Patent ID: 7848040
Filing Date: 2010-12-07
Classification: G11B

Abstract:
1. A magnetic recording disk comprising: a recording layer of magnetizable material for the recording of data in a plurality of generally concentric circular data tracks; and a plurality of nondata servo sectors extending generally radially across a plurality of the data tracks, the servo sectors comprising (a) a pattern of generally radially directed generally equally angularly spaced magnetized marks separated by nonmagnetic spaces, and (b) two and only two angularly spaced position error signal (PES) fields, each of the first and second PES fields comprising generally radially directed generally equally angularly spaced magnetized stripes separated by nonmagnetic spaces, each stripe comprising a plurality of discrete radially-spaced islands separated by nonmagnetic spaces, wherein the islands in the second PES field are shifted radially relative to the islands in the first PES field, and wherein a plurality of alternate stripes in the along-the-track direction in each field are magnetized in a first direction and the stripes between said alternate stripes in each field are magnetized in a second direction substantially antiparallel to said first direction.