Capacitive touch screen technology 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. The outermost layer is a thin layer of silica glass protective layer. The interlayer ITO coating is used as the working surface, and the four corners lead out Four electrodes, the inner ITO is a shielding layer to ensure a good working environment.
When a finger touches the metal layer of the capacitive touch screen layers, due to the electric field of the human body, a coupling capacitor is formed between the user and the surface of the touch screen. 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 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 calculates the position of the touch point by accurately calculating the ratio of these four currents. .
The integrated capacitive touch screen is mainly composed of a cover plate and an integrated touch function sheet. The integrated touch function sheet includes a cover plate insulating printing layer, a virtual key printing layer, a functional graphic printing layer, an infrared distance sensing hole printing layer and a silver paste circuit printing layer which are sequentially stacked together. The cover insulation printing layer is a black ink screen printing layer, the virtual key printing layer is a cold gray ink screen printing layer, the functional graphic printing layer is an etching printing layer, the infrared distance sensor hole printing layer is a semi-transparent screen printing layer, and the silver paste circuit printing layer is dry engraved printing layer.