Ricoh Aficio MP C3001 Service Manual page 1515

2.12.4 PUNCH SELECTION AND FIRING
The punch drive motor [A] turns the small, notched encoder wheel [B] through the gap in
the punch encoder sensor [C]. The sensor output is used to control the punch timing.
The timing for 2-hole punching [E] is different from 3-hole punching [F].
When the punch unit is at the punching position, the punch motor turns until the encoder
detects the starting position for 2-hole or 3-hole punching.
This is the '1' position in the diagrams (the first diagram is for 2-hole punching, and the
second diagram is for 3-hole punching).
Then, the punch drive motor turns counter-clockwise to the '2' position. This movement
punches the holes in the paper.
Then, the punch drive motor turns clockwise to the '1' position, to be ready for the next
sheet of paper.
SM 63
Punch Unit
B793