Patent ID: 9235302
Filing Date: 2016-01-12
CPC Classification: G06F

Claim Text:
1. An input device, comprising: a selection circuit that is connected to a plurality of electrodes provided on a capacitive touch panel and selectively connects the plurality of electrodes; a calibration resistor connected to the selection circuit; a constant current source for supplying constant current power to the plurality of electrodes and the calibration resistor; an A/D converter connected to the selection circuit to measure capacitance of the plurality of electrodes and a measured value measured when the calibration resistor is connected; and a control unit controlling the selection circuit to make the A/D converter measure the capacitance of one of the plurality of electrodes and the measured value measured when the calibration resistor is connected, and determining a contact coordinate of the touch object on a touch panel by calculating a ratio of the capacitance to the measured value, wherein the measured value measured when the calibration resistor is connected is measured when disconnecting all of the plurality of electrodes, and wherein the calibration resistor is connected in parallel with the plurality of electrodes to the selection circuit.