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. 24, 1991
Filed:
Aug. 14, 1990
Richard L Copeland, Boca Raton, FL (US);
Markus B Kopp, Pompano Beach, FL (US);
Sensormatic Electronics Corporation, Deerfield Beach, FL (US);
Abstract
A system for use in detecting the presence of an electronic article surveillance tag in an area subject to surveillance comprises first and second antenna units disposed on opposed sides of the area, each of the antenna units incorporating therein at least first and second antennas circumscribing a common center thereof at respective different distances from the common center. Excitation circuitry is provided for exciting each first antenna at a greater level than each second antenna, the excitation of the first and second antennas by the exciting circuitry being of respective opposite phasing. The system further comprises a receiver connected to the first and second antenna units and alarm circuitry connected to the receiver to provide output indication of the presence of the tag in the area subject to surveillance.