Patent ID: 7489470
Filing Date: 2009-02-10
Classification: G11B

Abstract:
1. A magnetic recording apparatus comprising: a magnetic recording medium having tracks formed in a concentric or spiral manner and having at least one servo signal recorded on each of the tracks; a spindle motor adapted to rotate the magnetic recording medium; a magnetic head provided to be movable in the approximately radial direction of the magnetic recording medium and positioned over one of the tracks formed on the magnetic recording medium so as to read signals including the servo signal at the position; a compensation information generating circuit adapted to feed a position error signal of the magnetic head relative to the track, based on the servo signal read by the magnetic head, to each of a plurality of repetitive control systems each having a frequency characteristic different from each other, wherein the compensation information generating circuit is adapted to use the plurality of repetitive control systems to detect repeatable runout during the rotation of the magnetic recording medium for a frequency characteristic of each of the repetitive control systems, and wherein the compensation information generating circuit is adapted to generate individual compensation information so as to compensate for each of the detected repeatable runout, wherein compensation information based on the individual compensation information generated for each of the repetitive control systems is feedback to the position error signal to suppress the repeatable runout.