Patent ID: 7671517
Filing Date: 2010-03-02
Classification: H04R

Abstract:
1. A piezoelectric electroacoustic transducer comprising: a piezoelectric diaphragm that is supplied with a periodic signal across electrodes thereof to bend and vibrate in a thickness direction; a casing including supports on an inner portion thereof to support four corners of a bottom surface of the piezoelectric diaphragm; terminals fixed to the casing, each having an inner connection portion exposed near the supports; a first elastic adhesive disposed between a periphery of the piezoelectric diaphragm and the inner connection portions of the terminals to secure the piezoelectric diaphragm to the casing; a conductive adhesive disposed between the electrodes of the piezoelectric diaphragm and the inner connection portions of the terminals across a top surface of the first elastic adhesive to electrically connect the electrodes of the piezoelectric diaphragm to the inner connection portions of the terminals; a second elastic adhesive filling and sealing a gap between the periphery of the piezoelectric diaphragm and the inner portion of the casing; and an overamplitude-preventing receiver disposed on the casing to limit an amplitude of vibration of the piezoelectric diaphragm to a predetermined range; wherein the overamplitude-preventing receiver includes a tor surface that is arranged at a height lower than the supports and below an area in which the conductive adhesive is applied, such that a gap is provided between the top surface of the overamplitude-preventing receiver and the bottom surface of the piezoelectric diaphragm; and the second elastic adhesive fills the gap between the bottom surface of the piezoelectric diaphragm and the top surface of the overamplitude-preventing receiver.