Early 1970s, the GaP, GaAsP homogeneous knot red, yellow, green, low-efficiency light-emitting LED light has been applied, numbers and text. Since then enter a variety of LED applications, including aerospace, aircraft, automotive, industrial applications, communications, consumer products, etc., throughout the national economy and household sectors. By 1996 sales of LED in the world has reached several billion dollars. Although over the years has been the color LED light-emitting efficiency and limitations, but because of GaP and GaAsP LED with long life, high reliability, small current can be TTL, CMOS-compatible digital circuitry and therefore has many advantages, such as has been the user's favor . The past decade, high-brightness, and full color LED technology has been a material and device research in cutting-edge technology topics. Ultra-high brightness (UHB) is the luminous intensity 100mcd meet or exceed the LED, also known as the candela (cd)-level LED. A1GaInP and high-brightness InGaN LED development have progressed very rapidly, has now reached conventional materials GaA1As, GaAsP, GaP unattainable performance levels. Toshiba Corporation of Japan in 1991 and the United States the development of HP company InGaA1P 620nm ultra-high brightness orange LED, 1992 yellow InGaA1p590nm years practical ultra-high brightness LED. That same year, Toshiba developed InGaA1P 573nm yellow-green ultra-high brightness LED, the light intensity of Law 2cd. 1994 Nichia Corporation of Japan developed blue InGaN 450nm (green) color ultra-high brightness LED. Thus, the color display required for trichromatic red, green, blue and orange, yellow variety of LED colors have reached a candela of luminous intensity level to achieve the ultra-high brightness, and full color so that the entire outdoor LED color show become a reality. China's development started in the seventies LED industry in the eighties. About more than 100 enterprises, 95% of manufacturers are engaged in the production of post-Road package, needed to die, almost all imported from abroad. Through several "Five-Year Plan" of technological innovation, technical research, the introduction of foreign advanced equipment and some key technologies, the production of our LED technology has been a step forward.
ª¤ ª¤ Second, ultra high brightness LED performance:
ª¤ ª¤ A1GaAsLED with ultra-high brightness red GaAsP-GaP LED compared with a higher luminous efficiency, low-contrast transparent (TS) A1GaAs LED (640nm) is close to the lumen efficiency of 10lm / w, than the red GaAsP-GaP LED big 10 times. InGaAlP LED provides ultra-high brightness of the colors and the same GaAsP-GaP LED include: yellow green (560nm), yellow light green (570nm), yellow (585nm), yellow (590nm), orange (605nm),dzºì(625nm crimson (640nm). transparent substrate A1GaInP LED light-emitting efficiency and the other LED and incandescent lighting structure comparison, InGaAlP LED absorbing substrate (AS) the lumen efficiency of 101m / w, a transparent substrate (TS) for the 201m / w, in the 590 -626nm wavelength range than that of the GaAsP-GaP LED lumen efficiency of 10-20 times higher; in the wavelength range of 560-570 while GaAsP-GaP LED than 2-4 times higher. ultra-high-brightness blue InGaN LED provided light and green light, blue for the wavelength range 450-480nm, blue green 500nm, green is 520nm; the lumen efficiency of 3-151m / w. ultra-high brightness LED lumen efficiency of the existing belt filter has exceeded the incandescent lamps, can replace the incandescent power 1w or less, and the LED array can be used to replace the power of incandescent 150w or less. For many applications, incandescent lamps are used in filters to get the red, orange, green and blue, and with ultra-high-brightness LED color can be the same. In recent years, AlGaInP and InGaN materials materials will be a number of ultra-high brightness LED (red, blue, green) super high brightness LED chips together, do not filter can be a variety of colors. including red, orange, yellow, green, blue, light-emitting efficiency of the present have more than their incandescent, fluorescent lamps are close to. higher than the brightness 1000mcd, can meet the outdoor all-weather, the need for full color display with LED large-screen color can be expressed in the sky and the sea, the realization of three-dimensional animation. a new generation of red, green and blue ultra-high brightness LED to achieve unprecedented performance.

ª¤ ª¤ III ultra-high brightness LED applications:
ª¤ ª¤ 1. Information Indicator
ª¤ ª¤ signaling vehicle: car lights in the car is the direction of the external lights, taillights and brake lights; in the car is mainly a variety of internal lighting and display instruments. Ultra-high brightness LED for automotive light compared with the traditional incandescent lamp has many advantages, in the automobile industry has a broad market. Strong LED can withstand mechanical shock and vibration. MTBF than the average working life of several order of magnitude higher than incandescent bulbs, which is far higher than the working life of the vehicle itself, the LED brake light can be packaged as a whole, without having to consider maintenance. Al.GaAs and transparent substrate AlInGaP LED and incandescent bulbs with a filter with very high compared to the efficiency of the lumen, so that the brake lights and direction of LED lamps can be driven at a lower current work, the typical drive current of only Incandescent 1 / 4, which reduces the car for the driving range. Lower electric power lines can reduce the car's size and weight of the system, but can also reduce the integration of the internal temperature rise of LED lights, lenses and housings allow the use of low heat resistance of plastic. LED brake light of the response time of 100ns, the response time than incandescent short, thus leaving more to the driver's reaction time, resulting in improved traffic safety guarantee. Car of the illuminance of external light and color are clearly defined. Shows that the internal lighting of motor vehicles, although not by an external signal as the control of the relevant government departments, but the car manufacturer and the color of the LED illumination is required. GaP LED has long been used in the car, ultra-high-brightness AlGaInP and InGaN LED illumination in the color and can meet the requirements of the manufacturer, which will replace the car more incandescent. From the price point of view, even though compared to LED or incandescent lamps with more expensive, but the entire system, both the price and no significant difference. With the ultra-high brightness TS AlGaAs and AlGaInP LED utility of the development of prices in recent years has been reduced to reduce the magnitude of the future will be greater.
ª¤ ª¤ directed traffic signals: The ultra-high brightness LED to replace incandescent lamps for traffic lights, warning lights, marker lamps are now available all over the world, a huge market demand growing rapidly. According to the U.S. Department of Transportation statistics for 1994, the United States to install traffic lights at the crossroads there are 260,000, each at a crossroads at least 12 red, yellow, blue and green lights. Many crossroads and some additional changes in signs and the crosswalk across the road warning light. In this way, each have 20 lights at a crossroads, and the luminescence at the same time. This can be projected that the United States about 135 million nationwide traffic lights. At present, the use of ultra-high brightness LED to replace the traditional incandescent lights to reduce power loss has achieved remarkable results. Japan every year in traffic lights on the power consumption of about one million kilowatts, the use of ultra-high brightness LED to replace the incandescent lamp, its power consumption is only 12% of the original.
ª¤ ª¤ traffic lights competent authorities of each country should formulate corresponding norms, the provisions of the color signal, the minimum illumination intensity, the spatial distribution of the beam pattern, as well as on the installation environment requirements. Although these requirements are prepared in accordance with incandescent, but the current ultra-high brightness LED traffic lights are applied. Incandescent traffic lights with LED compared to a longer working life, generally up to 10 years, taking into account the environmental impact of outdoor poor, life expectancy should be reduced to 5-6 years. At present, ultra-high-brightness AlGaInP red, orange, yellow LED has been the realization of industrialization, prices were relatively cheap, if ultra-high brightness red LED modules to replace the traditional composition of the red incandescent traffic signal head may be due to a sudden failure to red incandescent the impact of low security to the minimum. LED traffic signal modules in general a number of groups from a single LED lamp series, to 12-inch red LED traffic signal modules as an example, in the 3-9 group, single LED lamp series, each series of LED lights for a single 70 -- 75 (a total of 210-675LED single lamp), when there is a single LED lamp fails, it only affects a group of signals, and the rest of the group reduced to the original 2 / 3 (67%) or 8 / 9 (89% ), and not as incandescent lights, as the entire first failure.
ª¤ ª¤ LED traffic signal modules, the main problem is made more referrals is still high, with 12-inch TS-AlGaAs red LED traffic signal modules as an example, first used in 1994, its cost of $ 350, and 1996 performance good 12 British AlGaInP LED traffic signal modules, the cost is $ 200. The next will not be long, InGaN blue and green LED traffic signal modules, prices will be compared with the AlGaInP. Incandescent traffic signal head cost was low, but power consumption, and a 12-inch diameter of the incandescent traffic signal head of the power consumption of 150W, the sidewalk to cross the road traffic warning light for the power consumption of 67W, it has been calculated, each at a crossroads incandescent lights of the annual power consumption of 18133KWh, equivalent to $ 1450 a year for electricity; However, LED traffic signal module is very low power, each 8-12 inch red LED traffic signal modules for 15W power consumption, respectively, and 20W, at the crossroads bend the arrow of the LED signs available switches show that power consumption is only 9w, it has been calculated that each intersection could be saving each year 9916KWh, a considerable saving money on electricity bills each year $ 793. Each LED traffic signal modules, the average cost of $ 200, the red LED traffic signal modules of their savings in electricity in just 3 years after the initial construction costs of recovery and economic return has been started. Therefore the current traffic information AlGaInP LED modules, although the cost seems to, but from the long view, or cost-effective.

ª¤ ª¤ 2. Large-screen display
ª¤ ª¤ large-screen ultra-high brightness LED display is a huge market applications, including: graphics, text, figures, monochrome, color and full color display. In Table 2 lists the various uses LED display. Traditional large-screen display generally active incandescent, fiber optics, cathode ray tubes, etc.; showed that the use of passive methods flop. Table 3 lists the performance comparison of several shows. LED display has been the performance of LED and color their own restrictions. Today, ultra-high-brightness AlGaInP, TS-AlGaAs, InGaN LED has been able to provide a bright red, yellow, green, and blue colors, the realization of full color fully meet the requirements of large-screen display. LED display pixel size can be assembled into various structures, generally less than the diameter of the small pixel 5mm, each pixel monochrome display with a T-1 (3 / 4) of the LED lights, dual-color displayed for each pixel The two-color T-1 (3 / 4) of the LED lights, full color display is required three T-1 red, green, blue lights, or a multi-chip assembly of the T-1 (3 / 4) of the LED lights as a pixel. Large pixel is through the many T-1 (3 / 4) red, green and blue LED lights posed together. With InGaN (480nm) blue, InGaN (515nm) and green ALGaAS (637nm) red LED lights as a three-color LED display, full color can provide a realistic performance, but also a greater range of colors including: blue, green and red , with the International Television Systems Committee (NTSC) color television the scope of the provisions of the basic line.

ª¤ ª¤ 3. Liquid crystal display (LCD) back lighting
ª¤ ª¤ in the liquid crystal display, at least 10% of the use of active light as back lighting, the light source will enable the LCD display readable under a dark, full color LCD display also need light. LCD back lighting required for the main light source: incandescent bulbs, electroluminescent, cold cathode fluorescent, LED, etc., which are set out in Table 4 for comparison, including LED lighting in the LCD back in the most competitive, a new type of ultra-high brightness AlGaInP, AlGaAs, InGaN LED can provide high efficiency and wide range of luminous colors.
ª¤ ª¤ LED back lighting for LCD mainly in three ways. (1) the simplest is to direct the installation of LED light scattering film in the back of LCD, the LED package can be used in many lights, they should have a very wide beam angle, so that a better uniformity of the axial light. Can also be used not die package, the general use of GaP LED, but with AlGaInP, TS-AlGaAs LED can work in a small current, reducing power consumption. (2) Another approach is the edge of light LCD back lighting, with a transparent or translucent plastic block as a rectangular light guide body to be directly mounted on the back of LCD scattering film, plastic pieces of a white painted surface of the reflective material , LED light from the side of a plastic block into the goal, for the rest of the side with white reflective material. (3) LED light beam into optical fiber, the optical beam after the scattering form a flat film of the thin section, different methods can be used to thin out light from the back lighting as a LCD. Using LED back lighting as a liquid crystal display can be used in mobile phones, notebook computers, liquid crystal display with small-type communications products in the power of the wide use of ultra-high brightness LED will have a greater demand.
ª¤ ª¤ 4. According to the solid light
ª¤ ª¤ ultra-high brightness LED full color of practical use and commercialization, so that lighting technology is facing a new revolution, a number of ultra-high brightness red, blue and green LED lights are made of solid wavelength can be issued not only for adjustable range of light, but also can be issued up to a few dozen to a hundred bright white as a candlelight lighting. Recently, the Japanese company Nichia InGaN blue LED and the fluorescence technique, but also introduced a white light-emitting device of solid products, the color temperature to 6500K, the efficiency of 7.5 lumens per watt. The same brightness of incandescent and LED lights solid said that the power which the former accounted for only 10% -20%, the life of incandescent lamps are generally not more than 2000 hours, while the LED lights up to tens of thousands of hours of life. This small size, light weight, good direction, energy saving, long life, resistant to a variety of adverse conditions is bound to the solid source of the light source of traditional market. Although this new type of lighting the cost of solid light source is still high, but can be applied to some special occasions, such as mining, diving, rescue, military and other lighting devices. The long run, if the ultra-high brightness LED to further expand the production scale, the cost to further reduce its energy conservation and the advantages of long-lived enough to make up for the disadvantage of its high price. Ultra-high brightness LED will likely become a very competitive new power source.