Patent ID: 8754660

Claim:
A capacitive detection type electro-mechanical transducer comprising: a plurality of cells, each cell including a first electrode and a second electrode opposed to the first electrode with a gap between the first and second electrodes, and configured to vibrate; a plurality of detection circuits, each detection circuit being configured to detect a current output from a detection electrode that is one of the first and second electrodes; and an addition circuit for adding signals from the plurality of detection circuits, wherein the plurality of cells are classified into a plurality of groups, each group includes at least two cells, wherein a plurality of the detection electrodes of the cells in one group are commonly connected to one detection circuit, and wherein each detection circuit comprises a current amplifying circuit that amplifies currents output from the plurality of detection electrodes of the cells in one group, and wherein the addition circuit comprises a current addition circuit that adds currents output from the plurality of detection circuits, and a current-to-voltage conversion circuit that converts a current output from the addition circuit into a voltage.