Patent ID: 7388728

Claim:
A perpendicular media recording (PMR) servo track writer (STW) for writing servo sectors onto a disk, the servo writer comprising: a head positioner to position a head of a head disk assembly (HDA) relative to a disk, wherein the head writes servo sectors onto the disk with a perpendicular flux; and a controller to control the head positioner such that the head writes servo sectors onto the disk from one of an inner diameter (ID) or an outer diameter (OD) of the disk to a middle diameter (MD) of the disk, respectively, followed by writing servo sectors between the other of the OD or the ID of the disk to the MD of the disk, respectively, wherein a first servo pattern is created between the ID and the MD of the disk and a second servo pattern is created between the OD and the MD of the disk; and the first servo pattern includes a first plurality of gray coded servo patterns aligned with a starting point from the ID and the second servo pattern includes a second plurality of gray coded servo patterns aligned with a starting point from the OD such that the first and second plurality of gray coded servo patterns are offset from one another.