Potential Control For Transparency Mode - Canon GP605 Service Manual

G.

Potential Control for Transparency Mode

To prevent detachment of toner in high density areas on transparencies, the contrast is de-
creased to limit the amount of toner deposit. To enable the decrease in contrast, potential control for
transparency mode is executed to select a target value.
Potential sensor
Laser
Grid bias
Potential determined
Related Service Mode
COPIER>OPTION>BODY>
OHP-CNT
(transparency mode potential control
ON/OFF)
Main power switch
OFF/ON
Set
COPIER > OPTION > BODY > OHP-CNT
COPYRIGHT © 1999 CANON INC.
Using the target value for transparency mode,
potential control sequence is executed.
Potential control
sequence started
195˚C
WMUPR
WMUP
VD
Vg
Vg
Figure 6-209 Sequence of Operations
1: use the target value obtained for transparency mode
potential control during transparency mode operation.
(default)
0: disable potential control for transparency mode.
Potential control
sequence started
Figure 6-210 Timing of Control
CANON GP605/605V REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 IMAGE FORMATION SYSTEM
VD VL
corrective corrective
value value
+100V
Transparency potential
control sequence started
VL VLohp
Transparency mode
laser power determined
Pw
Pwohp
Pw Pwohp
Vdc
Transparency mode
potential control
Vdc
corrective
value
200˚C
STBY
6-11