Satisfying design standards is the basic guarantee for the application of LED in lighting engineering

1 LED product market application status and prospects

In 2008, the sales statistics of LED products in various major application areas showed that the architectural landscape is the largest application field of LED in China, accounting for 28% of the total market share; LED display and home appliances display the second largest application field, accounting for the total market share. 27%; mobile phones, computer notebooks and other small and medium-sized backlights are the third largest application area, accounting for 22% of the total market share; traffic lights, automotive lights, special lighting and other applications occupy a certain market share.

In the future, with the holding and preparation of major events such as Shanghai 2010 World Expo and Guangzhou Asian Games and the acceleration of urbanization, the application of LED in landscape lighting will further increase the proportion, and the market application space of LED display will continue to expand. With the continuous maturity of LEDs, backlights such as mobile phones and computers, traffic signals and indicator lights, automotive lighting, and special lighting such as flashlights, miner's lamps, explosion-proof lights, and navigation lights will become important application markets, and the application market structure of LEDs will also A big change is made. According to the National Semiconductor Lighting Engineering R&D and Industry Alliance, the total size of China's semiconductor lighting market will reach 100 billion yuan in 2010 (specific data forecasts are shown in Table 1). The LED backlight market will exceed the landscape decorative lighting and become the largest application. The market size of the field, functionality and general lighting will also grow rapidly. It is estimated that the compound annual growth rate from 2010 to 2015 is expected to reach 40%. In 2015, the industry scale will reach more than 500 billion yuan.

2010 China's semiconductor lighting main application market forecast

2 LED performance and characteristics

2.1 Low energy consumption (currently <10 W), small size LED as solid-state light-emitting device, single power is low, the most widely used are less than 0.5W, and the power type (single larger than 0.5W) is also 0.5W. ~1.0W. In addition to the advantages of LED in size, its small size, light weight and thin thickness greatly expand its application space, and it is easy to use in backlight and display system applications. It also makes the design of lamps more flexible in the field of traditional lighting. Diverse, light is easier to control.

2.2 Since the birth of the energy-saving LED in the 1960s, the “Hayz's Law” has increased rapidly by 30 times and the price has dropped 10 times every 10 years. According to reports, the laboratory data of white LED light efficiency has exceeded 160lm/W, and the power white LEDs entering the commercial field have reached 100lm/W. With the breakthrough of key technologies, the light efficiency of power LEDs in the future still has a large room for improvement, and the highest possible is 200 lm/W.

2.3 Rich color and vivid graphics (dynamic full color control) Different chip materials can obtain different monochromatic LEDs; and the same chip material has different light colors for LEDs grown in different epitaxial regions. As long as the chip alloy composition has a slight change, it will cause a large change in the color of the LED. In theory, various monochromatic and white LEDs can be obtained in the visible range.

2.4 Long life (theory is 100,000 hours, but it is currently difficult to do) LEDs with solid-state structure are different from ordinary heat radiation sources or gas discharge sources, with fragile bulbs and fragile filaments or brackets. It generally does not rupture or burst during the period of use, with a safety guarantee and a long life. In general, the life of LEDs can theoretically exceed 50,000 hours, which is a difference of level compared with traditional light sources. Applications in lighting engineering can greatly reduce maintenance costs.

2.5 Good seismic performance The structure of LED (Light Emitting Diode) is mainly composed of PN junction chip, electrode and optical system. It is an electroluminescent light source whose structural characteristics determine the influence of vibration on it.

2.6 Safety (low voltage) LED is a low-voltage device that drives a single LED with a voltage of only 2.5 to 3V and a drive current of several tens of milliamps. It does not cause an electric shock accident, so it is safer and suitable for low-voltage power supply. Such as car, train and other car lighting, and can be used with solar power plants.

2.7 Environmental protection (no mercury added to the light source) LED lighting devices are different from high-intensity gas discharge lamps, such as fluorescent lamps, fluorescent high-pressure mercury lamps, etc., and the inner wall is coated with a fluorescent coating, including the treatment after the phosphor is used, causing pollution to people and the environment. LED lighting devices do not add mercury, so pollution is reduced.

2.8 The principle of response fast electroluminescence gives the LED only a response time of several ms, which enables the LED to achieve full-light output in an instant, which has a strong advantage as signal illumination. Combined with its color diversity, LED products are easier to control color and brightness, allowing them to be used in many areas where control is required.