APPARATUS FOR REMOTE MEASURING OF DISTANCE USING SPEED DIFFERENCE BETWEEN ELECTROMAGNETIC WAVE AND ULTRASONIC WAVE

摘要

PURPOSE: An apparatus is provided, in which distance measuring is performed by utilizing the speed difference between electromagnetic wave and ultrasonic wave, to thereby simplify the structure of distance measuring apparatus. CONSTITUTION: An oscillator(11) outputs a radio frequency signal, and the radio frequency signal is modulated by an address pulse string for recognition of a transmitter generated from a pulse code generator and amplified to a predetermined power level in a radio frequency amplifier(12). Thus-amplified radio frequency signal is transmitted to an antenna(13). An output from an ultrasonic wave frequency oscillator(14) is amplified by an ultrasonic wave frequency amplifier(15), converted into ultrasonic wave by an ultrasonic wave transducer(16) and transmitted. An antenna at the receiver side receives electromagnetic wave, and a radio frequency amplifier amplifies the received electromagnetic wave. The amplified wave is mixed with the signal output from a local oscillator in a mixer, and converted into an intermediate frequency. The intermediate frequency is amplified by an intermediate frequency amplifier, after passing through a band pass filter. Thus-amplified frequency is converted into a pulse in a wave detector. When a decoder confirms transmitter's recognition, the decoder sends a distance calculation start signal to a distance calculation unit, and the ultrasonic wave signal received through an ultrasonic wave transducer is amplified by the ultrasonic wave frequency amplifier and utilized as a calculation stop signal. Thus-calculated distance is displayed onto a display.