虽然采用并行共焦测量提升了共焦测量速度, 但系统中的传统光分束器件参数固化后难以适应不同的被测对象。本文利用数字微镜器件(Digital Micromirror Device, DMD)可产生柔性化结构光的特点, 将其作为光分束器件引入共焦测量装置以提升系统对被测对象的适应性。理论分析了DMD的空间调制方法, 搭建了DMD的共焦测量装置, 研究了DMD结构光参数对共焦测量轴向分辨率、横向分辨率以及图像对比度等指标的影响。实验表明, 在光学系统参数匹配的条件下, 结构光光点参数越小, 测量分辨率越高。同时, 利用DMD进行柔性化照明, 改善了因光点参数小造成的图像对比度下降的问题。得到的结果为研究基于DMD的跨尺度测量方法提供了研究基础。

Parallel confocal measurement improves confocal measuring efficiency. However, the parameters of traditional optical divided devices (ODD) are fixed, which are not be suitable for different specimens. As the Digital Micromirror Device (DMD) is a flexible ODD and could produce different types of structured lights, this paper induces the DMDS into the confocal measurement system to improve the suitability of parallel confocal measurement devices. A modulation model of structured light produced by the DMD was analyzed, a confocal measurement device was constructed, and the effects of parameters of structured light from the DMD on the axial resolution, transverse resolution and the image contrast of measuring device were researched. The experiment results indicate that when the optical parameters are matched, the smaller the size of structured light is, the higher the measuring resolution is. Moreover, the DMD also could be applied as a flexible illuminator to improve the image contrast caused by a smaller structured light size. All of these researches provide a strong support for multi-scale measurement based on DMDs.