1 Introduction
With the improvement of LED luminous efficiency, especially in the late 1990s, the invention of white LEDs opened up space for LED applications in the field of lighting, making it a new generation of light source after incandescent, fluorescent and high-pressure gas discharge lamps. . LED light source has attracted attention from all walks of life with its energy saving and environmental protection, making it the biggest hot spot in the domestic lighting field in recent years. However, the emergence of a new technology and its maturity, resulting in a wide range of applications requires a process that cannot be achieved overnight. This article will review the development of domestic LED lighting in the past decade to explore the future development of domestic LED lighting.
2 Domestic LED lighting development background
Saving energy, protecting the environment, and developing green lighting products have been the focus of China's lighting industry since the early 1990s. Therefore, when high-efficiency LEDs appeared, they immediately attracted the attention of relevant domestic ministries. In June 2003, the Ministry of Science and Technology led the establishment of the “National Semiconductor Lighting Project Coordination Leading Groupâ€, which kicked off the domestic LED lighting industry. At the beginning of 2009, the Ministry of Science and Technology launched the pilot project of “Ten Cities and Ten Thousands†semiconductor lighting application engineering, which set off the development climax of domestic LED road lamps. In October 2009, in response to the development of domestic LED lighting, the National Development and Reform Commission and the Ministry of Housing and Urban-Rural Development and other six ministries and commissions issued the “Opinions on the Development of LED Lighting Energy-Saving Industryâ€, which clarified the development goals of China's LED lighting industry in 2015. The specific target is that the output value of the semiconductor lighting energy-saving industry will increase by 30% annually before 2015, of which functional lighting accounts for 20%, LCD backlights reach 50%, and landscape decorative lamp products account for more than 70%. In September 2010, the National Development and Reform Commission, the Ministry of Housing and Urban-Rural Development and the Ministry of Communications launched a tender for 50 LED demonstration projects, which attracted the active participation of many enterprises. A series of promotion activities and related policies for LED lighting products carried out by relevant national ministries and commissions have greatly accelerated the development of China's LED lighting industry and played an active role in promoting the application of LEDs in the field of lighting.
3 Domestic LED lighting industry development review
In the 21st century, with the breakthrough of LED luminous efficiency, the application of LED in the field of lighting is gradually unfolding. China has taken the lead in applying traffic lights. Since 2000, large-scale replacement of traffic lights has been carried out in China. By the end of 2005, LED traffic lights were basically used in cities from rural to rural areas. China is currently the fastest, most abundant and most popular country for LED traffic lights in all countries of the world. Interestingly, due to the immature green LEDs in the early stage, the traffic lights in many cities in China use red, yellow and blue colors. Later, with the green LEDs mature, they gradually return to the three standard colors of red, yellow and green. While a large number of LED traffic lights have been replaced, various traffic signs have also adopted LED light sources.
In 2005, in order to welcome the 2008 Beijing Olympic Games, Beijing increased its efforts to reorganize outdoor billboards, advertising light boxes and store signs. Previously, such products were mainly based on neon lights, but the neon lights had high energy consumption, short life span, and unstable quality. After the problems occurred, they could not be maintained in time, which affected the image of the city. Therefore, the Beijing Municipal Government has introduced some restrictions and regulations and advocated the use of energy-saving products. After that, various cities in the country followed suit, which provided an opportunity for LEDs to replace neon lights with 100 years of history. By 2008, a large number of billboards and store signs in domestic central cities basically adopted LED as a light source, and advertising light boxes were gradually replaced by display screens.
LED outdoor lighting products used in urban landscape lighting, due to their partial lighting functions, experienced some twists and turns in the process of research and development and promotion, such as light decay, light distribution, driving power, waterproof, etc. The lessons learned are gradually solved on the basis of the application. For example, in the 2008 Beijing Olympic Games, due to the immature LED landscape lighting products at that time, only a few projects in the central Olympic district used LED lighting, and most of the other environments still used traditional lighting products, while the LED lighting products that have been used were partially in use. The product still has quality problems. However, in the short span of two years in the 2010 Shanghai World Expo and the Guangzhou Asian Games, many technical problems of LED landscape lighting have been solved. The LED lighting products used in the landscape lighting of the Shanghai World Expo and the Guangzhou Asian Games have reached more than 90%. Its diverse color variations and strong visual impact have left a deep impression on the audience around the world.
In addition to the successful application of LED lighting in the development of LED lighting in China for more than 10 years, there are still quite a few fields that have been unknowingly replaced by traditional lighting products by LED lighting products, such as aircraft take-off and landing for airport runways. Indicator lights, mid-line lamps, commercial counter lighting, miners' cap lamps for coal miners, entertainment venue lamps and film stage lamps, various emergency lamps used in buildings, turn signals, brake lights, reading in cars Lights, train cars, aircraft cabin lighting, etc. Lighting lamps in the above fields, LED lighting products have become mainstream. In addition, because the LED does not contain ultraviolet light, it does not harm the cultural relics, and the museum also uses a certain amount of LED lighting products.
In the development of LED lighting for ten years, there are also unsuccessful cases, that is, road lamps. As we all know, LED road lamps are one of the most demanding functional lighting products in the field of lighting. Whether its technical performance indicators meet the requirements has a direct relationship with driving safety and personal safety. In 2007, a group of enterprises entered the field of LED road lighting production, driven by relevant government departments and local governments. Some of these companies have not been involved in the lighting industry before, and they do not understand the road lighting standards and usage requirements. Others, although formerly lighting companies, do not know enough about LED characteristics. This has led to the production of LED street lamp products that do not meet the technical requirements, and at the same time do not meet the requirements for use. Technical aspects such as light decay, secondary optical design, and driving power supply were installed on the road in the early stage when these problems were not solved, resulting in quality problems in a short period of time. In terms of use, the color temperature selection and secondary optical design of the LED chip are unreasonable, resulting in the lighting effect of the road not meeting requirements, such as illumination and uniformity, brightness and uniformity, glare limitation, and environmental ratio. It is precisely because of these reasons that many installed LED street lamps are constantly being maintained and replaced during the use process. Some roads have been changed several times in a few years, and some have been installed for a short time and have been taken down and re-installed. Replace the street light with a traditional light source. This result has left a negative impression on the LED streetlight users' brains while causing economic losses to the participating companies, and has hidden hidden dangers for the future promotion of LED street lamps.
Through review and analysis, we will find that in the past ten years, the successful application of domestic LED lighting products has been concentrated in the lighting fields with display, indication and color change, such as traffic lights, emergency lighting, film and television stage. Lighting, airport runway lighting, outdoor landscape lighting, etc., rarely involve functional lighting products or general environmental lighting products. Due to various technical problems and problems in the development of LED street lamps, the promotion of LED street lamps is not smooth. Under the influence of the market, some LED street lamp manufacturers gradually calm down, reducing or abandoning further investment in LED street lamps, and the heat of LED street lamps has declined.
Ten years of LED lighting development history, there are successes and lessons, and products that meet market rules and adapt to the market can be developed. By administrative means and violation of market rules, the results will naturally not be ideal.