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:
May. 11, 1976
Filed:
Aug. 12, 1974
Applicant:
Inventors:
Harold James Beecroft, Minneapolis, MN (US);
Srinivasan Venkata Chari, Foster City, CA (US);
Assignee:
Control Data Corporation, Minneapolis, MN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ;
U.S. Cl.
CPC ...
360 77 ; 360131 ;
Abstract
Magnetic recording apparatus employing a medium characterized by having a relatively high coercivity recording layer having servo tracks recorded therein, and a second layer of lower coercivity in which data may be recorded. The servo tracks are read by a head and this signal is used to properly position the head for writing and reading of data. If the medium is a disc, e.g. the servo tracks may be either concentric circles or a single spiral concentric with the center of the disc.