【正文】 c. 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 development 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. Third LED advantages Conductor lightemitting diode (LED) as a thirdgeneration semiconductor lighting source. This fantastic product has a lot of advantages: (1) efficient light: spectra of almost all concentrated in the visible light frequency, the efficiency can reach 80% 90%. The luminous efficiency of incandescent visible light efficiency of almost 10% 20% only. (2) high quality of light: not as a result of spectrum UV and infrared, there is no heat, no radiation, is typically a green light illumination. (3) energy consumption of the small: single power generally , through the cluster can be tailored to meet different needs, and waste very little. As a light source, under the brightness in the same power consumption of only ordinary incandescent 1/810. (4) long life: flux attenuation to 70% of the standard life expectancy is 100,000 hours. A semiconductor light can be used under normal circumstances 50 years, even if the long life of the people, life will be used up to two lights. (5) durable and reliable: No tungsten wire, glass and other easily damaged ponents, nonnormal retirement rate is very small, very low maintenance costs. (6) the application of flexibility: small size, can flat pack, easy to develop into a short thin products, make point, line, face various forms of specific applications. (7) Security: working voltage or less in between the current 2070mA in between. (8) green: recyclable waste, no pollution, unlike fluorescent lamps containing mercury as ingredients. (9) response time is short: to adapt to frequent and highfrequency switching operation of occasions. In recent years, China39。 the field of puter and microelectronics technology development in the field of display control technology, the video control technology, the screen dynamic display effect of greatly increased. In this stage, LED display in China has developed rapidly, LED display industry turn into a new hightech industry. Today, LED display used in broader field, here I will talk my point about the LED in the hotel and leisure field applications. I. LED display of the effectiveness of the hotel LED electronic display is the fourth largest advertising media after television， newspaper, work. It will bring tangible social benefits for investors and economic benefits, LED electronic display can be received from the puter, TV, VCR, VCD, video cameras and other information transmitted, and play dimensional or threedimensional animation, text information at anytime. With economic grows, Accelerated pace of social work life, the hotel in people39。s demand for investors with a huge, immeasurable, longterm social and economic benefits. 1. Social A, promote the hotel39。s image. B, promote the hotel39。 Hotels flowintensive, information requirements wide。s best advertising media, can be, within 365 days a year to undertake a variety of advertising an unlimited number of foreign business。 Xiamen Egret Plaza on the state of largescale fullcolor, in just three years time, the recovery of more than 500 million yuan of total investment, and is nearly 200 million a year profit for the investors steady flow of economic benefits. The foregoing analysis, the Grand Hotel to configure a large LED electronic display, will give you and your guests with huge, longterm, good social and economic benefits, play a doubleedged sword effect. Ⅱ .The role of hotel LED display the hotel mood. Through the display screen to play the higherups and all kinds of guests e to visit, guide words of wele, a variety of major festivals such as celebration of the word. spreading A, through the LED electronic display that can play a variety of laws, rules, regulations and all kinds of knowledge and so on. B, through the LED electronic display can play hotel new service introduction。s service mitment and so on. 3. Play the role of bulletin boards. Through the display screen can be broadcast lectures, meetings of the notice, all notices, job placement and advanced individuals, the Hall of Fame and advanced deeds and so on. the role of public service ads. ① , through the display screen can be broadcast weather forecasts。 ③ , local maps, tourist traffic map and various tourist spots, maps。s slogan and important news. 5. Creation of well economic benefits As the world39。s information technology step to high level. China3