Toner Density Control - Printronix L5535 Maintenance Manual

Chapter 8
Control System Descriptions
flow to the main charger in accordance with the difference between the
measured drum surface potential and the target potential value stored in the
EEPROM of the CPU. The EEPROM value is set through the operator control
panel, "Drum Surface Voltage" setup command.
LED printhead
The potential measurement circuit actuates 400 msec after the main charger
turns ON. It subsequently actuates at 400 msec intervals until the main
charger turns OFF. (Note, however, that the surface potential target value
(Vc) which is selectable from the panel, etc., ranges from above 45 V to below
70 V [45 V < Vc < 70 V], and that the current flow to the main charger (I)
ranges from above 0 A to below 127 A [0 A < I < 127 A].)

Toner Density Control

When the density of the toner in the developing unit agitation chamber is
lowered, the proportion of the carrier in the developer relatively increases,
varying the overall magnetic permeability of the developer. The printer checks
II–152
MC-PCBA
Drum surface voltage
setup command
Controller board
Control panel