Abstract: An electronic article surveillance (EAS) systems includes an asynchronous noise suppression adaptive filter which removes asynchronous interference from the signal of interest with minimum distortion of the transients emitted when a sensitized tag is interrogated. The system also includes a synchronous noise suppression filter which removes interrogation synchronous noise from the signal of interest. The resulting EAS system increases the likelihood that a sensitized tag will be detected when one is present and reduces the occurrence of false alarms.

Abstract: An embedded system controller-based vehicle tracking system using vehicle positioning. An embedded system controller controls a traffic intersection using an optical system. The embedded system controller receives a vehicle location and a vehicle schedule. The embedded system controller calculates whether the vehicle is on time and reports the on-time status to the driver interface. The driver may -request that the system report a panic or emergency situation to the dispatch center through an external data communications network. The external data communications network may also send vehicle status, such as vehicle position and vehicle condition. A transit company using the system may provide vehicles equipped with the vehicle tracking system with schedules on a daily basis, using a portable data transfer device. The embedded system controller also communicates to the vehicle data network for the communication of vehicle position.

Abstract: A dual status marker for use with a magnetic-type EAS system has a signal-producing layer including at least one magnetic thin-film of high permeability and low coercive force such as permalloy, and a signal-blocking layer including at least one remanently magnetizable thin-film such as an Fe-Cr alloy. The remanently magnetizable thin-film or thin-films should have a total thickness at least equal to, and preferably at least twice, the total thickness of the magnetic thin-film or thin-films of high permeability. By doing so, the marker is more reliably deactivated when the signal-blocking layer is magnetized. For even greater assurance of deactivation, the signal-blocking layer should include more than one remanently magnetizable thin-film, thus giving it a squarer B-H loop and greater assurance against false alarms.

Abstract: An ear device protects a user from damaging sound levels while permitting the user to hear and understand conversation in a noisy environment. The device includes an enclosure system for at least partially isolating the user's ear drums from ambient sounds, at least on directional microphone, an adaptive band pass filter and a speaker. The adaptive band pass filter further includes adaptive high pass and adaptive low pass filters which adaptively and independently control the range of the pass band depending upon the characteristics of the noise in the user's environment. A speaker transmits the processed signal to the user. The adaptive filter also includes a detector connected to receive the processed signal which controls the gain of the system to prevent overcompression of the audio signal. The adaptive filter further includes an adaptive compression circuit utilizing multiple time constants to control the response time of the adaptive filter under various conditions.

Abstract: A traffic control preemption system uses data received from a global positioning system (GPS) to determine whether a vehicle issuing a preemption request is within an allowed approach of an intersection. GPS signals are received and processed by the vehicle module to generate vehicle data, including the vehicle's position, heading and velocity. The vehicle data is transmitted via radio transmission or some other medium. Each intersection has an associated intersection module which, if within range of the vehicle's transmitting equipment, compares the received vehicle data with a preprogrammed map of allowed approaches to the intersection. If the vehicle data sufficiently matches the map of allowed approaches, the vehicle's preemption request is forwarded to the intersection controller to appropriately control the phase of the traffic signal at the intersection.

Abstract: A detector system filters the effects of periodic noise such as magnetic flux from nearby power lines or other periodic sources. The detector system further adapts in the case that the system incorporates microloops for the inductive sensors. The detector system further counts multiple vehicles while in presence mode. The detector system also logging of vehicle data and system faults.

Abstract: A reference value used in a vehicle detector is checked and adjusted. The vehicle detector determines the speed of a vehicle which it has detected and then makes a sample measurement after the vehicle has left the detection area of its inductive sensor. The timing of the measurement is based on the speed of the vehicle. The sample measurement is compared to the reference value, and adjustment of the reference value is made accordingly. In order to identify the cause of changes in the sensor drive oscillator signal frequency, the frequency of the oscillator signal is measured while connected to a dummy sensor not affected by vehicles. The reference value also is adjusted to reflect slow changes (drift) in sensor drive oscillator frequency. To identify changes in sensor drive oscillator frequency caused by mechanical difficulties which require maintenance activity to correct, a rate of frequency change of the sensor drive oscillator signal is determined over the plurality of measurement scanning segments.

Abstract: A composite marker providing electronic article surveillance (EAS), identification, and authentication. The marker preferably includes an EAS detection element which includes a low-coercive force, high-permeability ferromagnetic material, and an adjacent, remanently-magnetizable ferromagnetic material which, when magnetized, alters a characteristic response produced by the first material when in an interrogation zone of an associated EAS system, an intermediate layer containing UPC or similar optically-readable information and a substantially-transparent, optically-detectable security element overlying said intermediate layer and having means integrally associated therewith for thwarting counterfeiting or other unauthorized duplication.

Abstract: A deactivating device for magnetic markers in an electronic article surveillance (EAS) system includes a housing adapted to constrain typical audio and video cassettes in preferable orientations with respect to first and second deactivating surfaces. The first deactivating surface includes a first magnetic insert, which includes a first magnet designed to produce a deactivating magnetic field which deactivates markers affixed to audio and/or video cassettes without causing audible signal degradation of the prerecorded magnetic media within the audio or video cassette. The second deactivating surface includes a second magnetic insert and second magnet designed to produce a deactivating magnetic field which deactivates markers placed in the recessed edge of video cassette without causing audible signal degradation of the prerecorded magnetic media contained in the video cassette. An alternate magnetic insert which can be substituted for the first and second magnetic inserts is also described.

Abstract: An antenna lattice for use in a magnetically based electronic article surveillance system. The lattice includes a field-producing coil assembly which includes a pair of trapezoidal-shaped segments, each having a diagonally extending lower portion, the segments being juxtaposed in a mirror image so that the diagonal portions are opposite each other. The segments are connected so that vertical components of the currents in the diagonal sections at least partially cancel. Preferably, top horizontal sections of each segment are located at different levels, thereby extending the upper coverage, and a detector coil preferably also juxtaposed extends above the top horizontal section of the field-producing coil to further extend the range of detection.

Abstract: A dual-status marker for use in electronic article surveillance systems having an alternating magnetic field within an interrogation zone. The marker comprises a piece of a high permeability, low coercive force magnetic material substantially coextensive with a piece of remanently magnetizable material. The first piece is rectangular and exhibits lengthwise sections at which the material is removed, thus leaving narrow width regions forming switching sections, portions adjacent each end forming flux collectors. The marker is desensitized by uniformly magnetizing the piece of remanently magnetizable material.

Abstract: A method for manufacturing a nonlinear, dual-axis thin-film magnetic device which can be used as an electronic article surveillance system marker. The method includes providing a substrate having a surface characterized by first and second generally perpendicular axes. A magnetic field oriented parallel to the first axis is applied on the surface of the substrate. A first stack of relatively thin thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the substrate. The relatively thin thin-tim layers are grown in the presence of the magnetic field to a thickness sufficiently thick that the layers exhibit magnetic properties that are substantially independent of surface effects, but sufficiently thin that the easy axis of magnetization is oriented parallel to the second axis. A second stack of relatively thick thin-film magnetic layers separated by nonmagnetic thin-film layers is grown on the first stack.

Abstract: A vehicle detector includes an inductive sensor which is driven by an oscillator to produce an oscillator signal having a frequency which is a function of inductance of the inductive sensor. Presence of a vehicle is detected when measured frequency of the oscillator signal changes by more than a threshold value. The effects of magnetic flux produced by adjacent power lines are compensated by measuring the frequency of the oscillator signal during a plurality of sample periods and characterizing the fluctuation of the measured frequency as a function of phase of a power main signal. During a normal measurement period, the frequency of the oscillator signal is measured, and the phase of the power main signal during the measurement period is determined. An output signal is produced based upon the measured frequency, the phase, and the known fluctuation of measured frequency as a function of phase of the power main signal.

Abstract: To detect a marker element, a transmitter generates an alternating magnetic field. A receiver arranged in this field generates an electrical signal having a waveform corresponding to the magnetic flux density of the alternating magnetic excitation field superimposed by peaks produced upon reversal of the magnetic state of the marker element. The position of these peaks, relative to the alternating magnetic excitation field, is determined, and if different from half the period duration of the alternating magnetic excitation field by less than a predetermined value, a first state of the marker element may be detected. Otherwise, it may be determined that, either, no marker element is present in the alternating magnetic excitation field, or that the marker element is in a second state different from the first state.

Abstract: A universal lattice assembly for use in a magnetic-type electronic article surveillance system is disclosed which comprises a frame formed of two identical molded plastic half-shells, a metal chassis within which specific electronic sub-assemblies may be positioned and a coil assembly including a field-producing coil and a detector coil. The frame includes a substantially continuous series of tabs and notches which are positioned to be inter-connected as the half-shells are pressed together, the resulting assembly becoming dimensionally rigid, thus firmly anchoring a coil assembly in place, preventing any relative movement as the assembled unit may be jostled in operation.

Abstract: An optical information storage disk especially adapted for tamper-proof monitoring by an electronic article surveillance (EAS) system. The compact disk hereof includes a generally planar, annular first disk surface and an opposed, generally annular second disk surface, a plurality of generally concentric data tracks on at least one of the disk surfaces, a centered aperture and a generally annular EAS magnetic marker concentrically oriented about the centered aperture. The annular EAS marker comprises a dual status, multi-directional marker with a selectively demagnetizable, essentially linear magnetic switching field. The marker is preferably received within a grooved recess in one of the disk surfaces and is immovably retained within the grooved recess by a coating covering the disk surface.

Abstract: A marker assembly adapted for use with an electronic article surveillance (EAS) system, and particularly for use with books to be monitored by an EAS system, includes a flat elongated, marker strip of low coercive force, high permeability ferromagnetic material, adhesive layers carried on both the front and rear surfaces of the marker strip and a release liner which extends along the rear surface of the marker strip, around opposed end margins of the marker, and along the front surface thereof, terminating at the approximate midpoint of the marker strip with opposed, graspable tabs carried clear of the adhesive layer on the front surface. Pulling the opposed tabs away from each other removes the wrapper from the front surface, thereby exposing the adhesive carried on that surface and allowing attachment of the front surface to a selected page of the book.