Patent ID: 7385216

Claim:
A sensor device for detecting wetting on a windshield comprising: a control unit; a light emission element for emitting a light; a first light reception element for receiving the light in a first light path that includes reflective redirection by the windshield; a second light reception element for receiving the light in a second light path that does not include redirection by the windshield; and an optical device comprising a transparent portion adapted to transmit light therethrough and intersecting said first light path so that the first light path passes therethrough toward the windshield, the optical device further comprising a reflective surface for redirecting the light from the light emission element to the second light reception element without redirection by or passing into the windshield, the reflective surface being spaced from so as not to intersect the first light path; wherein a ratio of the amount of the received light by the first light reception element and the amount of the received light by the second light reception element is used by the control unit to determine the wetting on the windshield.