Patent attributes
A rainfall determination apparatus for determining rainfall based on data relating to a wiping operation of a wiper. The apparatus includes a detection device for detecting the wiping operation every time this operation is performed; a timer for starting to clock a predetermined period of time for each wiping operation; a counter for counting the number of times of the wiping operation performed before the predetermined period of time has elapsed; and a determination device for determining that rainfall occurs when the counter counts a predetermined number of times of the wiping operation which is successively performed. The timing of lighting the headlight of a vehicle can be changed in accordance with the result of the determination about the rainfall situation based on the wiping operation of the existing wiper. The apparatus is inexpensive and can be easily built in an automatic lighting system for vehicles, which is relatively expensive.