设计了一种边发射型的白光LED封装结构,通过全反射和反光镜的反射使LED发出的光由两侧出射,并且可以通过调节锥形反光镜的锥顶角来控制光强角分布中峰值的位置。利用光路追迹软件对所设计的结构进行模拟,并将所设计的边发射型LED用于直下式背光源中。通过对模拟结果的分析,当背光源灯箱大小为228mm×150mm,灯箱厚度在20-30mm时,均匀度可以达到85%以上。利用具有表面布点的导光板结构,使侧向出射的光线经过导光板底面的锥形网点时,经历一次折射和一次全反射。这样将侧向出射的光线导向正向出射,提高了背光源正向的亮度。
A new structure of side-emitting LED was designed. Using internal total reflection, parabolic reflector and conical reflector, the original light of LED could be guided to the sides of the structure. And peak value of the intensity distribution can be controlled by changing the apex cone angle of the Conical reflector. Furthermore, the designed side-emitting LED was used in the direct-lighting backlight whose length×width is 228 mm×150 mm. When thickness of light box changes from 20 mm to 30 mm, the brightness uniformity is all over 85%. By using lightguide with conical dots, when side- emitting rays pass through the bottom of the lightguide, the rays will experience refracfior/and totaI internal reflection. So the side-emitting rays are guided to the front of the backlight, and the luminance of the front is enhanced.