Temperature And Pressure Control - Ricoh Aficio 480W Dolphin-C2 Service Manual

FUSING UNIT

6.10.3 TEMPERATURE AND PRESSURE CONTROL

The fusing pressure is automatically adjusted, so
nip-band width is not required.
During warmup and during printing, the pressure
roller thermistor [A] monitors the temperature of
the pressure roller to determine the target control
hot roller temperature. (☛ Table 6-1)
The hot roller thermistor [B] monitors the actual
temperature of the hot roller, and the CPU
determines the difference between the actual
temperature and the target control temperature.
Based on this data, the pressure on the hot roller
[C] is increased or decreased, until the leading
edge of the paper reaches the fusing unit. (☛
Table 6-2)
If the hot roller temperature drops below a certain
level during printing, the CPU uses CPM Down
Control to reduce the hot roller speed. (☛ Table 6-3)
Table 6-1 Pressure Roller and Hot Roller Temperature
Temp. Control 1
Temp. Control 2
Temp. Control 3
Temp. Control 4
X: Pressure roller temperature
PLAIN PAPER/FILM
Pressure Roller Temp.
Below 117.5°C
168°C ~ 117.5°C
Above 168.5°C
Below 96.5°C
96.5°C ~ 156.5°C
Above 156.5°C
Below 70°C
70ºC ~ 128°C
Above 128°C
Below 63.5°C
96.5°C ~ 115.5°C
Above 111.5°C
Target Hot Roller Temp.
195°C
-0.6667X + 273.33°C
161°C
195°C
-0.6667X + 259.33°C
155°ºC
194.5°C
2
-0.0048X + 0.3086X + 196.42°C
157°C
195°C
-0.6667X + 237.33°C
163°C
6-52
28 April 2005
[A]
[B]
[C]
B188D952.WMFF