Patent ID: 8395595

Claim:
A touch sensor for locating an external input point on an operating plane, which expands in an X direction and in a Y direction, by an electrostatic capacitive coupling technique, the touch sensor comprising: a first location sensing transparent conductive film having electrical conductivity, which is provided parallel to the operating plane and which is electrically connected to a Y coordinate detecting conductive portion for detecting a coordinate of the input point in the Y direction; a second location sensing transparent conductive film having electrical conductivity, which is provided so as to face the first location sensing transparent conductive film and which is electrically connected to an X coordinate detecting conductive portion for detecting a coordinate of the input point in the X direction; a dielectric layer, which is provided between the first and second location sensing transparent conductive films; and a switching circuit for selectively applying a predetermined voltage to one of the first and second location sensing transparent conductive films, wherein a display panel, of which the display plane is provided with the touch sensor, is provided for a display device, wherein the display panel includes: a display medium layer; an electrode, which is provided closer to a viewer than the display medium layer is and which drives the display medium layer; and an insulating layer, which is provided even closer to the viewer than the electrode is, wherein a selected one of the first and second location sensing transparent conductive films is provided so as to face the electrode with the insulating layer interposed between them, wherein by applying a periodically changing oscillating voltage to the electrode, an induced voltage, and eventually an electric field, are generated in the selected location sensing transparent conductive film, and wherein in accordance with a variation in the current to be produced by forming a point of contact on the first and second location sensing transparent conductive films, location data is generated for the point of contact.