Ricoh G133 Service Manual page 713

Image Transfer and Paper Separation
The ITB drive motor [A] drives the image transfer belt [B] and the cleaning unit via gears
and the ITB drive roller [C]. The speed of ITB drive depends on the process line speed (see
'p.6-3 "Optical Path"').
Transfer belt speed control
This machine uses the rotation encoder to control the transfer belt speed.
The encoder [A] is on one of the rollers. This encoder checks the rotation speed of the
image transfer belt. The controller analyzes the signals from the encoder. Then it adjusts
the rotation speed of the image transfer belt.
The encoder contains a disk that has 550 notches on its surface [B]. These notches are
read by the sensor [C]. The controller counts the number of notches that the sensor has
read in the unit of time. If the sensor has read an unusually large number of notches or an
unusually small number of notches, the controller ignores such unusual signals. Therefore,
incorrect reading does not affect the rotation speed.
SM 6-41 G133