Method and device for driving capacitance transducer
AssigneeCanon Kabushiki Kaisha
InventorsAyako Kato, Kazutoshi Torashima
Life of this patent
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Abstract
Provided are a method, a device and the like for driving a capacitance transducer that enable reduction of transmission sound pressure variation caused by variation in characteristics of a capacitance transducer used for, e.g., an ultrasound conversion element. A method for driving a capacitance transducer including a plurality of elements each including cells each having a structure in which a vibration membrane including one electrode of a pair of electrodes formed with a cavity therebetween is supported in such a manner that the vibration membrane can vibrate is provided.
Claims10
A method for driving a capacitance transducer including a plurality of elements each including a cell having a structure in which a vibration membrane including one electrode of a pair of electrodes formed with a cavity therebetween is supported in such a manner that the vibration membrane can vibrate, the method comprising:
- in a mode in which an element group that is at least a part of the plurality of elements receives acoustic waves, applying a voltage that is lower than a lowest pull-in voltage of pull-in voltages of respective elements in the element group to the element group as a reception bias voltage;
- and
- in a mode in which the element group transmits acoustic waves, applying a voltage that is lower than the reception bias voltage to the element group as a transmission bias voltage.
A device for driving a capacitance transducer including a plurality of elements each including a cell having a structure in which a vibration membrane including one electrode of a pair of electrodes formed with a cavity therebetween is supported in such a manner that the vibration membrane can vibrate,
- the device comprising a voltage control unit that controls a voltage to be applied between the pair of electrodes,
- wherein in a mode in which an element group that is at least a part of the plurality of elements receive acoustic waves, the voltage control unit applies a voltage that is lower than a lowest pull-in voltage of pull-in voltages of respective elements in the element group to the element group as a reception bias voltage;
- and
- wherein in a mode in which the element group transmits acoustic waves, the voltage control unit applies a voltage that is lower than the reception bias voltage to the element group as a transmission bias voltage.
Dependencies are inferred from the claim text.