Application of LED technology in automotive lamps

'China Building Materials Network' 1885, German engineer Carl. Benz (Karl. Benz) A three-wheeled diesel locomotive powered by the world's gasoline engine was developed, and the car was born and developed rapidly. However, in order to drive at night or in areas with insufficient lighting, there must be lighting fixtures. As a result, a car headlamp was generated in 1880s, and a hanging steam lamp for classic cars appeared in 1912. In the early days, tungsten filament incandescent lamps were used for headlamps of automobiles, and dim lights were only suitable for slower automobiles. With the increasing number of vehicles and the increasing speed of vehicles, automobile headlamps have developed into halogen tungsten headlamps with higher brightness and high-intensity gas discharge headlamps, there are many kinds of lights such as dipped light, high beam light and front fog light. At the same time, it is not enough to only look at the front, but also need to look left and right and avoid worries, thus giving birth to a series of lamps such as brake lamps, turn signals, rear fog lamps, etc, it plays a key role in avoiding rear-end collision or collision during turning at night. As an essential safety component for automobile driving, automobile lamps play a vital role in automobile active safety. According to statistics, traffic accidents occurred at night or under the condition of insufficient natural light accounted for 25 of the total accidents, and 50 of the casualties occurred at night. Among the more than 100 ECE regulations, there are nearly 40 regulations related to lights. Among the more than 70 mandatory inspections of automobile products in China, nearly 25 items related to headlights are accounted. Therefore, in order to improve driving safety, more and more new technologies are gradually applied to automobile lamps, such as optical fiber conduction technology for side turn signals and AFS technology for headlamps. Of course, this also includes LED technology ( LightEmittingDiode (LED) Application in automobile lamps, especially in automobile headlamps. In recent years, LED lamps have been used more and more in automobile design, which not only adds a modern sense to the appearance of automobiles, but also is familiar to more people, and the trend and direction of the development of automobile lamps today. Application of 2LED technology in automotive lamps LED is a kind of field luminescence light source, which is a semiconductor device that directly converts electricity into light energy. LED lighting principle is in p- Direct voltage is applied to both ends of the n junction, then the cavity in the p region will flow to the n region; Electrons in the n region will flow to the p region. With the correct recombination of electron holes, some of the energy is converted into heat and the other is converted into light. This new generation of solid-state Cold Light Source came out in 1960s and has been initially applied in signal indication such as instruments and telecommunications, forming the early application market of LED, however, due to its performance index problems such as light intensity and light attenuation, it cannot be widely used in automobile lamps. In the late 1980s S, with the emergence of high-brightness light-emitting diode technology, the application of LED lighting signals outside the vehicle became possible. The typical landmark event is: in 1988, Nissan first used 72 AlGaAs red high-brightness LEDs produced by STANLEY as high-altitude brake lights on 280Z cars. Since then, LED has officially entered the automotive lighting market. In 1990s, the development of LED materials continued to evolve. Toshiba and Hewlett- Packard jointly developed aluminum gallium indium phosphide in 1991 (InGaAlP)Made of four-element high brightness LED. In terms of technology and mass production, it paves the way for LED light sources of automobile lamps and lanterns. Entering the * century, LED technology has advanced by leaps and bounds, it has gradually replaced traditional light sources such as incandescent lamps and vacuum fluorescence, and has been widely combined and applied to interior lighting such as backlight lighting of automobile instruments, Operation switches, dome lights, reading lights, door lock lights, etc. In addition, LED has the advantages of strong reliability, long service life, high color purity, fast response speed, small volume and convenient design, and has been more and more widely used in automobile external lighting. Especially in recent years, LED lamps have been widely used in steering lights, brake lights, position lights, reversing lights, fog lights, license plate lights and other lamps, and have become the new favorite of automobile trends. At present, more than 80 European and Japanese cars are equipped with LED high brake lights. Several major automobile manufacturers in the market have also continuously introduced new types of cars with LED as the light source, such as Teana, Crown and Reiz launched by Japanese manufacturers such as Toyota, Mitsubishi, Honda and Nissan, american General car's the Cadillac, Buick and German factory of Mercedes- Benz, BMW, AUDI, etc. have all adopted LED taillights and gradually formed the industrialization of LED automotive lamps. With the development of LED module technology, LED modules with high brightness output have also been successfully launched, such as white LuxeonLED module developed by Lumileds and OSTAR white LED module of OSRAM, this makes the application of LED in automobile headlamp also possible and brings the trend of new generation headlamp technology. However, due to the high cost limit, the current LED headlights are mainly used in luxury vehicles. 2004 AudiA86. The 0L luxury car uses Lumileds's 6 white LuxeonLED as daytime running lights. In 2007, Toyota Motor Corporation of Japan introduced Lexus hybrid cars LS600h and LS600hL, becoming the first mass production vehicle equipped with all-white NichiaLED headlights.