| 摘要 |
PURPOSE: To eliminate the need of a mechanism for correcting an optical path length by providing the above machine with a moving range of an optical system for condensing a laser beam in a nearby range inclusive of a position apart a Rayleigh length from the position of the beam west diameter of the laser beam. CONSTITUTION: The laser beam LB oscillated by a laser oscillator 9 is made incident on the optical system 19 for condensing in a processing head 21 via bend mirrors 11, 13, 15. The laser beam processing head 21 moves in a Y-axis direction and a work piece 5 in an X-axis direction, by which processing is executed. A laser oscillator 9 is so disposed that the moving range of the optical system 19 for condensing comes near to the position apart the Rayleigh length from the position of the beam west diameter of the laser beam LB. Since the Rayleigh length is sufficiently large with respect to the focal length of the optical system 19 for condensing, the change in the condensing position of the optical system 19 for condensing is minimized in spite of a change in the optical path length even if the change in the optical path length is so set as to be confined near to the Rayleigh length. |
