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. 23, 2000
Filed:
Jul. 09, 1998
Ming-Ren Lian, Boca Raton, FL (US);
Dennis M Gadonniex, Delray Beach, FL (US);
Richard Tellshow, Boynton Beach, FL (US);
Senormatic Electronics Corporation, Boca Raton, FL (US);
Abstract
A magnetomechanical EAS marker includes a housing, a magnetostrictive active element in the housing, and a bias magnet mounted on the housing adjacent to the active element. Both the active element and the bias magnet are substantially planar metal strips. The length and/or surface area of the bias magnet is substantially less than the length and/or surface area of the active element. The reduction in the size of the bias magnet relative to the active element enhances reliable deactivation of the marker by increasing the resonant frequency shift obtained by degaussing the bias magnet. The increased reliability of deactivation is obtained without increasing the sensitivity of the marker, when in an active state, to variations in applied bias magnetic field.