Canon iR7086 Series Service Manual page 256

Chapter 7
Increases the laser power
(i.e., increasing the contrast)
to enable reproduction of fine lines,
each as wide as the diameter of a
single toner particle.
Potential sensor
Laser
Grid bias
Selected potential
SERVICE MODE:
- COPIER> OPTION> BODY> CNT-W/PR (enabling/disabling density variable mode during printing)
0: corrects the target value to permit variation of density during printing. (default)
1: does not permit variation of density during printing.
2. Adjustment of Density During Printing (scanner input)
7-10
Lighter
Density
Darker
Corrects the laser power/developing
bias to suit the F value setting.
Potential control
sequence started
193
WMUPR
WMUP
VD
Vg
Vg
Main power switch
Set OFF/ON
Potential
control
COPIER > OPTION > BODY > CNT-W/PR
Vdc
Laser power
F
correction correction
value
value
value
1
0.6
2 0.7
3 0.8
4 0.9
5
1.0
6 1.1
1.2
7
8 1.2
+20V
9
1.2
+40V
The laser power reaches the upper limit,
causing the machine to correct the
developing bias and to increase the
contrast.
VL
Pw
Pw Vdc
F-7-14
A laser power output Vdc
suited to the F value setting
is used.
Printing
F value
started
changed
F-7-15
VD
correction
value
198
STBY