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. 08, 1998
Filed:
Mar. 18, 1993
Applicant:
Inventors:
Assignee:
Minnesota Mining and Manufacturing Company, Saint Paul, MN (US);
Primary Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340551 ; 340572 ;
Abstract
A magnetic security marker of an article surveillance system is deactivated by first determining the status of the marker by exposing it to the interrogating field. If the marker is active, a deactivation field is applied to the marker. The marker is again interrogated using the interrogating field and, if an active marker is detected, an incrementally increased deactivation field is applied. The marker is continually interrogated and, as long as an active marker is detected, the intensity of the field is incrementally increased until the field reaches a level effecting deactivation.