Abstract: Cameras take images of a predetermined area around a door. A distance measurement unit measures a distance from the cameras to each object in the taken images. Based on the measured distance, a floor detection unit detects a floor, and an object height/position detection unit detects a height and position of any object other than the floor. A door position detection unit and a door position identification unit 57 specify position of the door (i.e. open or closed) in the images taken by the cameras. A judgement unit judges presence or absence of an object which is neither the floor nor the door. If an object other than the floor and the door is observed in the images taken by the cameras, an output unit produces an object detection signal, so that the door is kept in an open state.

Abstract: Cameras 51, 52 take images of a predetermined area around a door. A distance measurement unit 53 measures the distance to each object in the taken images. Based on the measured distance, a floor detection unit 54 detects a floor, and an object height/position detection unit 55 detects the height and position of any object other than the floor. A door position detection unit 56 and the door position identification unit 57 specify the position of the door (i.e. open or closed) on the images. A judgement unit 58 judges the presence or absence of an object which is neither the floor nor the door. If an object other than the floor and the door is observed in the images, an output unit 59 produces an object detection signal, so that the door is kept in an open state.

Abstract: A security sensor equipped with a sighting device in which respective optical axes of a beam projector and a beam receiver can be adjusted easily and quickly. The beam receiver A includes an adjustment (50) for adjusting the optical axis, a mirror-equipped sighting device (C) having a viewing window (12) through which viewing is possible from a lateral side of the beam receiver (A), a light emitting element (8) and a mirror (14) accommodated therein for presenting an image of the beam projector (B), and a lamp control (6) for changing a status of the light emitting element (8) in correspondence with the amount of light received from the beam projector (B).

Abstract: An electronic security system includes a detector (S1, S2) for detecting unauthorized entry of a trespasser into a predetermined outdoor area (A1) or an indoor area (A2) and for generating a detection signal (d1 or d2) indicative of the entry of the trespasser. A mode setting circuit (2) is operated by an input keying operation to select one of an alert mode, in which any possible entry into the predetermined outdoor area (A1) or the indoor area (A2) is monitored, and a non-alert mode in which the possible entry into the predetermined outdoor area (A1) or the indoor area (A2) is not monitored. A control unit (4) preferentially transmits a warning through a telephone line (1) when it receives the detection signal (d1 or d2) generated during the alert mode, but transmits no warning during the non-alert mode. A warning device (12) acknowledges dispatch of the warning.

Abstract: An intruder detection system for senses infrared radiated by an intruder through a window-pane and detecting the intrusion through the reception of an output from the infrared sensors. The system includes a light emitter for projecting infrared rays toward a detection area and a light acceptor for receiving at least part of the infrared rays projected by the light emitter through an obstruction detection optical path. The light emitter and the light acceptor are located on opposite sides of the window-pane.

Abstract: In a separate type infrared intruder-detection system consisting of an infrared beam projector and an infrared detector, the infrared detector is provided with a signal transmitter for transmitting an output level of the infrared detector, while the infrared beam projector is provided with a signal receiver for receiving a signal transmitted by the signal transmitter. These additionally equipped signal transmitter and signal receiver make it possible to achieve an initial beam-axis adjustment operation by one installation operator.