Assist Action - Riso ComColor X1 series Technical Manual

Registration Section

1-4. Assist Action

Assist control by the vertical paper feed unit is as follows.
Assist control by the vertical paper feed section (paper feeding from the internal paper feed tray) serves the
following two purposes.
1. To control slippage during paper transfer by the registration roller section, caused by back tension created by
stripper pressure from the stripper section and resistance in the paper path.
2. To reduce noise created by flattening paper that has buckled as it is fed in the registration section.
Unlike paper feeding from the external paper feed section, paper feeding from the internal paper feed tray may
generate significant back tension from stripper pressure in the stripper section and resistance in the paper path.
This is due to differences in the layout of the paper path and feed rollers. The back tension may cause slippage
when paper is transferred by the registration rollers.
Controlling back tension is one purpose of assist control by the vertical paper feed section, in which back tension
from the vertical paper feed section is counteracted by running the external paper feed motor in reverse to drive
vertical paper feed roller 5.
In conjunction with action by the registration rollers, vertical paper feed roller 5 is also operated for assist control.
Assist control, which occurs until the trailing edge of sheets leave the vertical paper feed sensor 5, can counteract
the effect of back tension occurring in the stripper section or other areas.
Assist control is activated in sync with the activation of the registration motor, and the external paper feed motor
stops when vertical paper feed sensor 5 is deactivated.
Note: By the default setting, the noise reduction is performed in external paper feeding, internal paper feeding, and
re-feeding (duplex printing).
External paper feed rollers
Vertical paper feed sensor 3
Vertical paper feed roller 3
Vertical paper feed
roller 2
Vertical paper feed
sensor 2
Vertical paper feed
clutch 2
Force to push against
paper by vertical paper
feed roller 5
(back tention)
Top edge sensor 1
Registration sensor
Registration rollers
Vertical paper feed sensor 5
Vertical paper feed roller 5
Vertical paper feed clutch 1
Tray 1
Internal paper feed clutch 2
Paper feed roller 2
Tray 2
Force to transfer paper by registration rollers
Slippage occurs in registration section paper
feeding due to back tention from vertical paper
feed section
Tray 1
Tray 2
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ComColor Series (Revision 2.4)