| 摘要 |
PURPOSE:To obtain a comparatively inexpensive and sure data communication system resistant to electric noise by using an ultrasonic wave of the 1st wavelength as a carrier and turning on/off the ultrasonic wave of the 2nd wavelength to transmit information with a Doppler wave. CONSTITUTION:A carrier forming section 1 at the transmission side T generates a wave of a prescribed frequency, a sounding section 2A converts the wave into an ultrasonic wave and irradiates it in air. A reception side R detects the carrier and prepares the reception. A generating section 3 of the transmission side T applies time interval conversion to a transmission data. The electric wave is converted into an ultrasonic wave by the 2nd sounding section 2B. In transmit the two ultrasonic waves at the same time, a Doppler effect is generated, the reception section R receives (11) the ultrasonic wave and amplifies (12) it, detects (13) the time interval, and a data analysis section 14 detects the data from the time interval. Thus, the sure data communication resistant to electric noise is attained in this way. |
