光电编码器LED光源准直特性研究

发光二极管（LED）光束的准直度对光电编码器性能影响很大。通过分析光源辐射角对光栅光通量的影响，运用图像旋转理论和频域分析方法，导出莫尔条纹透光特性函数式并且获得不同a’值下的莫尔条纹仿真波形，分析了光源准直特性对莫尔条纹对比度和光栅最大允许间隙的影响，实验结果与仿真波形吻合。本文对高可靠性编码器设计和生产具有参考价值。

Research on Features of Collimated LED Beam in Optical Encoder

The collimation degree of the light beam of LED exerts a tremendous influence to the performance of optical encoder. Through analyzing the impact that the radiation angle of light source has on flux, and applying of Rotation matrix and frequency-domain solution, authors have lead to moiré patterns’ light distribution function as well as its simulation waveform with various slit width. Furthermore, they analyze the influence of collimated light source to the contrast ration of moiré patterns and the max gap of grating, whose result shows the identity with the simulation waveform. Therefore, this paper is very helpful to the design and the production of the high quality encoder.