II-33
2.5.5 Drum Cleaning Stage
In the image transfer stage, not all the toner on the photosensitive drum is transferred
onto the paper but some remains on the drum. In the drum cleaning stage, the drum
surface is cleaned by the cleaning roller, so that residual toner on the drum surface is
removed and collected on the cleaning roller itself. The residual toner on the cleaning
roller will be discharged to the drum during starting or non-printing time. The toner will be
collected by the developing roller and reused (for further developing).
2.5.6 Erasing Stage
Before the cleaning stage, the drum surface is exposed to the light emitted from the
erase lamp (LED lamp). This stage prepares the drum by decreasing its surface voltage
uniformly, ready to receive a uniform charge in the primary charging stage.
2.5.7 Fixing Stage
The image transferred to the paper by static electricity is fixed by heat and pressure when
passing through the heat roller and the pressure roller in the fixing unit. The thermistor
ASSY keeps the surface temperature of the heat roller constant by detecting the surface
temperature of the heat roller and turning on or off the halogen heater lamp.
Fig. 2-41
Pressure roller
Thermistor ASSY
Halogen heater lamp
Heat roller
Cleaner ASSY