Since {HEAD ~ the laser power detection circuit} 11 often has {TAIL ~ an abnormal emission slice level} n1 of about 1.5 mW set relative to the signal m of about 1 mW, the detector 11 detects this interval as the abnormal emission, thus producing the output signal p of H1 voltage by which the laser drive circuit 21 is controlled to stop the beam emission of the laser beam source 1 
has
Since { HEAD ~ the laser power detection circuit } 11 often has { TAIL ~ an abnormal emission slice level } n1 of about 1.5 mW set relative to the signal m of about 1 mW , the detector 11 detects this interval as the abnormal emission , thus producing the output signal p of H1 voltage by which the laser drive circuit 21 is controlled to stop the beam emission of the laser beam source 1
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH