Patent attributes
A disk access device records to and plays back from a disk on which data recording is performed according to the ZCLV format, and includes a head that reads/writes data from/to the disk. The disk access device calculates a deferment time period that begins upon completion of data reading/writing in the user area of a currently accessed zone and ends when the head enters a predetermined area of the guard track zone following the user area, and a setting time period for performing settings for data reading/writing in the zone to be accessed next. If the deferment time period is shorter than the setting time period, the disk access device moves the head back, when data reading or writing in the currently accessed zone ends, to a position such that the setting time period ends before the head advancing from the position arrives at the predetermined area.