English LED Light Emitting Diode, light-emitting diode, is a semiconductor light-emitting solid device, it is the use of solid semiconductor chip as luminescent materials, when both ends with a positive voltage, the semiconductor carrier recombination occurs and cause photon emission It produces light .LED can emit red, yellow, blue, green, blue, orange, purple, white light. the first commercial diode produced in 1960. its basic structure is an electroluminescent semiconductor materials, placed on a wire rack, then sealed with epoxy resin around, protect the internal core wire, so the seismic performance of the LED.