Patent ID: 7746595

Claim:
A disk drive comprising: a disk comprising servo data defining a plurality of servo tracks, wherein the servo data comprises: a preamble; and a plurality of slanted line servo bursts recorded at a tilt angle with respect to the preamble, wherein at least one of the slanted line servo bursts comprises a first magnetic polarity along a first segment of the slanted line and a second magnetic polarity along a second segment of the slanted line; a head actuated radially over the disk for generating a read signal; and control circuitry operable to: generate a preamble read signal when the head passes over the servo data preamble; generate a burst read signal when the head passes over at least one of the slanted line servo bursts; generate a position error signal (PES) in response to a phase difference between the preamble read signal and the burst read signal; and position the head in response to the PES.