Potential Control During High Humidity Mode - Canon ImageRunner 600 Service Manual

CHAPTER 6 IMAGE FORMATION SYSTEM
2.

Potential Control during High Humidity Mode

In a low humidity environment,
the resistance of paper
decreases and, on the other
hand, the transfer efficiency
increases; as such, the laser
power is reduced to prevent
excess deposit of toner.
In a high humidity environment,
the moisture of paper decreases
the transfer efficiency; as such,
the laser power is increased to
increase the density.
Potential sensor
Laser
Grid bias
Potential determined
Related Service Mode
COPIER>OPTION>BODY>
CNT-W/HM
(high humidity mode potential control
setting)
Main power switch
Set
OFF/ON
COPIER > OPTION > BODY > CNT-W/HM
6-14
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Lighter
Extra low humidity
Low humidity
Density
Normal humidity
High humidity
Darker
Extra high humidity
Potential control
sequence started
195˚C
WMUP WMUPR
VD
Vg
Vg
Figure 6-212 Sequence of Operations
1: correct the laser power/developing bias to suit the
environment (default)
0: disable correction of the target value
2: extra low humidity mode (See the above figure.)
3: low humidity mode (See the above figure.)
4: normal humidity mode (See the above figure.)
5: high humidity mode (See the above figure.)
6: extra high humidity mode (See the above figure.)
7: laser power corrective value +15%
Vdc correction value +40 V
VD correction value 0 V
Potential control
Table 6-203 Timing of Control
Laser power
correction
value
-5%
+5%
The laser power/Vdc is corrected
to suit the environment.
VL
Pw
Pw
Vdc
The laser power/Vdc suited to
the environment is updated
each time the Copy Start key is
pressed.
Copy Start
key ON
CANON imageRUNNER 600 REV.1 JAN. 2000 PRINTED IN U.S.A.
Vdc
VD
correction
correction
value
value
+20V
+30V
200˚C
STBY