The capacitive touch screen technology uses the current induction of the human body to work. Capacitive screens need to achieve multi-touch by adding mutual capacitance electrodes. Simply put, the screen is divided into blocks, and a group of mutual capacitance modules are set in each area to work independently, so the capacitive screen can work independently. The touch situation of each area is detected and processed to realize multi-touch easily.

Capacitive technology touch panel CTP uses the current induction of the human body to work. The capacitive touch screen is a four-layer composite glass screen. The inner surface and the interlayer of the glass screen are each coated with a layer of ITO (nano indium tin oxide). The capacitive touch screen manufacturer tells you that the outermost layer is only 0.0015mm thick silica glass protection. The interlayer ITO coating is used as the working surface, four electrodes are drawn from the four corners, and the inner ITO layer is the screen layer to ensure the working environment.
When the user touches the capacitive touch screen, due to the electric field of the human body, the user's finger and the working surface form a coupling capacitance. Because the working surface is connected with a high-frequency signal, the finger absorbs a small current, which is respectively from the four sides of the screen. The electrodes on the corners flow out, and theoretically, the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position through precise calculation of the four current ratios. It can achieve 99% accuracy and has a response speed of less than 3ms.