Cause
When the toner [1] is fixed on paper, since the pressure roller [2] and the toner [1] are negatively charged,
the toner [1] that has failed to be fixed on the paper [3] may repel against the pressure roller and adhere to
the fixing roller [4]. This toner is called as offset toner [5].)
Offset toner is removed by the cleaning web. However, a part of the offset toner [5] was escaped through the
cleaning web, and transferred to the pressure roller [2] at paper [3] to paper [3"] interval.
The offset toner transferred to the pressure roller [2] was then heated up and adhered to [a] the backside of
the paper [3"], which caused the symptom.
pg. 236