Electronic article surveillance system with metal detection capability and method therefor
First Claim
Patent Images
1. A method for detecting a metal object and an electronic article surveillance (“
- EAS”
) marker, the method comprising;
establishing an interrogation zone by transmitting only a first signal at only a predetermined frequency, the establishing occurring only during a metal detection window of an EAS/metal detection cycle;
during the establishing, receiving at least a portion of the first signal at the predetermined frequency;
detecting a metal object by;
determining a first voltage of the received portion of the first signal at the predetermined frequency;
comparing the first voltage to a second voltage; and
responsive to determining that the first voltage is different from the second voltage by more than a prescribed amount, determining the metal object is present; and
during an EAS detection window of the EAS/metal detection cycle, wherein the EAS detection window occurs after the metal detection window, detecting an EAS marker response to the transmitting.
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Accused Products
Abstract
A method for detecting metal using an electronic article surveillance (“EAS”) system. The EAS system includes a transmitter and a receiver. An EAS interrogation signal is transmitted to establish the interrogation zone. The EAS interrogation signal is used to detect EAS markers and metal objects within the interrogation zone. The EAS signal is received and a metal object present in the interrogation zone is detected during a metal detection cycle. The metal object is detected based upon perturbations in the received EAS interrogation signal. The metal detection cycle is periodically interspersed with at least one EAS detection cycle.
8 Citations
13 Claims
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1. A method for detecting a metal object and an electronic article surveillance (“
- EAS”
) marker, the method comprising;establishing an interrogation zone by transmitting only a first signal at only a predetermined frequency, the establishing occurring only during a metal detection window of an EAS/metal detection cycle; during the establishing, receiving at least a portion of the first signal at the predetermined frequency; detecting a metal object by; determining a first voltage of the received portion of the first signal at the predetermined frequency; comparing the first voltage to a second voltage; and responsive to determining that the first voltage is different from the second voltage by more than a prescribed amount, determining the metal object is present; and during an EAS detection window of the EAS/metal detection cycle, wherein the EAS detection window occurs after the metal detection window, detecting an EAS marker response to the transmitting. - View Dependent Claims (2, 3, 4, 5)
- EAS”
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6. A system for detecting a metal object and an electronic article surveillance (“
- EAS”
) marker, the system comprising;a transmitter configured to establish an interrogation zone by transmitting only a first signal at only a predetermined frequency, the establishing occurring only during a metal detection window of an EAS/metal detection cycle; a receiver configured to receive, during the establishing, at least a portion of the first signal at the predetermined frequency; and a metal detector configured to detect a metal object by; determining a first voltage of the received portion of the first signal at the predetermined frequency; comparing the first voltage to a second voltage; and responsive to determining that the first voltage is different from the second voltage by more than a prescribed amount, determining the metal object is present; and a controller electrically connected to the transmitter, to the receiver and to the metal detector, the controller configured to detect an EAS marker response to the transmitting during an EAS detection window of the EAS/metal detection cycle, the EAS detection window occurring after the metal detection window. - View Dependent Claims (7, 8, 9, 10)
- EAS”
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11. A metal object and electronic article surveillance (“
- EAS”
) marker detection system comprising;a transmitter configured to establish an interrogation zone by transmitting only a first signal at only a predetermined frequency, the establishing occurring only during a metal detection window of an EAS/metal detection cycle; a receiver configured to; during the establishing, receive at least a portion of the first signal at the predetermined frequency; and during an EAS detection window of the EAS/metal detection cycle, detect an EAS marker response to the transmitting, the EAS detection window occurring after the metal detection window; and a metal detector configured to detect a metal object by; determining a first voltage of the received portion of the first signal at the predetermined frequency; comparing the first voltage to a second voltage; and responsive to determining that the first voltage is different from the second voltage by more than a prescribed amount, determining the metal object is present. - View Dependent Claims (12, 13)
- EAS”
Specification