Patent ID: 9321080
Filing Date: 2016-04-26
CPC Classification: B06B

Claim Text:
1. An electromechanical transducer comprising: a plurality of elements each including at least one cell, the cell including a first electrode and a second electrode with a gap therebetween, the cell comprising a vibration membrane that has one of the first and second electrodes; a voltage applying unit configured to apply an AC voltage to the first electrode of each of the elements; and wherein the voltage applying unit applies the AC voltage having a frequency that is different from a mechanical resonance frequency of the vibration membrane, and further comprising a control unit configured to switch between a mode of the electromechanical transducer in which the sensitivity variation is computed and a mode in which elastic waves are detected. wherein the control unit includes an amplifier circuit configured to convert the electrical current into a voltage and a data conversion unit configured to convert the voltage output from the amplifier circuit into a digital signal, and wherein the control unit controls a frequency of the AC voltage applied by the voltage applying unit based on a difference in phase between the AC voltage and the digital signal.