Ricoh Beluga-C1 Training page 228

Wrinkling Prevention
Paper speed at the fusing unit is slightly faster than at the
registration rollers
This prevents the paper from wrinkling in the fusing unit
Slide 228
The basic point is on the slide.
When the paper reaches the fusing unit, the fusing motor starts to pull the paper
through the machine and out of the exit.
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.
To counter this, the registration motor and fusing motor both slow down by the
same amount, to maintain constant magnification.
The fusing unit is faster than the registration roller, to ensure that there is no
wrinkling.
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.
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.
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).
However, the fusing unit only pulls the paper slightly faster than the
registration rollers. The speed difference is about 2%.
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.
Registration
Roller
228
Beluga-C1/C1.5 Training
Exit
Sensor
Fusing Unit