Fusing Temperature Control - Ricoh Aficio MP2550B Service Manual

Image Fusing and Paper Exit

6.13.6 FUSING TEMPERATURE CONTROL

Temperature Control
Just after the main power switch is turned on, the CPU turns on the fusing lamp to obtain a
fusing temperature of 190 °C (Main fusing lamp), 195 °C (Sub fusing lamp) for the first 60s,
or for the first three consecutive pages of printing, whichever comes first. After that, the
machine keeps the fusing temperature at 190 °C for the first 20 consecutive pages of
printing. Then the fusing temperature is kept at 180 °C.
The three-page and 60-second limits can be adjusted with SP1-105-8 and -9.
Note that the fusing temperature is higher if the user uses special paper in the 2nd tray or
thick paper mode from the bypass tray.
Fusing Lamp Control
When the fusing lamp power turns off and on, this causes fluorescent lights in the room to
flicker. To reduce the flickering, use the following SP modes.
Fusing temperature detection cycle (SP mode 1-108)
The CPU checks the output from the fusing thermistor once a second (default setting). The
CPU compares the current and previous temperatures. Based on the result, it then decides
how long the fusing lamp power should be on during the next one-second interval (also, if
the current temperature is too high, the power will not be needed).
SM 6-73 D017/D018/D019/D020