设计了一种适用于光滑表面的调制度显微测量系统, 系统包括两个远心镜头、一个半透半反镜、一个显微物镜、一个 CCD相机和一个DMD数字投影仪。由远心镜头和显微物镜结合将数字投影仪产生的条纹图像成像到显微物镜物面, 得到虚拟的 标准条纹图, 待测表面对该虚拟条纹图的反射像将沿显微物镜光路返回进入CCD像平面, 待测物体在高精度一维平移台的控制 下沿光轴移动, 根据相移算法可以从获取的条纹图中计算出每个位置的图像调制度, 通过查找调制度最大值对应的位置, 即 可完成待测物点的三维形貌测量。实验结果表明该显微调制度测量方法能获得高精度面形, 特别适用于微小形貌剧烈变化物 体面形测量。

A modulation microscopy system for specular surfaces is proposed. The system includes two telecentric lenses, a transflective lenses, a microscope objective, a CCD camera and a DMD digital projector. The fringe image generated by the digital projector is imaged by the telecentric lens and the microscope objective to the object surface of the microscope to obtain a virtual standard fringe pattern. The reflected image of the virtual fringe surface to be tested will return along the optical axis of the microscope objective. Entering the CCD image plane, the object to be measured moves along the optical axis under the control of a high-precision one-dimensional translation stage. According to the phase shift algorithm, the modulation image of each position can be calculated from the acquired fringe pattern, and the maximum modulation curve is found. The corresponding position can complete the three-dimensional shape measurement of the object to be tested. The experimental results show that the micro-modulation measurement method can obtain high-precision surface shape, and is especially suitable for surface shape measurement of objects with drastic changes in micro-morphology.