Fuser Drive; Heating Roller Drive Control - Xerox Phaser 6120 Service Manual

Fuser Drive

Heating Roller Drive Control

Speed Change Control
Drive for the Heating Roller is provided by the Fusing Motor (M7).
To prevent fusing failure, the fusing speed is changed according to the media type in use.
Speed Stabilization
To prevent ghosting or smearing, the difference between the fusing speed and paper
transport speed during image transfer is corrected.
The fusing speed is changed in two steps relative to the system speed, either at high speed
(which is +2% of the system speed) or low speed (which is -2.5% of the system speed).
The Fusing Motor (M7) is controlled to achieve this speed change in two steps.
Fuser Sequence
1. The initial fusing speed is set to the low speed, thereby forming a loop in the paper
between the 2nd Transfer Roller and Fusing Rollers.
2. The Fusing Paper Loop Sensor (PC8) is activated (blocked) when the loop is formed.
3.
While the Fusing Paper Loop Sensor (PC8) remains activated, the fusing speed is kept at
the high level.
4.
When the Fusing Paper Loop Sensor (PC8) is deactivated, the fusing speed is immediately
switched to the low level.
Phaser® 6120 Color Laser Printer Service Manual
Print Engine Theory of Operation
Fusing Motor
Heating Roller
4139to2094e0
7-48