| 摘要 |
PURPOSE:To prevent the molten substance from the work piece to be worked from sticking on a lens or a window glass, by fitting a roll film onto the inner surface of the window glass and winding the same, in case when laser beam is supplied to said work through the window glass. CONSTITUTION:The laser beam 2 emitted from a laser source 1 is changed its direction at a mirror 3, and is sent to a convex lens 4. The beam passes through a window glass 12 provided to vessel 11 and a roll film 13, and makes a focus on the surface of the work piece 5 to be worked and melts its vicinity. The spatters and vapour from the work 5 generated by the irradiation of the laser beam 2 are allowed to collide with the roll film 13, thus preventing the window glass 12 from stains. When the rate of transparency of the beam 2 gets lower than the prescribed value by the stains of the roll film 13, the rolled film 13 is wound up on a roller 14 of the winding device 15. |
