减光式烟雾报警系统中的准直系统收集大角度红外光线获得平行光, 保证光线长距离传输不发散, 逐点计算并优化减光式烟雾报警准直系统。针对理想点光源, 依据等光程原理及折射定律, 求解烟雾报警准直系统初始结构的离散数据点, 将离散数据点拟合成自由曲线。利用光学仿真软件建模并优化准直系统的初始结构, 得到较好的LED自由曲面准直系统。自由曲面准直系统的厚度为20 mm, 口径为28 mm, 准直角度为±1.5°, 光能效率高达89.82%。

The collimation system of reducing smoke alarm system collects wide angle near infrared rays to generate the parallel beam, which ensures that the rays travel long distances without divergence. Reducing smoke alarm collimation system is optimized by point by point calculation. The initial discrete data points of smoke alarm system for ideal point light source are calculated based on the principle of equal optical path and refraction law. The discrete data points are fitted into freeform curves. Using optical simulation software to build the model and optimize the initial structure of the collimation system, and better LED freeform collimation system is got. The thickness of freeform surface collimation system is 20 mm, the diameter is 28 mm, the collimation angle is ±1.5° and the energy efficiency is 89.82%.