2.13.6 Duplex paper feed and separation
Five notches are provided on the air knife casing. Air is
sent from the duplex blower to the surface of the duplex
tray throughout duplex paper feeding. The air flow from
air knife casing prevents double paper feed.
Duplex paper feed
After the paper is stacked in the duplex tray, the vacuum
solenoid of the duplex blower is energized by a paper
feed signal from the main control board. The lowest
sheet of paper on the transport belt is held against the
transport belts by the suction of the blower. When the
duplex paper feed motor is turned ON, the transport
belts are driven via the gears and the paper is
transported to the paper feed roller.
For separation, an FRR system is used as in the paper
feed tray. The air knife also helps the paper separation.
The vacuum unit is equipped with two one-way clutches.
The clutch for the paper feed roller ensures that the
paper continues on after it is picked up by the grip roller.
The other clutch on the paper feed roller drive shaft
prevents reversing of the transport belt when the duplex
paper feed motor is turned OFF. Rotational torque is
always applied counterclockwise to the reverse roller
during operation.
The spacer between the vacuum tank and the transport
belt facilitates the entry of air from the air knife to ensure
easier handling.
If the paper in the duplex tray is curled face up, paper
feed problems tend to occur more often than when it is
curled face down. When surface curling occurs during
stacking, the paper stacking direction on the paper feed
tray must be changed so it can reverse and be up-side
down.
Air flow
Reverse roller Paper
Bottom sheet
Transport belt
Duplex feed motor
Duplex
feed roller
Air knife casing
Spacer
Reverse roller
Transport unit
One-way clutch
locking direction
One-way clutch
locking direction
Duplex feed roller
drive shaft
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