Laser beam optical system and laser beam machining method using the same

摘要

A laser beam optical system has a plurality of beam reflectors having respective reflecting faces and spacedly supported for rotation in one direction about a common axis which is either in alignment with or parallel to the path of travel of a laser beam emitted from a single beam oscillator. Each of the reflectors is also supported on a common drive shaft with the respective reflecting face inclined at a predetermined angle relative to the drive shaft so that the laser beam can impinge thereupon at an angle of incidence of 45 DEG . Those reflectors on the common drive shaft are so coordinated with each other that the reflectors can selectively deflect the laser beam, emitted from the single beam oscillator, towards corresponding condenser lenses during the rotation of the reflectors together with the drive shaft.