Control apparatus for capacitive electromechanical transducer, and method of controlling the capacitive electromechanical transducer

摘要

Provided is a control apparatus and control method for a capacitive electromechanical transducer with small decrease in transmission/reception efficiency, and with sets of transmission/reception characteristics with different frequency ranges. The apparatus has cells each including first and second electrodes facing each other via a gap; includes a driving/detecting unit and an external stress applying unit. The driving/detecting unit performs at least one of causing the second electrode to vibrate and transmit elastic waves by generating an AC electrostatic attractive force between the electrodes, and detecting a change of capacity between the electrodes, the change being caused by the second electrode vibrating upon receipt of elastic waves. The external stress applying unit changes the external stress applied to the second electrode. The driving/detecting unit adjusts frequency characteristics by changing a parameter defining the frequency domain used in a transmitting/receiving operation, corresponding to the change of the external stress.

主权项

1. A control apparatus for a capacitive electromechanical transducer that includes cells each including first and second electrodes that face each other with a gap being interposed in between,
the control apparatus comprising: a driving/detecting unit that performs at least one of a driving operation to cause the second electrode to vibrate and transmit elastic waves by generating an AC electrostatic attractive force between the first and second electrodes, and a detecting operation to detect a change of capacitance between the first and second electrodes, the change of capacitance being caused by the second electrode vibrating upon receipt of elastic waves; and an external stress applying unit that applies an external stress to the second electrode, wherein external stress applying unit changes the external stress to be applied to the second electrode, wherein, when the driving/detecting unit performs the driving operation, the driving/detecting unit adjusts frequency characteristics of a driving signal which is supplied to the capacitive electromechanical transducer and generates the AC electrostatic attractive force between the first and second electrodes, corresponding to a change of the external stress to be applied by the external stress applying unit and wherein, when the driving/detecting unit performs the detecting operation, the driving/detecting unit adjusts frequency characteristics of a current detecting unit in the driving/detecting unit, corresponding to a change of the external stress to be applied by the external stress applying unit.