{TAIL ~ The laser beam} scans the output medium and is modulated in {HEAD ~ accordance} with the image to be formed 
{ TAIL ~ The laser beam } scans the output medium and is modulated in { HEAD ~ accordance } with the image to be formed
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH