Ricoh Beluga-C1, Training

Page: 228 / 253

Beluga-C1/C1.5 Training
228
Slide 228
Wrinkling Prevention
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Paper speed at the fusing unit is slightly faster than at the
registration rollers
‰
This prevents the paper from wrinkling in the fusing unit
Fusing Unit
Exit
Sensor
Registration
Roller
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The basic point is on the slide.
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When the paper reaches the fusing unit, the fusing motor starts to pull the paper
through the machine and out of the exit.
ˆ
However, when the paper reaches the fusing unit, if it starts to move past the
drum faster, the image will be enlarged in the sub scan direction.
ˆ
To counter this, the registration motor and fusing motor both slow down by the
same amount, to maintain constant magnification.
¾
The fusing unit is faster than the registration roller, to ensure that there is no
wrinkling.
¾
The speed change occurs when the leading edge of the paper reaches the
exit sensor.
The exit sensor is not on this diagram. The arrow indicates roughly where
it is.
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The distance between registration roller and exit sensor is about 360 mm (14.2"),
so this speed correction is only used when paper is longer than 360 mm.
ˆ
Alert students may observe that for a short while, the paper is moving past the
drum faster (from when the fusing unit grabs the leading edge, until the leading
edge reaches the exit sensor).
¾
However, the fusing unit only pulls the paper slightly faster than the
registration rollers. The speed difference is about 2%.
¾
Look at a copy and see if you can spot any changes in the sub scan
reproduction ratio between the 300 mm and 360 mm mark.