Just bought back the LED strip is very bright, why after a while will be increasingly dark

I think we all have such a life experience, just bought back the LED strip, always particularly bright, but after using a period of time, the strip will be increasingly dark, what is the reason?

Lighting products, there will be a light failure, light failure is what?

Is the use of lamps and lanterns after a period of time, its light intensity will gradually reduce the process, and can not be restored, its reduced part is called the LED light decay.

Light failure generally refers to its luminous flux, when charging the surface of the photoconductor drum, with the accumulation of charge on the surface of the photoconductor drum, the potential is also rising, and finally reached the "saturation" potential, which is the highest potential. Surface potential will decline over time, the general working potential is lower than this potential, this potential over time to naturally reduce the process, called the "dark decay" process. Light-sensitive drum by scanning exposure, the dark area (refers to the part of the light conductor surface not irradiated by light) potential is still in the dark decay process; bright area (refers to the part of the light conductor surface irradiated by light) photoconductor layer carrier density increases rapidly, the conductivity rises rapidly, the formation of photoconductive voltage, the charge disappears rapidly, the photoconductor surface potential also decreases rapidly. Called "light decay", and finally tends to slow down.

General LED strip packaging manufacturers to do testing is in the laboratory conditions (25 ℃ at room temperature), with 20MA DC continuous lighting LED 1000 hours to compare its light intensity before and after lighting.

Light decay calculation method.

N hours of light decay = 1 - (N hours of luminous flux / 0 hours of luminous flux)

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

The degree of light decay is different for various manufacturers of current products, high-power LED light strips, there is usually light decay, which is directly related to the temperature generated during the use of the strip, mainly by the chip, phosphor, packaging and other decisions.