ANTENNA SIGNAL PROCESSING TYPE EAS DEVICE

Japanese Patent JP3483275

B2

PURPOSE: To provide an EAS(electronic article supervisory) device which performs the effective detection in a wide question area, has a small number of transmitting magnetic fields for the given question area width and also supplies all of magnetic field components included in the question area by means by multiplex transmitting antennas.
CONSTITUTION: An EAS device 1 applies the individual front end processing to the 1st and 2nd received signals and generates the 3rd and 4th signals which indicate the absolute value of the 1st and 2nd received signals. Then the 3rd and 4th signals are connected together and sent to a tag evaluation processor 15 for execution of the time and frequency area processing. The processor 15 performs evaluation to decide whether a tag 101 exists in a question area. The front end processing is carried out in such a way where the fault signals including the shielding faults are eliminated in a certain time period with no elimination of the tag signal components included in the received signals. This method drives the 1st and 2nd transmitter antennas 3 and 4 of the device 1 by the drive signals having a phase difference of 0° or 180° and can carry on the tag evaluation processing in all periods of the drive signals.

Christopher B. Pronskey
Jack H Schneider
Stanley A. Stozelek

JP23083393A

January 06, 2004

August 24, 1993

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SENSORMATIC ELECTORONICS CORPORATION

G06K19/07; G08B13/24; H04B1/10; H04B1/59; (IPC1-7): G08B13/24; G06K19/07; H04B1/10; H04B1/59

JP1236399A
JP3195223A

Yuzo Yamazaki (1 person outside)

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