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:
Sep. 12, 1978
Filed:
Oct. 15, 1975
Applicant:
Inventor:
Cyril Arthur Lee, Maidenhead, GB;
Assignee:
E M I Limited, Hayes, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06K / ; G06K / ; G11B / ;
U.S. Cl.
CPC ...
235449 ; 235493 ; 360-2 ;
Abstract
Magnetic recording media including permanent structures of aligned acicular particles have been proposed as a means of identifying and authenticating a medium. A structure of such a media by which information can be recorded and read-out without interference from the structural remanence difference is described. An apparatus and method for the examination of such media for their permanent structures, particularly when used in security documents such as credit cards, are also described.