The requirement of edge LED backlgiht
It is going to minimize the number of LED, enhance of illumination , light efficiency and light power.
It is going to be ultra light and thin and low cost so that the light guide plate is going to be thinner, and illumination area of LED is going to be smaller.
Light guide plate is becoming long and narrow, and the the number of LED lamp is decreasing , so that LED backlight is decreasing emitting light angle to enhance the light efficiency in the narrow side , and it is also increasing emitting light angle to decrease shadow between LED lamps in the long side.
The requirement of bottom LED backlight
It is going to be thinner and lower cost so that the number of LED lamps is decreasing and emitting light angle is increasing from 120 degree to160-170 degree.
So far, the main solution is that using twice optical lens which is high cost and low light efficiency.
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