Panasonic UF-5500, Service Manual

Page: 243 / 365

243
UF-5500 / 4500
13.2.6. Fixing
On the process of the transfer, the transferred toner is weakly attached on the paper. Fixing means the process to fix the toner on
the paper permanently. The fixing part melts the toner at the high temperature using the halogen heater. The toner is fixed on the
paper by the heat and pressure through the fixing part with the image. The surface of the heat roller is rosined by Teflon and lubri-
cated to prevent from attaching the toners. The press roller is made of silicon, and its spring compresses the melted toner.
Fixing Part
The fixing part becomes high temperature, so the thermistor and the two thermostats are provided.
1. Thermistor
The thermistor touches the heat roller and check the temperature to feed back to the control circuit. The surface temperature
should be kept 383
°
F (195
°
C) while printing.
2. Thermostat
The thermostat is located near the heat roller, and it turns OFF the power when the temperature around the thermostat
becomes over 320
°
F (160
°
C).
Spring
Pressure Roller
Paper Path
Halogen Heater Thermistor
Heat Roller
Two thermostats
Separater
Thermostat
Thermister Thermister
Heat Roller