Adjusting The Density In Various Modes - Canon iR6570 series Service Manual

Chapter 7
4: OFF

7.4.7 Adjusting the Density in Various Modes

The machine corrects the development bias determined as a result of potential control for the following operating modes, and uses the result as the target
value for the individual modes:
1. Density Adjustment for Copying
Purpose: to obtain the density suited to the user's needs.
Method of correction: uses the developing bias and image processing (binary density processing) according to the F-value setting
2. Density Adjustment for Printing
Purpose: to obtain the density suited to the user's needs.
Method of correction: uses the developing bias and image processing (thickening) to suit the F-value setting.
Adjusting the Density for Copying
The machine increases the developing bias to decrease the copy density. If increased in excess, the bias can cause light images; if decreased in excess, on
the other hand, the background can developing fogging. In light of this, the machine executes density processing using changes in the developing bias and
image processing (binary density processing).
F value
1
2
3
4
5
Adjusting the Density for Printing
The machine increases the developing bias to increase the print density. If increased in excess, the background can develop fogging. At the lower limit of
the developing bias, the machine uses the changes in the developing bias and image processing (thickening processing) to ensure appropriate density.
F value
1
2
3
4
5
6
7
8
9
*1: Thickening processing may be enabled for all F values in user mode ('correct fine line').
7-10
Developing DC bias standard value
(V)
240
220
180
140
120
Developing DC bias standard
value (V)
218
205
194
182
170
153
137
120
120
T-7-5
Shift (V) Image processing
60 yes
40 no
0 no
-40 no
-60 yes
T-7-6
Shift (V) Thickening*1
48 no
35 no
24 no
12 no
0 no
-17 no
-33 no
-50 no
-50 yes
0009-3546
Image density
lighter
darker
Image
density
light
dark