Each trough shaped reflector has an associated flat reflecting mirror for directing {TAIL ~ its beam} of {HEAD ~ illuminating light} toward the document 
Each trough shaped reflector has an associated flat reflecting mirror for directing { TAIL ~ its beam } of { HEAD ~ illuminating light } toward the document
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH