Down Sequence Control - Canon imageRUNNER 1750 Series Service Manual

2
Technical Explanation > Fixing System > Controls > Down Sequence Control

■ Down Sequence Control

● Down sequence when feeding small-size paper
Purpose:
To prevent fixing offset and deterioration of the Fixing Film by controlling temperature
increase at a non paper feed area at continuous printing of small-size paper (paper
that has smaller than A4R of width-direction length)
Starting conditions:
Down sequence is performed in a stepwise manner. This is a control to reduce
throughput on a step-by-step basis as the detected temperature of the Sub Thermistor
reaches the specified temperature or higher as shown in the table below for
consecutive 400msec during printing.
Stages Normal
A temperature to go
235 degrees C 245 degrees C 255 degrees C 260 degrees C
for the next stage
Operation:
Increasing paper interval (to make longer temperature control at a temperature lower
than that of normal print) to reduce fixing temperature in 4 stages at most.
Fixing mode Stages LGL
Plain paper (64 to 90g/m2) Normal 43/40/30 50/40/30
Heavy paper 1 (91to 105g/
1 25
m2)
2 20
Special Mode N (Medium)
3 15
Heavy paper 2 (106 to Normal 14
128g/m2)
1 10
2 8
3 6
Bond paper Normal 13
1 10
2 8
3 6
Transparency Normal ---
1 ---
2 ---
3 ---
Envelope Normal ---
1 ---
2 ---
3 ---
2 Technical Explanation > Fixing System > Controls > Down Sequence Control
The 1st stage The 2nd stage The 3rd stage
T-2-36
A4R A5R/B5R Custom
Envelope
LTRR EXE-R/STMTR size
25 23
25 20 20
20 18 18
15 15 15
21 17 17
17 14 10
14 10 8
6 6 6
22 17 17
15 14 10
14 10 8
6 6 6
17 --- ---
14 --- ---
10 --- ---
6 --- ---
--- --- ---
--- --- ---
--- --- ---
--- --- ---
Termination condition:
When the machine detects 175 degrees C or lower for consecutive 400msec after
reaching the 3rd stage, the machine is recovered to move to the 1st stage.
245deg C,400msec
255deg C,400msec
260deg C,400msec
Related Service Mode
Temperature settings to start down sequence
PRINT > SW > 64
<Setting value>
0: +20 deg C
1: +10 deg C
2: 0 deg C [default: 2]
---
3: -10 deg C
---
4: -20 deg C
---
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---
---
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12
10
8
6
T-2-37
Normal
1st Step
Return
2st Step
210deg C,400msec
3st Step
F-2-81
2-56
2-56