Can the LED light source be certified by 3C? What certification does light source need to be certified?
LED light source can do 3C authentication: in 60s of last century, scientists and technicians made use of the principle of semiconductor pn junction to develop LED led. The LED was then made of GaASP, whose emitting color was red. After nearly 30 years of development, now we are very familiar with the LED, has been able to issue red, orange, yellow, green, blue and other colors. However, the white light LED required for illumination has only developed in recent years. Here we introduce the white light LED for illumination.
The relation between the spectrum of visible light and LED white light.As far as we can see, the wavelength range of light spectrum is 380nm ~ 760nm, which is the seven chromatic light that can be perceived by human eyes - red, orange, yellow, green, cyan, blue and purple, but each of the seven colors is a monochromatic light. For example, the peak wavelength of red light produced by LED is 565nm. In the visible light spectrum is not white light, because white is not monochromatic light, but light composite by a variety of monochromatic light synthesis, as the sun light is composed of seven kinds of monochromatic and white light, white light color TV is composed of three primary colors of red, green and blue synthesis. Thus, to make LED emit white light, its spectral characteristics should include the entire visible spectral range. But to manufacture this kind of LED, it is impossible under the present process condition. According to the research of visible light, the human eye can see white, mixed with at least two light, two light emitting wavelength (blue light and yellow light emitting wavelength) or three (blue light + + red light green light) model. Blue light is needed for all two modes of white light, so the uptake of blue light has become the key technology for manufacturing white light, the Blu ray technology pursued by major LED manufacturers". The international master "Blu ray" only a handful of manufacturers, such as Japan, Japan's Nichia chemical synthesis, TOYOTA CREE of America, Germany's OSRAM, so white LED application, especially the high brightness white LED spread in China there is a process.
Application foreground of white light LED lighting new light source.In order to explain the characteristics of white light LED, first look at the current situation of the lighting source. The incandescent lamp and halogen tungsten lamp have a luminous efficiency of 12~24 lumens / watt, and the luminous efficiency of fluorescent lamp and HID lamp is 50~120 lumens / watt. The white LED: in 1998, light white LED is only 5 LM / W, in 1999 has reached 15 LM / W, this index is similar to general household incandescent lamps, and in 2000, light efficiency of white LED has reached 25 LM / W, the index and the tungsten halogen lamp is similar. The company predicted that by 2005, the LED luminous efficiency of up to 50 LM / W, such as kvidi opto Electronics (http://www.kvidi ) 1W white light production has reached 60 LM / W, by 2015, the optical efficiency of LED is expected to reach 150 to 200 LM / W. At that time, the working current of white light LED can reach ampere level. Thus, the development of white LED writers using lighting sources, will become possible reality.
Process structure and white light source of white light LED.For general lighting, the white LED is usually formed in two ways on the process structure. The first is the use of blue light technology to match the phosphor to form white light; the second is a variety of monochromatic light mixing methods. Both of these two methods have been successful in producing white light devices. The system shown in Figure 1 the first method to produce white light, blue chip LEDGaM diagram (2 p=465NM), and YAG (yttrium aluminum garnet) phosphor package together, when a yellow light phosphor can be excited by blue light and the blue and yellow light mixed into white light (consisting of LED structures such as as shown in Figure 2). The second method uses different colors of the chip to wrap together and produces white light by mixing each shade of light.
