Cleaning Roller Engaging Control - Canon MF8100 Series Service Manual

Mf8100 series

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Chapter 2

The cartridge consists of the photosensitive drum, primary charging roller, waste toner transport plate, etc. These parts are driven by the main motor (DCM701).

This cartridge performs engaging operations for two rollers, the ITB cleaning roller and auxiliary ITB cleaning roller, with the DCM701. Position detection for

these two rollers are performed with a common sensor.

A memory tag is installed into the drum cartridge. The memory tag contact makes contact with the memory tag in the cartridge constantly when the cartridge is

installed in the printer.

The waste toner detection is performed by an LED (light emitter) and a photodiode (light receiver) on the waste toner detection circuit.

The functions and controls of the cartridge are discussed next.

2.3.6.2 Cleaning Roller Engaging Control

In this control, the two rollers, the ITB cleaning roller and auxiliary ITB cleaning roller, are engaged/disengaged from the ITB to clean residual toners on the ITB.

The operations of this control are described in the following:

1) At printing, the DCNT Board checks that the two rollers, ITB cleaning roller and auxiliary ITB cleaning roller, are at their home positions (Note:1) in secondary

transfer roller position detection.

2) At the timing of the start of secondary transfer, the DCNT Board let out the roller engaging clutch (CL2). This transmits the drive of the main motor (DCM701)

to the engaging cam.

Then the roller bushing is pushed out and the two rollers start to engage to the ITB.

3) At this point, the DCNT Board is monitoring the output of the PS714, When the output becomes "L", it lets out the CL2. This allows the cam to stop and the two

rollers to stop at each engaging position.

4) After a print operation, the DCNT Board let in the CL2 again for 0.2 seconds. This disengages the two rollers from the ITB.

5) The DCNT Board monitors the output of the PS 714, When the output becomes "L", it lets out the CL2. This allows the cam to stop and the two rollers to stop

at each home position. Then, it is ready for the next print operation.

Note 1. The home positions of each roller are positions at where the rollers are disengaged from the ITB by the roller bushing.

Note 2. The operation of the engaging cam used in this control is also used in the secondary transfer roller engaging control.

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ITB feed roller

ITB

Main

DCM

motor

701

Waste toner screw

Primary