针对直下式LED背光模组厚度大的缺点,设计了一种带有圆台的超薄直下式LED背光模组。通过调整圆台斜面角度和底面直径,来改变LED灯珠光强极大处的指向和位置,降低混光高度。利用圆台、圆锥、反射隔板构建正六边形照明单元,用TracePro软件模拟不同的排列间距、混光高度、圆锥尺寸对均匀度的影响。结果表明：当排列间距为26 mm,混光高度为16 mm,圆锥高度为10 mm时,均匀度达到了94.27%。该背光模组在确保高均匀度的同时极大地降低了厚度,为直下式背光模组的轻薄化提供了理论依据和研究方向。

In order to solve the problems of large thickness of traditional direct-down type LED backlight, an ultra-thin direct-down LED backlight model with conical table is proposed. By adjusting the angle of the bevel and the diameter of the bottom of the conical table, the direction and position of maximum light intensity of the LED are changed, and the height of light mixing are reduced. The hexagonal lighting units are made of conical table, cones, and reflective baffles. The simulation of the effect on uniformity of different arrangement pitch, mixed light height, and cone size is performed on TracePro. The results show that when the arrangement pitch is 26 mm, the mixed light height is 16 mm, and the cone height is 10 mm, the uniformity reaches 94. 27%. The backlight module greatly reduces the thickness while ensuring high uniformity, and provides a theoretical basis and research direction for the light and thin direct-down backlight.