Coordinate input device

A coordinate input device comprising:

• an insulating substrate;
• a plurality of sensor electrodes disposed on the insulating substrate and having a plurality of detection points;
• a top panel covering the plurality of sensor electrodes, the top panel having an operation surface to be operated by an operation body;
• a measurement circuit configured to measure a capacitance at each of the plurality of detection points, thereby providing a plurality of measured values of the capacitance;
• and
• a calculation circuit configured to calculate a position of the operation body in two-axis directions on the operation surface based on the plurality of measured values of the capacitance,
• wherein the calculation circuit is further configured to:
• correct at least three measured values including a maximum measured value from among the plurality of measured values so as to reduce differences among the at least three measured values including the maximum measured value, thereby obtaining corresponding at least three first corrected values;
• and
• calculate the position of the operation body in the two-axis directions on the operation surface using one of the at least three first corrected values corresponding to the maximum measured value and two of the at least three first corrected values corresponding to adjacent measured values among the at least three measured values which are adjacent to the maximum measured value in one of the two-axis directions.