Capacitive touch screen technology is the use of the human body's current induction to work.Capacitive touch screen is a four-layer composite glass screen. The inner surface and interlayer of the glass screen are each coated with a layer of ITO. The outermost layer is a thin layer of silica glass protective layer.
When the finger touches the metal layer, due to the human electric field, the capacitive screen manufacturer and the user form a coupling capacitor on the surface of the touch screen. For the high-frequency current, the capacitor is a direct conductor, so the finger absorbs a small current from the contact point.This current flows out from the electrodes at the four corners of the touch screen respectively, and the current flowing through the four electrodes is proportional to the distance from the fingers to the four corners. The controller gets the position of the touch point through the accurate calculation of the ratio of these four currents.
Capacitive touch to achieve multi-touch, rely on is to increase the mutual capacitance electrode, capacitance screen manufacturers, in a nutshell, is to screen block, in every region set up a set of mutual capacitance modules are independent, so the capacitance screen can detect a touch of the regional independence, after processing, simply realize multi-touch.