LED lighting engineering research and application

Over the past 10 years, LEDs have changed dramatically in color, brightness and power. With its amazing and delightful application, LEDs play an unparalleled role in traditional indoor lighting in urban indoor and outdoor lighting. With a lifespan of 100,000 hours, LEDs mean eight hours of work a day and can be guaranteed for 35 years without maintenance. Low-voltage operation, almost 100% light output, low to zero output during dimming, can be combined with thousands of light colors, and the light-emitting area can be small, can be made into 1 square millimeter. After the secondary optical design, the lighting fixture achieves an ideal light intensity distribution. The rapid development of LED technology will bring new possibilities for lighting design and application, which is impossible for many traditional light sources.

Know the characteristics of LED

Today, it seems that the eyes of the whole world are focused on the new light source of LED. It is known as the green lighting product of the 21st century. Even people predict that most of the future will replace the traditional light source. Because it has long life, short starting time, firm structure, energy saving, illuminant close to point light source (lighting LED design), thin luminaire, luminaire material selection range, no need to add reflector, low voltage, no ultraviolet radiation, Especially in the public environment, it is safer to use. In addition, the production of LED light source can achieve mercury-free, which is more important for environmental protection and energy conservation.

Traditional LEDs are mainly used in signal display fields, building aviation obstacle lights, navigation lights, car signal lights, and instrument backlights. Nowadays, applications in entertainment, indoor and outdoor buildings, urban beautification, and landscape lighting are becoming more and more widespread. However, the current life of LED light sources can not reach the 100,000 hours indicated, and the actual life expectancy is about 50,000 hours, which is mainly related to the problem of heat dissipation. In a small space, as the power increases, the semiconductor components will overheat. Moreover, white LEDs cannot achieve the brightness of ordinary light bulbs.

LED application direction in lighting engineering

1. Building exterior lighting

A projected area of the building, is that the use of the control beam angle round and square shaped head with a flood light, it is entirely consistent with the traditional concept of the light projecting lamps. However, due to the small and thin LED light source, the development of linear projection lamps has undoubtedly become a highlight of LED projection lamps, because many buildings do not have a place to place traditional spotlights. It is easy to install, can be installed in a vertical or vertical direction, and is better integrated with the surface of the building, bringing a new lighting vocabulary to the lighting designer and expanding the creative space. It will also have an impact on the lighting practices of modern and historic buildings. î—¥

2, landscape lighting

Since LEDs are not glass bulbs like traditional light sources, they can be well integrated with urban street furniture. It can be illuminated in the city's leisure spaces such as paths, stairs, decks, waterfronts, and gardening. For flowers or low shrubs, LEDs can be used as a light source for illumination. LED recessed floodlights are particularly popular. The fixed end can be designed as a plug-in type, which is easy to adjust depending on the height of the plant.

3. Logo and indicative lighting

Spaces where space limitation and guidance are required, such as separation display of road pavement, local illumination of stair steps, and indication lighting of emergency exits, LED self-illuminating buried lights with appropriate surface brightness or lamps embedded in vertical wall surfaces, such as The ground guide light in the auditorium of the theater or the indicator light on the side of the seat, and the guide light on the floor inside the shopping mall. In addition, compared with neon lights, LEDs are low-pressure, have no fragile glass, and do not increase the cost due to bending during production. It is worthy of being promoted in logo design. î—¥

4, indoor space display lighting

As far as the lighting quality is concerned, since the LED light source has no heat, ultraviolet and infrared radiation, it does not cause damage to the exhibit or the product. Compared with the conventional light source, the lamp does not need an additional filter device, the lighting system is simple, the cost is low, and the installation is easy. Its precise lighting can be used as a substitute for museum fiber optic lighting. Commercial lighting metropolis uses colored LEDs. Interior white LEDs combined with interior decoration provide auxiliary lighting for indoors. Concealed light strips can use LEDs, which is especially beneficial for low spaces.

5, entertainment venues and stage lighting

Due to the dynamic, digital control of color, brightness and dimming of LEDs, lively saturated colors create static and dynamic lighting effects. From white light to any color in the full spectrum, the use of LEDs opens up new ideas in the lighting of such spaces. Long-life, high lumen maintenance (90% lumens after 10,000 hours) reduces maintenance costs and frequency of lamp replacement compared to 50-250 hours of PAR and metal halide lamps. In addition, the LED overcomes the phenomenon of color shift after the metal halide lamp is used for a period of time. Compared to PAR lamps, there is no heat radiation, which makes the space more comfortable. At present, the application of LED color decorative wall surface in catering buildings has become a common practice.

6, video screen

Full-color LED display is the most attractive outdoor large-scale display device in the world. It adopts advanced digital video processing technology and has unparalleled large area and super high brightness. According to different indoor and outdoor environments, different specifications of illuminating pixels are used to achieve different brightness, color and resolution to meet various purposes. It can dynamically display graphic animation information, and use multimedia technology to play various multimedia files. The most influential LED display in the world, which is the New York Stock Exchange of Manhattan Times Square, uses a total of 18,677,760 LEDs and an area of ​​10,736 square feet. The screen can be divided into multiple screens, and at the same time, the market of Wall Street stocks is presented to the public at a glance. In addition, the Aurora International Headquarters, which is located in the Lujiazui Financial Center in Pudong, Shanghai, has a 100m long LED screen with a total area of ​​3,600 square meters. It is the first in the world.

7, combined with industrial design

LED is the darling of European product designers in recent years. They use LED as part of the product design element, and they are in the space of imagination, combining light, glass or other materials to become a beautiful art.

LED product development issues to be solved

LED is the most promising high-tech lighting field in the 21st century. As a new high-efficiency solid-state light source, it has the significant advantages of long life, energy saving and environmental protection. It will be another leap in the history of human lighting following incandescent lamps, fluorescent lamps and high-pressure gas discharge lamps. In the epitaxial production, chip manufacturing, device packaging, integration application of semiconductor lighting products, a relatively complete industrial chain has been initially formed, but there are many constraints in the realization of LED functional lighting in white lighting. Therefore, in the current situation, the development and design of LED lighting products should be given the hope:

1. Meet the individual needs of people for lighting

The modularization of LEDs brings convenience to the lighting design, and the LEDs are in good working condition through the designer's reasonable and reasonable layout. LED products are dwarfed by traditional light sources in terms of individualized lighting, and the diversification of LED products will reach an unprecedented level. Therefore, the individualized R&D and design of LED products is the biggest challenge that all LED lighting suppliers must face.

2, surface-emitting LED products consider the modularization of architecture

Face-lit LEDs must be combined with urban design and architectural design to meet the designer's needs. For example, as a night decoration of the ground pavement, the size of the product is coordinated with the size of the floor tile, that is, it meets the requirements of the modulus: 150×15; 200×200; 200×100; 300×300; 400×200, and the like.

3, low power LED lighting design

Urban night lighting is not the pursuit of brightness, but the creative design of art, low-power LED products should be able to find his use. The LED has a small illumination angle and strong directivity, and can be used as a local key illumination. The problem is to give the designer a large enough range of choices and aesthetics. It is safe to say that LED will lead the fashion and fashion of lighting in the future.

4. Environmental protection and energy conservation, rational use of LED

The concept of green lighting is an eco-design goal that the world follows. If LEDs can be combined with solar cells, the application range and location of LEDs will be expanded.

5. High-power, high-efficiency, high-color rendering of white LED lighting products.

The use of LED in the field of lighting is currently limited by the technical level and price. At present, the difficulty of LED application in the field of lighting in China is that Led White Light is not efficient (only about 20 lumens per watt), and the power is not large (tens of milliwatts to One watt), expensive. However, the development prospect of white LED is promising, the luminous efficiency will reach 100 lm/w, and the output power of single LED will reach 10W. The research on high-power, high-brightness LED integrated packaging technology, including the development of driving circuits and special lamps, is undoubtedly the final LED. The key to entering the field of lighting. Once the light efficiency and price issues are resolved, LEDs will be the mainstay of future lighting.