DETECTING DEVICE FOR BODY POSITION

摘要

PURPOSE:To easily measure the position of a body to be detected from the frequency of a variable delay means by adjusting the frequency so that a detection wave from the object body is maximum. CONSTITUTION:Pulses P generated by a timing pulse generating circuit 2 are delayed successively by a specific time through a variable delay circuit 3 and transmitters 4A-4D are driven on the basis of respective delay pulses P1-P4 from the circuit 3 to send ultrasonic waves i1-i4 from an ultrasonic wave oscillator 4 for transmission. An ultrasonic wave (j) reflected by the body 7 is received by an ultrasonic wave oscillator 5 and sent to a signal processing circuit 6, and a peak value decision circuit 63 decides whether the level of the received signal attains to its peak value or not and outputs a voltage signal corresponding to the shift of the received signal from the peak value. A voltage-controlled oscillator 64 outputs a control signal (k) corresponding to this voltage signal and the clock frequency of a shift register 30 is varied until the transmission direction of the transmitted wave coincides with the direction of the body 7, thereby finding the direction theta of the body 7 from the clock frequency at which a stable state is obtained. Further, a time difference detecting circuit 65 calculates the distance to the body 7 from the difference between the generation time of the pulses P and the reception time of the received signal.