Technical Explanation Of Print Process - Epson AcuLaser C2600 Service Manual

EPSON AcuLaser C2600/2600

2.1.3 Technical Explanation of Print Process

This section describes the operating principles of the printing process and the main
components.
2.1.3.1 Charging Process
PRINCIPLE OF CHARGING
In charging process, the surface of the photoconductor drum, which rotates at a
constant rate, is uniformly charged to a negative charge by a corona discharge
generated by the scorotron charger in the photoconductor unit.
PHOTOCONDUCTOR UNIT
Photoconductor Drive Motor
Drives the photoconductor unit.
Charging Device
This printer employs a scorotron charger, which generates a corona discharge, as
drum charging system. The scorotron charger, consists of a corona discharging
wire (a tungsten wire) with a grounded backing plate, parts to support the wire,
and a grid, maintains a fixed gap with the drum. When a high voltage is applied to
the corona discharging wire, the wire produces negative ions. The negative ions
move through the grid and adhere to the surface of the drum to charge it uniformly.
The potential of the surface is controlled to the desired potential by the grid which
is charged and maintained at the desired potential. The corona discharging wire
(tungsten wire) is gold plated to protect the wire and to increase its life. The wire is
cleaned by taking in and out the finger grip located on the Photoconductor Unit
when dust or spattered toner adheres to it causing an unevenness of printout
(because the foreign matters on the wire prevent the drum from being charged
uniformly). An unevenness of printout can also be caused by discharge products
on the wire. They are formed by the degeneration of ozone which is produced by
corona discharging.
There is a mechanism to blow air to the wire(s) to prevent ozone from
accumulating and forming extraneous products on the wire(s), .
Operating Principle
Drum Surface
Potential on the Drum
Parts to Support the Wire
Print Process
: Negative Charge
: Positive Charge
Scorotron
Figure 2-3. Charging
Grid
Grounded
Backing Plate
Tungsten Wire
Figure 2-4. Scorotron
Revision B
HV
POWER
SUPPLY
02000301
Parts to Support
the Wire
02000401
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