The so-called "drift" of capacitive screens mainly refers to the following situations:

1. Make a mistake in the touch operation, that is, touch point A, but make a touch response to point B

2. Make a wrong action without touching, that is, when the body or conductive object is close to the screen, and has not touched, it makes a touch response

3. There is no action for touch operation, that is, the touch screen has been touched with a finger, but the screen has not responded to the touch.

Before introducing the cause of "drift", it is necessary to introduce the working principle of capacitive screen.

Capacitive screens work by using the current induction of the human body. The capacitive touch screen is a four-layer composite glass screen. The inner surface of the glass screen and the interlayer are each coated with a layer of ITO (transparent conductive film), the outermost layer is a thin layer of silica glass protective layer, and the interlayer ITO coating is used as a working surface. Four electrodes are drawn from the four corners, and the inner layer of ITO is a shielding layer to ensure a good working environment.

When a finger touches the metal layer, a coupling capacitance is formed between the user and the touch screen surface due to the electric field of the human body. For high-frequency current, the capacitance is a direct conductor, so the finger draws a small current from the contact point. This current flows out from the electrodes on the four corners of the touch screen, and the current flowing through these four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position of the touch point by accurately calculating the ratio of the four currents. .

It is precisely because of this working principle of the capacitive screen that the phenomenon of "drift" occurs. After clarifying the working principle of the capacitive screen, it is easy to know the cause of the "drift" of the capacitive screen.