Other Functions - Canon i-SENSYS MF229dw Service Manual

2
Technical Overview > Fixing System > Other Functions > Throughput Down Control
4) Abnormal low temperature detection
After temperature of the Fixing Assembly exceeds 50 deg C at least once, monitor
temperature of the Thermistor for every 5 msec. It is judged as heater abnormal low
temperature when the following condition is detected 240 consecutive times: the
temperature is 100 deg C or lower while paper is at fixing nip, or it is 55 deg C or lower
during paper interval temperature control or at cleaning mode.
5) Thermistor open detection
After temperature of the Fixing Assembly exceeds 50 deg C, monitor temperature of the
Thermistor for every 5 msec. When it is detected that the temperature is lower than 20 deg
C for 6 consecutive times, it is judged as Thermistor open failure.
6)Startup failure detection
If temperature of the Fixing Assembly is 100 deg C or higher when the machine becomes in
pickup enabled state after entering fixing low voltage inlet sequence, it is judged as startup
failure.
7) Thermistor low temperature detection 2)
Temperature of the Thermistor is monitored for every 200 msec when paper is at fixing
nip during the Fixing Assembly control. When the temperature is lower than 135 deg C
(120 deg C), increase the value of low temperature detection counter by 1 (+1). When it
is 135 deg C (120 deg C) or higher, decrease the value by 1 (-1). When the value of low
temperature counter becomes +150, it is judged as Thermistor low temperature failure. The
default and minimum value of low temperature detection counter is 0.
8)Frequency detection circuit error (230V models only)
When frequency measurement is not completed within 3255 msec after the completion of
previous frequency measurement, it is judged as frequency detection circuit error.
● Processing after failure detection
If the Main Motor is in driving state when Fixing Assembly failure is detected, rotation of the
motor is maintained for 300 msec after the machine moves in Fixing Assembly failure state.
Then, drive systems (Main Motor system, Laser/Scanner system, high voltage system, and
fixing system) are stopped immediately and the machine moves in failure state.
If the Main Motor is not in driving state, drive systems are stopped immediately and the
machine moves in failure state.
2 Technical Overview > Fixing System > Other Functions > Throughput Down Control

Other Functions

■ Throughput Down Control
This machine performs the throughput down control that extends the paper interval and lower
the printing speed to prevent the edge of the fixing heater from overheating at continuous
printing of small paper (the paper with narrow width) and to prevent the fixing heater unit from
overheating at high-volume continuous printing.
An extended paper interval lowers the fixing heater temperature between the papers,
preventing the edge of the roller of fixing assembly and the delivery unit from overheating.
This control has the following 6 modes and the operation sequence differs depending on each
modes.
Small-sized or
Paper Type Large-sized
Narrow
Length: 271 mm or Length: less than
more 271 mm
Width: 190 mm or (Width: less than
more 190 mm)
Plain Paper 25 (Full speed)
1
-> 12 (Half speed) *
Plain Paper L 25 (Full speed)
-> 12 (Half speed) * 1
Heavy Paper
-
Rough Paper
-
1
Rough Paper
-
2
Label Paper -
Transparency -
Postcard (4)
Envelope -
*1 : When the number of fed paper reaches 270 after starting from Cold state, the speed
changes from full speed to half speed, and the throughput changes from 25ppm to 12ppm.
The number of fed paper at which the throughput changes from full speed to half speed
may vary according to temperature control of the Fixing Assembly.
*2 : Measures against wrinkle and curl.
Paper Size
Long and Narrow
Length: less Length: 313 Length:
than 313 mm mm or more 270 +/- 15
Width: less Width: less
than 190 mm than 190 mm
3 ppm 1 ppm
(2)
2
(half speed) (half speed) *
3 ppm 1 ppm
(2)
(half speed) (half speed) * 2
3 ppm 1 ppm
(1)
2
(half speed) (half speed) *
3 ppm 1 ppm
(1)
(half speed) (half speed) * 2
3 ppm 1 ppm
(1)
2
(half speed) (half speed) *
- - -
- - -
(4) - -
(1) - -
2-25
16K
mm
(5)
(5)
(6)
(6)
(6)
-
-
-
-
T-2-9
2-25