Laser processing apparatus

摘要

When an IGBT turns on, a current from a laser power supply unit is supplied via a switching element to an excitation lamp of a laser oscillation unit so that the excitation lamp lights to oscillatorily output a laser beam. A switching control unit uses as a main feedback signal a measured-value-of-laser-output signal from a laser output measurement unit and uses as a sub-feedback signal for correction an AC component of a lamp measured-value-of-power signal from a power computing circuit or of a measured-value-of-lamp-current signal from a current measuring circuit. The switching control unit compares the feedback signals with a reference signal having a desired pulse waveform from a CPU to obtain a comparison error. The switching control unit then generates a switching control signal, PWM so as to nullify the comparison error and provides a switching control of the IGBT via a drive circuit in response to the switching control signal.