Western Digital Technologies, Inc.

Teddy T C Chen

Jie Yu

Jonathan V Nguyen

Jinsheng Bill Jang

Guoxiao Guo

Masao Miyamura

John Yin Kwong Li

Eugene Chun-Tsing Wu

Tuong M Vu

A disk drive is disclosed comprising a plurality of servo sectors that define a plurality of tracks, and a head comprising a read element radially offset from a write element. The read element is positioned over a first track, and the first track is read to generate first read wedge repeatable runout (WRRO) values. A first seek operation of the head positions the read element over a second track, and the second track is read to generate first write WRRO values. The first write WRRO values are used to write the first read WRRO values to the first track. A second seek operation of the head positions the read element over a third track, and the third track is read to generate second write WRRO values. The second write WRRO values are used to write the first write WRRO values to the second track.

Disk drive writing wedge RRO values in a butterfly pattern

A disk drive operable with first and second servo patterns in a perpendicular media recording (PMR) environment is disclosed. The disk drive comprises a head operable with a perpendicular flux, a disk, and a servo controller. The disk includes a plurality of tracks, wherein each track has a plurality of servo sectors utilized in seek operations. The servo sectors of the disk include a first servo pattern between one of an inner diameter (ID) or an outer diameter (OD) of the disk and a middle diameter (MD) of the disk, respectively, and a second servo pattern between the other of the OD or the ID of the disk and the MD of the disk, respectively. The servo controller operates in a first mode when seeking within one of the first or second servo patterns and a second mode when seeking between the first servo pattern and the second servo pattern.

Disk drive operable with first and second servo patterns in a perpendicular media recording environment

A perpendicular media recording (PMR) servo track writer (STW) system and method for writing servo sectors onto a disk is disclosed. The servo writer includes 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. The servo writer includes 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.

System and method for writing servo sectors in a perpendicular media recording environment

Growing community of inventors

Huntington Beach, CA, United States of America

Teddy T C Chen