1. Low level: Before image transfer starts, the high voltage supply board supplies +10μA to the transfer
roller. This prevents the transfer roller from attracting any positively charged toner on the drum surface.
2. High level: During image transfer, the high voltage supply board supplies a high level current (see
the table) to the transfer roller. This enables the transfer roller to attract toner onto the paper.
When the trailing edge of the paper has passed the transfer roller, the high voltage supply board stops
supplying the transfer current. If the copier is printing more pages, the high voltage supply board supplies
the low level current.
You can adjust these levels (* SP2-301). When increasing a transfer current level, use caution:
• Increasing a transfer current level may produce ghost images–some part of image near the leading
edge reappears in other part of the page.
• Increasing a transfer current level might damage the OPC drum.
The table lists the default settings and SPs.
Job type Amp SP
Normal paper 0 μA SP2-301-001
Thick paper 0 μA SP2-301-002
Duplex copying 0 μA SP2-301-003
Transfer Roller Cleaning
Toner may transfer to the roller surface following a paper jam or if the paper is smaller than the image.
Periodic cleaning of the roller is required to prevent this toner from migrating back to the rear of new
printouts.
The machine cleans the roller at the following times:
• After initial power on.
• After clearing of a copy jam
• At the end of a job, if at least 10 sheet have been printed since the last cleaning
The high voltage supply unit first supplies a negative cleaning current (about –4 μA) to the transfer roller,
causing negatively charged toner on the roller to move back to the drum. It then applies a positive cleaning
current (+5 μA) to the roller, causing any positively charged toner to migrate back to the drum.
The cleaning current can be adjusted using SP2-301-4.
6. Detailed Section Descriptions
282
To Next Page
Loading...
