where, in said scanning lens system, focal distance in said {HEAD ~ scan direction} of said {TAIL ~ first scanning lens} is designated by f1 and in said sub scan direction is designated by f1 
of
where , in said scanning lens system , focal distance in said { HEAD ~ scan direction } of said { TAIL ~ first scanning lens } is designated by f1 and in said sub scan direction is designated by f1
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH