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. 20, 1999
Filed:
Mar. 18, 1998
Wing K Ho, Boynton Beach, FL (US);
Jiro Yamasaki, Fukuoka, JP;
Richard Tellshow, Boynton Beach, FL (US);
Sensormatic Electronics Corporation, Boca Raton, FL (US);
Abstract
A marker to be used in an article surveillance system is formed by processing a continuous ribbon of magnetic material having a longitudinal axis. Domains are developed in the magnetic material to produce a wall configuration which includes a plurality of substantially parallel domain walls extending in a wall direction that is canted at least 15.degree. from the longitudinal axis of the continuous ribbon. The continuous ribbon is then further processed to cause the wall configuration of substantially parallel domain walls to remain in a pinned state for values of applied field below a threshold value. The processed continuous ribbon can be cut to produce discrete magnetic elements which exhibit a step change in magnetic flux when the applied field crosses a threshold value.