Patent ID: 8148652

Claim:
A position detecting device comprising: X-axis electrodes formed by a plurality of conductors that are arranged substantially parallel to each other; Y-axis electrodes formed by a plurality of conductors that are arranged substantially parallel to each other and that extend perpendicularly to the X-axis electrodes; a driving section configured to supply an AC signal to the X-axis electrodes; a synchronous clock generating section configured to generate a synchronous clock signal at the timing when the AC signal passes through a zero-cross point; a first change-over switch configured to selectively supply the AC signal to a determined electrode among the X-axis electrodes at the timing of the synchronous clock signal, which is generated at the timing of the AC signal passing through a zero-cross point; a second change-over switch configured to select a determined electrode among the Y-axis electrodes at the timing of the synchronous clock signal, which is generated at the timing of the AC signal passing through a zero-cross point; a synchronous detector configured to detect a signal outputted by the Y-axis electrodes through the second change-over switch, and outputting the detected signal; and a position calculating section configured to calculate a position indicated by an indicator on the position detecting device, based on the signal outputted from the synchronous detector, the position corresponding to one or more intersections of the X-axis electrodes and Y-axis electrodes.