LED display screen is made up of two parts: Main led panel which is composed by several led display units(Led cabinet or led panel)that can connected together. This part is the main body of the led display. another part is the controller. the controller can also devided into two parts: control board( hardware) and control system( software). The control board are include the sending card,receiving cards and computer. Multifarious display panels (or cabinet units) with different specifications and controllers with different control technology can be constituted into various kinds of LED display screen to satisfy different application environments with diverse requirements.( such as video processor and multifunction card). The Structure of the Screen: 1. Led module: No matter indoor or outdoor led display, they all composed by led modules. Led modules are include( led lamps, driving IC, pcb board and module frame). its size can not be changed easily. 2. Display Panel Display Panel is the main body of the screen. It is made up of light-emitting materials and driving circuit. The LED display screen panel of indoor and outdoor screen are unit cabinet. 3. Display Controller Display controller are mainly include sending card, receiving cards and computer. The sending card should be installed inside the computer, the receiving cards should be installed inside the cabinets. usually one cabinet needs one receiving card. 4. Switching Power Supply It is used to transform the 220V or 110V alternating current into all kinds of direct current to support various circuits. 5. Transmitting Cables The led display screen data and all kinds of controlling signals generated by the host controller are transmitted through twisted-pair cables to the screen. 6. Scanning Control Board The function of it is to cushion the data, generate all kinds of scanning signals and duty cycle grey scale control signals. 7. Special Videocard and Multifunction Card The special videocard of full color LED screen not only bear the basic functions of computer videocard, but can also output RGB digital signals and row, field and blanking signals to the host controller. Besides functions the same as the special videocard, multifunction card can also change the input simulated video signals into RGB digital signals (that is the collection of video communication). 8. Other information sources and devices Including computer, TV set, blue-ray disc, DVD, VCD, video camera and recorder and so on.