基于全内反射透镜的扩展光源准直照明系统特性研究

Characteristics of Collimating Illumination System with Extended Source Based on Total-Internal-Reflection Lens

在理论上,全内反射透镜可对所有光线进行收集,因而是远距离准直照明系统二次光学设计的首选结构。利用光学软件进行仿真和实验测试,分析了基于该类型配光元件的扩展光源准直照明系统的照明特性,包括光强分布特性、光斑照度均匀性和光通量利用率,并揭示了出射光束发散特性的决定机制。研究发现:与同口径平凸准直透镜的配光效果相比,全内反射透镜的光通量利用率提升显著,但出射光束发散角也明显增大,使得二者出射光束光强无明显差别;且由于中心折射部分和边缘全反射部分的出射光束发散角不同,故全内反射透镜的照明光斑照度均匀性明显变差。

In theory,the total-internal-reflection lens can collect all the rays from the source,thus it is the preferred structure for secondary optical design in long-distance collimating illumination systems.The illumination characteristics of a collimating illumination system with extended source based on this type of light distribution element,including the intensity distribution characteristic,spot illuminance uniformity,and flux utilization,are analyzed by using optical software and experiment measurement,and the determining mechanism of divergence characteristic of the outgoing beam is explored.It is found that compared with the light distribution effect of the same-aperture plano-convex collimating lens,the flux utilization of the total-internal-reflection lens is improved significantly.However,the divergence angle of the outgoing beam is also remarkbly increased,which leads to no essential difference in the outgoing beam intensities of these two light distribution elements.Because the divergence angle of the outgoing beam from the core refraction part is different from that from the edge total-internal-reflection part,the illuminance uniformity of illumination spot for the total-internal-reflection lens is obviously deteriorated.