Disk drive compensating for track squeeze by writing non-circular servo tracks

摘要

A servo writer is disclosed operable to write servo sectors on a disk to define non-circular servo tracks. The servo writer comprises control circuitry including a servo control system operable to measure a position of a head over the disk to generate a position signal, generate a position error signal (PES) representing a difference between the position signal and a reference signal, process the PES with a servo compensator to generate a control signal, and position the head over the disk in response to the control signal. A disturbance is induced into the servo control system, and while positioning the head over the disk in response to the control signal, a plurality of servo sectors are written on the disk to define a servo track, wherein the disturbance induced into the servo control system causes the servo track to be non-circular relative to a rotation axis of the disk.

主权项

1. A servo writer operable to write servo sectors on a disk to define non-circular servo tracks, the servo writer comprising control circuitry including a servo control system operable to:
measure a position of a head over the disk to generate a position signal; generate a position error signal (PES) representing a difference between the position signal and a reference signal; process the PES with a servo compensator to generate a control signal; and position the head over the disk in response to the control signal; wherein the control circuitry is operable to: induce a disturbance into the servo control system; and while positioning the head over the disk in response to the control signal, write a plurality of servo sectors on the disk to define a servo track, wherein the disturbance induced into the servo control system causes the servo track to be non-circular relative to a rotation axis of the disk.