{HEAD ~ The optical element} includes {TAIL ~ lenses}, fθ lenses, prisms, parallel flat plates and fly eye integrators 
{ HEAD ~ The optical element } includes { TAIL ~ lenses } , fθ lenses , prisms , parallel flat plates and fly eye integrators
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH