| 摘要 |
PROBLEM TO BE SOLVED: To provide a product which has excellent reverberation characteristics even though soldering is applied to a printed circuit board and wiring. SOLUTION: In an ultrasonic sensor wherein a unimorph vibrator is formed by laminating a piezo-electric device to the inside of the bottom surface of a cylindrical case having a bottom, ultrasonic waves are transmitted and received at the outer surface of the case of the vibrator. A board for sealing is made smaller than the inner diameter of the bottomed cylindrical case, a foaming elastic material and the board for sealing are adhered, and the foaming elastic material fixes the board for sealing to the bottomed cylindrical case to thereby prevent vibrations from being transmitted to the outside. Thus a reverberation is made short and stable even though a lead pin is soldered to the printed circuit board, the wiring, etc. Consequently, an obstacle in a short range is reliably detected. COPYRIGHT: (C)2005,JPO&NCIPI
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