The choice of mobile phone screen size is mainly determined according to the actual needs. If it is too small, the field of vision for viewing information is too small, and if it is too large, it is not convenient to carry.
Capacitive touch screen technology works through current induction of human body. Capacitive touch screen is a four-layer composite glass screen. The inner surface and interlayer of the glass screen are coated with a layer of ITO, and the outermost layer is a thin protective layer of silica glass. Interlayer ITO coating is used as working surface, and four electrodes are led out from four corners. The inner ITO is the shielding layer to ensure a good working environment. When a finger touches the metal layer, a coupling capacitor is formed between the user and the touch screen surface due to the electric field of the human body. For high frequency current, the capacitor is a direct conductor, so the finger draws a small current from the contact point. This current flows out from the electrodes at 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 through the accurate calculation of these four current ratios.