| 摘要 |
PROBLEM TO BE SOLVED: To widely transmit informing sound to a side of a vehicle when vehicle speed is slow, and to widely transmit informing sound to a rear side of the vehicle and a rear side when the vehicle moves backward, in a vehicle presence informing device 1 generating the informing sound by radiating an ultrasonic wave based on a modulated ultrasonic wave signal. SOLUTION: This vehicle presence informing device 1 includes a speaker 3 generating the informing sound by making the ultrasonic wave as a carrier wave and radiating the ultrasonic wave modulated according to audible sound into air. The speaker 3 radiates modulated waves toward a road surface when the vehicle speed is prescribed speed or below or the vehicle moves backward. As a result, when the vehicle speed is the prescribed speed or below or the vehicle moves backward, the informing sound can be widely transmitted to also the side of the vehicle by utilizing irregular reflection on the road surface. COPYRIGHT: (C)2011,JPO&INPIT
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