Abstract: A method of determining distances and angular positions of stationary and moving objects (3), for example in an area to be monitored in connection with for instance swing doors. The determination is done by means of triangulation where light, which in the main part is collimated, is transmitted (1) into the area at different angles and in a certain sequence. The reflected light is correspondingly registered on a position-sensitive sensor (5) which is positioned at a certain distance from the transmitter (1). The position (5a, 5b), where the reflected light falls on the sensor (5), represents the distance, and the moment when the light is received represents the angular position of the detected object. The values are compared to stored reference values which change when the angle of the door's opening is changed.

Abstract: A microprocessor-based door control unit includes a programmable, non-volatile-memory for storing door operating parameter values. A separate programming unit, arranged for connection to the door control unit, includes a second microprocessor, a keyboard and a display. The parameter values stored in the non-volatile memory can be read by the programming unit, and new values can be stored in the non-volatile memory using the programming unit.

Abstract: An object sensing apparatus includes a plurality of light emitting diodes for illuminating a region of space and a plurality of closely arranged light detectors for receiving light reflected from an object. The apparatus is particularly useful in connection with automatically operated doors.

Abstract: An object sensing apparatus includes a plurality of light emitting diodes for illuminating a region of space and a plurality of closely arranged light detectors for receiving light reflected from an object. The apparatus is particularly useful in connection with automatically operated doors.

Abstract: An arrangement for controlling operation of a motor operated door is provided with doppler radar sensors facing the approach to the door from both sides. The doppler signals from the sensors are analyzed to determine the presence of motion toward or away from the door and the door is controlled to open upon motion toward the door and close upon motion away from the door.

Abstract: The invention comprises a pulse transmitter (2,3) for infrared light, the reflected radiation from which is received by photo-diodes (5) converting the light pulses to electric pulses (FIG. 3), which are amplified (9) and applied to a balancing circuit (12), which operates digitally and with a given working or threshold level. Applied pulses give the output of the balancing circuit (12) a low state, which is supplied to a first integration circuit (16) having relatively rapid integration time, and which is in series with a second integration circuit (18). The integration circuits each control an input (21,26) of a comparison circuit (22), which generates an operation signal on its output (27,28) when there is a difference in integration conditions, the slower integration circuit (18) controlling the working or threshold level of the balancing circuit (12).

Abstract: An object sensing apparatus includes a plurality of light emitting diodes for illuminating a region of space and a plurality of closely arranged light detectors for receiving light reflected from an object. The apparatus is particularly useful in connection with automatically operated doors.