Canon iR C2880 Series Service Manual page 245

MEMO:
The patch pattern formed in the course of this control may be either of the following 3 types:
- pattern with priority on characters (6 patches in total for each color)
- pattern with priority on photo (6 patches in total for each color)
- reference pattern for abridged D-half (1 patch for each color)
Flow of Computing the Correction Value for Abridged D-half
EX: D-half correction table for Y
Actual gradation
characteristics
Y6
Y5
100
Y4
Y3
Ideal gradation
Y2
characteristics
Y1
100
0
Data output(V-CON)
100
Ideal gradation
characteristics
Gradation characteristics
after correction
0 100
Data output(V-CON)
Start-up
Main controller
Patch pattern data output
DC controller
Patch pattern formation
UN16
Patch reading
DC controller
Density data output
Main controller
D-half correction table creation
(Y, M, C, Bk)
F-7-26
Chapter 7
7-21