Duplo DP-S Series, Service Manual

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65
c
Paper Feed Section
chap.2
(3) Elevator Top Limit Sensor
Description
Circuits
Operation
The elevator top limit sensor senses decrease of the paper pile, and the top limit position of the feed tray.
It does so by detecting the up/down motion of the paper feed shaft.
Sensing of feed tray top limit
2
When the feed tray rises, the paper in it presses the paper feed roller upward, making the paper feed shaft
lever (photointerrupter) rotate upwards about its fulcrum, until it no longer obstructs the sensor’s light
beam. Restoration of the sensor’s light beam signals that the paper tray has reached the top limit, and
triggers stopping of the feed tray’s rise.
Sensing of paper decrease
2
As printing progresses and the paper decreases, the paper feed roller gradually descends, until it obstructs
the sensor’s light beam. When this happens, the feed tray is raised until the light beam is restored.
If the elevator top limit sensor does not detect "photointerrupting
\
photopassing " within 30 seconds of sending
of the RAISE FEED TRAY command, the error " E002 " (elevator lock) is displayed.
R8S02E17e
Paper feed roller
Elevator top limit sensor
Paper
Paper feed shaft lever
Paper
R8S02051