Density Adjustment In Each Mode; Density Adjustment During Copying - Canon Image Reader-A1 iR5000i Service Manual

CHAPTER 4 IMAGE FORMATION SYSTEM

2.6 Density Adjustment in Each Mode

For the following operation modes, the developing bias determined during potential con-
trol is corrected, and the result is used as the target value in each specific mode for density
adjustment.
[1] Density Adjustment in Copying
Purpose: Density adjustment is executed to obtain a level of density suited to the needs of
the user.
Correction: The developing bias is corrected in keeping with the F value setting, and it is
also performed as part of image processing.
[2] Density Adjustment During Printing
Purpose: Density adjustment is executed to obtain a level of density suited to the needs of
the user.
Correction: The developing bias is corrected in keeping with the F value setting, and it is
also performed as part of image processing.

2.6.1 Density Adjustment During Copying

The developing bias is raised to decrease the copy density. Too high a developing bias
will result in hazy images, while too low a bias will result in foggy images.
To avoid these problems, the changes in the developing bias are corrected and correction
is also executed as part of image processing (binary density processing) near the upper and
lower limits of the bias.
F value Developing DC bias
standard value (V)
1
2
3
4
5
4-16 P
240
220
180
140
120
T04-206-01
COPYRIGHT © 2001 CANON INC.
Shift Image processing
(V)
60 Yes
40 No
0 No
-40 No
-60 Yes
2000 2000 2000 2000
Image density
Lighter
Darker
CANON iR5000i/iR6000i REV.0 JUNE 2001