Thus, a signal proportional to {TAIL ~ the total amount} of light received by the photo detecting elements 6a and {HEAD ~ 6b} is supplied to the light intensity control circuit D 
Thus , a signal proportional to { TAIL ~ the total amount } of light received by the photo detecting elements 6a and { HEAD ~ 6b } is supplied to the light intensity control circuit D
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH