Patent ID: 7639445
Filing Date: 2009-12-29
Classification: G11B

Abstract:
1. A disk drive device comprising: a disk media in which a plurality of spiral servo patterns are written; a head configured to read data from and write date in the disk media; a head moving mechanism configured to move the head in a radial direction on the disk media; a detection signal producing module configured to produce a detection signal comprising particular signal pattern by reading each of the spiral servo patterns, the spiral servo patterns being read by the head while the head scans a circumferential direction region on the disk media; a position error computation module configured to produce at least one of a first, second, third and fourth servo burst signal using a plurality of predetermined frames obtained by dividing the detection signal at even time intervals, the first, second, third and fourth servo burst signals being included in each of a plurality of radial servo patterns used to define a concentric track on the disk media, and to produce each of the other burst signals of the first, second, third and fourth servo burst signals using predetermined one frame of the plurality of frames, and to compute a position error of the head based on amplitude values of the produced burst signals; and a positioning module configured to position the head at a target position on the disk media based on the computed position error.