Drum Unit; Photosensitive Drum; Primary Charger; Developer Roller - Brother HL1060 - B/W Laser Printer Service Manual

2.4

Drum Unit

2.4.1

Photosensitive Drum

Generates the latent electrostatic image and develops the image on the drum surface.
2.4.2

Primary Charger

Forms a uniform charge on the drum surface.
(1) Corona wire
Generates the ion charge on the drum.
(2) Grid
Spreads the ion charge evenly over the drum surface.
2.4.3

Developer Roller

Develops the latent electrostatic image on the drum surface by the addition of the toner.
2.4.4

Transfer Roller

Transfers the toner image to the paper from the drum surface.
2.4.5

Cleaner Roller

Removes and recycles the toner remaining on the drum surface.
2.4.6

Erase Lamp

Discharges the electrostatic latent image on the drum.
2.5

Print Process

2.5.1

Charging

The drum is charged to approx. +1000V by an ion charge which is generated by the primary
charger. The charge is generated by ionization of the corona wire, which has a DC bias
from high-voltage power supply applied to it. The flow of the ion charge is controlled by the
grid to ensure it is distributed evenly on the drum surface. The drum sleeve is regulated to
approx. 280V by the voltage regulator.
Voltage
Regulator
The primary charge uses a corona wire, but since the drum is positively charged, only less
than 1/10 of the usual quantity of ozone is generated compared with the negatively charged
drum. The level of ozone expelled from the printer is therefore not harmful to the human
body. Applicable safety standards have been complied with.
-
+ -
-
+
- -
+
- -
+
- - - -
+ +
+ + +
1000V +
+
+
+
+
+
+
+
+
+ + +
Corona wire
Fig. 2.25
CHAPTER II -20
280V
Aluminum drum sleeve
Organic Photoconductor layer
Grid
HVPS
Passive Type
Voltage Regulator
Drum