Vehicle presence notification apparatus

摘要

A vehicle presence notification apparatus generates a notice sound by emitting an ultrasonic wave in mid air based on an ultrasonic signal modulated according to an audible sound. During proceeding in mid air, the modulated ultrasonic wave is self-demodulating to become an audible sound. The audible sound posterior to the self-demodulation has a significant directionality like the ultrasonic wave. The notice sound is thus conveyed mainly to a pedestrian who is present in a dangerous area range where a danger needs to be taught. In addition, the vehicle presence notification apparatus includes a sensor-use ultrasonic transducer device having a transducers. The transducer device serves as a vehicle velocity sensor by transmitting an ultrasonic wave towards a road surface based on an ultrasonic wave signal or modulated ultrasonic wave, thereby enabling the vehicle presence notification apparatus to acquire vehicle velocity information by itself.