The improvement 1, wherein {HEAD ~ said adjusting means} further comprises {TAIL ~ a light shielding member} restricting the amount of light leaving said main reflecting means 
comprises
The improvement 1 , wherein { HEAD ~ said adjusting means } further comprises { TAIL ~ a light shielding member } restricting the amount of light leaving said main reflecting means
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH