Detecting The Double-Feed; Detecting Double Feeding - Canon imageRUNNER 7095 Service Manual

Chapter 8

8.10 Detecting the Double-Feed

8.10.1 Detecting Double Feeding

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The machine uses the ultra-sonic wave sensor (for transmission, reception) located downstream of the reg-
istration roller to check for double feeding, and stops the ongoing printing operation upon detection. Ul-
trasonic 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.
[3] [2]
[1]
F-8-53
[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 ma-
chine.
- The control panel screen indicates the presence of a jam (0C00).
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