PURPOSE: To detect the existence direction and distance of an obstacle, by switching the receiving operations of plural ultrasonic devices by time sharing switching control in accordance with the projection timing of an ultrasonic pulse and detecting the distance up to the obstacle time-sharingly.
CONSTITUTION: Receiving a reference oscillation signal (a) from a reference oscillation circuit 1 as a clock input signal, a reference pulse generating circuit 2 generates a carrier pulse signal (b) for transmission, sensor switching signals (f), (g) for reception, display zone selecting signals (j)W(l), distance comparison reference signals mWp, and alarm reference signals T, (i), receives obstacle distance signals QWS from a reception discriminating circuit 9 and generates hysteresis to the distance comparison reference signals mWp. Received waves from receiving sensors 5-a, 5-b are selected by receiving sensor switching signals (f), (g) and the receiving circuit 6 receives the receiving signal and generates a receiving pulse. Receiving the receiving pulse from the receiving circuit 7 and the display zone selecting signals (j)W(l) from the circuit 2, a gate circuit 8 outputs a reception display signal. Receiving the reception display signal and the distance comparison reference signals mWp, the reception discriminating circuit 9 discriminates the distance up to the obstacle and displays the distance on the display device 10. Receiving obstacle distance signals QWS an audible alarm signal is generated, an alarm circuit generates an alarm.
HIRAMATSU SEIICHIROU
MAENO TAKESHI
OOTSUKA MITSUGI
| JPS5390800A | 1978-08-09 | |||
| JPS496056U | 1974-01-19 | |||
| JPS505081A | 1975-01-20 | |||
| JPS51380A | 1976-01-06 | |||
| JPS4921747U | 1974-02-23 |