DISCRETE TRACK MEDIUM ECCENTRICITY DETECTING METHOD AND ECCENTRICITY DETECTING DEVICE

摘要

[PROBLEMS] To provide a track eccentricity detecting method and an eccentricity detecting device for detecting the amount of eccentricity and the direction of the eccentricity of a track of a DTM without referencing a servo pattern. [MEANS FOR SOLVING PROBLEMS] An eccentricity detecting method for detecting the eccentricity of the center of the track of a DTM having a track where a magnetic body is present and a groove where a magnetic material is absent and the eccentricity of the center of the rotation of the spindle motor. The method comprises a step of writing predetermined data in a predetermined region while stepwise moving the head radially with respect to the DTM, a step of reading the written data by means of the head made to be at rest in the predetermined region, a rest detection step of detecting the amount of eccentricity and the direction of the eccentricity by detecting the number of crossings of the track by the head while the DTM rotates by a predetermined amount and their timings according to the read signal.