Image Fusing - Ricoh FT4220 Service Training Manual

11. IMAGE FUSING

11.1 OVERVIEW
[F] [E] [D]
[H]
[G] [A]
[C]
[B]
After the image is transferred, the copy paper enters the fusing unit. The
image is fused to the copy paper by the process of heat and pressure
through the use of a hot roller [A] and pressure roller [B].
The fusing lamp [C] located inside the hot roller is turned on and off to
maintain the operating temperature of 185°C. The CPU monitors the hot
roller surface temperature through a thermistor [D] which is in contact with
the hot roller's surface. A thermofuse [E] protects the fusing unit from
overheating.
The hot roller strippers [F] separate the copy paper from the hot roller and
direct it to the exit rollers [G]. The exit sensor [H] monitors the progress of the
copy paper through the fusing unit and acts as a misfeed detector while the
exit rollers drive the copy paper to the copy tray. When the sorter is installed,
the paper sensor on the sorter also functions as a misfeed detector.
STM 2-76 FT4220/4222