In order to illustrate the characteristics of white LEDs, first look at the condition of the lighting source used. Incandescent lamps and halogen tungsten lamps have an optical efficiency of 12-24 lumens/watt; fluorescent lamps and HID lamps have an optical efficiency of 50-120 lumens/watt. For white LEDs: In 1998, the luminous efficiency of white LEDs was only 5 lumens/watt. By 1999, it had reached 15 lumens/watt. This index was similar to ordinary household incandescent lamps. In 2000, the luminous efficiency of white LEDs It has reached 25 lumens per watt, which is similar to the tungsten halogen lamp. Some companies predict that by 2005, the luminous efficiency of LEDs can reach 50 lumens/watt, and by 2015, the luminous efficiency of LEDs is expected to reach 150-200 lumens/watt. At that time, the working current of the white LED could reach the ampere level. It can be seen that the development of a white light LED writer's lighting source will become a possible reality.

Although the incandescent lamps and halogen tungsten lamps for general lighting are cheap, they have low luminous efficiency (the thermal effect of the lamp consumes nothing power), short lifespan, and heavy maintenance workload. However, if white LEDs are used for lighting, not only the luminous efficiency is high, but also the longevity Long (more than 10,000 hours of continuous working time), almost no maintenance.

LED light source has the advantages of using low-voltage power supply, low energy consumption, strong applicability, high stability, short response time, no pollution to the environment, multi-color luminescence, etc. Although the price is more expensive than existing lighting equipment, it is still considered to be it. It will inevitably replace existing lighting devices.