The LED trend of automotive lighting is becoming more and more obvious
At present, LEDs are welcoming the industrial explosion period, and their application fields are gradually expanding with the advancement of technology. Among them, the three major areas of automotive, agriculture and medical care are the most eye-catching, and automotive lighting is also known as the new blue ocean of the LED lighting market. At the China (Shanghai) International Semiconductor Lighting Application Technology Forum, Yang Weiqiao, deputy director of the Shanghai Semiconductor Lighting Engineering Technology Research Center, introduced the development of LED in the field of automotive lighting. Director Yang said that the reason why automotive lighting stands out in many LED applications is precisely because of its large market size and high product added value. In 2012, the global automotive lamp production value was 2.1 billion US dollars, while the output value of China's LED automotive lighting reached about 3 billion yuan, and the development trend should not be underestimated. Since the first application of LED car lights in passenger cars in 1985, LED lamps have gradually turned on the LED process of car lamps with their advantages of energy saving, environmental protection, longevity, earthquake resistance, small size and fast response. Initially, LED is the exclusive equipment for high-end models, but in the past two years, the mid-end models including the Mercedes-Benz CLS series have also adopted LEDs, and the LED lighting trend of automotive lighting is becoming more and more obvious. Director Yang pointed out that at present, LED headlamps are the latest LED car lamps that are commercialized. In addition to meeting the technical high-brightness output and maintaining the junction temperature of 120 °C, the excessive price also restricts the commercial development of LED headlamps. In the case of automotive headlamps, there are two difficulties in making a product: optical system design and thermal design. In terms of optical system design, the automotive LED headlamp GB25991-2010 national standard requires that the spatial distribution of the headlamp's light intensity needs to meet the following requirements: 1. Illuminate the road surface and traffic signal signs in front of the car 2. Can not give the other party The driver of the car causes uncomfortable glare 3. The light distribution of the low beam headlights is completely asymmetrical. In the middle is a high light intensity area to illuminate the road ahead as much as possible. The beam is spread out in the horizontal direction to facilitate the identification of the roadside conditions. The light intensity is small in the direction of pointing the opponent's eyes to the driver's eyes, and no glare is generated. There is a very clear boundary between the bright and dark areas produced by the headlights. The director said that the projection lens type LED headlights and the emission type LED headlights can achieve the above requirements. How to provide a better thermal solution is more difficult than optical system design. An increase in junction temperature will result in a decrease in light efficiency, a shift in wavelength chromaticity, and a shortened lifetime. When the junction temperature exceeds 150 ° C, the luminaire will fail. Director Yang said that the commonly used heat dissipation methods include heat sinks, heat pipes, fans, and coated high-radiation materials. In fact, as early as the 11th Five-Year Plan, China has already focused on the deployment and research and development of LED car lights. The National 863 Program's major project for semiconductor lighting engineering, in the first batch of the first batch of the first batch of projects, arranged the development of automotive LED light source system, research on the integration of car headlights, and research and large-scale application of high-power LED lights. Question. Excellent results have been achieved so far. With the advancement of technology, the cost of LED lamps has gradually decreased, but compared with traditional lamps, the price of LED lamps still has a certain gap. Faced with the huge potential of LED in the field of automotive lighting applications, the author believes that reducing the price of LED lamps under the premise of ensuring product quality is the key point to promote the LEDization of automotive lamps.