Generally, the luminous life of LEDs is very long, and manufacturers generally indicate that they are more than 100,000 hours. Actually, attention should also be paid to the brightness decay period of LEDs. For example, most of the UR red tubes used for automobile taillights are illuminated for ten to several tens of hours. It’s only half of the original. The brightness decay period has a lot to do with the material process of LED production. Generally, four-element LEDs with slower luminance decay should be used when economic conditions permit.
Generally, the active illuminator adopts a luminous intensity unit candle CD, such as an incandescent lamp, an LED, etc.; a reflective or penetrating object uses a luminous flux unit lumen L, such as an LCD projector, and the illuminance unit Luxe Lux, which is generally used in photography and the like. . The three units of measure are numerically equivalent, but need to be understood from different angles. For example, if the brightness (light flux) of an LCD projector is 1600 lumens, and the size of the projection to the total reflection screen is 60 inches (1 square meter), the illumination is 1600 lux, assuming that the light exits from the light source 1 In centimeters, the area of the light exit is 1 square centimeter, and the luminous intensity of the light exit is 1600CD. The true LCD projector is greatly reduced in brightness due to loss of light propagation, loss of reflection or light transmission film, and uneven light distribution. Generally, 50% efficiency is good.