Canon imageCLASS MF8450c, Service Manual

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Chapter 8
8-9
T-8-4
*1: For the universal-size paper or the paper of which width is smaller than A4-size, an interval between sheets is changed step by step according to the
temperature detected by the fixing sub thermistor.
*2: Although throughput-down control is not performed, a restriction is applied to the power supplied to the fixing heater.
Print speed when the throughput down control is executed
When the throughput down control is ON, print speed is switched step by step depending on the paper type or the temperature on the edge of the fixing sleeve etc.
Following shows the print speed list in case of the minimum throughput.
T-8-5
*: Throughput down is executed in the same manner in case of plain paper H, thick paper 1, thick paper 2 and rough paper.
8.2.6 Feeding Speed Control
0019-5031
imageCLASS MF9170c / imageCLASS MF9150c
The machine switches the paper feeding speed depending on the type of paper fed in order to prevent a fixing failure.
The DC controller switches the paper feeding speed over 4 settings (1/1 speed, 4/5 speed, 1/2 speed, 2/5 speed) depending on the paper type specified by the main
controller.
T-8-6
8.2.7 Feeding Speed Control
0020-9284
imageCLASS MF8450c
The machine switches the paper feeding speed depending on the type of paper fed in order to prevent a fixing failure.
The DC controller switches the paper feeding speed over 3 settings (1/1 speed, 5/8 speed, 1/2 speed) depending on the paper type specified by the main controller.
T-8-7
8.2.8 Warp Control
0019-5032
imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
To prevent an image failure, it is necessary to keep the paper warped at an appropriate level between the fixing assembly and the ETB.
When the paper transport speed of the pressure roller is slower than that of the ETB, the paper warp increases, and an image defect or paper crease occurs. Con-
versely, the speed is faster than that of the ETB, the paper is pulled by the pressure roller, and a color displacement occurs in the sub-scanning direction.
The machine controls the rotational speed of the fixing motor (M1), which drives the pressure roller, to keep an appropriate level of paper warp.
Paper displacement
The paper is displaced
to the left side
The paper width is
smaller *1
The paper is not
displaced
The paper is displaced
to the right side
Paper displacement detection
sensor (SR714)
No paper detection is performed Paper detection is performed
Fixing sub thermistor (TH2)
Lower than the
specified temperature
Higher than the
specified temperature
Lower than the
specified temperature
Higher than the
specified temperature
Throughput-down control
Instantly executed (the
lowest value)
Executed step by step
No throughput-down
control performed
No throughput-down
control performed *2
Paper Print speed (ppm)
Type Size 1st level 2nd level 3rd level Last level
Plain paper/Recycled paper/Color paper * B5R/A5R/EXECR
16.1 4.4 3.4 2.76
Transparency
- 3.6 2.4 - 1.8
Postcard/Return postal card
- 10.1 3.8 3 2.5
Paper Grammage Paper type Paper feeding speed
Plain paper 60 to 105 g/m2 Plain paper 1/1
Thick paper 105 to 120 g/m2 Thick paper 1 4/5
Thick paper 121 to 176 g/m2 Thick paper 2 4/5
Postcard up to 190 g/m2 Postcard 1/2
Rough paper - Rough 2/5
Label - Label 4/5
Envelope - Envelope 4/5
Transparency - Transparency 2/5
Paper Grammage Paper type Paper feeding speed
Plain paper 60 to 105 g/m2 Plain paper 1/1
Thick paper 105 to 120 g/m2 Thick paper 1 1/1
Thick paper 121 to 176 g/m2 Thick paper 2 1/1
Postcard up to 190 g/m2 Postcard 5/8
Rough paper - Rough 1/2
Label - Label 1/1
Envelope - Envelope 1/1
Transparency - Transparency 1/2