Fusing Lamp Control - Ricoh FT6645 Manual

23 April 1993

7.4 FUSING LAMP CONTROL

°C
200
150
100
50
*1
When the main switch is turned on the CPU starts sending a trigger pulse to
the fusing control circuit to turn on the fusing lamp.
When the CPU detects a fusing temperature of 200°C through the thermistor,
the copier starts fusing idling. This idling period can be adjusted by SP mode
( SP Adjustment: PAGE 1). When the fusing idling finishes, the warm-up
1
period is completed and the Ready indicator turns on. After this, fusing
temperature is controlled at 185°C. If the fusing temperature is above 100°C
when the main switch is turned on, the copier does not go into the fusing
idling mode.
When the fusing temperature reaches 180°C (in the case that the main
switch is turned on while the fusing temperature is less than 100°C), the
machine starts the process control data initial setting.
The CPU also changes the fusing lamp on period at every check cycle. The
change is calculated according to the result of the previous check. This
keeps the fusing temperature as close as possible to the target temperature.
If the fusing lamp (950 W) is turned on or off while the exposure lamp is on,
the power supplied to the exposure lamp may fluctuate, possibly degrading
the copy image. To prevent this, the fusing lamp does not change while the
exposure lamp is on: it stays either on or off.
The standard fusing temperature control mode is:
On-off control.......European version
Phase control......Other versions
By cutting the JP501 on the optics control board, the control mode become to
the another mode.
200 °C
180 °C
2-97
IMAGE FUSING
185°C
: Main SW on
: Process control data
initial setting start
: Idling start
: Get ready