The imaging lens 18 can be a graded index fiber lens or a conventional spherical lens, in which case {HEAD ~ the sensor} 20 could be shorter than {TAIL ~ the length} of the scan line 16 
shorter than
The imaging lens 18 can be a graded index fiber lens or a conventional spherical lens , in which case { HEAD ~ the sensor } 20 could be shorter than { TAIL ~ the length } of the scan line 16
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH