数字微镜器件在光电设备中的应用

Application of Digital Micromirror Device in Photoelectric Equipment

鉴于数字微镜器件(DMD)良好的空间光调制性能,对其在光电设备中的应用及关键技术进行了深入研究。在分析DMD在数字投影系统中所能实现的最大帧频与系统结构形式、灰度级及DMD类型的关系基础上,给出了多DMD串联实现高灰度级的方案。探讨了利用DMD空间调制特性增强系统性能的具体实现方式,包括高动态范围成像、像素内目标特征检测、探测器像元几何超分辨、压缩感知及成像光谱仪等,并给出了应用过程中涉及的关键技术,如高动态范围成像中各像元曝光时间的确定、DMD微镜与探测器像元之间的几何配准、运动平台条件下探测器和目标之间相对运动以及DMD微镜填充率对系统性能的影响。各微镜角度可灵活控制、存储单元更新频率更高的DMD应用于可编程成像系统将是未来的发展方向。

Considering the super spatial-light-modulation feature, the application and related technologies of digital micromirror device （DMD） in photoelectric equipments are analyzed in detail. Based on analyzing the relationship between maximum frame frequency that could be realized, systemic architecture, gray-scale level and the type of DMD, the project with several DMDs in series to achieve high gray-scale level is given. The realizations of DMD＇s spatial modulation feature used to enhance system performance are discussed. DMD can be used for high dynamic range imaging, intra-pixel target feature detection, superresolution of detector pixel, compressive sensing and imaging spectrometer. Also, the key technologies in the application are given, including time of exposure determination for every pixel in high dynamic range imaging, geometrical alignment between micromirror in DMD and detector pixel, relative motion between target and detector on motorial platform and the effect of DMD micromirror fill factor on system performance. The programming imaging system with DMD, which allows greater control over the orientations of individual mirrors and has higher updating frequency of memory, is regarded as the new trend.