激光差动共焦透镜中心厚度测量系统的研制

基于高精度光学共焦定位技术研制了一种全新的非接触透镜中心厚度测量系统,该系统利用差动共焦技术的高轴向层析特性和轴向响应曲线的绝对零点对被测透镜的前表面顶点和后表面顶点分别进行精密瞄准定位;同时,利用激光干涉仪获得透镜前、后表面顶点的位置坐标;然后通过光线追迹算法计算透镜中心厚度,进而实现了透镜中心厚度的高精度非接触测量。实验结果表明,该系统测量精度高,测量标准差小于1μm,满足透镜中心厚度测量的精度要求。

Development of lens central thickness measurement system using laser differential confocal microscopy

A new non-contact lens central thickness measurement system is developed based on high precision optical confocal positioning technique.The developed system uses the high axial chromatography property of differential confocal microscopy and the absolute zero of the axial response curve to precisely identify the vertexes of the lens front and back surfaces,uses a laser interferometer instrument to record the position coordinates of the vertexes,and then uses the ray tracing algorithm to calculate the central thickness of the lens;thus the high precision and non-contact measurement of the lens central thickness is achieved.Experiment results indicate that the system has high measurement accuracy;and the standard deviation of the measurement is less than 1 μm,which meets the requirements of measurement accuracy in lens thickness measurement.