D-Half Control; Pascal Control - Canon imageRUNNER ADVANCE 8105 Series Service Manual

2
Technology > Image Formation System > Controls > Image Stabilization Control
●

D-half Control

This control determines gradation correction value based on the image density detected by
the Patch Sensor
Execution timing
•
Last rotation after 6,000 sheets (or more) have been passed through since execution of the
last D-half control
When PASCAL (User mode > Settings/Registration > Adjustment/Maintenance > Image
•
Quality Adjustment > Image Stabilization Control > PASCAL (Full/Quick Adjust)) is executed
First power-on when Service Mode > COPIER>OPTION>FNC-SW>DMAX-SW is 2
•
First power-on + last rotation when Service Mode > COPIER>OPTION>FNC-SW>DMAX-
•
SW is 3
Control description
1) Based on the gradation data sent from the Main Controller, patch images (up to 9 patterns)
are formed on the Drum.
2) Patch density is detected to feed the value back to the Main Controller.
3) The Main Controller corrects the gradation data (LUT table)*1
*1: Gradation data (LUT table) is generated when executing Full Adjust: Auto Adjust Gradation
> Full Adjust
Related service modes
COPIER > OPTION > FNC-SW > DH-SW
2
Technology > Image Formation System > Controls > Image Stabilization Control
●

PASCAL Control

This control stabilizes gradation density characteristics on the image.
This control is executed when the following is selected in user mode: Auto Adjust Gradation >
Full Adjust
Patch pattern on the test print is scanned by the Reader to create a gradation table
(PASCALγLUT).
Then, a D-half patch gradation table is created to be used as the target in D-half control.
The foregoing table corrects image gradation characteristics caused by change of
environment and deterioration of the Photosensitive Drum.
Execution timing
During execution of Full Adjust: User mode > Settings/Registration > Adjustment/Maintenance
> Adjust Image Quality > Image Stabilization Control > Full Adjust
Full adjustment execution of
auto gradation adjustment
Potential control
DC Controller PCB
D-max control
DC Controller PCB
Send data of test print
Main Controller PCB 2
Output test print
DC Controller PCB
Read test print
Reader
Density data output
Main Controller PCB 2
Generate gradation table
(PASCALγLUT)
Main Controller PCB 2
NO YES
3-sheet output
for test print?
2-82
Send D-half patch
image data sending
Main Controller PCB 2
Form D-half patch image data
DC Controller PCB
Read patch
Patch Sensor
Density data output
DC Controller PCB
Generate D-half patch gradation
table (PASCALγLUT)
Main Controller PCB 2
End
F-2-110 F-2-110
2-82