Davin J012, Service Manual

Page: 295 / 365

No. Component Function
sensor detects the position of the tip every time it passes through the
gap of the sensor.
SN
Maintenance HP
Sensor
An interrupt sensor mounted in the maintenance unit that controls
the operation of the maintenance motor in the print head cleaning
cycle. At the beginning of the cleaning cycle, a feeler leaves the
gap of this sensor and switches the motor on. At the end of the
cleaning cycle the feeler rotates into the gap, switches the sensor
off. This switches the motor off and the caps and wiper remain down
at the home position.
SN PFU Paper Sensor 1
Located below the bottom plate of the paper cassette in Tray 2 (the
optional paper feed unit). A spring loaded bottom plate keeps the
top of the stack against the pick-up roller for paper feed. A free-
swinging feeler rests on top of the stack. After the last sheet feeds,
one end of the feeler falls down through a cutout in the bottom plate.
An actuator on the other end of the feeler swings up and out of the
gap in the paper end sensor. This signals paper end.
SN
Paper End Sensor –
Tray 1
Located below the transport belt. A spring loaded bottom plate
keeps the top of the stack against the pick-up roller for paper feed.
A free-swinging feeler rests on top of the stack. After the last sheet
feeds, one end of the feeler falls down through a cutout in the bottom
plate. An actuator on the other end of the feeler swings up and out
of the gap in the paper end sensor. This signals paper end.
SN
Temperature/
Humidity Sensor
Located inside the printer near the transport belt. The temperature/
humidity sensor constantly measures temperature and humidity
around the transport belt. The printer uses these readings to adjust
the amount of charge applied to the areas of the belt that contact
the leading edge, center, and trailing edge of the paper. For more,
please refer to Section "4. Troubleshooting".
SN Trailing Edge Sensor
Mounted at the right, rear corner of the printer (viewed from the
back). The feeler of this interrupt sensor is mounted in the center of
the paper path and connected to a long shaft. The end of the shaft
has an actuator that moves in and out of the sensor gap. The feeler
is pushed down by every sheet of paper and the actuator leaves
the gap, then the feeler pops up again after the trailing edge passes
and the actuator enters the gap and switches the sensor off. The
length of time the sensor remains on is used to measure the length
of the paper for print timing control. The sensor issues a paper end
6. Detailed Section Descriptions
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