Fixing Pressurizing/Release Control; Fixing Sleeve Pressuring/Releasing Control - Canon Color imageCLASS MF9170c Service Manual

Chapter 9

9.2.2 Fixing Pressurizing/Release Control

9.2.2.1 Fixing Sleeve Pressuring/releasing Control

imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
This machine controls the pressure between the fixing sleeve and the fixing pressure roller as needed to prevent the fixing failure and the breakdown of fixing as-
sembly (see MEMO).
Pressuring/releasing of the fixing sleeve is performed by the fixing motor (M1). When the pressure spring pushes the pressure arm, the pressure is applied on the
fixing film. When the fixing motor rotates reversely, the fixing pressure release cam pushes the pressure arm and the pressure on the fixing film is reduced.
The pressuring/releasing status of fixing sleeve has following 3 conditions depending on the position of the fixing pressure releasing cam.
- Pressurized condition (home position)
Fixing film is pushed by the pressure roller.
This condition is called at power-ON, the front cover closed and the cancel of sleep condition.
- Released condition
The fixing film is disengaged with the pressure roller.
This condition is called at power-OFF, JAM occurrence and the entry of sleep mode.
- Slightly pressurized condition
The fixing film is pushed slightly by the pressure roller.
This condition is called at printing envelope.
Fixing pressure releasing cam
Pressure arm
Pressure spring
Fixing pressure release sensor (SR705)
The pressuring/releasing status of the fixing sleeve is identified by ON/OFF status of the fixing pressure release sensor (SR705) and the rotation period of the fixing
motor (M1).
MEMO:
If pulling out jam paper with fixing sleeve pressured, the fixing sleeve may get damaged. In addition, if the pressurized condition continues for a long time, a mark
may remain on the nip of the fixing sleeve.
To prevent those, there is a mechanism for releasing the fixing sleeve pressure.
Error Codes:
E840 Error in pressure release mechanism
When the pressure control is commanded, if the pressurized condition (home position) cannot be detected after 2.5 sec, the machine stops and an error code
is displayed on a control panel.
Error in no fixing assembly
When the pressure control is commanded, if the pressure release sensor (SR705) is not turned ON after 2.5 sec, the machine stops and a message indicating
the absence of the fixing assembly is displayed.
9-4
Pressurized
Released
Slightly pressurized
Released
F-9-3
Fixing pressure roller
Fixing sleeve
Pressurized
Slightly pressurized
0020-0962