Canon IR1600 - 1 Controlling the Primary Charging Roller Bias; Outline

CHAPTER 5 IMAGE FORMATION SYSTEM
COPYRIGHT © 22002 CANON INC. 2000 CANON iR1600/iR2000 REV.1 JAN. 2002
5-4
2 1 Controlling the Primary Charging Roller Bias
2.1 Outline
The machine uses a charging roller for primary charging (direct charging method), and it
applies an AC bias to stabilize the charging in addition to the DC bias.
The following items of control are used in relation to the primary charging control system:
[1] turning on and of the bias.
[2] performing constant voltage control for the DC bias.
[3] performing constant current control for the AC bias.
The primary charging control system is constructed as shown in the following diagram:
F05-201-01
TB401/TB402Pr
PRACON*
PRACFOT*
DCPWM*
PRDCFOT*
To developing bias circuit
To primary
charging roller
DC controller PCB
Primary charging circuit
ASIC
CPU
Primary DC
bias voltage
detection circuit
Primary AC
bias voltage
detection circuit
DC generation
circuit
AC generation
circuit
Comparison
circuit
Comparison
circuit
Superimposition