HEAD POSITION CONTROL METHOD AND DISK DEVICE

摘要

When a repeatable runout (RRO) component having a large amplitude and synchronized with the rotation is discretely included in a track trajectory drawn on a disk up to a high-frequency band, if a filter having a resonant characteristic only in components of integer times the rotational frequency and being excellent in suppressing the RRO is used to determine the position of a magnetic head so as to match the track trajectory, a large number of the filters are required, so that it takes long time for all the filters to become a steady state. According to the head position control method, after learning until the filters become a steady state, the output values of the filters in the steady state are stored on a disk or in a memory and the magnetic head is controlled using the stored output values, thereby eliminating the time required until the filters become the steady state.