wherein the first condition that requires {HEAD ~ a larger storage capacity} of {TAIL ~ the storage unit} in the document reading is a reading condition where a difference is larger than an enough storage capacity to implement the functions other than the image reading function, which difference is a storage capacity difference between: 
of
wherein the first condition that requires { HEAD ~ a larger storage capacity } of { TAIL ~ the storage unit } in the document reading is a reading condition where a difference is larger than an enough storage capacity to implement the functions other than the image reading function , which difference is a storage capacity difference between :
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH