Canon imageRUNNER C1325 Series, Service Manual

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Technical Explanation > Image Formation System > Controls > Image Stabilization Control
Technical Explanation > Image Formation System > Controls > Image Stabilization Control
Start
Patch pattern is created
Patch scanning
Registration Patch Sensor Unit
(Front,Rear) (UN31,UN32)
PASCAL correction table is
created (Y,M,C,BK)
(Y) PASCAL correction data
Actual gradation
characteristics
Ideal gradation
characteristics
0
100
D
en
sit
y d
ata (
D
-C
O
N
)
Y1
Y2
Data output (M-CON)
Y63 Y64
Output of patch pattern data
Main Controller PCB (UN81)
DC Controller PCB (UN04)
Main Controller PCB (UN81)
Output of density data
100
Gradation
characteristics
after correction
Ideal gradation
characteristics
0
100
D
en
sit
y d
ata (
D
-C
O
N
)
Data output (M-CON)
100
DC Controller PCB (UN04)
Patch patterns (2 types)
printed on paper
Printed test patterns
are scanned by the reader
F-2-83
● D-half Control
Optimal image gradation is determined.
Control timing
1) During installation and when replacing the Drum Unit
2) At last rotation on a specified print basis (1000 sheets or more)
3) At last rotation when PASCAL control is executed
Control description
1) Main Controller PCB outputs patch data in each color (Y, M, C, and Bk) to the DC Controller
PCB.
2) From the data above, the DC Controller PCB forms patch pattern in each color (Y, M, C,
and Bk) on the ITB.
3) The DC Controller measures the patch pattern by the Registration Patch Sensor Unit (Front)
(UN31) and the Registration Patch Sensor Unit (Rear) (UN32) and the result is returned to
the Main Controller PCB.
4) Based on the data above, the Main Controller PCB executes gradation correction to obtain
ideal halftone image.
NOTE:
The following
3
types of patch patterns are formed with this control:
• A pattern for copy (9 patches for each color)
• A pattern for text priority (9 patches in each color)
• A pattern for photo priority (8 patches in each color)