The so-called "drift" of capacitive screen mainly refers to the following situations:
Making mistake action to touch operation, i.e. touching point A, but touching response to point B;
Without touching, but make a mistake action, that is, the body or conductive material is close to the screen, and has not touched, it has made a touch response;
There is no action to touch operation, that is, the touch screen has been touched with fingers, but the screen has not made a touch response.
Before introducing the cause of "drift", it is necessary to introduce the working principle of capacitive screen.
Capacitance screens are supposed to work by utilizing the human body's electric flu. Capacitive touch screen is a four-layer composite glass screen. The inner surface and sandwich of the glass screen are coated with ITO (transparent conductive film). The outer layer is a thin silica glass protective layer. The sandwich ITO coating acts as a working face. Four electrodes are drawn from four corners, and the inner ITO is a shielding layer to ensure a good working environment.
When the finger touches the metal layer, due to the electric field of the human body, the user and the surface of the touch screen form a coupling capacitance. For high frequency current, the capacitance is a direct conductor, so the finger sucks a small current from the contact point. The current flows from the electrodes on the four corners of the touch screen, and the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller calculates the proportion of the four currents accurately to get the position of the touch point.
It is precisely because of the working principle of capacitive screen that the phenomenon of "drift" exists. After understanding the working principle of the capacitive screen, it is easy to know the cause of the "drift" of the capacitive screen.
