When the finger touches the metal layer, the capacitance of the contact changes, causing the frequency of the oscillator connected to it to change. By measuring the frequency change, the position of the touch can be determined to obtain information. Because capacitance varies with temperature, humidity, or ground condition, its stability is poor and drift phenomenon often occurs.

advantages of capacitive touch screen: Capacitive touch screen is by touch, change the capacitance by changing the electrolyte capacitor, touch, electrolyte change, capacitance change, so mobile phones have a reaction, such as mobile phones don’t match, the screen is not easy to scratch, and the most practical identification method is: use two fingers hold the capacitive touch screen on the phone a picture at the same time, the fingers on both sides to open or close, images will be enlarged or reduced, and this point, resistive touch screens.