Toner Density Control; Development Bias - Gestetner G056 Service Manual

PRINTING PROCESS

Toner Density Control

[B]
More toner is fed when the toner coating
on the development roller is thin
A mixture of toner and developer circulates at the pre-doctor blade [A].
• When the amount of toner on the development roller decreases, the circulation
[C] decreases to allow more toner to reach the development roller.
• When the amount of toner on the development roller increases, the circulation
[C] increases to allow only a little toner to reach the development roller.

Development Bias

-140V
-700V
-900V
• Toner transfers from the development roller to the areas on the drum that were
exposed to the laser.
G056/G058
[A]
[C]
G058D120.WMF
[A]: Pre-doctor blade
[B]: Doctor blade
[C]: Circulation of developer
Print Data:
G N D
[B]
Less toner is fed when the toner coating
on the development roller is thick
White Black
6-12
G058D121.WMF
Toner
Laser Exposed Area
Developmemt Roller
Drum Surface Voltage
G058D510.WMF
[A]
[C]
SM