Canon imageCLASS D530 - Fixing Temperature Control; Protective Functions; Various Control Mechanisms

2
2
2-23
2-23
Technical Overview > Fixing System > Various Control Mechanisms > Protective Functions
Technical Overview > Fixing System > Various Control Mechanisms > Protective Functions
Various Control Mechanisms
■
Fixing Temperature Control
●
Heater Temperature Control
The heater temperature control is to keep the xing heater in the xing lm unit to the
specied temperature.
The engine controller monitors the xing heater temperature detection signal (FSRTH) and
outputs the xing heater drive signal (FSRD) according to the detected temperature.
The xing heater drive PCB controls the xing heater according to this signal to keep the
xing heater temperature within the target values.
(220-240V model only)
FU101
RL101
+24V
FREQSNS
FSRD
24VOFF
FSRTH
CPU
Engine controller
Fixing heater (H1)
Pressure
roller
Thermistor (TH1)
Thermal fuse (TP1)
Fixing film
Low-voltage
power supply
Frequency
detection
circuit
Fixing control
Relay drive
circuit
Fixing heater
drive circuit
Fixing heater
safety circuit
F-2-30
There are 11 types of target xing temperature depending on the xing mode.
These types are according to the paper type settings and resolution settings on a driver.
■
Protective Functions
●
Protective Function of xing assembly
Host machine carries the following 3 functions to prevent the xing heater from overheating.
1) Protective function by CPU
CPU of engine controller monitors the thermistor (TH1) temperature consistently.
When TH1 reaches approx 220 deg C, CPU determines that the xing heater is overheating
and stops the xing heater drive signal (FSRD) output and also turns OFF relays to shut
the power supply to xing heater.
2) Protection function by xing heater safety circuit
Fixing heater safety circuit monitors the thermistor (TH1) temperature consistently.
When TH1 reaches approx 235 deg C, it determines that the xing heater is overheating
and the xing heater safety circuit turns OFF the relay drive circuit to shut the power supply
to the xing heater.
3) Protection function by temperature fuse (TP1)
When the xing heater temperature rises abnormally and temperature fuse (TP1)
temperature reaches approx 226 deg C, TP1 opens to shut the power supply to the xing
heater.
●
Failure detection
With this machine, 8 types of failure detection are available.
1) Initial startup failure detection
When temperature of the Fixing Assembly does not exceed 50 deg C within 1.48 sec after
the start of temperature control performed at initial rotation, it is judged as initial startup
failure.
2) Initial Thermistor open detection
When temperature of the Fixing Assembly does not exceed 35 deg C within 1.48 sec after
the start of temperature control at warm-up rotation temperature control or at cleaning
mode, it is judged as Thermistor open failure.
3) Short circuit of Thermistor/abnormal high temperature detection
When temperature of the Fixing Assembly is 220 deg C or higher for 30 consecutive times