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