Image Forming Apparatus for Parallel Toner Purge and Charging Roller Cleaning

The patent combines toner purge operation and charging roller cleaning operation into a single integrated maintenance cycle. By controlling the charging member to execute both operations simultaneously during the post rotation period, the system reduces total maintenance time while ensuring both operations are performed thoroughly, thus resolving the contradiction between maintenance effectiveness and productivity.

The patent implements continuous maintenance operations by eliminating idle time between toner purge and charging roller cleaning. The charging member continuously performs both operations in sequence without stopping the rotation or entering idle states, maintaining productive use of the maintenance period and improving overall image formation productivity.

The patent employs dynamic voltage control where the charging voltage is adjusted in real-time based on the operational phase. During toner purge, a first charging voltage is applied, and during charging roller cleaning, a second charging voltage is applied. This dynamic adjustment allows the single charging member to perform multiple functions effectively while the control portion manages the complexity through automated voltage switching based on operational timing.

The patent changes the charging voltage parameter to differentiate between toner purge and charging roller cleaning operations. By varying the voltage magnitude or polarity according to the specific maintenance operation required, the system achieves effective performance of both operations using a single charging member, with the control portion managing parameter transitions to handle operational complexity.