Vibration and acoustic wave detecting device employing a piezoelectric

Abstract

A vibration and acoustic wave detecting device employing a piezoelectric element has a construction such that a piezoelectric element comprises a first surface electrode disposed on a first surface of the piezoelectric element and having a first output terminal of the detecting device, a second surface electrode opposite to the first surface thereof, a side electrode disposed to surround a side surface of the detecting device and having portions respectively extending over the first and second surfaces, the three electrodes being disposed separately from each other, and a resistor disposed on the piezoelectric element to extend across the first surface electrode and the side electrode and to be connected therewith electrically, and the piezoelectric element further comprises a conductive member which is attached to the piezoelectric element to be in contact with the second surface electrode and the side electrode and hence to provide electrical connection between both electrodes. The conductive member supports the piezoelectric element and also provides its second output terminal. Thus, the piezoelectric element and the resistor are electrically connected in parallel between the first and second output terminals of the detecting device. This construction makes it possible to simply and easily manufacture a detecting device incorporating a resistor for increasing the available frequency bandwidth without causing any problem in the manufacturing process.