Canon iR C2880 series, Руководство по обслуживанию

Страница: 232 / 610

Chapter 7
7-22
F-7-29
7.3.9 Color Displacement Correction Control
0013-8493
/ / / / iR C3380i / iR C3380 / iR C2880i / iR C2880
The machine performs the following 3 types of control to correct displacement of color possibly caused by differences among components of its laser scanner unit
and drum unit:
- main scanning write start correction
- sub scanning write start correction
- main scanning magnification correction control
The DC controller forms patterns for detection of color displacement for individual colors, and uses the color displacement sensor to detect the position of the pat-
terns.
The DC controller computes the degree of displacement with reference to the position of the pattern detected; based on the result, the DC controller or the main
controller corrects the displacement for individual colors.
Comparison of measurement data (SIN)
and reference data (INT)
Main controller
Data output(V-CON)
Density data(D-CON)
100
20
40
40
Gradation characteristics
after correction
60
Current gradation
characteristics
UN16
Measurement data (SIN) transmission
Patch reading
Start-up
DC controller
Patch pattern formation
DC controller
Data output(D-CON)
Density data(D-CON)
40
20
40
10
INT
SIN
Offset value (alpha) determination
(i.e., difference between SIN and INT)
Main controller
Main controller
Inclusion of result in
D-half correction table