Touch screen, also known as touch panel, PCAP is an inductive liquid crystal display device that receives touch-first input signals, which, when exposed to a graphical button on the screen, can be used to drive various connecting devices according to a preprogrammed program. Can be used to replace the mechanical button panel, and by the liquid crystal display screen to create a vivid audio-visual effect. As a new type of computer input device, touch screen is the simplest, convenient and natural man-machine interaction method at present. It gives the multimedia a new look and is an attractive new multimedia interactive device. Mainly used for public information inquiries, leading office, industrial control, military command, video games, song à la carte, multimedia teaching, real estate pre-sale and so on.