The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 1995
Filed:
Mar. 25, 1993
David B Jeppson, Livermore, CA (US);
Benjamin M Miller, San Jose, CA (US);
Quantum Corporation, Milpitas, CA (US);
Abstract
A hard disk drive spindle synchronization method comprises the steps of: sending an index marker pulse generated within each disk drive to mark in time a beginning of each rotation of the disk spindle thereof to a party line to which all drives are connected, rotating the disk spindle at a slightly different rotational velocity than any other drive of the array, monitoring drive pulses present on the spindle reference party line from other disk drives of the plurality to locate a center of gravity of pulse clusters which is within approximately plus or minus one quarter revolution of the drive's own index marker pulse, upon detection of a said center of gravity, ceasing to rotate the disk spindle at a slightly different rotational velocity during a second phase, adjusting the rotational phase of each drive to converge toward the center of gravity until all drive pulses present on the spindle reference party line converge into a single composite marker pulse present on the spindle reference party line, and maintaining convergence of the drive pulses during continuing operations of the disk drives by monitoring the spindle reference party line and making slight phase adjustments of the rotational phase of each drive, thereby phase locking all of the disk spindles of the plurality of hard disk drives to a single composite index marker signal present on the party line.