1962, the first practical visible light led appeared, led development has reached a very high degree, LED has been widely used as a bulb, neon and light tube the most ideal replacement. And it is expected that with its further development led will completely replace the above-mentioned light source. The future of mankind will be brighter. Because the use of LED can save a lot of energy, money and time.
Led development can be divided into three stages: the emergence of red LED, Blu-ray led and white light led appear. Red and green LEDs have been developed for decades, but they are monochrome LEDs. If it is used as a light source, the object will wear a color, rather than the color of the body itself, so the application of LED has a certain limit.