精密光学元件在加工过程中如果工艺控制不当, 产生的划痕、麻点等疵病分布范围虽然较小, 但对整个光学系统的性能影响却很大, 破坏力非常强, 目前的表面疵病检测仪基本上针对平面或球面光学元件进行离线检测。文章以光学加工机床为运动平台, 采用暗场散射成像方法, 设计多光束均匀照明系统, 研究表面疵病微细特征的识别算法, 实现大口径光学表面疵病的在位检测与评价; 标定结果表明, 表面疵病宽度偏差为2.05%, 长度偏差为2.39%, 满足指标要求; 在此基础上针对Φ280 mm平面硅镜进行自动化在位检测, 给出了不同类型疵病的统计数据, 解决了离线检测中非加工时间长与多次装夹引起定位误差等问题。

If the technology is not properly controlled in the machining process of precision optical elements, although the distribution range of defects such as scratch and pitting is small, it has great influence on the performance of optical system and is very destructive. At present, the surface defect detectors are mainly used for off-line detection of planar or spherical optical elements. The optical machine tool was used as the motion platform, the method of scattering imaging was adopted in dark field, the uniform illumination system with multi-beam was designed, the recognition algorithms of fine features on surface defects were studied, and in-situ detection and evaluation of surface defects for large-aperture optical elements were achieved. Calibration results show that the width deviation of surface defect is 2.05% and the length deviation is 2.39%, which meet the index requirement. On this basis, automated in situdetection is carried out for Φ280 mm planar silicon mirror. The statistical data of different defects is given, and the problems of long non-machining time and locating error caused by multiple clamping in off-line detectionare solved.