Surface Capacitive Sensor Materials Glass substrate, transparent metal oxide coating Principle of Operation.

• Voltage is applied to the corners of the touch screen.
• A pattern of electrodes around the periphery of the touch screen distribute the voltage to form a uniform electric field across the conductive surface.
• A finger touch draws a minute amount of current from the surface and is measured by the controller.
• The relative magnitude of current is inversely proportionate to the distance from the contact point to the touch screen corners.
• Ratios of the four corner currents are calculated to determine the X,Y coordinate.