DATA COMMUNICATION APPARATUS

摘要

Upper transmitter 141 converts an electric signal transmitted from upper electronic device 101 into an ultrasonic signal and transmits the ultrasonic signal. First communication medium 146 transports the ultrasonic signal to lower receiver 142. Lower receiver 142 converts the received ultrasonic into an electric signal and transmits the electronic signal to lower electronic device 110. Thus, the electronic signal transmitted from upper electronic device 101 to lower electronic device 110 is modulated into the ultrasonic signal and then the ultrasonic signal is demodulated into the electronic signal, thereby the electronic signal cannot return to upper electronic device 101. Therefore, a data communication apparatus which can reliably regulate the direction of the transmitted electronic signal is provided.