Disk drive comprising slanted line servo bursts having reverse polarity segments

1. 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.

2. The disk drive as recited in claim 1 , wherein:

the burst read signal comprises a periodic signal; and

a phase of the periodic signal changes 180 degrees at the transition between the first segment and the second segment.

3. The disk drive as recited in claim 1 , wherein the servo data is recorded on the disk by fabricating magnetic slants and non-magnetic grooves.

4. The disk drive as recited in claim 3 , wherein the first segment and the second segment are formed by the slants.

5. The disk drive as recited in claim 1 , wherein the servo data is recorded on the disk by stamping a servo pattern on the disk using a master stamping disk.

6. A method of writing servo data to define a plurality of servo tracks on a disk of a disk drive comprising:

recording a preamble; and

recording a plurality of slanted line servo bursts 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.

7. The method as recited in claim 6 , wherein:

the burst read signal comprises a periodic signal; and

a phase of the periodic signal changes 180 degrees at the transition between the first segment and the second segment.

8. The method as recited in claim 6 , wherein the servo data is recorded on the disk by fabricating magnetic slants and non-magnetic grooves.

9. The method as recited in claim 8 , wherein the first segment and the second segment are formed by the slants.

10. The method as recited in claim 6 , wherein the servo data is recorded on the disk by stamping a servo pattern on the disk using a master stamping disk.

11. A disk for use in a disk drive, the disk comprising servo data defining a plurality of servo tracks, the servo data comprising:

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.

12. The disk as recited in claim 11 , wherein:

the burst read signal comprises a periodic signal; and

a phase of the periodic signal changes 180 degrees at the transition between the first segment and the second segment.

13. The disk as recited in claim 11 , wherein the servo data is recorded on the disk by fabricating magnetic slants and non-magnetic grooves.

14. The disk as recited in claim 13 , wherein the first segment and the second segment are formed by the slants.

15. The disk as recited in claim 11 , wherein the servo data is recorded on the disk by stamping a servo pattern on the disk using a master stamping disk.