Canon i-SENSYS D450d Service Manual - page 104
Chapter 8
8-4
In order to prevent temperature increase at the end of the fixing film that occurs when putting papers on one side and passing them through the machine while the
paper width guide is fully opened, the machine has the delivery paper width sensor.
The relationship between paper size when putting papers on one side and passing them through the machine and the fixing mode is shown below. (E and F indicate
paper size.)
F-8-4
T-8-3
*1: Eight modes, except envelop/small size paper
*2: When setting papers at the end of the paper guide and passing them through the machine, it becomes the small size paper mode regardless of paper length.
8.3 Protection Function
8.3.1 Protection Function
0020-2717
i-SENSYS MF4300dn / i-SENSYS MF4350d / i-SENSYS MF4380dn / i-SENSYS MF4310/4318 / i-SENSYS MF4320d / i-SENSYS MF4330d / i-SENSYS
MF4340d / i-SENSYS D450d / i-SENSYS MF4370dn
In order to prevent the fixing heater runaway, the machine has the following 3 protection functions.
1. Protection function with CPU
2. Protection function with the fixing heater safety circuit
3. Protection function with the temperature fuse
The description of each function is as follow:
1. Protection Function with CPU
CPU always monitors voltage of the fixing heater temperature detection signal sent from the thermistor. If the fixing temperature greatly exceeds the specified value,
CPU judges as failure of the fixing assembly, and it blocks the power distribution to the fixing heater.
Moreover, error (E000) is displayed in the operation part at the same time.
T-8-4
D
Less than 267.4 mm
Not detect
Not detect
Envelop
Paper length
Paper width sensor Delivery
paper
width sensor
Fixing mode
E
No object *2
Detect
Not detect
Small size paper mode
F
No object *2
Not detect
Detect
Small size paper mode
Failure of fixing assembly
Thermistor temperature
Heater temperature detection time
From the start of temperature control until 1.47 sec
Less than 55 deg C
Normal times
230 deg C or above
0.15 sec in a row
E
267.4 mm
PS802
PS804
F