Patent ID: 8564898
Filing Date: 2013-10-22
Classification: G11B

Abstract:
1. A magnetic disk device comprising: a magnetic disk having spiral data tracks extending from an outer circumference towards an inner circumference or from an inner circumference towards an outer circumference; a head configured to read data recorded in the data tracks of the magnetic disk that is rotating and to write data to the data tracks; a calculating module configured to calculate, based on the data read by the head from a predetermined data track, information indicating repeatable run-out of the data track; a writing module configured to write the calculated information to a servo area of the magnetic disk; and a controller configured to control the head to follow the predetermined data track in units obtained by subtracting the seek time, which is the time to return the head from an end point of a data track to a start point of the data track, from an integer multiple of the rotation period, which is the time for one revolution of the magnetic disk, when the information is calculated.