Ricoh D131 Service Manual page 1512

FM4 Letter Fold-in
In Fold Method 4 (FM4):
The leading edge of the paper is stopped by Fold Stopper 1.
The paper flexes toward the nip of fold rollers
Fold Stopper 2 stops the paper and flexes it into the nip of fold rollers
Fold rollers and
Fold Stopper 3 is not used.
FM3 and FM4 follow the same sequence but the resultant fold is different:
In FM3 Fold Stopper 1 is positioned high so a short length of paper is allowed to feed
before flexing toward the nip starts.
In FM4 Fold Stopper 1 is positioned low so a long length of paper is allowed to feed
before flexing toward the hip starts.
This positioning of Fold Stopper 1 accounts for the difference in folding at the next nip.
SM
perform the second crease and feed the folded paper in exit path.
119
Paper Folding
and which performs the first fold.
and .
D454/D615