Controlling The Output To Suit The Environment - Canon iR7086 Series Service Manual

Chapter 7
When '1', high-voltage
output is ready.

7.8.1.2 Controlling the Output to Suit the Environment

iR7105 / iR7095 / iR7086
The transfer guide bias is optimized to suit the environment (identified with reference to the data from the environment sensor).
Normally, +600 V is applied to prevent
adhesion of toner to the transfer guide.
SERVICE MODE:
- COPIER> OPTION> BODY> TRNSG-SW (transfer guide bias control mode switchover)
0: switches to +200 V in a high-humidity environment (default)
1: fix the transfer guide bias to +600 V
2: fix the transfer guide bias to +200 V
3: switches to +200 V in a normal humidity condition
4: switches to +200 V in a low humidity condition
Set it to '2' through '4' if a transfer fault is noted.
7.8.2 Transfer Charging Mechanism
7.8.2.1 Outline
iR7105 / iR7095 / iR7086
7-26
J723
J510A
18
1
17
2
0 V
3 16
HVDC_REMOTE
4 15
14
5
6 13
7 12
11
8
10
9
When '1', the transfer
9
10
guide bias goes on.
11
8
7
12
6
13
14
5
15
4
3
16
FEEDER_GUIDE_ON
2
17
FEEDER_GUIDE_CNTR
1
18
"1": +200V
"0": +600V
A bias of the same polarity as the toner is
applied in sync with the rotation of the
photosensitive drum.
Normal/low humidity
High humidity
In a high humidity environment, paper tends to absorb moisture
(lower resistance), charging the paper in excess to affect transfer
(faulty transfer); as such, the output is decreased.
Relay PCB
J721
1 2 3 4
J733
1
2
DC 600V/200V
3
F-7-36
The photosensitive drum is rotating;
yet, paper is not being fed.
Transfer guide bias
Paper passing
+600
+200
F-7-37
Transfer guide
Paper being fed
+600
+600
0010-8069
0010-8070