Canon iR7086, Service Manual

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Chapter 8
8-34
8.10 Detecting the Double-Feed
8.10.1 Detecting Double Feeding
0011-7360
iR7105 / iR7095 / iR7086
The machine uses the ultra-sonic wave sensor (for transmission, reception) located downstream of the registration roller to check for double feeding, and stops the
ongoing printing operation upon detection. Ultrasonic waves are often characterized as follows, and
may be used for the detection of double feeding regardless of the type of medium used (plain
paper, heavy paper, colored paper, transparency, etc.).
- propagation is subject to significant attenuation between different densities (e.g., air and paper).
- propagation is free of attenuation in regard to the color or thickness of the object being checked.
F-8-54
[1] Double feeding sensor (transmission)
[2] Double feeding sensor (reception)
[3] Registration roller
MEMO:
Some models (for sale in specific countries) may not come standard with this detection mechanism. Its use requires a Double Feeding Detection Kit (optional).
<Timing of Detection>
- interval extending several 100s of msec after the registration roller clutch goes on
<Sequence of Operation>
1) The mechanism is started.
2) The machine identifies double feeding.
3) The machine turns off the fixing motor as soon as the paper reaches the fixing nip area.
- The paper stops at the fixing nip area, with paper found downstream thereof discharged outside the machine.
- The control panel screen indicates the presence of a jam (0C00).
Delivery speed switching clutch (CL21) Turns on in reversal delivery mode to speed up the rotation of the external delivery roller.
Reversing flapper solenoid (SL11) Turns off in reversal delivery mode to lead paper to the reversing assembly.
Reversal motor (M11) Moves paper to the reversing assembly.
Parts (notation) Description
[1]
[2] [3]