The LED light band just bought is very bright. Why is it getting darker and darker after using it for a period of time?

People who often touch the LED light belt will find such a phenomenon. The LED light belt just bought is always particularly bright, but after using it for a period of time, the light belt will become darker and darker. What is the reason?

That is because all lighting products will have a light failure phenomenon. What is the light failure?

Lamp failure refers to the process that the light intensity of the lamp will gradually decrease and cannot be recovered after a period of use. The reduced part is called LED light failure.

Light attenuation generally refers to its luminous flux. When charging the surface of the photosensitive drum, with the accumulation of charge on the surface of the photosensitive drum, the potential also increases, and finally reaches the "saturation" potential, which is the highest potential. The surface potential will decrease with the passage of time. Generally, the potential during operation is lower than this potential. The process of natural reduction of this potential with time is called "dark decay" process. When the photosensitive drum is scanned and exposed, the potential of the dark area (referring to the photoconductor surface of the part not irradiated by light) is still in the dark decay process; In the bright area (referring to the photoconductor surface of the part irradiated by light), the carrier density in the photoconductive layer increases rapidly, the conductivity increases rapidly, the photoconductive voltage is formed, the charge disappears rapidly, and the surface potential of the photoconductor also decreases rapidly. It is called "light decay" and finally slows down.

Generally, the test conducted by the manufacturer of LED lamp belt packaging is to compare the light intensity before and after lighting led1000 hours continuously with 20mA DC under the conditions of the laboratory (normal temperature of 25 ℃).

Light attenuation calculation method:

Light attenuation in n hours = 1 - (luminous flux in n hours / luminous flux in 0 hours)

The longer the LED light belt is used, the darker it will be, because the LED light belt will have the phenomenon of light decay.

At present, the degree of light attenuation of lamp strips produced by various manufacturers is different. For high-power LED lamp strips, there is usually light attenuation, which is directly related to the temperature generated during the use of lamp strips, which is mainly determined by chips, phosphors, packaging, etc.