For general lighting, white LED is usually formed by two methods in the process structure. The first is to use "blue light technology" to form white light with phosphor; Snowing Musical LED Lantern Prelit Christmas Decoration the second is to use a variety of monochrome light mixing methods. Both methods have been successful in producing white light devices. The first method of generating white light is shown in Figure 1. The LED GaM chip in the figure emits blue light (lambda P = 465 nm), which is packaged with YAG (yttrium aluminium garnet) phosphor. When the phosphor is stimulated by blue light,Snowing Musical LED Lantern Prelit Christmas Decoration it emits yellow light. As a result, Snowing Musical LED Lantern Prelit Christmas Decoration blue light and yellow light mix to form white light (the structure of the LED is shown in Figure 2). In the second method, chips with different colors are packaged together, and white light is produced by mixing different colors.
To illustrate the characteristics of white LED, first look at the lighting source used. The light efficiency of incandescent lamp and halogen tungsten lamp is 12-24 lumens/watt, and that of fluorescent lamp and HID lamp is 50-120 lumens/watt. For white LED: In 1998, the light efficiency of white LED was only 5 lumens/watt, and reached 15 lumens/watt in 1999. This index is similar to that of common household incandescent lamps. In 2000, the light efficiency of white LED reached 25 lumens/watt, which is similar to halogen tungsten lamps. Some companies predict that the light efficiency of LED will reach 50 lumens/watt by 2005 and 150-200 lumens/watt by 2015. At that time,Snowing Musical LED Lantern Prelit Christmas Decoration the working current of white LED could reach ampere level. Therefore, it is possible to develop white LED lighting source for writers.
The incandescent lamp and halogen tungsten lamp for general lighting are cheap, but their light efficiency is low (white power consumption of thermal effect of lamp), Snowing Musical LED Lantern Prelit Christmas Decoration life is short and maintenance workload is large. But if white LED is used as lighting, not only light efficiency is high, but also life is long (continuous working time is more than 10,000 hours), almost no maintenance is needed.
LED light source has the advantages of low-voltage power supply, less energy consumption, strong applicability, high stability, short response time, no pollution to the environment, Snowing Musical LED Lantern Prelit Christmas Decorationmulti-color luminescence and so on. Although the price is more expensive than the existing lighting devices, it is still considered that it will inevitably replace the existing lighting devices.