Ricoh K-C3 Service Manual page 264

B245/B276/B277/B268/B269 Service Manual
The fusing temperature is controlled using the thermistors [A].
The CPU checks the output from the fusing thermistor once every 1.5 seconds. The CPU
decides how long the lamps must be switched on during the next 1.5 seconds by comparing
the following temperatures:
The center thermistor temperature and the target center temperature
The end thermistor temperature and the target end temperature
The fusing lamp works to maintain a target fusing temperature of 160C during copying.
Temperature Control
According to the operation mode, the fusing temperature is controlled. The diagram
illustrates the transition of fusing temperature. After you turn the main switch on, the fusing
temperature rises from the room temperature (t0) to one of the specified temperatures. You
can adjust some of the temperatures.
A1: Regular Start Mode/A2: Cold Start Mode (SP 1107 1-2)
Turning the fusing lamp on and off may affect the voltage of the power source in the room,
causing the fluorescent lights in the room to flicker. To lighten this problem, you can reduce
the checking repetition to 20 times.
When machine initialization ends, the fusing temperature is set to one of the following
temperatures:
The Standby Temperature (T2: SP 1105 3-4) when there is no print job.
The First Print Temperature when the copier has received a print request during machine
initialization.
You cannot directly adjust the First Print Temperature. This temperature is 10C higher (up to
185C) than the Copying Temperature (
C: Copying Mode
When the copier is making copies, the fusing temperature is set to one of the following
p.111).
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