This paper presents a novel uniaxial microscopic 3D profilometry method using a structured light system with dual-telecentric lenses in micro-scale devices. Specifically, a telecentric lens can produce an orthographic view of an object and provide the exact size of objects in x and y-direction. An electronically focus-tunable lens attached to the projector rapidly and precisely changes the focal plane of the projected structured patterns, a camera captures the structured patterns from the same perspective, and a computational framework analyzes the relationship between captured structure images and the drive current of the electronically focus-tunable lens to obtain depth information for each pixel. By replacing the normal lens with telecentric lenses, the proposed method dodges perspective error and is easier for precision measurement. We developed a shadow-free coaxial 3D shape measurement system with dual telecentric lenses that achieved approximately 5.86 μm spatial resolution and 4.08 μm root-mean-square (RMS) error with a depth range of 1200 μm.

中文翻译：

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在微型器件中使用双远心结构光系统进行单轴 3D 相移轮廓测量

本文提出了一种新的单轴显微 3D 轮廓测量方法，该方法在微型设备中使用具有双远心透镜的结构光系统。具体来说，远心镜头可以生成物体的正交视图，并提供物体在 x 和 y 方向的准确尺寸。安装在投影仪上的电子调焦镜头快速精确地改变投影结构图案的焦平面，相机从同一角度捕获结构图案，计算框架分析捕获的结构图像与驱动电流之间的关系。电子调焦镜头以获得每个像素的深度信息。该方法通过用远心镜头代替普通镜头，避免了透视误差，更容易进行精确测量。