Seagate Technology Incorporated

Steven Alan Koldewyn

David L Schell

Timothy Francis Ellis

Abhay Tejmal Kataria

Reed David Hanson

Michael Edward Baum

Brent Jay Harmer

Christopher Thomas Settje

Chris Thomas Settje

Marinko Bosnich

Mike E Baum

Kar Wei Koay

Using a 'reference' sensor, a reference position is detected in a frame of reference that is moving along a predetermined path relative to the reference sensor. The reference position is used to derive a position-dependent indicator of a position-dependent 'longitudinal' offset component (i.e. along the path). An output from the target sensor is monitored using a &#x201c;target window&#x201d; that is partially based on the position-dependent indicator.

Monitoring a sensor's output using a target window that is based on a longitudinal offset's position-dependent indicator

An apparatus and method for tracking radially-dependent repeatable run-out in a disc drive having a servo loop for positioning a head over a rotating disc is provided. The disc includes multiple tracks. Radially-dependent repeatable run-out control components for at least a subset of the multiple tracks are first determined. The subset of the multiple tracks being boundary tracks of established zones of a disc. Data representative of the radially-dependent repeatable run-out control components for the subset of the multiple tracks is then stored in a table. The stored data representative of the radially-dependent repeatable run-out control components is utilized to interpolate or extrapolate the radially-dependent repeatable run-out control components for tracks within a zone or outside of the zones for which data is known.

Radial dependent low frequency repeatable run out compensation apparatus and method

An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.

Dynamic head switch timing recalibration apparatus and method

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Berthoud, CO, United States of America

Steven Alan Koldewyn