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:
Jul. 01, 1997
Filed:
Dec. 15, 1994
Teiichi Isshiki, Tokyo, JP;
Masayuki Hatano, Tokyo, JP;
Junichi Hashimoto, Tokyo, JP;
Tomoaki Karino, Tokyo, JP;
Yoshifumi Kanda, Tokyo, JP;
Tokyo Magnetic Printing Co., Ltd., Tokyo, JP;
Abstract
A fixed permanent pattern is used for identifying a magnetic recording medium and a high security against forgery or modification is obtained by a magnetic recording medium including a non-magnetic support and at least two magnetic layers formed on said support, characterized in that at least one of said at least two magnetic layers contains magnetic particles having a coercive force of 4,000 Oe or less dispersed in a binder and has a non-rewritable fixed signal which has been recorded by magnetic field generated by a signal recorded on one or more other magnetic layers under the influence of an orientation magnetic field.