Canon BJ-W9000, Service Manual

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Pressure roller sensor
The pressure roller photo interrupter-based sensor, detects the open/closed
(release/pressing) state of pressure roller unit.
When the pressure roller is closed, the sensor light is blocked by the rotary flag
interlocked with the pressure roller cam shaft, and the printer recognizes that the
pressure roller unit is in the pressing mode.
Manual set sensor
The manual set photo reflection-based sensor, detects whether cut paper exists or
not in the manual paper feed slot.
The two skew sensors are installed in parallel near the location where the right end
of the paper traverses. These sensors detect the paper availability 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 set in place. If both sensors detect or do
not detect the paper, the printer determines that the paper has not been set in place.
The printer determines that the paper feeding operation is possible, only if the
manual set sensor has detected that the paper is set, and the manual paper end
sensor has detected that the paper is in place.
Part 4: Technical Reference BJ-W9000
4-80
Sensor
Rotary flag
The pressure roller unit is in
the open (released) state. The pressure roller unit is in
the closed (pressing) state.
Figure 4-57 Pressure Roller Sensor Flag
Print paper
Photo reflection sensors
Cut sheet is set
correctly.
Print paper
Cut sheet is not
set correctly.
Print paper
Cut sheet is not
set correctly.
Figure 4-58 Manual Set (Skew) Sensors (Conceptual Representation)