| 摘要 |
<p>PROBLEM TO BE SOLVED: To cause an optical deformation resulting from galvanoscanner and fθlens not to appear in a spot shape of a laser beam emitted on a material to be worked. SOLUTION: A laser beam from a laser oscillator goes through a first and second galvanoscanner 40, 50 and a fθlens 60, and thereby optical deformation given to a sectional shape of the laser beam is beforehand measured, and then by providing a mask having a passing-through hole in consideration of thus measured optical deformation on the incident side of the first galvanoscanner 40, the spot shape of the laser beam on a work 70 is made tetragonal and machining is executed by the laser beam having this tetragonal spot shape.</p> |
