Canon BJ-W9000 Service Manual page 217

BJ-W9000
Skew sensor
The paper skewing photo reflection-based sensors, detect skewing of roll media
paper.
The two skew sensors are installed in parallel near the location where the right end
of the paper traverses. These sensors detect paper skew by receiving the light
reflected from the paper surface.
If only the left sensor detects the paper during the paper feeding operation, the
printer recognizes that the paper has been conveyed without skewing. If both the two
sensors detect or do not detect the paper, the printer determines that the paper has
been fed obliquely.
Paper guide A sensor
The paper guide A photo interrupter-based sensor, detects the open/closed state of
paper guide A.
When paper guide A is opened, the sensor light is blocked by the sensor flag of the
release lever a, indicating that paper guide A is in the open state.
Paper guide C sensor
The paper guide C photo interrupter-based sensor, detects the open/closed state of
paper guide C.
When paper guide C is opened, the sensor light is blocked by the sensor arm of the
paper guide C, indicating that paper guide C is in the open state.
Paper guide D sensor
The paper guide D photo reflection-based sensor, detects the open/closed state of the
paper guide D.
When paper guide D is closed, the sensor receives the light reflected from the paper
guide D, indicating that paper guide D is in the close state.
Photo reflection sensors
Print paper
Test passed.
Figure 4-56 Skew Sensors (Conceptual Representation)
Print paper Print paper
Test failed. Test failed.
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Part 4: Technical Reference