PCAP Working Principle
Since the human body is a conductor, when a finger approaches an electrode, the capacitance between the finger and the electrode will change. By detecting the change in electrostatic capacitance in the XY axes, touch point locations can be determined. PCAP touch principle operation does not require pressure on the touch surface to detect changes in capacitance. In addition, the surface of a PCAP touch panel is glass. Glass is scratch resistant, durable, and environmentally resistant.
The actuation principle of a PCAP touch panel begins with two layers of ITO beneath a glass surface which form separate X axis and Y axis electric fields. The electric fields extend beyond the glass surface and maintain a field balance. Once a finger nears the glass surface, it forms new electric fields with X axis or Y axis electrodes, partially changing capacitance. The controller determines touch location according to capacitance changes.