Device for visibility measurement for a motor vehicle

Device for visibility measurement for a motor vehicle with a driver's compartment bounded by a windshield, comprising:

• a light emitter means for generating light pulses or flashes,
• a light sensor for registering the light scattered back from scatter zones in the light path upon emission of the light pulses or flashes;
• and
• an evaluation circuit for converting output signals of the light sensor into control signals for a visibility display,
• wherein both light backscatter from scatter zones outside the windscreen of the driver's compartment and the light backscatter caused by soiling on the windshield can be evaluated by virtue of the fact that the light emitter means and the light sensor are arranged inside the windshield and the light pulses or flashes are directed onto the windshield and through the windshield to the outside;
• and
• wherein said light emitter means includes a plurality of light emitters for light of different wavelengths to facilitate distinction of different types of viewing hindrances.