Canon Image Reader-A1, Service Manual

Page: 279 / 916

COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON iR5000i/iR6000i REV.0 JUNE 2001
CHAPTER 4 IMAGE FORMATION SYSTEM
4-39 P
4.3 Controlling the Developing Bias
The system used to control the developing bias serves the following functions:
[1] Controlling the DC bias to a specific level of voltage.
[2] Controlling the AC bias to a specific level of voltage.
F04-403-01
The following signals are used:
[1] developing DC bias current control signal; if about 3 V or higher and lower than 11 V,
the output of developing DC bias current turns ON; if about 12 V or higher, it turns
OFF.
[2] developing DC bias remote signal; turns on/off the output of developing DC bias cur-
rent.
DC controller PCB
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DEV-AC-REMOTE [2]
DEV-DC-CNT [1]
Developing cylinder
J4504
600V
Image area
Non-image area
The developing DC bias varies as
follows in keeping with the potential
of DEV-DC-CNT.
3V
11V 12V
DEV-DC-CNT
De
v
eloping DC bias
AC output 1500Vpp
High-v
oltage PCB
J102A J4502