Laser machining apparatus and laser machining method for performing laser machining while controlling reflected light

摘要

A laser machining method includes the steps of: outputting a laser beam to the workpiece at a laser power low enough not to melt or oxidize the workpiece to measure reflected light of the laser beam; selecting a laser power suitable for melting or oxidizing the workpiece based on a measured value of the reflected light; determining whether or not the workpiece can be melted or oxidized based on the selected laser power; when the workpiece can be melted or oxidized, outputting a laser beam to the workpiece at a laser power high enough to melt or oxidize the workpiece; outputting again a laser beam to the workpiece at the low laser power to measure reflected light of the laser beam; and checking the degree of the melting or oxidization of the workpiece based on a measured value of the reflected light to determine whether or not to start laser machining.