| 摘要 |
PURPOSE:To improve the reliability of a device and the precision of measurement of a distance thereof, by generating ultrasonic pulses intermittently, changing a transmission pulse width and a repetition cycle according to a measured distance, and detecting reflection signals from an object. CONSTITUTION:A pulse controller 1 controls a clock generator 2 and a transmission pulse generator 3 to change a transmission pulse width and a repetition cycle sent from a converter 6, according to a measured distance to an obstacle 7. Reflected waves from the obstacle 7 are inputted in shift registers 9a-9f constituting a memory circuit, via a converter 6', a transformer 5' and an amplified detector 8. The output of each of the shift registers 9a-9f is added by an adder 9, and the level thereof is detected later by a pulse level detector 10 and given to a counter 11. The output of the counter 11, which is an output corresponding with the distance to the obstacle 7, is given to a display 12 and an alarm generator 13. |
