Compact auto-stereoscopic display based on directional backlight using side-glowing polymer optical fiber array

A compact directional backlight module of time-multiplexed auto-stereoscopic display based on side-glowing polymer optical fiber (SGPOF) is proposed. The optical system is mainly composed of SGPOF array and cylindrical lens array. Spatial crosstalk is reduced by inserting a grating film as multi-slit diaphragm between the SGPOF array and the cylindrical lens array. A theoretical model is constructed based on the imaging optics principle of the off-axis ray. In the experiments, the cylindrical lens array concentrates a small number of views on three different view zones, the display can provide high luminance. The measurement results show that the luminance uniformity of the backlight module is up to 89.6%, and in the viewing zone the crosstalk is lower than 10%. The backlight module is compacted that the thickness being only 7 mm. The full-resolution and low-crosstalk 3D images are realized by using SGPOF backlight.     

塑料光纤激光打标散射点实验研究

塑料光纤（Plastic Optical Fiber,POF）纤芯散射点的形状和大小尺寸控制对基于半导体激光器（LD）和侧面发光POF的LCD背光源设计具有重要意义。研究了一种表面无损伤的POF纤芯散射点的激光打标方法,基于非成像光学的边缘光线原理分析了激光打标制作POF纤芯散射点的二次聚焦过程,推导出激光侧面入射在POF上表面时的焦点坐标的表达式计算式。实验研究了1.06 m波长激光在POF纤芯制作打标散射点时,激光光束半径（打标聚焦透镜高度）、激光功率和重复打标次数对POF散射点形状和体积尺寸的影响。纤芯内散射点的检测采用650 nm激光的散射光相对光强分布进行检测,通过显微照片的对比判断散射点的形状和尺寸。实验结果表明,POF纤芯散射点的形状决定于激光光束半径（打标聚焦透镜高度）,当聚焦透镜高度激光光束半径为束腰半径透镜焦距时,可以得到光纤径向细而长的条散射点;。当聚焦透镜高度小于聚焦透镜焦距时,在POF上下两个表面附近形成漏斗状散射点。而随着激光功率增大和重复打标次数增加,散射点的体积尺寸随着增加。单次打标时POF的激光损伤阈值约为80 W/mm2,而要使POF散射点具有稳定的细长条状,激光功率密度应大于140 W/mm2。