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. 17, 1988
Filed:
Sep. 09, 1985
Applicant:
Inventor:
Samuel Montean, Blaine, MN (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
340572 ; 343188 ; 343895 ; 333175 ; 333185 ; 342 51 ;
Abstract
A marker for use in radio frequency electronic article surveillance systems where the marker contains an inductive-capacitive resonant circuit and is made reversibly deactivatable and reactivatable by the addition of a piece of magnetic material and means, such as a piece of permanently magnetizable material, for biasing the first material to prevent alternating fields induced therein from changing the magnetic state of that material, thereby preventing hysteresis losses from causing a lowering of the Q of the resonant circuit below the point of detection.