ULTRASONIC BODY DETECTING DEVICE

摘要

PURPOSE:To narrow down a dead angle area and widen body detection area by providing an ultrasonic pulse transmitter, a coupler of ultrasonic sensors which receive pulse signals, and an exclusive OR circuit interposed between both ultrasonic sensors and an output circuit. CONSTITUTION:A period transmitter 1 transmits a pulse signal intermittently and an amplifier 2 inputs and amplifies the pulse signal from the transmitter 1 to output it to the ultrasonic transmitter A. The ultrasonic sensors B and C are provided at equal distance from transmitters B and C. Amplifiers 3b and 3c amplify electric signals that the sensors B and C receive and convert ultrasonic pulse signals into. Waveform shaping devices 4b and 4c input output signals of the amplifiers 3b and 3c and shape them into rectangular waves. The exclusive OR circuit 5 inputs signals from the shaping devices 4b and 4c and a detection signal generating circuit 7 is operated to output a signal from an output circuit 8. This constitution shortens a delay time most, so the dead angle area is narrowed down and the body detection area is widened.