on the basis of a focus control signal used to just-focus the light beam on a recording surface of the disk;
• calculating tilt correction amounts for the respective regions in accordance with the tilt amounts of the respective regions;
• correcting a tilt of the optical axis with respect to a predetermined region on the basis of the tilt correction amount corresponding to the predetermined region;
• and
• reproducing data from the predetermined region while the tilt of the optical axis with respect to the predetermined region is corrected.