Patent ID: 7466097

Claim:
A method for controlling operation of a wiper for a windshield glass of a vehicle, comprising the steps of: (a) reflecting light emitted from a light emitting element on a detection surface provided at a part of a wiper wiping area of the windshield glass and detecting adhesion of raindrops on the detection surface by receiving the reflected light by a light receiving element, (b) determining a rainfall level based on an output signal of said light receiving element; (c) determining entrance and exit of said vehicle to and from a rainfall shutoff environment, respectively; (d) controlling a wiping state of the wiper in response to the rainfall level determined in step (b) and said determination in step (c), the wiping state being classified and defined as a plurality of stepwise wiping levels according to wiping waiting time and wiping speed and step (d) further including: (d1) making setting to lower the wiping level for a low-level rainfall less than a predetermined rainfall level in the rainfall shutoff environment and to raise the wiping level for a high-level rainfall equal to or more than the predetermined rainfall level in preparation for exit of said vehicle from the rainfall shutoff environment; and (d2) determining the wiping state of said wiper based on the wiping level set in said Step (d1).