Patent ID: 7729073

Claim:
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, each track having a track centerline and the track centerlines having a track pitch (Tp) radial spacing; and a plurality of nondata servo sectors extending generally radially across a plurality of the data tracks, the servo sectors comprising (a) a synchronization pattern of generally radially directed generally equally angularly spaced magnetized marks separated by nonmagnetic spaces, (b) a first position-error-signal (PES) field comprising generally radially directed generally equally angularly spaced magnetized stripes having a circumferential pitch ½*Ii and separated by nonmagnetic spaces, each stripe comprising a plurality of discrete islands, each island having a radial height of approximately Tp and a circumferential width Wd less than ½*Ii, each island being centered approximately halfway between two adjacent track centerlines, the islands at the same radial location in alternating stripes having a circumferential pitch Ii and the islands in alternating stripes in the along-the-track direction being shifted radially by approximately Tp, and (c) a second PES field angularly spaced from said first field and comprising generally radially directed generally equally angularly spaced magnetized stripes having a circumferential pitch ½*Ii and separated by nonmagnetic spaces, each stripe comprising a plurality of discrete islands, each island having a radial height of approximately Tp and a circumferential width Wd less than ½*Ii, each island being centered approximately at the track centerlines, the islands at the same radial location in alternating stripes having a circumferential pitch Ii and the islands in alternating stripes in the along-the-track direction being shifted radially by approximately Tp; wherein the islands in the second PES field are shifted radially relative to the islands in the first PES field by approximately one-half Tp, and wherein all of the islands in both of said fields have a magnetization in the same direction.