| 摘要 |
PURPOSE:To remove the low power intensity beam giving adverse influence upon working quality by providing a beam shielding device which shields only the outside circumferential part of a laser beam, on the laser beam between a laser oscillator and the workpiece to be worked. CONSTITUTION:A prescribed working to the workpiece to be worked 4 is executed by irradiating the laser beam 1 released from a laser oscillator 7 to the workpiece 4. A beam shielding device 11 which shields only the outside circumferential part of the laser beam 1 is provided on the optical path of the laser beam 1 between the laser oscillator 7 of this device and the workpiece 4, and the surface of the shielding plates 11a, b thereof in contact with the laser beam 1 are so ground as to assume an acute angle to the axis of the laser beam 1. The laser beam 1 is reflected by a reflecting mirror 2 and is irradiated to the workpiece 4 through a condenser lens 3, but the part of low power intensity in the outside circumferential part of the laser beam 1 is removed by the plates 11a, b, and is dissipated off from the beam axis by the contact surfaces ground to an acute angle. |
