Minolta PagePro 1200 Series Service Manual page 55

(1) Overview
• The toner image transferred onto the paper is securely fixed to the paper.
• A heat roller system is used as the fusing system. The toner image is fused by the Heat Roller
heated by the Heater Lamp, and securely fixed by the pressure between the Heat Roller and
Backup Roller.
Paper Separator
Thermostat (TS1)
Thermistor (TH1)
Heater Lamp (H1)
Heat Roller
(2) Fusing Temperature Control Circuit
• The Thermistor detects the surface temperature of the Heat Roller and inputs that analog voltage
into IC1. Corresponding to this data, the Heater Lamp ON/OFF signal is output from IC1A-55,
causing the Heater Lamp to turn ON or OFF to control the fusing temperature.
• When the Heater Lamp is not turned OFF even if the Thermistor detects a high temperature mal-
function (if the surface temperature of the Heat Roller exceeds 230°C), the signal from IC1-79
changes from L to H to turn OFF the Heater Lamp forcibly.
CN1
H1
TS1
PJ2
1 1
TH1
2 2
PU1
PJ7
CN2
+24V 1
GND
2
GND 3
GND 4
+5V 5
1 HEAT_N
+5V
6
2 N.C.
7
FUSER_LAMP
3 HEAT_L
L H1: ON
H H1: OFF
55
PagePro 1200 Series Mechanical / Electrical
Paper
Backup Roller
Fusing Entrance Guide
4127s025
PWB-P
78
CMPIN/AN8/P63
1
2 DC5V
GND GND
1
IC1
2
3
4
5
6
DT1
L
IC2
7
L
3 79
H CMPOUT
1
L
2 55
P01
DC5V
GND
4121s037