| 摘要 |
The purpose of the present invention is to provide an ultra-directional speaker with a new technique different from a conventional modulation technique inhibiting the popularization of the ultra-directional speaker by modulating music and sounds at an audible frequency band into sounds at an ultrasound band and, more specifically, modulating music and sounds according to principles so as to generate the music and the sounds having a real audible frequency in the air. A system for ultra directional speaker comprises: an ultrasonic modulator for modulating a carrier wave in which an audio signal is modulated by frequency into a first ultrasonic modulation signal at an ultrasonic band higher than an audible frequency band; one ultrasonic generator for generating a second ultrasonic modulation signal having output strength higher than that of the first ultrasonic modulation signal, based on an ultrasonic modulation signal at an ultrasonic band modulated by the ultrasonic modulator; and another ultrasonic generator for combining the second ultrasonic modulation signal generated by the one ultrasonic generator to the front end of the first ultrasonic modulation signal modulated by the ultrasonic modulator to generate a third ultrasonic modulation signal having superdirectivity. [Reference numerals] (20) Audio signal source; (50) Ultrasonic modulator; (60) Ultrasonic generator; (AA) Oriented audio signal |
