wherein {HEAD ~ the light} emitted from the secondary light source is prevented from entering {TAIL ~ the light emitting plate} 
wherein { HEAD ~ the light } emitted from the secondary light source is prevented from entering { TAIL ~ the light emitting plate }
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL