The problem of dark area about Panel and Plate light

When we talk about ultra-thin panel lights and flat panel lights, the main problem is that the dark areas and low light efficiency . Why some of that the light is very uniform and bright, but other is only dark and also out of light?Let's solve this problem. The difference is obvious. What is the main reason of the difference?then we need to take a look about structure of the panel lamp. We see that both the panel light and the large flat panel have the same structure, and the light comes out from the SMD led and passes through the diffuser plate.And the one that affects the light distribution most is the guide plate.Let's take a look at the real picture of the guide plate. The most important function of the guide plate is to make the light f...