| 摘要 |
<p>The detecting light is applied from a detecting light source (122) to a work (1), and the light reflected from the work is detected by a photodetector (126), and the light emitted from the plume produced due to the laser beam machining is also detected by the photodetector (126) at the same time. In a laser beam controller (26), a detection signal from the photodetector (126) is binarized and a rectangular wave signal TP is generated, and a triggering signal TP2 for the oscillation of a machining laser beam is generated on the basis of the rectangular wave signal TP. During this time, a signal generated due to the emission of light from the plume is eliminated in a gate circuit 245 on the basis of a gate signal GP generated by feeding back the triggering signal TP2, to generate a triggering signal TPG. By delaying the triggering signal TPG by a delay time TD, a triggering signal TP1 is generated, and a triggering signal TP2 is generated synchronously with this triggering signal TP1. This prevents unnecessary laser beam machining due to the light emitted during a laser beam machining.</p> |
