Patent ID: 7468523
Filing Date: 2008-12-23
Classification: B60S

Abstract:
1. A raindrop detection apparatus comprising: at least one light emitting unit for emitting light toward an inner side of a windshield; a light receiving unit for receiving the light reflected by an outer surface of the windshield; at least one first lens unit which is arranged between the windshield and the light emitting unit to convert the light from the light emitting unit into parallel light; and a second lens unit which is arranged between the windshield and the light receiving unit to converge the reflected light at the light receiving unit, wherein: the second lens unit is larger than a radial cross section of the reflected light, a surface of the second lens unit disposed for passing the reflected light has a larger area than a surface of the at least one first lens unit through which the light from the light emitting unit passes, and a thickness of the second lens unit in a direction perpendicular to the outer surface of the windshield is larger than a thickness of the first lens unit in a direction perpendicular to the outer surface of the windshield; and an amount of raindrop landed on the outer surface of the windshield is detected based on an intensity of the light received by the light receiving unit.