Abstract: Both a motion detector and a presence detector receive doppler shifted reflected microwave radiation to detect the passage of a person or an animal in a field of view. The motion sensor is adapted to detect the passage of a person or an animal near a doorway and to actuate the doorway in response thereto, to permit the passage of the person or animal thereto. The presence detector detects "swaying motion" of a person or an animal in a field of view much closer to the location of the sensor as its gain is much lower than that of the motion detection channel. In addition the presence detector is activated only in the event the motion sensor is deactivated. The output signals from the motion sensor and presence sensor are gated through an OR gate and to a timer to activate the door opener.

Abstract: A supervisory circuit for use with an audio intrusion detection system is disclosed. The supervisory circuit periodically generates an audio test signal which is supplied to a sounder which emits an audio test sound. The audio test sound is directed into a volume of space, in the same volume of space as which the audio intrusion detection system is directed to detect. The audio intrusion detection system detects the test sound and generates an audio test signal in response thereto. During the generation of the audio test sound, the comparing apparatus of the audio intrusion detection system is disabled. The audio test signal generated by the audio intrusion detection system is then compared to a test threshold signal. A test result signal is generated in response to the comparison with the test result signal indicative of the operability of the audio intrusion detection system.

Abstract: A ceiling mounted infrared intrusion detection system achieves 360-degree viewing capability by employing concentric rings of mirrors arranged to view multiple segments within an annular volume of space and focus on a centrally located detector. The rings of mirrors have multiple facets, each of which facets reflects radiation from a segment of space being viewed and focuses the radiation on the detector. The rings are disposed in spaced relationship to one another to provide shorter focal lengths for the mirror facets disposed to view space closest to the detector and a path between the rings through which reflected radiation focused on the detector may pass. the centermost ring is open to permit the detector to view directly therethrough.

Abstract: A microwave transceiver comprising a Gunn diode microwave radiation source, a Schottky-barrier diode mixer, a closed rectangular waveguide cavity, a coaxial-waveguide joint, and a monopole antenna providing a microwave radiation dispersion/collection pattern occupying a spatial region elevated from and extending radially outward and 360.degree. in azimuth with respect to said antenna, said spatial region having a substantially spatulate radial cross-section.

Abstract: A 360.degree. pattern field of view optical system for passive infrared detection device is disclosed. The optical system uses a combination of a fresnel lens and a fresnel prism to gather infrared radiation, focus the radiation, and refract radiation onto a focal point. Each of the combination of fresnel lens and prism is positioned substantially circumferentially about a central location to gather the infrared radiation from a 360.degree. field of view and for focusing radiation gathered onto the central location. At the central location, a sensor is located. The sensor converts the focused infrared radiation into an electrical signal.

Abstract: A dual sensing intrusion detection system includes a passive infrared radiation detection sensor that generates a first output signal in response to the detection of an intruder in the volume of space. A second detection sensor is directed to the same volume of space and generates a second output signal in response to detection of the intruder. A switch activates the second detection sensor in response to the detection of the intruder by the infrared radiation detector. Logic circuit receives the first and second output signals and produces an alarm signal in response thereto to indicate the detection of the presence of the intruder in the volume of space.

Abstract: In the present invention, an infrared intrusion detection system is disclosed. The infrared intruder detector is typically mounted at a vertical height from a ground plane. The detector has a fresnel lens which has a plurality of lines of focus for focusing infrared radiation received by the detection system through the fresnel lens. A detector in the detection system is located at the focal point for receiving infrared radiation through the fresnel lens. A curvilinearly-shaped mirror is placed apart from the detector in the direction away from the detection plane for receiving infrared radiation from the detection plane and the reflecting and focusing the detected infrared radiation onto the detector.

Abstract: In an improved intrusion detection device system of the dual-sensor type, wherein one sensor is a PIR sensor and the other is a microwave sensor, the improvement comprises counting the detection of intrusion separately by the microwave sensor and by the passive infrared sensor. Thereafter, the counts by the two separate detectors are compared and an indication is given if the number exceeds a certain user selectable threshold, to indicate fault in one of the two sensor subsystems.