Fusing: Stage Sk - HP LaserJet II Serie Manual De Instrucciones

HP 33440/HP 33449 COMBINED SERVICE MANUAL
FUSING: Stage Six
Untfl the paper reaches the fusing station, the toner is held on the paper ody by gravi@ and
weak electrostatic forces. At the fusing station, toner is malted and forced into the paper by heat
and pressure to produce a permanent image. The fusing station (see Figure 5-12) consisk of an
upper non-stick ro~er that is hated from the inside by a high intensity quartz lamp and a lower
sofi ro~er that Wows pressure to be apptied over a large contact area between the paper and the
upper fusing ro~er. At this point the toner is melted and squeezed into the paper fibers. To
keep the toner or paper from sticking to the Fusing RoUer, the roller is covered with a non-stick,
Teflon-@e resin. A cleaning pad, which is in contact with the Fusing Ro~er, appties a thin coat of
sificone ofl b the surface of the roller to dso help prevent sticking. The cleaner pad dso serves to
wipe off any toner or debris that is transferred to the roller.
The Fusing RoUer temperature is monitored by the Machine Control System via a thermistor. The
Machine Control System maintins a temperature of 165° C (330° F) during standby mode and
180° C (355° F) during printing.
A thermoprotector switih is dso located in the Fusing Assembly, adjacent to the thermistor. The
thermoprotector shuti down (opens the power circuit b the fuser bulb) when the temperature is
in ~cess of 210° C (410° F). If the fising system is shut down by overheating, an ERROR 50 is
displayed. E this occurs, the printer mu~ be powered off and the thermoprotector replaced. The
printer mum remain powered off for at least seven to ten minutes or the ERROR 50 condition will
remain.
Fused Toner
\
,Fusing roller cleaning pad
\
area
Pressure roller
Figure 5-12= Fusing Process
5-12