Avatar Systems LLC

Brier Technology, Inc.

Western Digital (Singapore) Pte. Ltd.

Dan Cautis

Michael C McGrath

John F Bizjak

Joseph C Cardona

Philip C Kenny

Vinay K Agarwal

An engagement interface between a removable cartridge containing a rigid disk for storage of data and a disk drive. The cartridge includes an opening for a hub of the disk for spinning and the disk drive has a magnetic spindle with connecting mechanism for extending the spindle into contact with the hub and retracting it out of contact. The cartridge also includes a disk immobilizer to hold the disk with its hub centered in the opening when the cartridge is outside the disk drive, and a detachable mechanical interconnection between the hub and the housing to retain the hub generally centered in the opening when the disk immobilizer is deactivated as the cartridge is inserted in the disk drive but before the spindle has engaged the hub for instances when the cartridge is inserted in the disk drive with other than a vertical orientation.

Removable disk to drive engagement

A servo system moving a transducer between tracks in a sector servo disk drive generates a velocity profile representing the variation of the desired velocity of the head in moving from a first track to a second track. The velocity profile has an acceleration phase and deceleration phase, with the transition from acceleration phase to deceleration phase identified as a switch point. The velocity of movement of the head is periodically sampled from the sector servo pattern in a sequence of sample periods during movement of the head. The energization of the head moving element is controlled so that the switch point occurs during one of the sample periods, thereby resulting in improved performance in positioning the head at the desired track. The system accommodates itself to variations, such as mechanical or electrical disturbances, which would otherwise affect the system.

Seek system for sector servo disk drive

A method and apparatus for performing adaptive calibration of a disk drive assembly and for determining an offset value to compensate for differences in servo head to data head distance from a nominal value. The present invention has particular application in a relative track count servo system where absolute track position is not known from a reading of the servo track itself. In the preferred embodiment, a single head assembly having both a data head and a servo head is utilized. The distance between the data head center and the servo head center must be known so that a disk written on one drive assembly can be read in another drive assembly. This distance is a nominal value but may vary due to manufacturing tolerances. In the present invention, both the data and servo heads are utilized to establish a servo anchor reference track and to determine an offset correction value to compensate for variations in the servo/data head spacing. A dual reference track architecture is employed on the disk surface. The data head is positioned over the first reference track and centered to within a desired accuracy. Once the data head is in place, the servo track beneath the servo head is established as the anchor reference servo track. The heads are then moved across the disk until the data head is positioned over the center of the second reference track. During this movement, the servo tracks are counted to determine the number of servo tracks between the first reference track and the second reference track. This count is then compared to a table storing the number of servo tracks crossed when the data/servo head distance corresponds to the nominal value. The difference in the actual number of tracks crossed and the stored value is used to generate an offset value to compensate for data/servo head distance variations during seeks and other positioning operations.

Dual reference track scheme

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San Mateo, CA, United States of America

Dan Cautis