Toner may transfer to the paper transfer roller surface following a paper jam or if the paper is smaller than the image. Periodic cleaning of the paper transfer roller is required to prevent this toner from migrating back to the rear of new printouts.
The machine cleans the paper transfer roller at the following times:
- After initial power on.
- After clearing of a copy jam
The PSU first supplies a negative cleaning current (about -4 A) to the paper transfer roller, causing negatively charged toner on the paper transfer roller to move back to the image transfer belt. It then applies a positive cleaning current (+5
A) to the paper transfer roller, causing any positively charged toner to migrate back to the image transfer belt.