球面上微透镜阵列超精密慢伺服加工精度影响因素的研究

超精密慢伺服车削可加工出高精度的连续和非连续自由曲面,但是在微透镜阵列的加工过程中,不同位置的透镜加工精度也不同,个别子透镜的质量降低可能引起整个功能部件的失效。为了研究曲面上微透镜阵列超精密慢伺服加工精度的影响因素,本文采用实验的方法分析基面几何形状和子透镜位置对球面上微透镜阵列慢伺服车削加工精度的影响,通过在三种不同球径的基面上加工微透镜阵列,并使用Bruker GT-X白光干涉仪测量所加工的基面和微透镜阵列,分析了不同基面上不同位置的子镜表面粗糙度和形状精度的变化趋势。实验结果表明,同一基面上不同位置的子透镜,慢伺服车削加工表面微观形貌不同,表面粗糙度和形状精度也不同;基面的几何形状也会影响子镜的加工精度,当基面球径从50 mm增大至150 mm时,外圈子镜的表面粗糙度从75.78 nm(Ra)变小为69.08 nm(Ra)。在超精密慢伺服加工微透镜阵列过程中,必须考虑基面几何形状和子透镜位置两个因素对加工精度的影响,这将有助于提高微透镜阵列加工精度的一致性并保证微透镜阵列功能的有效性。

Factors affecting the machining precision of a micro-lens array on a spherical surface in slow tool servo machining

Ultra-precision slow tool servo (STS) machining can directly generate high-precision continuous and discontinuous freeform surfaces. However, in the fabrication of a micro-lens array (MLA) by STS, a single lens achieves different levels of quality. In addition, the low quality of a single lens may induce the failure of the entire functional component. To study the factors affecting the machining precision of an MLA on a spherical surface in STS, an experimental investigation was conducted. Specifically, the effects of the geometries of the base surface and position of a single lens on the machining precision of an MLA were examined. In the experiments, an MLA was machined by STS into three spherical surfaces having different radii, and Bruker GT-X was used to measure the base surface and micro lenses. The effects of the base surface and lens positions on the surface roughness and form error of a single lens were studied. Experimental results show that the position of the single lens changes the surface topography, surface roughness, and form accuracy of the lenses on the same base surface. In addition, the geometrical information of the base surface changes the machining precision. When the radii of base surfaces are increased from 50 to 150 mm, the surface roughness of the outer circle lens decreases from 75.78 to 69.08 nm (Ra). Therefore, considering the effect of the base surface and lens position on machining precision in the ultra-precision STS machining of MLAs is necessary. This may contribute to improving the precision consistency of MLAs and ensuring proper component function.