| 摘要 |
<p>PURPOSE:To detect the trouble of a reflective type object detecting apparatus, by detecting ultrasonic waves directly reaching an ultrasonic wave receiver from an ultrasonic wave generator without passing through an obstruction. CONSTITUTION:Ultrasonic wave generators 20a, 30a and ultrasonic receivers 20b, 30b are arranged at a predetermined interval and discriminative circuits 60, 80 multiple the signals from the receivers 20b, 30b. In addition, the presence of an object and the distance of the object and a detecting apparatus are judged by the level of the multiplied signal and a time required from the generation of ultrasonic waves to the reception thereof by a microcomputer 90. Moreover, the generators 20a, 30a are energized to judge the presence of the reception of ultrasonic waves at predetermined timing corresponding to the distance of the generators 20a, 30a and the receivers 20a, 30b and abnormality is judged when ultrasonic waves are not received to energize a buzzer 102 and the lamp 121 of an alarm lamp. Therefore, the operational check of an apparatus can be certainly carried out even if a special obstruction is prepared.</p> |
