Xerox Phaser 6120 Service Manual page 269

5.
The sequence of these operations is repeated so that the fusing speed is changed
automatically according to the loop length. This effectively makes for the difference
between the fusing speed and paper conveyance speed during image transfer.
Fusing Temperature Control
A thermistor is used to detect the surface temperature of the Heating Roller. The Heater Lamp
(H1) is then turned ON and OFF as necessary to achieve the set temperature.
Warm-Up
The lamp is on until the Heating Roller temperature reaches 178° C.
This control is performed when the Power Switch is turned ON, a malfunction or paper
misfeed is reset, the Energy Saver mode is canceled, or the door is opened and closed.
Ready
The fusing temperature in the Ready (or standby) state is maintained at a constant temperature.
During Print Cycle
To ensure good fusing performance, the set temperature of each roller is varied according to
the paper type and environment.
Energy Saver Mode
Heater control is suspended when a malfunction or paper misfeed occurs or in the Energy
Saver mode.
Protection Against Abnormally High Temperature
The machine provides protection at three different stages to prevent abnormally high
temperature of the Fusing Unit.
Soft Protection (Warning)
If the Thermistor (TH1) detects a temperature exceeding a predetermined value, the
malfunction code representing abnormally high temperature is displayed. At this time, the
Phaser® 6120 Color Laser Printer Service Manual
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Print Engine Theory of Operation
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