Touch type input device and method for detecting touching of touch panel

摘要

A touch type input device (5) includes a touch panel (11) having a sensor array (14) of drive electrodes (12) and sensor electrodes (13). Capacitors (C) are formed at intersections of the drive electrodes (12) and the sensor electrodes (13). A controller (21) determines whether or not a conductive foreign matter exists on the touch panel (11) from raw data values indicating a change amount in the capacitance of each capacitor (C) from an initial reference value. Further, the controller (21) determines whether or not the touch panel (11) has been touched from control data values indicating a change amount in the capacitance of each capacitor (C) from a control reference value that is changed for each capacitor (C) in accordance with whether or not the foreign matter exists. When the raw data values indicate the existence of the foreign matter, the controller (21) sets the control reference value of each capacitor (C) to a raw data reference value corresponding to the present raw data value.