Patent ID: 7589836

Claim:
Optoelectronic sensor device ( 08 ) arranged for recording of soiling on a cover ( 09 ) transparent for electromagnetic waves of a certain wavelength range, with at least one light source ( 12 , 13 ) that emits at least two light beams ( 10 , 11 ), a test surface ( 15 ) arranged in cover ( 09 ), having a concave surface ( 14 ) exposed to environmental effects, through which the light beams ( 10 , 11 ) emerge and reenter, as well as at least one receiver ( 16 , 17 ) that measures the radiation powers of the light beams ( 10 , 11 ), on which the light beams ( 10 , 11 ) are imaged independently of each other after reentry in an unsoiled surface ( 14 ), characterized by the fact that the test surface ( 15 ) has at least two areas ( 18 , 19 ) with different microstructurings, in which a first microstructuring is designed, so that a liquid applied to the area ( 18 ) provided with the first microstructuring is held together drop-like, and a second microstructuring is designed, so that a liquid applied to the area ( 19 ) provided with the second microstructuring is distributed film-like, in which case, in the unsoiled state of surface ( 14 ), at least a first light beam ( 10 ) emerges and reenters through the first area ( 18 ) and at least a second light beam ( 11 ) emerges and reenters through the second area ( 19 ), so that a conclusion can be drawn concerning the transparency of the cover ( 09 ) exposed to soiling by evaluation of the radiation powers.