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:
Feb. 07, 1978
Filed:
Jul. 19, 1976
William J Case, Winchester, EN;
Robert D Commander, Eastleigh, EN;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Data track positioning information for data tracks on a stack of recording disks is provided by servo information pre-recorded on one surface of the stack. In addition, each data track on the remaining surfaces of the stack has servo information relative to that track pre-recorded in sectors around the track. Track following operations are controlled in a closed loop servo system using on-track position information derived from the sectored servo tracks associated with the track being followed. The bandwidth of the position error signal derived from the sectored servo information is increased by adding high frequency components obtained from the continuous servo information on the servo surface. Track access operations are controlled using track crossing information derived from the pre-recorded servo information on the servo surface.