The analog to digital converter 44, of course, only samples {HEAD ~ the analog input} from {TAIL ~ the light sensor} 26 at discrete intervals as the stationary light sensor 26 scans the path 22 of the moving media 12 
from
The analog to digital converter 44 , of course , only samples { HEAD ~ the analog input } from { TAIL ~ the light sensor } 26 at discrete intervals as the stationary light sensor 26 scans the path 22 of the moving media 12
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL 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