SENSORVORRICHTUNG ZUR FESTSTELLUNG DES VORHANDENSEINS VON WASSERTROEPFCHEN AUF EINER FAHRZEUG-SCHEIBE UND MIT DER SENSORVORRICHTUNG ARBEITENDES SCHEIBENWISCHER-STEUERGERAET

摘要

A sensor device (1) for detecting the presence of water droplets (2) on a vehicle window (3) comprises a light source (12) which emits light rays towards the window (3) on which is fitted a diffractive optical element (7) operable to convey the light rays towards a photodetector (13) which generates a signal corresponding to the intensity of light incident on it. Means (16, 17, 18 and 21) for processing the electrical signal from the photodetector (8) may include a comparator (16) and be connected to means (22 and 23) for controlling the actuation of a windscreen wiper according to whether the signal reacting the comparator (16) from the detector (8) is above or below a reference signal. <IMAGE>