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:
Sep. 28, 1993
Filed:
Oct. 31, 1991
Robert D Murphy, Yukon, OK (US);
David C Waugh, Oklahoma City, OK (US);
Mark A Hickl, Austin, TX (US);
Clyde E Goodner, III, Oklahoma City, OK (US);
Seagate Technology, Inc., Scotts Valley, CA (US);
Abstract
A data storage system comprised of a plurality of disc drives which each comprise a plurality of data storage discs rotated by a polyphase motor. Each disc drive has a servo system for radially positioning transducer heads proximate the disc surfaces and generating an index signal for a selected orientation of the discs. A reference signal generator in each disc drive produces a reference signal at each of a succession of time intervals equal to the desired period of rotation of the discs and the disc drives are interconnected to enable each disc drive to sense a reference signal generated by any other disc drive. Each disc drive includes a microcomputer that is periodically interrupted and, during the interrupt, transmits the reference signal generated by the disc drive to the other disc drives in the absence of reception of a reference signal from another disc drive prior to the interrupt to provide a common reference signal for all of the disc drives. The speed of the motor of each disc drive is controlled in relation to the time interval between generation of the index signal in the disc drive and generation of the common reference signal. Alternatively, each disk drive can be operated independently to control the motor speed in relation to the time between successive index signals.