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