Canon Color imageCLASS MF8580Cdw, Service Manual

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Technical Overview > Image Formation System > Controls > Image stabilization control
Technical Overview > Image Formation System > Controls > Image stabilization control
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Image stabilization control
● Overview
This product controls image stabilization to avoid faulty images due to environmental
changes, deteriorated photosensitive drum or toner, etc. The controls listed in the table below
are executed when needed to stabilize image quality.
Control Description
D-max control Correct values of the primary charging bias and/or developing bias based
on signals from the environment sensor.
D-half control Correct the gradation data in the main controller PCB based on signals
from the color displacement / density sensor.
Color displacement
correction control
Correct the video signal output timing based on signals from the color
displacement / density sensor.
Auto-gradation
correction control
To stabilize the image gradation density characteristics, users execute full
or quick correction, or copy image correction.
High-voltage
power supply PCBs
Reader unit
D-max
D-half
Color displacement
correction control
Toner cartridge
Laser scanner unit
ITB unit
Color
displacement/density
sensor
Signal from color
displacement/density signal
Bias
Video signal
Auto-gradation
correction control
T-2-13
F-2-29
● Execution timing
The table below lists the execution timing and duration of each control.
No.
Execution
timing
Duration
D-max D-half
Color
displacement
correction
Remarks MF8500
series
MF8200
series
1 Power-ON Approx.195
seconds
Approx.120
seconds
○ ○ ○ Executed at initial
rotation
2 Toner cartridge
replacement
Approx.195
seconds
Approx.120
seconds
○ ○ ○ Executed at initial
rotation
3 Environmental
changes
Approx.195
seconds
Approx.120
seconds
○ ○ ○ Executed after job
completion
Detected by the
environment sensor
4 After the pre-
defined counts
printed
Approx.195
seconds
Approx.120
seconds
○ ○ ○ Executed after job
completion
5 After the pre-
defined time
elapsed
Approx.195
seconds
Approx.120
seconds
○ ○ ○ Executed after job
completion
6 Resumed from
sleep (after 8
hours or more)
Approx.100
seconds
Approx.60
seconds
○ ○ - Executed after job
completion upon
resumed
7 Full correction Approx.100
seconds
Approx.60
seconds
○ ○ - Executed by users
8 Quick correction Approx.100
seconds
Approx.60
seconds
○ ○ -
9 Copy image
correction
Approx.100
seconds
Approx.60
seconds
○ ○ -
T-2-14