The working principle of mobile phone capacitive screen

The capacitive screen of the mobile phone adopts the working principle of human body thermal induction. Generally, it can only be touched by heat-sensitive objects such as fingers.

In terms of physical structure, it has a four-layer composite glass screen. The inner surface and interlayer of the glass screen are coated with a thin layer of ITO.screen manufacture， The outermost layer is a protective layer of quartz glass that we can barely see. The inner layer of ITO is the screen layer, which ensures the stable working environment of the entire capacitive screen.

When a person does not touch the touch screen, the electrode potentials on the four screens are the same. However, once the capacitive touch screen is clicked with a finger, coupling capacitance will be generated between the electric field of the human body, the fingertip and the conductor layer, and the electrodes at the four corners will emit current one by one and flow to the contact.

The significance of the capacitive touch screen at the multi-touch level is completely beyond the limit of what the resistive screen can do. It can effectively judge complex actions.