Patent ID: 11044023

Abstract:
A carrier wave generating unit for generating a carrier wave signal; a modulating unit for generating a modulated wave signal by performing amplitude modulation on the carrier wave signal generated by the carrier wave generating unit with an audio signal; an adding unit for adding the carrier wave signal generated by the carrier wave generating unit and the modulated wave signal generated by the modulating unit to generate a signal; an ultrasonic emitter for emitting the signal generated by the adding unit, and an ultrasonic emitter arranged on the central axis of the ultrasonic emitter and ahead of the emitting surface of the ultrasonic emitter, for emitting the carrier wave signal generated by the carrier wave generating unit in the same direction as the emitting direction of the ultrasonic emitter are included, wherein the phase of the carrier wave signal emitted by the ultrasonic emitter is opposite to that of the carrier wave signal included in the signal emitted by the ultrasonic emitter.