Magnetic recording disk drive with write position error signal values written in the data tracks for compensation of track misregistration

摘要

A hard disk drive is adapted to take the most recent estimated read head positions (the position error signal or PES values) that are obtained during writing and write those values into the data sectors as written PES (WPES) values. The WPES values are available on readback for use as a predictor of the positions in which subsequent data sectors were written and are also available for use in a data recovery procedure should a particular data sector fail to be recovered. In two-dimensional magnetic recording, the difference between the WPES value and the read PES value is a quantity required to rapidly select the best 2D equalizer. The PES values may be encoded prior to being written into the data sectors. The WPES values are appended to the data sectors after the preamble and sync fields, which occur after every servo sector.

主权项

1. A magnetic recording disk drive comprising;
a magnetic recording disk comprising
a plurality of radially spaced data tracks, the data tracks including data sectors;a plurality of radially spaced servo tracks having a plurality of angularly spaced servo sectors extending across the servo tracks and data tracks, the servo sectors containing position error signal (PES) blocks; at least one read head for reading data from the data tracks and PES blocks from the servo tracks; a write head for writing to the data tracks; a head carrier supporting the read head and write head; an actuator connected to the carrier for moving the read and write heads radially across the disk; read/write electronics coupled to the read head and write head for decoding the PES blocks read by the read head into PES values and for causing data to be written into the data sectors by the write head, the read/write electronics being adapted to cause the write head to write PES values into the data tracks when writing data into the data sectors; and servo electronics coupled to the actuator for adjusting the radial position of the read head in a data track in response to the written PES values (WPES values) read by the read head.