Canon iR3570 Series, Service Manual

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Chapter 9
9-3
2. uses thermistor reading = T1 (deg C) occurring 400 msec after the start of 65% power supply.
3)uses thermistor reading = T2 (deg C) occurring 500 msec after the start of 65% power supply.
4. computes the difference between T2 and T1, refers to a power supply ratio table to compute a power supply ratio X (%), and uses the result.
5. uses the thermistor reading = T3 (deg C) occurring 200 msec after the start of X (%) power supply.
6. uses the thermistor reading = T4 (deg C) occurring 300 msec after the start of the X (%) power supply.
7. computes the difference between T4 and T2, refers to a power supply ratio table, computes a power supply ratio Y (%), and uses the result.
8. repeats step 5 through 7 until the start-up control target temperature is reached.
9. when the start-up control temperature is reached, shifts to copying temperature control.
F-9-3
A: start-up control
B: copying temperature control
C: 65 (%) power supply
D: X (%) power supply
E: Y (%) power supply
9.3.2.4 Copying Temperature Control
0006-6584
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
The machine uses this mechanism to control the temperature of the fixing heater to an optimum level while a recording medium is passing through the fixing film
assembly; specifically,
1.the machine varies the power ratio in relation to the difference between the temperature detected by the thermistor and the target control temperature.
2.if the temperature detected by the thermistor is higher than the target control temperature for a specific period of time (0.6 sec), the machine will decrease the
power ratio; if lower, it will increase the power rate.
9.3.2.5 Changing the Fixing Film Control Temperature
0007-5452
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
When a fixing failure occurs or creases appear, the fixing film control temperature can be changed in the service mode as shown below.
COPIER> OPTION> BODY> TEMP-CON (to switch the fixing temperature mode for heavy paper)
COPIER> OPTION> BODY> TEMPCON2 (to switch the fixing temperature mode)
0: OFF (default), 1: -10 deg C, 2: -6 deg C, 3: -3 deg C, 4: +3 deg C, 5: +6 deg C, 6: +10 deg C, 7: 15 deg C
9.3.2.6 Temperature Control in Response to Automatic Double-Sided Copy
0007-5453
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
The second side of an automatic double-sided copy requires lower control temperature in comparison with the first side. For this reason, the control temperature is
lowered for the second side of an automatic double-sided copy so as to prevent adverse effects such as rises in temperature.
9.3.2.7 Temperature Control in Response to Change of Paper Size
0007-5454
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
The machine has a function to switch the paper size during continuous mode such as in rotation sort. When small-size paper is qenerated continuously, the temper-
ature of the end portion of the fixing film rises. Immediately thereafter, if large-size paper is passed, high-temperature offset might occur at the end portion where
the temperature is likely to have risen. To prevent high-temperature offset, the control temperature is changed when the paper size chanqes.
9.3.3 Cleaning
9.3.3.1 Fixing Film Cleaning
0007-5300
iR2270 / iR2870 / iR3570 / iR4570 / / iR2270N / / iR2870N / / iR3570N / / iR4570N / iR2230 / / / iR3530 /
Purpose
In the event of a jam or when wear on the fixing film advances, the fixing film is rotated idly for collection of toner from both the film and the pressure roller to the
cleaning roller.
The timing of control is as follows:
1. If the reading of the cleaning counter has exceeded the interval (expressed in terms of the number of sheets), the machine starts cleaning with the fixing motor
rotating at 1/4 speed. The length, timing, and intervals of cleaning may be set in service mode: COPIER>OPTION>BODY>FIX-CLN. Further, the cleaning
counter reading is reset at the end of cleaning.
T-9-2 COPIER > OPTION > BODY > FIX-CLN
0 (default) 1 2 3
Cleaning control temperature 0 225 225 225
Cleaning control time 0 60 60 60
Cleaning intervals 0 500 200 100
180
85
400ms
500ms
200ms
300ms
A
B
C D E