LED is a solid-state semiconductor device, which can directly convert electricity into light. The heart of LED is a semiconductor chip, one end of which is attached to the bracket, one end is the negative electrode, and the other end is connected to the positive electrode of power supply, so that the whole chip is encapsulated by epoxy resin. The semiconductor wafer consists of two parts, one is a P-type semiconductor, in which holes are dominant, and the other is an N-type semiconductor, mainly electrons. But when these two semiconductors are connected together, a "pn junction" is formed between them. When the current acts on the chip through the wire, the electrons will be pushed to the P region, where the electrons will recombine with the holes, and then the energy will be emitted in the form of photons, which is the principle of LED display.

LED system composition?

The system consists of special computer equipment, display screen, video input port and system software. ?

Computers and special equipment: Computers and special equipment directly determine the functions of the system, and different types can be selected according to the different requirements of users for the system. ?

Display screen: the control circuit of the display screen receives the display signal of the computer, drives the LED to emit light to generate a picture, and outputs sound by adding a power amplifier and a sound box.

Video input port: provides a video input port. The signal source can be a video recorder, DVD player, video camera, etc. It supports NTSC, PAL, S_Video and other formats. ?

System software: provide LED playing special software, powerpoint or ES98 video playing software. ?