Presumably, everyone has a life experience where newly purchased LED light strips are always exceptionally bright, but after a period of use, the light strips become darker and darker. What is the reason for this?
Lighting products will have a light failure, what is the light failure?
It refers to the process in which the light intensity of a lamp gradually decreases after a period of use, and cannot be restored. The reduced part is called LED light decay.
Light decay generally refers to its luminous flux. When charging the surface of a photosensitive drum, as the charge accumulates on the surface of the drum, the potential also increases continuously, and finally reaches the "saturation" potential, which is the highest potential. The surface potential will decrease over time, and the electrical potential during normal operation
The process of falling below this potential, which naturally decreases over time, is called the "dark decay" process. When the photosensitive drum is scanned and exposed, the potential of the dark area (referring to the surface of the photoconductor that is not illuminated by light) is still in the dark decay process: the bright area (referring to the surface of the photoconductor that is illuminated by light)
The carrier density inside the photoconductive layer increases rapidly, the conductivity increases rapidly, and a photoconductive voltage is formed. The charge disappears rapidly, and the surface potential of the photoconductor also decreases rapidly. It is called "light decay" and eventually slows down.
Generally, LED strip packaging manufacturers conduct tests under laboratory conditions (at room temperature of 25 ℃) by continuously lighting LED1000 with 20MA DC for 1000 hours to compare the light intensity before and after lighting.
Calculation method for light attenuation:
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 becomes because the LED strip will experience light decay.
The degree of light decay in various manufacturers' light strip products varies. High power LED light strips usually have light decay, which is directly related to the temperature generated during the use of the light strip, mainly determined by chips, fluorescent powder, packaging, etc.
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