Print Process Mechanism - Brother IntelliFax-3550 Service Manual

2.2.2

Print process mechanism

Toner augers
Toner cartridge
Toner sensor
Polygon mirror
Polygon motor
The print process unit works with laser beam, electrical charges, and toner. The graph be-
low shows the transition of electrical charge on the surface of the laser-sensitive drum
through the five processes: charging, exposing, developing, transferring, and erasing pro-
cesses.
+1000
+700
+400
+300
Laser unit
Cover glass
A single cycle of laser-sensitive
drum operation
1 2
3
(a)
(b)
Time
Paper
Developer
roller
Toner supply
roller
Mirror
1 Charges the drum surface positively.
4
2 Exposes the drum surface to a laser beam to
form a latent image and develops the latent
image with toner.
(a) Unexposed area (Non-image area)
(b) Exposed area (Image area)
3 Transfers the toner-formed image from the
drum to paper.
4 Erases the residual potential.
III – 6
Transfer roller
Drum unit
Laser-sensitive drum
Cleaner roller
Charger (Corona wire)
Mirror