DETECTION OF FOCAL POSITION OF LASER BEAM MACHINE AND ITS DEVICE

摘要

PURPOSE:To execute automatic focusing of a laser beam only by one time of operation. CONSTITUTION:A nozzle 1 is moved in one direction until the focal position of a lens 2 passes the position focusing on the surface of a work 4 from the position not existing on the surface of the work 4 and attains the state having no focus on the surface of the work 4 as the method and device for detecting the focal position of a laser beam machine. The distribution of data on reflected light 5 of the laser beam 3 from the work 4 for the relative coordinates of the nozzle 1 from the surface of the work 4 during the movement period thereof is approximated by a quadratic curve by a data analyzing section 11 and the resultant relative coordinates of the peak point of the quadratic curve are determined as the relative position of the nozzle 1 from the surface of the work 4 for focusing with the lens 2 on the surface of the work 4.