Classification of surface capacitance touch screen and projection capacitance touch screen

With the development of time and technology, Capacitive Touch Screen has gradually become the mainstream application of mobile phones, touch displays and other products. Capacitive Touch screen represents the mainstream technology of multi touch Interface. The projection capacitive touch screen can accurately locate the position of finger Touch Screen by measuring the tiny change of capacitance. The most critical problem in the application of capacitive touch screen is the influence of electromagnetic interference on the system performance. At present, the capacitive touch screen has gradually reduced this kind of interference problem. What is the classification of surface and projection Touch Screens? Let's talk about the working principle and classification of capacitive touch screens:

The working principle of capacitive touch screen is to use one or more layers of ITO on the surface of glass to make x-axis and y-axis electrode matrix. When the finger touches, a coupling capacitance is formed between the finger and ITO surface, which causes the weak change of current. By scanning the x-axis and y-axis electrode matrix, the change of electric capacity of the touch point is detected, and the position of the finger is calculated.

The capacitance touch screen can be divided into surface capacitance touch screen and projection capacitance touch screen. The projection capacitance touch screen can be divided into self capacitance touch screen and mutual capacitance touch screen. The x-axis and y-axis electrode matrix of the self capacitance touch screen respectively form capacitance with the ground. When the finger touches the capacitance screen, the finger capacitance and electrode capacitance overlap, so that the electrode capacitance increases.