LASER BEAM CUTTING METHOD AND LASER BEAM MACHINING APPARATUS

摘要

PURPOSE:To allow high-speed cutting by changing an optical path length by utilizing the spreading angle of a laser beam introduced to a condenser lens system, thereby varying an incident beam diameter. CONSTITUTION:A material to be cut is cut by introducing the laser beam introduced into a processing head from a laser oscillator while this laser beam is condensed by the condenser lens system in the head. The optical path length of the laser beam introduced into the condenser system is changed by utilizing its spreading angle (diverting angle), by which the incident beam diameter is varied. The incident beam diameter is varied stepless or stepwise. The optical path length from the laser oscillator to the processing head is varied. More preferably the laser beam is set at a focal depth and convergent beam density in this way.