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. 10, 1977
Filed:
Oct. 15, 1975
Applicant:
Inventor:
Cyril Arthur Lee, Maidenhead, EN;
Assignee:
EMI Limited, Hayes, EN;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ; G06K / ; G11B / ;
U.S. Cl.
CPC ...
360 56 ; 235 / ; 360-2 ;
Abstract
Magnetic record media including permanent structures of aligned acicular particles have been proposed as a means of identifying and authenticating a medium. A method of recording and reading out information on such media without interference from the permanent structure remanence variation is described. Suitable forms of magnetic record media and their manufacture are described. The use of the media and method for security documents such as credit cards is also described.