Canon ImageCLASS MF4690, Service Manual

Page: 90 / 182

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.
Memo:
The following are the throughput at down sequence.
8.3 Protection Function
8.3.1 Protection Function
0016-1860
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.
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
Fixing mode Number of fixed sheets Throughput
Plain paper - 20 ppm
Thick paper - 16 ppm
Thick paper H - 8 ppm
Envelope 5 or less
15 or less
40 or less
41 or more 9 ppm
7 ppm
5 ppm
4 ppm
Postcard/double postal card 5 or less
15 or less
40 or less
41 or more 5 ppm
4 ppm
3 ppm
3 ppm
E
267.4 mm
PS802 PS804
F