Optoelectronic sensor device for detecting the degree of wetting of a transparent motor vehicle window with precipitation

摘要

An optoelectronic sensor device for the detection of the degree of wetting of a transparent vehicle screen with precipitation, includes a beam guide with two opposing parallel surfaces and two surfaces which lie opposite to one another and which are angled in opposing fashion through which beams enter and exit, one of the parallel surfaces being coupled to the vehicle screen in an optical fashion, the beam entry surface cooperating with an optical transmitter and the exit surface cooperating with an optical receiver. The device limits the wavelength of rays which exit from the beam guide to the operating range of the beam transmitter. Two filters (4) are incorporated in the beam path whose pass ranges overlap within a narrow frequency band.