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:
Apr. 29, 1997
Filed:
Jan. 11, 1996
Peter J Zarembo, Shoreview, MN (US);
Philip E Edstrom, Minneapolis, MN (US);
Anthony M Belka, Stillwater, MN (US);
Dennis L Sando, Minneapolis, MN (US);
William R Weber, III, Vadnais Heights, MN (US);
Mark R Crellin, St. Paul, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
The present re/desensitizer is an apparatus for changing the status of a magnetic marker of an electronic article surveillance system. The markers are attached to or otherwise associated with an object to be protected, such has a book, CD, etc. The device can be set up as a resensitizer, a desensitizer, or with the inclusion of a mode switch, a combination re/desensitizer. The apparatus includes a magnetic field generator for generating a marker status changing magnetic field, detection means for detecting presence of an object, a control means for controlling the activation time of the magnetic field generator such that the marker status changing magnetic field is generated when an object is present. The magnetic field generator includes an offset core designed for continuous operation without excessive heat build up. The offset core is oriented such that the marker status changing magnetic field is substantially horizontal and adjacent to the mounting surface, thus reducing the complexity of movement of the hands and arms required when operating the device. The re/desensitizer also includes a control circuit which controls power to the magnetic field generator such that the marker status changing magnetic field is produced only when an object containing a marker is present. The control circuit also controls the duty cycle of the device by controlling the amount of time that the device is activated and by controlling the amount of time between successive activations.