Patent ID: 8730189
Filing Date: 2014-05-20
Classification: G06F

Abstract:
1. A coordinate input device comprising: a coordinate input unit having a plurality of first detection electrodes, which are disposed in parallel to each other, and a plurality of second detection electrodes intersecting the first detection electrodes; an electrode drive circuit configured to apply a drive signal to one or more of the first detection electrodes; a capacitance detection circuit configured to detect a capacitance of the second detection electrode in synchronization with the drive signal; wherein the electrode drive circuit is configured to select one or more of the first detection electrodes to which the drive signal is not applied as a reference electrode; wherein the capacitance detection circuit is configured to detect a capacitance of the selected reference electrode, which capacitance represents noise; an input coordinate computing circuit configured to correct a capacitance detection result of the capacitance detection circuit on the basis of the detected capacitance representing noise of the reference electrode, and to calculate an input coordinate from the corrected capacitance detection result.