| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser beam machine capable of irradiating the laser beam on a work in an excellent condition without staining an objective lens surface. SOLUTION: In a laser beam machine to irradiate the laser beam L1 converged by an objective lens 5 on a work 8, an objective lens protective plate 6 is provided between the objective lens 5 and the work 8, and the objective lens protective plate 6 is illuminated through the objective lens 5 to pick up the image of protective plate 6 by a photographing device 30. An image processor 40 measures the stained condition of the protective plate 6 through the image processing of the observed image, and when the stained condition is advanced, a computer 70 instructs to change the protective plate 6 with a new protective plate 6' in a holder 10. |
