Ultrasonic receiver transmitter

Abstract

To solve the problem that a temperature compensating capacitor used as a remedy for change in electrostatic capacity due to change in temperature, increase in reverberation time, and inability of obstacle detection in a close range is high-cost, and that the reflection sensitivity is deteriorated when invar alloys or the like of low thermal expansion are adhered between a bottomed cylindrical case and a piezoelectric element, to the opposite side of the piezoelectric element on the side of the case in the shape of a cylinder with bottom or to both sides of a piezoelectric element, in a conventional ultrasonic wave transmitting and receiving device. In the ultrasonic wave transmitting and receiving device, annularly formed invar alloys or the like of low thermal expansion are embedded in an annular groove provided on the surface for adhesion of the piezoelectric element of the bottomed cylindrical case by adhesion, press-fitting or the like, and the piezoelectric element is adhered on it. In this way, obstacles can be stably detected in a wide range of temperature without using a temperature compensating capacitor and without deterioration of reflection sensitivity.

Description

technical field [0001] The present invention relates to an ultrasonic transceiver for transmitting and receiving in an ultrasonic frequency band. Background technique [0002] The ultrasonic wave transmitter of the previous embodiments refers to that the ultrasonic receiver transmitter is embedded in the car muffler, etc., and when the obstacle around the car is to be detected, the ultrasonic receiver transmitter is input with a pulse train electrical signal, so as to communicate with the ultrasonic receiver transmitter. The ultrasonic signal corresponding to the pulse group electrical signal input from the ultrasonic receiving transmitter generates oscillations, the oscillating ultrasonic signal reaches the obstacle, the ultrasonic signal that hits the obstacle is reflected by the obstacle, and a part of the transmitted ultrasonic signal returns to the same ultrasonic receiver in the transmitter. Ultrasonic transceivers detect obstacles by receiving their reflected signals...

AI Technical Summary

Problems solved by technology

[0005] However, this method has the following problems: Although this method can obtain improvement effects such as suppressing changes in the electrostatic capacity of the ultrasonic transceiver due to temperature changes and suppressing changes in reverberation, it is different from conventional ultrasonic receivers. Transmitters are less sensitive to reflections compared to

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