【文章內(nèi)容簡(jiǎn)介】 is mainly electronic. But linking the two semiconductors, among them the formation of a PN junction. When the current through the wires role in this chip, will be pushing eP, P zone in the hole with electronic posite, and then to be issued in the form of photon energy, and this is the principle of LED luminescence. The wavelength of light that is the color of light, is formed by the PN junction of the decisions of the material. Second LED history and development 50 years ago, people have to understand semiconductor materials can produce light of the basic knowledge, the first mercial diodes in 1960. English is the LED light emitting diode (LED) acronym, and its basic structure is an electroluminescent semiconductor materials, placed in a wire rack, then sealed with epoxy resin around, that is, solid package, Therefore, the protection of the internal batteries can play the role of line, so the seismic performance LED good. LED is the core of the Ptype semiconductor and ponents of the Ntype semiconductor chips, the Ptype semiconductor and Ntype semiconductor between a transition layer, called the PN junction. In some semiconductor materials in the PN junction, the injection of a small number of carriercarrier and the majority of the extra time will be in the form of light energy to release, thus the power to direct conversion of solar energy. PN junction on reverse voltage, a few hardcarrier injection, it is not luminous. This use of injection electroluminescent diodes is produced by the principle of lightemitting diodes, monly known as LED. When it in a positive state of the work (that is, at both ends with forward voltage), the current flows from the LED anode, cathode, semiconductor crystals on the issue from the ultraviolet to infrared light of different colors, light and the strength of the currents. Instruments used for the first LED light source instructions, but all kinds of light colored LED lights in traffic and large screen has been widely applied, have a very good economic and social benefits. The 12inch red traffic lights as an example, is used in the United States have long life, lowefficiency 140 watt incandescent lamp as a light source, it produced 2,000 lumens of white light. The red filter, the loss90 percent, only 200 lumens of red light. In the light of the new design, Lumileds panies have 18 red LED light source, including the loss of circuit, a total power consumption of 14 watts to generate the same optical effect. Automotive LED lights is also the source of important areas. For general lighting, people need more white light sources. The 1998 white LED successful development. This is the GaN LED chip and Yttrium Aluminum Gar (YAG) package together cause. GaN chip of the Bluray (λ p = 465nm, Wd = 30nm), made of hightemperature sintering of the Ce3 + YAG phosphors excited by this Bluray after irradiating a yellow, the peak 550 nm. Bluechip installed in the LEDbased Wanxing reflection in the cavity, covered with a resin mixed with YAG thin layer, about 200500 nm. LEDbased tablets issued by the Bluray absorption part of the phosphor, the phosphor another part of the Bluray and a yellow light mixed, can be a white. Now, the InGaN / YAG white LED, YAG phosphor by changing the chemical position of the phosphor layer and adjust the thickness of the 350010000 K color temperature can be colored white. This blue LED through the method by white, constructed simple, lowcost, high technology is mature, so use the most. The development of LED display can be divided into the following phases: first phase 1990 to 1995, mainly monochrome and 16 color graphics screen. Used to display text and simple images, mainly used in railway stations, financial securities, banks, post offices and other public places, as public information display tools. The second stage is from 1995 to 1999, there have been 64, 256 level grayscale twocolor video screen. Video control technology, image processing, optical fiber munication technology applications will enhance the LED display to a new level. LED display control LSI chips special at this time developed by domestic panies, and can be applied. The third stage, from 1999, red, pure green, blue LED in bulk into China, while domestic enterprises indepth research and development work, using red, green, and blue LED production of fullcolor display has been widely used , poured into sports stadiums, convention centers, squares and other public places, which will bring the domestic largescreen fullcolor era. With the rapid development of LED materials market, surface mount device is available from 2022, mainly used in indoor full color, and its high brightness, colorful, low temperature characteristics, the point spacing can be adjusted by different price Requirements were accepted, in just two years time, product sales have more than 300 million yuan, surface mount fullcolor LED display application market entered the new century. To meet the 2022 Olympic Games, downsizing plan, Liard developed a surface mount dual color displays, a lot of time for the training center and game scoring. Full color in Olympic venues, in order to tighten investment, full color way is mostly detachable, live during the Olympic Games as a tool can be used for rental after the event, as the performance of national policies such as public places, tools released by In this way cost recovery as soon as possible. On the market, China39。s accession to WTO, Beijing39。s successful Olympic bid and so on, into the development of LED display industry, a new opportunity. Domestic LED display market continues to grow, currently in the domestic market, domestic LED display market share of nearly 95%. LED display the international market capacity is expected to 30% a year growth rate. Currently, LED display manufacturers concentrated