Display device with touch detection function

A display device with a touch detection function, the display device comprising:

• a first substrate having an input surface;
• a touch detection electrode provided to the first substrate and facing the input surface;
• a first electrode provided to a second substrate and facing the touch detection electrode;
• a second electrode facing the first electrode with a dielectric layer interposed between the first electrode and the second electrode;
• a touch detection controller configured to detect a position at which a detection target object is in contact with or in proximity to the input surface based on capacitance between the first electrode and the touch detection electrode;
• a force detection controller configured to detect a force applied to the input surface by the detection target object based on capacitance between the first electrode and the second electrode and calculate a force detection value indicating the force;
• and
• storage configured to store therein a plurality of reference values detected by the force detection controller,
• wherein the force detection controller configured to
• perform interpolation processing on the reference values to calculate an interpolation value when a reference force is applied to a position at which the force has been applied, and
• calculate the force detection value based on a ratio of a detection value detected based on the capacitance between the first electrode and the second electrode relative to the interpolation value,
• wherein the position at which the force is applied is specified based on a position detected by the touch detection controller as the position of contact with the input surface by the detection target object, and
• wherein the reference values are detected based on the capacitance between the first electrode and the second electrode when the reference force is applied to a plurality of reference positions.