This control is utilized to perform an engaging/disengaging operation between the secondary transfer roller and ITB in order to transfer the toner on the ITB to paper.

The operations of this control are described in the following:

1) At printing, the DCNT Board checks that the secondary transfer roller is at its home position (Note:1) in secondary transfer roller home position detection.

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

to the engaging cam. Then the engaging lever is pushed out and the secondary transfer roller starts 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

secondary transfer roller to stop at its engaging position.

4) After a print operation, the DCNT Board lets in the CL2 again for 0.2 seconds. This disengages the secondary transfer roller from the ITB.

5) The DCNT Board monitors the output of the PS714, When the output becomes "L", it lets out the CL2. This allows the cam to stop and the secondary transfer

roller to stop at its home position.

Note 1. The home position for the secondary transfer roller is the state in which it is disengaged from the ITB.

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

2-28

DCNT Board

Main

DCM

701

motor

PS714

Roller

engaging