Ricoh A-C2 - Fusing Temperature Control; Temperature Control

19 January, 2001 IMAGE FUSING AND PAPER EXIT
6-79
Detailed
Descriptions
6.15.8 FUSING TEMPERATURE CONTROL
The fusing unit has two fusing lamps: the
first fusing lamp (center: 650W) [A] heats
the center of the fusing roller, and the
second fusing lamp (ends: 550W) [B] heats
both ends of the hot roller. This
arrangement ensures even heat on all
surfaces of the roller.
In order to control the temperature of the
roller, two high response thermistors are
attached to the unit, one near the center
[C] and one at the end [D] of the hot roller.
Temperature Control
There are two types of temperature control:
• On/off control (Default)
• Phase control.
Either mode can be selected with SP1-104 (Fusing Temperature Control).
After the machine is powered on, the CPU checks the ac frequency for 500 ms, in
case phase control is selected later for the temperature control, and then switches
on the fusing lamp.
As soon as both the center and end thermistors detect the print ready temperature
(also known as the “re-load” temperature), the machine can operate. The “reload”
temperature is 30C below the fusing temperature (this depends on SP1105-05,
06). As soon as the thermistors detect the fusing temperature, the CPU switches
the lamps off but frequently switches on/off again in order to maintain the fusing
temperature.
B004D602.WMF
Center
End
Center
End
185°C
180°C
Main SW ON Re-load
50
200
150
100
°C
155
Fusing Temp.
Model A-C2c
B004D519.WMF
Center
End
Center
End
170°C
160°C
Main SW ON Re-load
50
200
140
100
°C
130
Fusing Temp.
Model A-C2b
B004D518.WMF
[A]
[B]
[C]
[D]