Abstract: A system and method for motion detection, useful, for example, in intrusion detection, access control, and energy management, including an incoherent detector, including at least one sensing element, operative to detect receipt of radiation having a wavelength between 0.05 mm and 10 mm from multiple fields of view, and a motion detector receiving an output of the incoherent detector and providing a motion detection output indicating receipt of radiation from an object moving between the multiple fields of view.

Abstract: A displacement sensing system including an oscillator circuit having a characteristic frequency which varies as a function of a magnetic field in the vicinity thereof, an element whose position relative to the oscillator circuit is varied by a displacement, the element being operative to vary the magnetic field in the vicinity of the oscillator circuit as a function of the displacement and circuitry for sensing a change of frequency of the oscillator circuit over time (delta f/delta t) and for providing an output indication when the change in frequency of the oscillator circuit over time exceeds a threshold.

Abstract: An optical element including a substrate which is generally transparent to infrared radiation in a wavelength range of 5-16 &mgr;m, a pigment disposed in the substrate in an amount that does not generally decrease transmission of the infrared radiation, the pigment being generally non-transmissive to at least one of visible and ultraviolet light, the pigment being reactable with the substrate over time to create a reaction product which can decrease transmission of the infrared radiation, and a protective agent disposed in the substrate in an amount that does not generally decrease transmission of the infrared radiation and which generally prevents creation of the reaction product which can decrease transmission of the infrared radiation. The optical element may be a lens for a passive infrared detector assembly, for example.

Abstract: This invention discloses circuitry for signal measurement including a signal input, a microprocessor, and an oscillator, the oscillator being operable to generate a pulse signal, the frequency of which is a function of amplitude of a first signal received at the signal input, and to supply the pulse signal to the microprocessor, and the microprocessor being operable to measure the frequency of the pulse signal by comparing the pulse signal with a timing signal, thereby providing an indication of the amplitude of the first signal.

Abstract: An improved infra-red lens array for use in a passive infra-red intrusion sensor, which maintains high detection capability for intruders moving in the middle and near field, and yet discriminates well between the movement of intruders and of pets in the near field. The upper part of the lens array is composed of at least one row containing convex lenses, operative to focus the far and middle field radiation of the area to be protected onto the detector of the sensor. The lower part of the array has at least one row containing cylindrical lenses, with their axes of symmetry aligned vertically, operative to focus infra-red radiation from the middle and near fields onto the detector. Each cylindrical lens focuses a vertical curtain of the protected area onto the infra-red detector.

Abstract: This invention discloses a microwave transceiver suitable for use in an intrusion detection system including a microwave radiation generator, a printed antenna on a first side of a printed circuit board for radiating the microwave radiation generated by the microwave generator, and a ground plane on a second side of the printed circuit board and having an outer edge which is generally coextensive with an outer edge of the printed antenna.

Abstract: This invention discloses a method for detecting the presence of a moving object in a detection area, including emitting a sequence of bursts of ultrasonic energy into the area, receiving ultrasonic energy reflected from within the detection area, in response to the sequence of bursts, and generating a sequence of signals respectively responsive thereto, comparing each signal in the sequence with a preceding signal, to find a variation in the signals over the sequence of bursts, and analyzing the variation in the signals to determine the presence of the moving object. Apparatus for detecting the presence of a moving object in a detection area is also disclosed.

Abstract: A method for determining malfunction of a microwave intrusion detector which transmits microwave radiation into a region and receives microwave radiation to produce a receiver signal, such that a detection pattern of microwave pulses is transmitted periodically during an intrusion detection mode, including initiating a self-test mode of the detector, transmitting during the self-test mode a test pattern comprising a plurality of microwave pulses having at least two different duty cycles, different from the detection pattern, receiving microwave radiation in the self-test mode and generating a receiver signal responsive thereto and analyzing the receiver signal to derive a parameter responsive to the test pattern, so as to determine a malfunction condition.

Abstract: A signaling network system including a plurality of receivers distributed in a protected region comprising multiple protected enclosures and including RF receivers as well as a plurality of non-RF receivers, located within said multiple protected enclosures, for receiving non-RF signals emanating from within the enclosure within which the receiver is located, said non-RF signals generally not capable of being received by a receiver located outside the enclosure from which they are transmitted and at least one portable emergency indicating signal transmitter which is selectably locatable in an enclosure and which is operative to transmit, when actuated, both RF and non-RF signals.

Abstract: A method of supervising the operation of an intrusion detector having a housing, the method including periodically generating in the housing at least one sound wave signal, sensing an acoustic image formed in the housing in response to the at least one sound wave signal, constructing a sensed signal envelope responsive to the sensed acoustic image, periodically comparing the sensed signal envelope with a reference signal envelope to determine whether a predetermined criterion of similarity between the sensed signal envelope and the reference signal envelope is met and, if the similarity criterion is not met, providing a predetermined, sensible, indication.

Abstract: A method of detecting glass breakage utilizing the sound produced by an event comprising the steps of sensing the sound and producing an electrical signal characteristic of the sound, producing a plurality of frequency band-limited signals from the sound signal, determining when a normalized rate-of-rise of a plurality of the band limited signals is above a given value specified for the particular band-limited signal and analyzing the sound signal further only if a plurality of the band-limited signals have a normalized rate-of-rise greater than their respective given value during a specified time period.

Abstract: Intrusion detection apparatus including a microwave transmitter comprising a generally unshielded dielectric resonating oscillator, whose parasitic field is radiated within a volume and Doppler detection apparatus for sensing received Doppler signals reflected by a moving object within the volume.