Differential confocal measurement method of linear scanning based on dual linear array camera

Current microscopic 3D surface topography measurement technology has low detection efficiency and small measurement range. To address these problems, a linear scanning differential confocal 3D morphology measurement method based on dual linear array camera was proposed. The linear scanning light source and linear scanning stitching algorithm were adopted to synthesize pre-focus and post-focus images respectively. The differential image of the sample in the measurement area was obtained by using the differential algorithm. Combined with the pre-calibrated axial response curve, the 3D morphology of the sample was restored to achieve a large range of efficient measurement. The experimental results show that the measurement range and the measurement efficiency of the linear scanning differential confocal three-dimensional topography measurement method based on the dual line array camera are 16.48 times and 6.59 times of that of the white light interferometer respectively in the same time. Moreover, this method does not require to pause in the measurement process, and it can scan and detect the sample continuously and uninterruptedly only achieving one focus. The research results provide a basis to meet the requirements of on-line, real-time, efficient and large-range measurement in intelligent manufacturing.