The pressure roller has a release control mechanism to release fusing pressure when a job is not in progress. This contributes to reducing deformation of the pressure roller.
When a job starts, the fusing release motor [A] drives, the pressure roller cams [B] turn, and the pressure roller unit [C] shifts up. When a job finishes, the fusing release motor [A] drives in the opposite direction, and the pressure roller unit [C] shifts down and pressure is released. With the actuators [D], the front and rear sensors near the axial points of the pressure roller cams detect the following:
- Pressure Roller Sensor (Front): Detects the angle of the cam in 3 steps to control the nip pressure
- Pressure Roller Sensor (Rear): Detects HP
The fusing release motor [A] is driven by a DC brushless motor with an encoder.
After the motor has applied pressure, it stays on because otherwise the roller rotation while paper is passing would tend to release the pressure.
In addition, the nip pressure is adjustable in 3 steps by changing the angle of the cam, depending on thickness of paper.
State | Default Value | |
|---|---|---|
Pressure Position 0 | Released | - |
Pressure Position 1 | The fusing drive motor drives in reverse to remove jammed paper (not changeable in SP mode) | 2mm |
Pressure Position 2 | For envelope feeding (changeable with SP1-989-xxx) | 3.5mm |
Pressure Position 3 | For paper feeding (not changeable in SP mode) | MP C6503/C8003: 16.7±0.2mm Pro C5200S/C5210S: 17.4±0.3mm |
[A]: Fusing Roller
[B]: Pressure Roller
[C]: Changing the nip width by changing the pressure position