A method for automatically positioning the material surface to the laser focus

Abstract

The invention relates to a method for automatically positioning the surface of a to-be-processed material to a laser focus and belongs to the technical field of laser processing. The method is based on the mirror surface imaging principle and the optical image measurement technology, the distance between the surface of the material and the center of a laser focus region is accurately calculated, and the surface of the material is automatically controlled to be accurately positioned to the center of the laser focus region. The method for automatically positioning the surface of the to-be-processed material to the laser focus has the advantages that full-automatic operation is achieved, the image processing target is simple and easy to achieved, the positioning accuracy is high, and the material cannot be damaged by lasers in the positioning stage.

Description

technical field [0001] The invention relates to a method for automatically positioning the surface of a material to be processed to a laser focus, and belongs to the technical field of laser processing. Background technique [0002] Laser processing has become one of the main methods of material processing. During the processing, the material usually needs to be positioned at the laser focus position, because the laser spot at the focus has the smallest light intensity and the largest. Positioning the material at the focal point increases processing accuracy while maximizing the use of laser energy. The laser focus usually mentioned refers to the point with the smallest cross-sectional area of ​​the beam in the direction of beam propagation, and according to the principle of optics, the focus point is a three-dimensional area in which the diameter of the spot changes most smoothly along the direction of beam propagation. This increases the difficulty of precise focusing, an...

AI Technical Summary

Problems solved by technology

This method can also be automated, but usually the brightness difference between the plasma bright spot and the material surface is large, which is not conducive to image processing, and even taking additional lighting measures as described in the document will require different lighting methods due to different material surface states and light intensity, which are not conducive to the automatic operation of the equipment

In addition, focusing can also be achieved by observing the size of the laser spot reflected by the surface of the material. Specifically, when the focus spot is observed to be the smallest, it is considered that the focus is completed. This method requires high optical path calibration, and there is also a need to control the material during the focusing process. The process of repeatedly moving and optimizing the surface before and after the focus cannot be achieved at one time, and it is more difficult to realize automatic control on this basis

Images