Patent ID: 7746593
Filing Date: 2010-06-29
Classification: G11B

Abstract:
1. A disk drive comprising: a discrete track media type disk comprising data regions and servo regions, the data regions comprising magnetic recording regions of data and non-magnetic regions separate from the magnetic recording regions, and the servo regions comprising servo information; a magnetic head comprising a write head and a separate read head; an actuator on which the magnetic head is mounted and configured to move the magnetic head in a radial direction on the disk; and a controller configured to control the actuator and to position the magnetic head to a position designated on the disk, wherein the controller is configured to make offset adjustment based on a dynamic offset value when the magnetic head is positioned to the designated position on the disk in accordance with a data write operation or a data read operation, the controller is configured to write offset measuring position information for measuring the dynamic offset value to a first position in the magnetic regions on the disk, the controller is configured to reproduce the offset measuring position information, the controller is configured to calculate the dynamic offset value using the offset measuring position information, and the controller is configured to write updated offset measuring position information to the first position of the magnetic regions using an estimated value according to a maximal dynamic offset value of the calculated dynamic offset value.