Automatic locating method and device of workpiece to be measured by white light interferometer

Abstract

The invention provides an automatic locating method and device of a workpiece to be measured by a white light interferometer. Aiming at the locating problem of the workpiece in the process of using the white light interferometer to measure a workpiece, by converting a two-dimensional inclination of an interference objective or an objective table into the amount of movement of a linear axis, the position of the center vertex of the workpiece is obtained, further, by calculating the offset of the linear axis when the interference objective or the objective table rotates by a certain angle, the amount of motion of each axis when any place of the workpiece at is measured is obtained, and the measurement of any position of the workpiece is achieved. In the process, with the help of the high calculation precision and speed of a computer, the locating speed of the workpiece is drastically improved; meanwhile, the using difficulty of an instrument is also lowered, and the workload of the instrument is also reduced.

Description

technical field [0001] The invention relates to the technical field of optical detection, in particular to an automatic positioning method and device for a workpiece to be measured by a white light interferometer. Background technique [0002] In the field of optical inspection, a white light interferometer is a commonly used inspection device for evaluating surface roughness. Since the detection range of the white light interferometer is very small, usually 1mm 2 Therefore, in order to evaluate the surface roughness of the optical element more effectively, usually a plurality of sampling points are selected on the surface for average processing and then used as the roughness detection result of the entire optical surface. [0003] In order to accurately and reliably evaluate the roughness of the measured plane, generally small planar components with a diameter of tens of millimeters need to detect 3 to 8 points, while for large-diameter optical components with a diameter o...

AI Technical Summary

Problems solved by technology

At the same time, because each axis is not independent of each other, the movement of the rotation axis has an impact on the linear position. It is difficult to position the interference objective lens to the correct position manually, so it is necessary to find the interference fringe every time it is positioned.

This process is not only time-consuming, but also heavily dependent on the operator's experience

For some optical elements with a small radius of curvature or a large steepness, it is difficult to locate the point at the edge position correctly, and there may even be dangers such as collisions in the process

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