Canon GP405 - Controlling the Developing Bias

COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
6-17
CHAPTER 6 IMAGE FORMATION SYSTEM
B. Controlling the Developing Bias
1. Outline
A DC bias and an AC bias are applied to the developing cylinder. The output is controlled by
the composite power supply PCB according to control signals from the image processor PC for the
following:
• Turning on and off the developing bias AC component.
• Turning on and off the developing bias DC component.
• Turning on and off the developing bias DC component.
Figure 6-201
Developing
cylinder
Photosensitive
DC controller PCB
Image processor PCB
Composite power supply PCB
High-voltage
main transformer
(DC component)
High-voltage
transformer for
development
(AC component)
AC power supply voltage input
Serial communication
DC-CPU
PW-CPU
Transformer
drive signal
Transformer
drive signal
AC bias ON signal(HVACEN*)
DC bias mode signal(HVDCSL*)
DC bias level signal
Voltage value
DC bias control signal
DC bias
AC bias
Output control
Voltage
detection
DC bias ON signal
(HVDCEN*)
+
J209AJ103A
J209BJ103B
J209BJ103B
J209BJ103B
drum