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.

10-4

Pressurized

Released

F-10-3

Fixing pressure roller

Fixing sleeve

Pressurized

Slightly pressurized

0020-0962

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