LED display application is a relatively mature link in the LED industry chain

The application of LED display is a relatively mature link in the LED industry chain. In recent years, with the technological progress and the continuous improvement of products, the application field of LED display has gradually expanded, showing a stable development situation. According to the statistical data of LED display application branch of China Optical and optoelectronic industry association, the overall scale of the development of China's LED display application industry continued to grow in 2012, with the total annual market sales of the industry reaching 25. 3 billion yuan, compared with 22 billion yuan in 2011, it increased by 15. However, with the continuous development of the industry, the market has put forward higher demand for all aspects of LED display screens, in this issue, experts in the industry are invited to conduct in-depth discussions on LED display screen testing, light pollution, safety design, and development bottlenecks for readers. Only the light radiation within the viewing angle range that meets the information display requirements is the effective luminous flux. In order to improve the energy efficiency of the display screen, the luminous flux that meets the requirements should be higher and higher. For the LED display screen, the output is the luminous flux for the audience to watch. However, unlike other photoelectric conversion devices, not all output luminous flux is useful, but only within the specified viewing angle range, the luminous flux meeting the display requirements is the effective light output of the LED display screen. The so-called designated viewing angle refers to the viewing angle range of different types of LED displays stipulated in the General Specification for LED displays or the viewing angle range required by the contract. Products that cannot meet the requirements of 'General Specification for LED display screen' or the contract are unqualified, while those beyond this range are waste of energy, not only that, but also light pollution. How to measure luminous flux? In order to measure and compare the energy efficiency coefficient of LED display screen, we use module as the measurement unit. Module is the basic unit of LED display screen, and large screen is formed by splicing many modules. Due to the difference in actual working environment, the screen may have its own particularity. Comparing the energy efficiency of modules will be more scientific, reasonable, fair and operable. Measuring and comparing with modules is scientific and reasonable, and is also beneficial to production management. The LED display screen and module are composed of discrete LED tubes. When viewed at a distance of practical value, they should be surface illuminators, but when measuring, in fact, it is still to measure a discrete LED tube or a bunch of LED tubes, and then calculate the luminous flux. It should be pointed out that the premise of the display screen or module for luminous flux measurement is qualified products, and the uniformity of chromaticity and brightness meets the provisions of 'LED display screen detection method.