Online measurement and calibration method for large-size flat glass surface shapes based on coaxial reverse Hartmann principle

In this paper, we present what we believe to be a novel method based on the coaxial reverse Hartmann principle for the online measurement and calibration of large-size flat tempered glass surface shapes. By embedding a pinhole-ring light source component at the center of a dot matrix pattern light source and employing a movable flat standard sample, we achieve rapid calibration of the optical axis and the mapping relationship between the spot centroid coordinates on detector surface and the incident angles of light. This coaxial reverse Hartmann optical path features no loss of light energy, a direct coaxial configuration, and no light obstruction, which minimizes the incident angle of light compared to off-axis optical paths, thereby reducing the influence of surface vibration on measurement accuracy. Experimental results confirm its accuracy, vibration resistance, and feasibility for online measurement.