| 摘要 |
<p>PURPOSE:To urge the recovery of an abnormal state and to improve the reliability of an ultrasonic sensor by actuating a detecting function when an object can be detected in a side lobe area and reporting an inactive state of the detecting function when the detection of the object is impossible. CONSTITUTION:A cable transmission signal circuit 2 is provided with a 2nd oscillation circuit 7 which outputs intermittently the pulses to an ultrasonic transmitter/receiver 1 at a frequency that secures the directivity of a side lobe. The circuit 7 processes the signals received by the transmitter/receiver 1 in a cable transmission state. Then the 1st detection gate production circuits 13 and the 2nd detection signal processing circuit 14 detect a prescribed object existing in a side lobe area. Furthermore a switch means 15 switches simultaneously the circuit 2 and a cable reception signal processing circuit 8 to the circuits 13 and 14 respectively. In such a constitution, a detecting function is active when the object can be detected. Meanwhile the inactive state of the detecting function is known when the detection of the object is impossible.</p> |
