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US 2014/0276080 A1Published application
Ultrasonic sensor and electronic device
AssigneeSeiko Epson Corporation
InventorKazuyuki KANO
Life of this patent
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Abstract
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.
Claims6
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.
7 more elements
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 receiver amplifier connected to each of the receiver electrodes;
- a first potential controller configured to apply negative voltage to one of the receiver electrodes;
- a second potential controller configured to apply the negative voltage to the other of the receiver electrodes;
- and
- a connection switching unit configured to switch a state of connection of the receiver electrodes, the connection switching unit having a first switch configured to switch a state of connection between the first potential controller and the one of the receiver electrodes, and a second switch configured to switch a state of connection between the second potential controller and the other of the receiver electrodes,
- during a transmission period in which the ultrasound is transmitted by the transmitter element, the connection switching unit being configured to switch the first switch to a connection state in which the first potential controller and the one of the receiver electrodes are connected, and to switch the second switch to a connection state in which the second potential controller and the other of the receiver electrodes are connected, and
- during a reception period in which the ultrasound is received by the reception element, the connection switching unit being configured to switch the first switch to a disconnected state in which the first potential controller and the one of the receiver electrodes are disconnected, and to switch the second switch to a disconnection state in which the second potential controller and the other of the receiver electrodes are disconnected.
7 more elements
An ultrasonic sensor comprising:
- a substrate having a plurality of opening portions;
- a support film covering the opening portions;
- a first piezoelectric element formed above the support film and in the inside region of a first opening portion among the opening portions in plan view;
- a second piezoelectric element formed above the support film and in the inside region of a second opening portion among the opening portions in plan view;
- a potential controller configured to supply negative potential;
- and
- a connection switching unit configured to switch a state of connection of the first piezoelectric element and the potential controller,
- the first piezoelectric element including a piezoelectric body and a pair of first piezoelectric element electrodes connected to the piezoelectric body,
- during at least part of duration of a transmission period in which a voltage is applied to the second piezoelectric element, the connection switching unit being configured to switch to a first state in which the potential controller and the first piezoelectric element electrodes are connected, and
- during at least part of duration of a reception period in which an electrical signal of the first piezoelectric element is picked up, the connection switching unit being configured to switch to a second state in which the potential controller and at least one of the first piezoelectric element electrodes are disconnected.
7 more elements
Dependencies are inferred from the claim text.