Patent ID: 7453664
Filing Date: 2008-11-18
Classification: G11B

Abstract:
1. A method for measuring a displacement amount between a center line of a physical track formed in between two guard bands on a discrete track recording (DTR) medium and a servo reference locus of a magnetic head which scans thereon, comprising: recording a repeat pattern, which is a repeatedly written magnetized state in data sector zone between each servo, in between the two guard bands; scanning repeatedly on the repeat pattern by the magnetic head while shifting a servo locus of the magnetic head in the radial direction of the discrete track recording (DTR) medium in steps from the servo reference locus; recording an amplitude variation of a signal reproduced by, and transmitted from, the magnetic head based on the repeat pattern during the scanning; and determining a displacement amount of the magnetic head from the servo reference locus in terms of an amplitude value which indicates the center of the physical track within the amplitude variation as the displacement amount of the physical track relative to the servo reference locus.