| 摘要 |
The ultrasonic sensor includes, on the same substrate, transmitter elements, receiver elements, a potential controller for receiver electrodes of the receiver elements, and a connection switching unit for the receiver electrodes and the potential controller. During the ultrasound transmission period of the transmitter elements, the connection switching unit connects the potential controller and one of the receiver electrodes, and connects the receiver electrodes. During the reception period of the receiver elements, the connection switching unit disconnects the potential controller and the one of the receiver electrodes, and disconnects the receiver electrodes. |
| 主权项 |
1. An ultrasonic sensor comprising:
a substrate, a transmitter element formed above the substrate, the transmitter element including an transmission film adapted to transmit ultrasound through oscillation, a transmission piezoelectric body for causing the transmission film to oscillate, and a pair of actuation electrodes for applying an actuation voltage to the transmission piezoelectric body; a receiver element formed above the substrate, the receiver element including a reception film adapted to oscillate through reception of the ultrasound, a reception piezoelectric body for converting oscillation of the reception film to an electrical signal, and a pair of receiver electrodes for picking up the electrical signal that is output from the reception piezoelectric body; a potential controller configured to apply a first potential to one of the receiver electrodes, the first potential being negative voltage; a receiver amplifier connected to each of the receiver electrodes; a potential control switch configured to switch a state of connection between the one of the receiver electrodes and the potential controller; and a short switch connected to each of the receiver electrodes and configured to switch a state of connection between the receiver electrodes, during a transmission period in which the ultrasound is transmitted by the transmitter element, the potential control switch being configured to switch to a connection state in which the potential controller and the one of the receiver electrodes are connected, and the short switch being configured to switch to a connection state in which the receiver electrodes are connected, and during a reception period in which the ultrasound is received by the reception element, the potential control switch being configured to switch to a disconnected state in which the potential controller and the one of the receiver electrodes are disconnected, and the short switch being configured to switch to a disconnected state in which the receiver electrodes are disconnected. |
