{HEAD ~ The invention} presents advantages over traditional double stacking in aspects of projector alignment, {TAIL ~ content copy protection}, banding artefacts and equipment costs 
{ HEAD ~ The invention } presents advantages over traditional double stacking in aspects of projector alignment , { TAIL ~ content copy protection } , banding artefacts and equipment costs
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH