| 摘要 |
<p>PURPOSE:To obtain a device of detecting an object which can surely detect whether the object is present. CONSTITUTION:A detecting device of an object comprises an ultrasonic wave circuit 1 and a determination circuit 2, roughly divided. An ultrasonic wave signal generating circuit 13 sends out an ultrasonic pulse signal only during a period of a transmission signal from a transmission pulse generating circuit 12. This ultrasonic pulse signal is given to an ultrasonic oscillator 15 through a transmission amplifying circuit 14. The ultrasonic oscillator 15 sends out an ultrasonic wave into a specified area. The ultrasonic oscillator 15 receives a reflected wave and gives it to a reception amplifying circuit 16 and a detection circuit 17. The determination circuit 2 compares the pulse pattern of the ultrasonic pulse signal sent out from the ultrasonic circuit 1 with that of a reflected wave signal. When these patterns do not coincide with each other, it specifies the reflected wave signal not being coincident and determines the presence of the object or an environmental change on the basis of comparison with the pulse pattern of the reflected wave thereof.</p> |
