Patent ID: 6657810
Filing Date: 2003-12-02
Classification: G11B

Abstract:
A disk drive comprising:(a) a disk comprising a plurality of tracks, each track comprising a plurality of data sectors for storing user data and a plurality of embedded servo sectors for storing servo data; (b) a head comprising a read element and a write element, wherein: the read element is offset from the write element; the write element for writing user data to the data sectors; and the read element for reading the user data stored in the data sectors and for reading the servo data stored in the embedded servo sectors; (c) an actuator, responsive to a control signal, for actuating the head radially over the disk; (d) a position error generator responsive to the servo data read from the embedded servo sectors, the position error generator for generating a position error signal representing a position of the read element with respect to a circumferential path along a selected one of the tracks; (e) a plurality of read repeatable runout (RRO) estimated values and a plurality of write RRO estimated values; (f) a means for combining the position error signal with the read RRO estimated values to generate a corrected position error signal during a read operation, and for combining the position error signal with the write RRO estimated values to generate the corrected position error signal during a write operation; and (g) a servo compensator, responsive to the corrected position error signal, for generating the control signal applied to the actuator, wherein: the plurality of servo sectors of a track comprise a first interleave and a second interleave; each servo sector of the first interleave stores the write RRO estimated values corresponding to a plurality of subsequent servo sectors; and each servo sector of the second interleave stores the read RRO estimated values corresponding to a plurality of subsequent servo sectors.