| 摘要 |
PURPOSE:To enable assurance of an always optimum focal length by bringing the nozzle member at the top end of a focusing head supported by a lifting member into contact with a material to be worked and controlling the lifting position of the lifting member by a detection signal of the lifting position. CONSTITUTION:A focusing head 1 is constituted of a lifting member 10 which is driven by a lifting mechanism 5 and a nozzle member 12. The top end of the member 12 is constituted in such a way that said end can contact with a material 4 to be worked. The focal position of laser light L by a condenser lens 25 is set in the position adequate for laser working of the material 4 while a member 13 is in contact with the material 4. Laser working is then started and the mechanism 5 is driven via a control device 31 by the signal from a detector 27 to control the lifting position of the member 10 to a prescribed lifting position. The irradiation position of the laser light is thus set always in the position substantially the same as the measuring position and always the optimum focal length is assured. |
