Specifications

EPL-5700 Chapter2 Operating Principles

Rev. A

2-1

2.1.8 Transfer Process

2.1.8.1 Overview

This process is to transfer the toner image, which is created on the

developing process, to the OPC drum. Transfer roller is charged with

transfer bias(+3KV).

Transfer method is not the corona transfer but roller transfer method by the

transfer roller. In the roller transfer, ozone caused by corona discharge does

not occur, and chances of dislocation for the transferred image is very small,

since the paper is always sandwiched between drum and transfer roller

during printing.

The transfer current is adjusted from 6 to 10

A(8

A is initial value),

according to the paper type and printing duty. This can improve the

effectiveness of the transfer, especially under the high temperature with high

humidity environment. Left over electric potential on the paper is removed by

the discharge needle. Since the left toner from OPC drum attach to the

transfer roller, it is necessary to clean the transfer roller. In the cleaning, the

reversed bias(-1KVDC) is charged on the transfer roller and returns the

toner to the OPC drum. This cleaning sequence is performed with OPC

drum cleaning. Even at the cleaning of the transfer roller before printing, the

reversed bias(-1KV) is charged on the transfer roller.

OPC drum

Paper

Transfer roller

OPC drum

Paper

Transfer rolle

Reversed bias

(-1KV)

Transfer bias

(3KV)

Dischar

e Needle

Figure 2-12. Transfer Mechanism