Canon ImageRunner iR8500 Series, Service Manual, Page: 352 / 1122

Chapter 8
8-12
F-8-16
T-8-5
F-8-17
8.3.10 Target Potential Correction in Each Mode
0006-9650
iR105i/iR105+ / iR9070 / iR8070
The laser power/developing bias determined in relation to potential control is corrected for the following operating mode, and the result is used as the target
value specific to each:
T-8-6
1. Adjusting the Density during Printing (PDL input)
Related Service Mode
COPIER> OPTION>
BODY> OHP-CNT
(transparency mode
potential control ON/OFF) 1: use the target value obtained for transparency mode
potential control during transparency mode operation.
(default)
0: disable potential control for transparency mode.
Purpose Correction
Density adjustment during
printing (PDL input) To enable reproduction of fine lines (PDL data
from a computer) to suit the needs of the user. Correct the laser power/developing
bias according to the F setting.
Density correction during
printing (scanner input) To attain density levels suited to the needs of
the user. Corrects the laser power/developing
bias according to the F setting.
During operation in high
humidity mode To prevent decreases in density (caused by a
lower developing efficiency because of moist
toner or a lower transfer efficiency caused by
moist paper). Corrects the laser power/developing
bias according to the environment.
WMUPR
WMUP STBY
195˚C
200˚C
Potential sensor
Laser
Grid bias
Vg
Pw
Pwohp
Pwohp
VD VL VLohp
Potential determined
Vg
Pw
Vdc
+100V
VL
corrective
value VD
corrective
value
Vdc
corrective
value
Using the target value for transparency mode,
potential control sequence is executed.
Potential control
sequence started
Transparency potential
control sequence started
Transparency mode
laser power determined
COPIER > OPTION > BODY > OHP-CNT
Set
Main power switch
OFF/ON
Potential control
sequence started
Transparency mode
potential control