中小口径双非球面数控抛光技术研究

Computer controlled polishing for middle or small double-sided aspheric lens

针对口径Φ62 mm双凸非球面透镜,进行了数控研磨和抛光技术研究。提出了规范性的加工工艺流程,实现了中小口径双非球面元件的高效、快速抛光。根据计算机控制光学表面成型技术,采用全口径抛光和小抛头修抛的两步抛光法,在抛光中对其面形误差进行多次反馈补偿,使被加工零件表面的面形精度逐步收敛。最终两面的面形精度均小于0.5μm,中心偏差小于0.01 mm,满足了光学系统中对非球面元件的精度要求,并且在保证有较高面形精度和较好表面光洁度的同时,解决了双非球面中心偏差和中心厚度难以控制的加工技术难题。

Taking a dual aspheric convex lens with a diameter oF 62 mm as example, CNC grinding and polishing technology was investigated. A standard procedure of processing was presented to fast and-efficiently polish small and medium double-sided aspheric lens. Based on the computer-controlled optical surface molding technology, two-step polishing was used, which included full aperture polishing and small-tool corrective polishing. Surface form error was fed back iteratively for compensation during polishing process, and the surface form gradually converged to the required accuracy. The experimental results show that the final accuracy on both sides of the surface is less than 0. 5 μm and the center deviation is less than 0. 01 mm, which fulfils the accuracy requirement of aspheric element in optical system. The technique handles the center deviation of the dual aspheric surfaces and the accuracy of the center thickness properly while ensuring excellent surface form accuracy and good surface polish.