Patent ID: 6668104
Filing Date: 2003-12-23
Classification: B60S,G01D,G01N

Abstract:
An optical sensor for detecting wetting of a surface (11), in particular of a vehicle window, comprising at least one transmitter (13) and at least one receiver (15) for electromagnetic waves, the surface being located in a sensor region (16) between the at least one transmitter (13) and the at least one receiver (15), wherein the development of wetting on the sensor region (16) of the surface (11) causes a signal change, wherein the optical sensor has a light-carrying element (18), in which the electromagnetic waves are guided bidirectionally into the sensor region (16) and out of the sensor region (16) in such a way that it returns the electromagnetic waves, reflected from the surface (11), back to the surface (11) and from there to the light-carrying element (18), wherein the light-carrying element (18) is a monomode or multimode optical waveguide, wherein a retroreflector (10) is provided and formed of a hologram (38) in the form of a plate or film, and wherein the disposition of the reflective segments of the retroreflector (10) is circular or striplike.