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:
Jan. 27, 1987
Filed:
Dec. 06, 1985
Joel N Harrison, Campbell, CA (US);
Vincent A Condito, San Jose, CA (US);
Randolph H Graham, Santa Clara, CA (US);
Brian J Nixon, Pleasanton, CA (US);
Richard C Simonsen, Pleasanton, CA (US);
Quantum Corporation, Milpitas, CA (US);
Abstract
A disk drive storage device employs two control subsystems, one for transducer position digital control and the other to control and precisely regulate spindle motor angular velocity in accordance with a crystal reference and a speed correction made at least once each revolution. A single servo sector on a data surface provides prerecorded track centering information. Overall electromechanical operations during track following activities are synchronized by the crystal controlled disk spindle motor subsystem which locates the position in time and space of the servo sector and which also interrupts program execution of the transducer position digital control subsystem and causes it to execute a subroutine for track centerline position correction. Direct digital commutation of the brushless DC spindle motor by a programmed digital microprocessor is an aspect of the present invention.