Abstract: A disc device includes a disc substrate having an information signal pattern formed on a surface thereof and a magnetic material layer formed on the information signal pattern which permits for detection of the device by an electronic article surveillance detection system.

Abstract: A gaming chip has a disc-like body in which is disposed an amorphous magnetic marker material.

Abstract: An EAS system in which first and second received signals are independently front-end processed to produce third and fourth signals indicative of the absolute values of the first and second processed signals. The third and fourth signals are then combined and the combined signal passed to a tag evaluation processor for time and frequency domain processing for evaluating whether a tag is present in an interrogation zone. The front-end processing is carried out in such a way that interference signal content including shield interference is extracted without extracting tag signal content in the received signals over a period of time. In this way, the first and second transmitter antennas of the system can be driven with drive signals having a phase difference of other than 0.degree. or 180.degree. and the tag evaluation processing can be carried out during the entire period of the drive signals.

Abstract: A deactivating device for deactivating a dual status EAS tag for use in an EAS system in which the device utilizes a detection field for detecting the presence of an active tag in a detection/deactivation zone and in which the device further utilizes a deactivation field which is matched to the detection field.

Abstract: A magnetic article surveillance system in which surveillance is carried out by operating the system in first and second different modes of a magnetic transmitting and receiver means in order to make a determination as to the presence of an article in the zone.

Abstract: Off premises cable television interdiction apparatus comprises a microprocessor actuation and control means for actuating and controlling a plurality of frequency agile voltage controlled oscillators. The voltage controlled oscillators selectively jam only unauthorized premium programming transmitted in the clear from a headend to a particular subscriber. Each voltage controlled oscillator is allocated a continuous band of frequencies consistent with the elimination of jamming signal frequency harmonics which may disturb authorized programming at a higher channel frequency. The microprocessor actuation and control means provides a calibration mode and a normal mode of operation. During the normal mode of operation, a frequency hopping rate on the order of four thousand hertz is achievable.