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:
Aug. 20, 1991
Filed:
Nov. 13, 1989
Harold C Ockerse, Boise, ID (US);
Donald J Fasen, Boise, ID (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A linear or rotary disk memory drive having provision for compensating or cancelling track position syncopation. Due to interference among the magnetic fields of magnetic dibits recorded in and adjacent to a servo code field in a magnetic memory disk, magnetic field intensities are displaced, producing an indication of a track center displaced from the actual track center. A magnetic head tracking such displaced magnetic fields is consequently displaced from track center, which is unacceptable. Four phases of magnetic dibits of servo code are recorded in each of at least four consecutive circumferential frames in a memory disk, in differing servo code formats or patterns of magnetic dibits. Magnetic head servo code signals derived from the magnetic fields of these servo code magnetic dibit patterns are logically processed to produce an AC signal representing track position syncopation which is cancelled by filtering, leaving servo code signals accurately reflecting the position of the magnetic head with respect to a track center.