Staple Detection - Canon imageFORMULA DR-G2140 Service Manual

5. Staple Detection

In this unit, a staple detection mechanism
is used which detects the jumping up of sta-
pled documents.
This mechanism is designed not to detect
the staple itself, but to detect the jumping up
of the stapled documents when the stapled
documents are picked up, and to stop the
feeding. As such, it prevents stapled docu-
ments from being torn apart.
A stapled document jumping up due to
the pickup roller, and the configuration of the
staple detection are shown below.
Figure 2-305
Figure 2-306
The staple detection mechanism consists
of staple LEDs and a staple photo-sensor, ar-
ranged on both sides of the document pickup
inlet. If there is no staple in the documents,
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the light emitted from the staple LEDs is di-
rectly received by the photo-sensor. If the
stapled documents jump up, the light gets
blocked and the documents are found to be
stapled, resulting in stopping the feeding.
The 4 staple LEDs are mounted on the
staple LED PCB. The staple photo-sensor
has 4 sensors that correspond to 4 LEDs on
the staple LED, and is directly mounted on the
sub-drive PCB.
Note: Because the documents do not jump up
under the following conditions, the sta-
ple detection sensor will not work:



Document curl must be 3 mm or less in
height and the documents cannot be
creased.
It is possible to change the level of de-
tection accuracy with the user mode.
CANON DR-G2140/G2110/G2090 FIRST EDITION
CHAPTER 2 FUNCTION & OPERATION
When there are two or more stapled
places.
When the staple is not positioned at a
corner.
When the documents are smaller
than A5.
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