Image Stabilization Control; Overview - Canon Color imageCLASS MF9170c Service Manual

7.2 Image Stabilization Control

7.2.1 Overview

imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
The quality of a printed image is affected by changes in environmental condition where the machine is installed or changes in the characteristics of the photosensitive
drum and toner.
The machine performs the following controls according to necessity to stabilize print operation.
- Environmental change corrective control
To correct values of primary charging biases and developing biases based on the result of detection performed by the environment sensor. This is comparable
to a conventional D-max control.
- D-half control
To correct the gradation data in the main controller PCB based on the result of detection performed by the color displacement/density sensor
- Color displacement corrective control
To correct the timing of sending a video signal based on the result of detection performed by the color displacement/density sensor.
- Auto gradation correction control
To make a stable gradation density feature of image, customers need to execute any of full correction, quick correction or copy image correction.
Timing of execution of each control
No. Execution timing Operation time
Replacement of the
1 Approx. 3 min
cartridge
2 Environmental change Approx. 2.5 min
After a specified period
3 Approx. 2.5 min
of time is passed
Recovery from sleep
4 Approx. 2.5 min
mode
After a specified
5 number of sheets is Approx. 3 min
printed
Full correction
6 Approx. 5 min
(PASCAL)
7 Quick correction Approx. 2.5 min
8 Copy image correction Approx. 4 min
*: Executed when 120 sheets are printed after the initial implementation
Executed when 500 sheets are printed after the 2nd implementation
Executed when 1000 sheets are printed after the 3rd implementation
Executed when 1000 sheets are printed thereafter
T-7-1
Environmental
change corrective D-half control
control
Yes Yes
Yes Yes
Yes Yes
Yes Yes
Yes * Yes *
Yes Yes
Yes Yes
Yes Yes
Color
displacement
corrective control
Executed at the time of multiple initial rotations after power-
Yes
on or door closing
- Temperature and humidity by the environment sensor
Executed 8 hours after the drum motor stops. The control is
-
not however executed during sleep mode.
- Executed 8 hours after the drum motor stops.
Yes
(Every 1000 Executed after a job is completed.
prints)
- Executed by user's operation.
- Executed by user's operation.
- Executed by user's operation.
Chapter 7
0019-5019
Remarks
7-7