ULTRASONIC OBJECT DETECTING DEVICE

摘要

PURPOSE:To provide an ultrasonic object detecting device which can correct its detecting distance in corresponding to the variation of the ambient temperature. CONSTITUTION:Only an object at a prescribed distance can be detected when the reflected waves of pulse-like ultrasonic waves intermittently transmitted from an oscillator 4 from the object are received by means of a reception circuit 6 and only the reflected waves returned from the prescribed distance are fetched by means of a detecting gate circuit 10 which opens a gate a prescribed period of time after the transmission of the ultrasonic waves. When the circuit element which decides the time constant for generating gate signals in the circuit 10 is constituted of a circuit element having a prescribed temperature characteristic which changes in accordance with the ambient temperature, the detecting distance of an ultrasonic object detecting device can be corrected in accordance with the variation of the ambient temperature.