DEVICE FOR CONTROLLING LASER BEAM

PURPOSE:To improve workability such as weldability and to obtain working quality which is stable for a long period of time by controlling a laser optical system cooperatively with the outputs from a sensor for measuring position and a sensor for measuring surface reflectivity. CONSTITUTION:The measuring output signals from a sensor 7 for measuring position and a sensor 11 for measuring surface reflectivity are inputted to a controller 14 and are converted to control outputs e1, e2 according to the preprogrammed process sequence. A DC servocontrol motor 12 for driving a collimation lens system and a DC servocontrol motor 13 for driving iris are further driven via servocontrol amplifiers 15, 15. Potentiometers 16, 17 for feedback are respectively interlocked to the motors 12, 13 and the outputs therefrom are fed back to the input side of the amplifiers 15, 15. Since the lens and stop are thus automatically controlled, the density of irradiation energy is maintained always constant and the welding workability having high quality is maintained for a long period of time.