Patent attributes
A headlight is turned on if an external illuminance value outside of the vehicle is equal to or lower than a first threshold value if the non-rainfall state is judged from windshield wiper activation, and is permitted to be turned on if the external illuminance value is equal to or lower than a second threshold value higher than the first predetermined illuminance value if the rainfall state is judged. When the vehicle is capable of being driven and the headlight is turned on, if an average illuminance value of the external illuminance value is equal to or higher than a predetermined value, then the second threshold value switches to the first threshold value. When the headlight is turned off, if the activation of the wiper has not been confirmed for a first predetermined period, then the second threshold value switches to the first threshold value.