{HEAD ~ The focus} of the projection lens 68 is located between the second aperture 65 b and {TAIL ~ the projection lens} 68 
is located between
{ HEAD ~ The focus } of the projection lens 68 is located between the second aperture 65 b and { TAIL ~ the projection lens } 68
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH