| 摘要 |
PURPOSE:To enable automatic focus follow-up by setting the focal position of laser light in an optimum position in the state in which a nozzle member contacts with a material to be worked and providing the nozzle member in a way as to maintain always the optimum focal length even if said member moves upward or downward. CONSTITUTION:A focusing head 1 is constituted of a lifting member 10 driven by a lifting mechanism 5 and a nozzle member 13 provided freely liftably to the member 10. A condenser lens 20 is attached to the top end of the member 13. The top end of the member 13 is made to contact with a work 4. The focal position of a laser beam L by the lens 20 is further set in the position adequate for laser working of the work 4 while the member 13 is in contact with the work 4. The mechanism 5 is then controlled via a control device 26 by the signal from a detector 22, by which the lifting position of the member 13 with respect to the member 10 is maintained in the prescribed lifting position. The always optimum focal position is thus maintained even if the nozzle member moves upward or downward. |
