fig1 shows a sectional diagram of an optoelectronic sensor device mounted on an automotive windshield 14 to detect wetting with moisture or soiling of windshield 14 . the sensor device has a casing 20 which is mounted on windshield 14 , in particular by gluing or pressing . a light guidance body 10 having two structures 22 projecting on a top side 18 of light guidance body 10 facing the interior of the sensor is also in direct contact with windshield 14 light guidance body 10 is pressed against windshield 14 by casing 20 with a clamping spring , for example , or is glued to it . structures 22 have lens - like optical surfaces 24 . a transmitter 6 and a receiver 8 are located at the focal point of optical surfaces 24 . both are mounted on and parallel to a circuit board 4 which is in turn arranged parallel to windshield 14 inside sensor device casing 20 . the beam path of transmitter radiation 30 is depicted along optical axes 28 of optical surfaces 24 . transmitter radiation 30 is aligned in parallel to optical surface 24 of structure 22 assigned to transmitter 6 and is sent in a light guide 26 to the base of fiber optic light guidance body 10 . beam path 30 , aligned in parallel , is first inputted into windshield 14 by light guidance body 10 and is subject to at least total reflection on outside 32 of clean and unwetted windshield 14 , and it is outputted from windshield 14 by light guidance body 10 and refractive surface 24 of additional structure 22 provided for receiver 8 and then it is focused on receiver 8 . fig2 shows a perspective view of light guidance body 10 having a rectangular contact area 12 aligned with windshield 14 and top side 18 having a peripheral web 16 . structures 22 . 1 and 22 . 2 integrally molded on light guidance body 10 are arranged in pairs and project out of top side 18 of light guidance body 10 . a total of four structures 22 each have two lense - shaped curved optical surfaces 24 and each have two cylindrical light guides 26 , with optical surfaces 24 extending into the troughs 27 of light guidance body 10 in front of them . both light guidance body 10 and structures 22 are made of the same material which is essentially transparent for the transmitter radiation . for example , plexiglass materials , which are pigmented or left transparent according to transmitter radiation 30 used ( infrared or visible light ), are suitable for this purpose . pigmenting fiber optic light guidance body 10 , e . g ., in black , makes it possible to filter out some of the interfering light , i . e ., ambient light 34 , striking light guidance body 10 through windshield 14 in an unwanted manner . fiber optic light guidance body 10 , shown in a perspective view in fig2 is illustrated with a view of top side 18 in fig3 . structures 22 are connected by dash - dot lines 28 a which correspond to the , projection of optical axes 28 of optical surfaces 24 on top side 18 parallel to windshield 14 . dash - dot lines 28 a form a parallelogram . a transmitter 6 or a receiver 8 is arranged at each corner point of the parallelogram . inside angles and of the parallelogram correspond to beam angle of the two bundled beams emitted by one of two transmitters 6 along optical axes 28 , i . e ., lines 28 a , and beam angle corresponds to transmitter radiation 30 bundled on one of the two receivers 8 from the two different directions . beam angle of transmitter 6 is approximately 110 °, and beam angle of receiver 8 is approximately 70 ° it can also be seen on the basis of fig3 that structures 22 . 1 and 22 . 2 are different . structures 22 . 1 assigned to beam angle of transmitters 6 are characterized by complete circular optical surfaces 24 and light guides 26 . structures 22 . 2 assigned to beam angle of receivers 8 have optical surfaces 24 and light guides 26 that are interlinked and merge into one another . fig4 a shows a section through light guidance body 10 and two structures 22 . 1 and 22 . 2 along line iva — iva according to fig3 . optical axes 28 of optical surfaces 24 and a transmitter 6 and a receiver 8 are shown here . angle of inclination of optical axes 28 relative to contact area 12 , i . e ., to outside 32 of the windshield , is approximately 45 ° and thus permits total reflection of incident transmitter radiation 30 on outside 32 of the windshield . fig4 b shows a section along line ivb — ivb , according to fig3 through light guidance body 10 and a structure 22 . 1 assigned to a transmitter 6 . optical axes 28 of optical surfaces 24 of structure 22 . 1 and transmitter 6 are shown here . this illustrates the parallelization of the transmitter radiation in two directions x 1 , x 2 in a section perpendicular to windshield 14 . fig5 illustrates another embodiment , depicting the arrangement of transmitters 6 and receivers 8 in a parallelogram . structures 22 have not been shown for the sake of simplicity . light guide 10 is now also shaped like a parallelogram , but otherwise it has the same properties and features as light guidance body 10 in the first embodiment according to fig1 through 4 . a feature common to both embodiments is , for example , the parallelization of the transmitter radiation of one transmitter 6 in two directions x 1 , x 2 as seen in the view parallel to windshield 14 along dotted lines 28 a and the focusing of the transmitter radiation from two directions x 1 , x 2 on one receiver 8 .