Fusing - Kyocera FS-1900 Service Manual

(5) Fusing

The toner on the paper is molten by heat and pressed into the paper as it passes between the heat
roller A and the press roller B in the fuser unit.
Fusing control temperature
Paper type
Temperature
Thin 175 °C
A4
Normal 188 °C
Thick 190 °C
Thin 188 °C
B5 Normal 190 °C
Thick 195 °C
A5 or Normal 188 °C
smaller Thick 190 °C
Ready 150 °C
The heat roller A has a heater (infrared) lamp C inside which continuously turns on and off by the
thermistor to maintain the constant temperature on the heat roller A surface. The fusing temperature
is also controlled based on paper types. See the table in the figure above.
The heat roller A is florin coated by to prevent toner from accumulating on the roller after a long
usage. Care must be taken while handling the heat roller A not to scratch the roller surface as
doing so may result in quality problems.
The heat roller A has four scraping claws (Separators) D which are continuously in contact with
its surface. These claws prevent the paper on which toner has been fused from being wound around
the heat roller A causing paper jam.
The press roller B is made of the heat resistant silicon rubber. This roller is used to strongly press
the paper towards the heat roller A by means of coil springs.
The temperature of the heat roller A is constantly monitored by the engine board using the thermistor
and triac. Should the temperature of the heat roller A exceed the predetermined value, the thermal
cutout is activated to effectively disconnect the heater lamp C from power.
Engine
board
THERM
YC202-6
HEATON*
YC202-11
Figure 4-1-13 Fusing
4-15
AC power
Power
off/on
supply
output
unit
D
C
A
B
FS-1900