Device and method for automatically adapting a light sensor to a windscreen

A device for automatically adapting a light sensor to light transmission characteristics of a windshield of a vehicle, wherein the light sensor is associated with an automatic control device for switching lighting devices of the vehicle on and off and is located adjacent the interior side of the windshield, the device comprising:

• at least one light receiver located adjacent the interior side of the windshield for receiving light beams;
• at least two light transmitters located adjacent the interior side of the windshield for transmitting respective light beams having a different fixed wavelength lambda n in the visible and/or infrared spectral range;
• and
• a light conducting body for coupling the light beams transmitted by the at least two light transmitters to the at least one light receiver along a path which includes transmission through the windshield and at least one reflection on the exterior side of the windshield.

A method for automatically adapting a light sensor to light transmission properties of a windshield of a vehicle, wherein the light sensor is associated with an automatic control device for switching lighting devices of the vehicle on and off and is located adjacent the interior side of the windshield, the method comprising:

• transmitting a light beam having at least two different fixed wavelengths γl, . . . , γn from at least one light transmitter located adjacent the interior side of the windshield;
• using a light conducting body to couple the light beam transmitted from the light transmitter to at least one light receiver located adjacent the interior side of the windshield along a path which includes transmission through the windshield;
• measuring light intensities Il, . . . , In of each of the at least two different fixed wavelengths γl, . . . , γn of the light beam received by the at least one light receiver;
• comparing the measured light intensities Il, . . . , In, with reference light intensity values Irl, . . . , Irn;
• calculating transmission properties of the windshield based on the comparison between the measured light intensities Il, . . . , In, and the reference light intensity values Irl, . . . , Irn ;
• and
• influencing operating parameters of the automatic control device or of the light sensor as a function of the calculated transmission properties of the windshield.