Xyratex Technology Limited

Seagate Technology Incorporated

Michael Alan Miles

Graham Collins

A method of generating a position error signal for a desired radial position of a read/write head relative to a data track of a disk is disclosed. The track has a plurality of servo bursts defining a plurality of servo nulls for the track, and are positioned such that they are at more than four different radial positions relative to the track, and define a predetermined locus having a known position relationship with the track. The method comprises determining a target null position on the null locus corresponding to the radial position of the head relative to the track; detecting the position of the servo null with the head; determining from the detected servo null position the position error of the head relative to the target null position; and, generating a position error signal.

Method of generating a position error signal, method of writing a data track, and method and apparatus for testing a head

A method of controlling the position of a read/write head relative to a disk in a test apparatus is disclosed. The test apparatus has a positioner for positioning the head. The positioner has a sensor to measure the actual position achieved by the positioner. The method includes generating a sensor signal measuring the actual position achieved by the positioner; generating a position error signal of the head relative to the disk detected at the head; high pass filtering the head position error signal and low pass filtering the sensor signal so that there is substantially no overlap in frequency between them; and, deriving a low frequency head error signal from the head position error signal corresponding to any drift of the head.

Method of controlling the position of a read/write head and apparatus for testing a read/write head

Methods and apparatus are disclosed for writing and verifying servo frames written on a storage medium, for verifying data areas of a storage medium, and for writing and verifying servo frames and data areas of a storage medium. In one example, the writing of at least a portion of a position field of a servo frame to a track of the storage medium is interleaved with reading of at least a portion of a previously written logic field of a servo frame of a track of the storage medium whereby said portion of the previously written logic field can be verified during the servo writing process.

Methods and apparatus for writing servo frames to and/or verifying data areas of a storage medium

Apparatus for loading a read/write head to a spinstand has a load area for receiving at least one head to be tested. The apparatus further has a first station having a coarse precisor arranged to provide a coarse positioning of the head. A first automation device is arranged to pick a head from the load area and to deliver it to the coarse precisor. The apparatus has a deck having a test station at which a head can be tested. The deck has a fine precisor arranged to provide a second, fine positioning of the head. A second automation device is arranged to pick a head from the first station and deliver it to the fine precisor where the head can be subjected to a second, fine precising and to pick a head from the fine precisor and to deliver it to the test station.

Method and apparatus for loading a read/write head to a spinstand

A first clock track is written to a data storage region of a storage medium at a first position between first and second boundaries. A first set of further clock tracks is written to other positions on the data storage region, these other positions lying between the first position and the first boundary. A second set of further clock tracks is written to other positions on the data storage region, these second other positions lying between the first position and the second boundary.

Method and apparatus for writing clock data to a storage medium

In a method of writing clock data to a storage medium whilst the storage medium is rotating, a burst of clock data is read from a present track. A burst of clock data for a subsequent track on the storage medium is generated in accordance with the burst of clock data read from the present track and its phase adjusted. The phase adjusted burst of clock data is written to the subsequent track. The steps are repeated for plural bursts of clock data around a revolution of the storage medium thereby to write clock data to the subsequent track.

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Rowlands Castle, United Kingdom

Michael Alan Miles