Touch panel device, touch panel control method, and storage medium storing touch panel control program

1. A touch panel device comprising:

a cover panel that has an operation surface on which a touch operation is performed and bends corresponding to a depressing force applied to the operation surface;

a touch sensor unit including touch sensor electrodes that output touch sensor signals corresponding to the touch operation;

a first elastic member integrally formed of an adhesive agent that has a dielectric constant changing corresponding to a temperature and deforms due to the bending of the cover panel, the elastic member being provided between the cover panel and the touch sensor unit;

a first sensor unit that includes respective electrodes adjacent to top and bottom surfaces of the first elastic member to detect a capacitance changing depending on the dielectric constant and a thickness of the first elastic member; and

processing circuitry

to estimate the temperature based on the capacitance detected by the first sensor unit;

to detect the depressing force based on the estimated temperature and the capacitance detected by the first sensor unit; and

to execute processing of the touch sensor signals based on the detected depressing force.

2. The touch panel device according to claim 1 , further comprising a display panel unit that displays an image,

wherein a second elastic member that includes an elastic material is provided between the display panel unit and the touch sensor unit.

3. A touch panel device comprising:

a cover panel that has an operation surface on which a touch operation is performed and bends corresponding to a depressing force applied to the operation surface;

a touch sensor unit including touch sensor electrodes that output touch sensor signals corresponding to the touch operation;

an elastic member integrally formed of an elastic material that has a dielectric constant changing corresponding to a temperature and deforms due to the bending of the cover panel;

a first sensor unit that includes respective electrodes adjacent to top and bottom surfaces of the elastic member to detect a capacitance changing depending on the dielectric constant and a thickness of the elastic member;

processing circuitry

to estimate the temperature based on the capacitance detected by the first sensor unit;

to detect the depressing force based on the estimated temperature and the capacitance detected by the first sensor unit; and

to execute processing of the touch sensor signals based on the detected depressing force; and

a display panel unit that displays an image,

wherein the elastic member is provided between the display panel unit and the touch sensor unit.

4. The touch panel device according to claim 1 , wherein

the first sensor unit includes a first capacitance sensor, and

the first capacitance sensor includes a first displacement detection electrode and a second displacement detection electrode arranged at positions to face each other across the adhesive agent.

5. The touch panel device according to claim 2 , wherein

the first sensor unit includes a second capacitance sensor, and

the second capacitance sensor includes a third displacement detection electrode and a fourth displacement detection electrode arranged at positions to face each other across the elastic material.

6. The touch panel device according to claim 2 , wherein

the first sensor unit includes a first capacitance sensor and a second capacitance sensor,

the first capacitance sensor includes a first displacement detection electrode and a second displacement detection electrode arranged at positions to face each other across the adhesive agent, and

the second capacitance sensor includes a third displacement detection electrode and a fourth displacement detection electrode arranged at positions to face each other across the elastic material.

7. The touch panel device according to claim 4 , wherein

the adhesive agent includes:

a first adhesive agent arranged between the first displacement detection electrode and the second displacement detection electrode; and

a second adhesive agent arranged between the cover panel and the touch sensor electrode, and

a rate of change of the dielectric constant of the first adhesive agent due to a temperature change is higher than a rate of change of the dielectric constant of the second adhesive agent due to the temperature change.

8. The touch panel device according to claim 1 , further comprising a second sensor unit that detects a capacitance changing depending on a distance between the cover panel and the touch sensor unit,

wherein the processing circuitry detects the depressing force based on the temperature, estimated based on the capacitance detected by the first sensor unit, and the capacitance detected by the second sensor unit.

9. The touch panel device according to claim 4 , further comprising a second sensor unit that detects a capacitance changing depending on a distance between the cover panel and the touch sensor unit,

wherein the processing circuitry estimates the temperature based on a difference between the capacitance detected by the first sensor unit and the capacitance detected by the second sensor unit.

10. The touch panel device according to claim 2 , further comprising a third sensor unit that detects a capacitance changing depending on a distance between the touch sensor unit and the display panel unit,

wherein the processing circuitry detects the depressing force based on the temperature, estimated based on the capacitance detected by the first sensor unit, and the capacitance detected by the third sensor unit.

11. The touch panel device according to claim 2 , further comprising a third sensor unit that detects a capacitance changing depending on a distance between the touch sensor unit and the display panel unit,

wherein the processing circuitry estimates the temperature based on a difference between the capacitance detected by the first sensor unit and the capacitance detected by the third sensor unit.

12. The touch panel device according to claim 1 , further comprising an AC voltage application unit that applies AC voltage to the first sensor unit.

13. The touch panel device according to claim 1 , further comprising an AC voltage application unit that applies AC voltage at a plurality of predetermined drive frequencies to the first sensor unit.

14. The touch panel device according to claim 12 , further comprising a transmissive conductive film control unit that supplies electric power for making the first sensor unit emit heat.

15. The touch panel device according to claim 1 , further comprising a touch operation judgment unit that judges that the touch operation is a valid touch operation when the depressing force detected by the depressing force detection unit is greater than or equal to a predetermined threshold value.

16. A touch panel control method executed by a touch panel device that includes a cover panel that has an operation surface on which a touch operation is performed and bends corresponding to a depressing force applied to the operation surface, a touch sensor unit including touch sensor electrodes that output touch sensor signals corresponding to the touch operation, an elastic member integrally formed of an adhesive agent that has a dielectric constant changing corresponding to a temperature and deforms due to the bending of the cover panel, the elastic member being provided between the cover panel and the touch sensor unit, and a first sensor unit that includes respective electrodes adjacent to top and bottom surfaces of the elastic member to detect a capacitance changing depending on the dielectric constant and a thickness of the elastic member, comprising:

estimating the temperature based on the capacitance detected by the first sensor unit;

detecting the depressing force based on the estimated temperature and the capacitance detected by the first sensor unit; and

executing processing of the touch sensor signals based on the detected depressing force.

17. A non-transitory computer-readable storage medium for storing a touch panel control program executed by a touch panel device that includes a cover panel that has an operation surface on which a touch operation is performed and bends corresponding to a depressing force applied to the operation surface, a touch sensor unit including touch sensor electrodes that output touch sensor signals corresponding to the touch operation, an elastic member integrally formed of an adhesive agent that has a dielectric constant changing corresponding to a temperature and deforms due to the bending of the cover panel, the elastic member being provided between the cover panel and the touch sensor unit, and a first sensor unit that includes respective electrodes adjacent to top and bottom surfaces of the elastic member to detect a capacitance changing depending on the dielectric constant and a thickness of the elastic member, wherein the touch panel control program causes the touch panel device to execute:

estimating the temperature based on the capacitance detected by the first sensor unit;

detecting the depressing force based on the estimated temperature and the capacitance detected by the first sensor unit; and

executing processing of the touch sensor signals based on the detected depressing force.