Ricoh A151 Operating Instructions Manual page 83

In this mode, the operator inserts a stack of originals into the original table.
These originals are individually fed onto and removed from the exposure
glass.
Correct any curl, fold, or crease
in the originals before setting.
Square the stack of originals.
Confirm that the Insert Original
indicator is lit before setting.
Confirm that no previous originals
remain on the exposure glass or
in the document feeder.
Adjust the original guides to the
original size.
OPTIONAL DOCUMENT FEEDER
!