| 摘要 |
PROBLEM TO BE SOLVED: To suppress spattering of a coating material to a condensing lens by providing a marking process to burn out a coated film with a laser beam and a cutting process to cut along a cutting line after the marking process thereby simplifying changing work of a working machine. SOLUTION: By drawing a marking line on a steel 1, adjusting a height of a condensing lens 5/cutting nozzle 6 from the surface of a steel 1 and irradiating the surface with laser beam at the state a focus is apart from the steel 1, a coating film only is burned out. The marking line is formed with the width set by an irradiating width corresponding to the distance between the focus and the steel 1. In the marking process, a laser beam output and speed is set to a degree the laser beam does not melt the steel 1. |
