Thus, {HEAD ~ the LED 7R} at {TAIL ~ the left end} of the light entrance surface 12T can be made to emit a quantity of light smaller than that from the other LEDs 7R by a predetermined amount 
Thus , { HEAD ~ the LED 7R } at { TAIL ~ the left end } of the light entrance surface 12 T can be made to emit a quantity of light smaller than that from the other LEDs 7R by a predetermined amount
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH