Patent ID: 8081168

Claim:
An on-screen input image display system, comprising: a touch panel for detecting two-dimensional coordinates of a touch position located on a display screen of a display device, the touch panel comprising a plurality of electrode terminals such that at least eight electrode terminals are aligned with one electrode terminal in each of the four corners and four center portions such that there are at least three electrode terminals on each side of the touch panel; and a touch panel control circuit for selecting two or four electrode terminals from among the plurality of electrode terminals, and then applying an AC signal through a current detection resistor and detecting a current that flows through each of the selected electrode terminals, wherein coordinate detection is performed in two separate periods so that in a first period of the two separate periods, a touch in one of four regions is detected by selecting terminals at four corners from among the plurality of electrode terminals, and in a second period of the two separate periods, coordinates are detected by controlling electrodes selected in accordance with the region detected in the first period; wherein in X-directional detection processing, the coordinate detection is performed by selecting one or two electrode terminals in each of two sides vertically facing each other such that the region identified on the basis of coordinate detection results obtained in the first period is included; and in Y-directional detection processing, the coordinate detection is performed by selecting one or two electrode terminals in each of two sides horizontally facing each other such that the region identified on the basis of the coordinate detection results obtained in the first period is included.