LASER CUTTING MACHINE

PROBLEM TO BE SOLVED: To provide a laser cutting machine which enhances cutting quality of a substrate. SOLUTION: The laser cutting machine is used for cutting a brittle substrate, and comprises a pre-cutting system 78 for forming a pre-cutting plane line on the substrate, a laser beam system for generating a laser beam which heats and thermally expands the substrate along the pre-cutting plane line, and a cooling system 79 for cooling the thermally expanded substrate. The laser beam system has a hollow body 7 which generates the laser beam, and an optical path distance adjusting system 75. The optical path distance adjusting system is placed in an optical path where the substrate is irradiated with the laser beam and is used to adjust the optical path distance. The laser cutting machine can meet different cutting requirements by placing the optical path distance adjusting system in the optical path of the laser beam to adjust the size of a light spot where the substrate is irradiated with the laser beam. COPYRIGHT: (C)2007,JPO&INPIT