Pressure detecting device
Each of a first electrode pattern Ty and a second electrode pattern Tx extends between third electrodes Rx neighboring in a Y direction among the plurality of third electrodes Rx so as to overlap only partly with each of the neighboring third electrodes Rx in a plan view. A microcontroller is configured to detect capacitance generated at those portions. The microcontroller is configured to calculate shear force based on a capacitance change obtained due to a change in an overlapping surface area between the third electrode Rx and the first electrode pattern Ty and the second electrode pattern Tx overlapping each other in a plan view, when a pressure is applied so that an insulator is deformed.
1. A pressure detecting device comprising:
a support substrate,
a second insulator having a lower stiffness than the support substrate so as to be elastically deformed by a pressure,
a first insulator, the support substrate, the second insulator, and the first insulator laminated in order from a side opposite to a pressure input side;
a plurality of land-like electrodes arranged to cover an entire surface between the second insulator and the support substrate;
a plurality of first belt-like electrodes extending in a first direction on a side of the first insulator opposite to the second insulator, each of the first belt-like electrodes extending along spaces between, among the plurality of land-like electrodes, land-like electrodes neighboring in a direction crossing the first direction so as to overlap only partly with each of the neighboring land-like electrodes in a plan view;
a plurality of second belt-like electrodes extending in a second direction crossing the first direction between the first insulator and the second insulator, each of the second belt-like electrodes extending along spaces between, among the plurality of land-like electrodes, land-like electrodes neighboring in a direction crossing the second direction so as to overlap only partly with each of the neighboring land-like electrodes in a plan view;
a capacitance measuring circuit configured to detect capacitance generated between each of the land-like electrodes and the corresponding first belt-like electrode overlapping each of the land-like electrodes in a plan view, and configured to detect capacitance generated between each of the land-like electrodes and the corresponding second belt-like electrode overlapping the land-like electrodes in a plan view; and
a pressure calculating circuit configured to calculate shear force based on capacitance measurement results detected by the capacitance measuring circuit, due to a change in an overlapping surface area between the land-like electrodes and the corresponding first belt-like electrode overlapping each other in a plan view and/or an overlapping surface area between the land-like electrodes and the corresponding second belt-like electrode overlapping each other in a plan view, when a pressure is applied so that the second insulator is deformed.
2. The pressure detecting device according to claim 1 , further comprising:
a plurality of switching elements connected to the plurality of electrodes, respectively;
a plurality of read lines connected to a plurality of switching elements arranged in the first direction or the second direction among the plurality of switching elements, the plurality of read lines extending in an arrangement direction of the plurality of switching elements so as to be connected to the capacitance measuring circuit;
a plurality of control lines extending in a direction crossing the arrangement direction so as to be connected to the plurality of switching elements arranged in the direction crossing the arrangement direction; and
a switching control unit configured to perform on-off control of the plurality of switching elements via the plurality of control lines.
3. The pressure detecting device according to claim 2 , wherein an elastic modulus of the second insulator is 0.001 to 10 MPa.
4. The pressure detecting device according to claim 3 , wherein an elastic modulus of the second insulator is 0.001 to 0.01 MPa.
5. The pressure detecting device according to claim 2 , wherein the first insulator is thinner than the second insulator.
6. The pressure detecting device according to claim 1 , wherein an elastic modulus of the second insulator is 0.001 to 10 MPa.
7. The pressure detecting device according to claim 6 , wherein an elastic modulus of the second insulator is 0.001 to 0.01 MPa.
8. The pressure detecting device according to claim 7 , wherein the first insulator is thinner than the second insulator.
9. The pressure detecting device according to claim 6 , wherein the first insulator is thinner than the second insulator.
10. The pressure detecting device according to claim 1 , wherein the first insulator is thinner than the second insulator.
11. The pressure detecting device according to claim 1 , wherein the land-like electrodes are arranged in a matrix.