Disk drive writing radial offset spiral servo tracks by reading spiral seed tracks

摘要

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral seed tracks. The head is positioned at a first radial location over the disk, and the head is servoed over the disk in response to the spiral seed tracks starting from the first radial location in order to write a first spiral servo track on the disk. The head is positioned at a second radial location over the disk different from the first radial location, and the head is servoed over the disk in response to the spiral seed tracks starting from the second radial location in order to write a second spiral servo track on the disk.

主权项

1. A disk drive comprising:
a disk comprising a plurality of spiral seed tracks; a head; and control circuitry operable to:
position the head at a first radial location over the disk;servo the head over the disk in response to the spiral seed tracks starting from the first radial location in order to write a first spiral servo track on the disk;position the head at a second radial location over the disk different from the first radial location;servo the head over the disk in response to the spiral seed tracks starting from the second radial location in order to write a second spiral servo track on the disk; andconfigure a difference between the first and second radial locations according to:Δ⁢⁢r=vf⁢TN*vsvs+vf where:Δr represents the difference between the first and second radial locations;vf represents a velocity of the head while writing the first and second spiral servo tracks;T represents a number of servo samples in a revolution of the disk;N represents a number of spiral servo tracks written to the disk; andvs represents a velocity of a trajectory of the spiral seed tracks.