SENSOR FOR DETECTING CONTAMINANTS AND/OR RAIN AND METHOD FOR OPERATING A SENSOR
The invention relates to a sensor to detect contaminants and/or water with at least one transmission unit ( 12, 112 ) and at least one receiver unit ( 16, 116 ) as well as a test surface ( 22, 122 ) in which the deposit ( 30, 32 ) can be detected on the test surface ( 22, 122 ) by a light beam ( 24, 26; 124, 126 ) emitted by a transmission unit ( 12, 112 ) and received by the receiver unit ( 16, 116 ). The transmission unit ( 12, 112 ) emits at least two different wavelengths allocated to a common receiver ( 18, 118 ) of the receiver unit ( 16, 116 ).
1 . A sensor for detecting contaminants and/or rain with at least one transmission unit ( 12 , 112 ) and at least one receiver unit ( 16 , 116 ) as well as one test surface ( 22 , 122 ), in which a deposit ( 30 , 32 ) on the test surface ( 22 , 122 ) can be detected by a light beam ( 24 , 26 ; 124 , 126 ) emitted by the transmission unit ( 12 , 112 ) and received by the receiver unit ( 16 , 116 ), characterized in that the transmission unit ( 12 , 112 ) emits at least two different wavelengths allocated to a common receiver ( 18 , 118 ) of the receiver unit ( 16 , 116 ).
2 . A sensor according to claim 1 , characterized in that the transmission unit ( 12 , 112 ) comprises at least two transmitters ( 114 , 114 a , 114 b , 114 c ) with different wavelengths.
3 . A sensor according to claim 2 , characterized in that the transmitters ( 114 , 114 a , 114 b , 114 c ) are closely neighboring.
4 . A sensor for detecting contaminants and/or rain with at least one transmission unit ( 12 , 112 ) and at least one receiver unit ( 16 , 116 ) as well as a test surface ( 22 , 122 ) in which a deposit ( 30 , 32 ) on the test surface ( 22 , 122 ) can be detected by a light beam ( 24 , 26 ; 124 , 126 ) emitted by the transmission unit ( 12 , 112 ) and received by the receiver unit ( 16 , 116 ), characterized in that the transmission unit ( 12 , 112 ) comprises at least two spatially closely neighboring transmitters ( 114 , 114 a , 114 b , 114 c ) allocated to a common receiver ( 18 , 118 ).
5 . A transmitter according to claim 4 , characterized in that the light beams ( 24 , 124 ) emitted by the transmitter ( 12 , 112 ) have different wavelengths.
6 . A sensor according to one of the previous claims, characterized by an embodiment as a passing light sensor.
7 . A sensor according to one of the previous claims, characterized by an embodiment as a reflection sensor.
8 . A sensor according to one of the previous claims, characterized in that means are provided to analyze a variation of intensity of the received light beams ( 26 , 126 ) depending on wavelengths.
9 . A sensor according to one of the previous claims, characterized in that means are provided to analyze a variation in intensity of the received light beams ( 26 , 126 ) depending on location.
10 . A sensor according to one of the previous claims, characterized in that the transmission unit ( 12 , 112 ) comprises light-emitting diodes as the transmitter ( 14 , 114 , 114 a , 114 b , 114 c ).
11 . A sensor according to one of the previous claims, characterized in that the transmission unit ( 12 , 112 ) comprises at least one broadband transmitter.
12 . A sensor according to one of the previous claims, characterized in that the receiver unit ( 16 , 116 ) comprises one or more individual receivers.
13 . A sensor according to claim 12 , characterized in that one or more individual receivers can by temporarily synchronized with the transmission unit ( 12 , 112 ).
14 . A sensor according to claim 12 or 13 , characterized in that means are allocated to one or more individual receivers, allowing the detection of the light independent from the wavelengths.
15 . A sensor according to one of claims 12 through 14 , characterized in that the light can be spectrally evaluated by one or more individual receivers.
16 . A method for operating a sensor ( 10 , 100 ) to detect contaminants and/or rain with at least one transmission unit ( 12 , 112 ) and at least one receiver unit ( 16 , 116 ) as well as a test surface ( 22 , 122 ) in which a deposit ( 30 , 32 ) on the test surface ( 22 , 122 ) can be detected by a light beam ( 24 , 26 ; 124 , 126 ) emitted by a transmission unit ( 12 , 112 ) and received by the receiver unit ( 16 , 116 ), in particular according to one of the previous claims, characterized in that a signal received by a receiver ( 18 , 118 ) of the receiver unit ( 16 , 116 ) is analyzed depending on its wavelength and/or the geometric origin of the allocated transmission unit or units ( 114 , 114 a , 114 b , 114 c ).
17 . A method according to claim 16 , characterized in that a transmitter ( 14 , 114 ) of the transmission unit ( 12 , 112 ) emits a polychromatic signal.
18 . A method according to claims 16 or 17 , characterized in that at least two transmitters ( 114 , 114 a , 114 b , 114 c ) of the transmission unit ( 12 , 122 ) are allocated to a common receiver ( 18 , 118 ) of the receiver unit ( 16 , 116 ) operating temporarily offset.
19 . A method according to one of claims 16 through 18 , characterized in that a variation of the received signal is examined as a function of the wavelength and/or the geometric location of the transmitter ( 114 , 114 a , 114 b , 114 c ).
20 . A method according to one of claims 16 through 19 , characterized in that the presence of water is detected as a deposit ( 32 ) when a critical value of the variation is crossed.
21 . A method according to one of claims 16 through 20 , characterized in that the presence of dust is detected as a deposit ( 30 ) when a critical value of the variation is fallen short of.
22 . The use of a sensor ( 10 , 100 ) according to one of claims 1 through 15 in a system to adjust the light intensity of vehicle lights.