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:
Mar. 27, 1990
Filed:
Apr. 28, 1988
Karl A Belser, Los Gatos, CA (US);
Tarek Makansi, Pleasanton, CA (US);
Ian L Sanders, Morgan Hill, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A discrete track thin film metal alloy or metal oxide magnetic recording disk has a plurality of angularly spaced sectors, each sector being formed of a plurality of discrete blocks of magnetic material which are magnetically polarized in the disk's circumferential direction. These discrete servo blocks and the discrete magnetic tracks are both formed at the same time during the fabrication of the thin film disk such that each servo block is precisely and permanently radially aligned with an associated discrete data track. Following the fabrication of the disk, each of the servo blocks is exposed to the magnetic field generated by passing a direct current (DC) through a recording head. In this manner each of the servo blocks becomes magnetized in the circumferential direction and thereby presents two discrete magnetic transitions to a servo read head or a read/write head.