US Patent 10061433 Touch-type input device

A touch-type input device includes a touch panel in which drive electrodes and sensor electrodes are arranged in a grid pattern that provide capacitors. The touch-type input device also includes a controller that determines whether or not there is a touch based on data values that each indicate an amount of change in capacitance of each capacitor from a predetermined reference value. The controller sets the reference value by obtaining a parasitic capacitance of each capacitor when the touch-type input device is activated. When determining from a variation range of the parasitic capacitances of the capacitors that an erroneous reference value has been obtained, the controller re-obtains a parasitic capacitance.