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:
Jun. 19, 2001
Filed:
Aug. 16, 1999
Eric Eckstein, Merion Station, PA (US);
John Davies, Sewell, NJ (US);
Edwin Hopton, Philadelphia, PA (US);
Nimesh Shah, Marlton, NJ (US);
Bent Svendsen, Glen Mills, PA (US);
Checkpoint Systems, Inc., a Corp. of Pennsylvania, Thorofare, NJ (US);
Abstract
A pulse-listen electronic article security (EAS) system for detecting the presence of a security tag within a detection zone is disclosed. The EAS system includes a transmitter for radiating a first electromagnetic signal into the detection zone. The first electromagnetic signal is a time sequence of RF bursts emitted during each of a plurality of contiguous frame intervals in which the duration of each of the frame intervals is one of a plurality of different values. The EAS system also includes a receiver synchronized with the transmitter for receiving a second electromagnetic signal re-radiated from a security tag in the detection zone in response to the first electromagnetic signal. The receiver provides an output signal if a security tag is detected. The values of the plurality of the frame interval durations are selected to be different from the values of frame interval durations of other EAS systems thereby rendering the EAS system substantially free of false alarms or blockages caused by the operation of other EAS systems.