Ricoh DD 5450, Field Service Manual, Page: 137 / 403

３
135
Chapter 3 Paper Feed Section
CN9-14
-15
-16
(3) Elevator (Paper Feed Tray) Top Limit Sensor
Detection of the elevator (paper feed tray) upper limit
● When the paper feed tray rises, the paper in it presses the paper feed roller upward, making the
paper feed shaft lever (photointerrupter) rotate upward around its fulcrum, until it no longer
obstructs the sensor's light beam. When the upper limit is detected, the rise of the paper feed tray
is stopped.
Detection of paper decrease
● 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 after "RAISE FEED TRAY" command is given, the error "E002" (Elevator lock)
is displayed.
Elevator (paper feed tray)
top limit sensor
● Detection of paper feed tray upper limit ● Detection of paper decrease
Description
The elevator (paper feed tray) top limit sensor detects decrease of the paper and the upper limit
position of the paper feed tray by detecting the up/down motion of the paper feed shaft.
Circuit
Blue
Orange
Red
Photopassing: 0V
Photointerrupting: 5V
Main PCB unit
Paper
Paper
Elevator top
limit sensor
Paper feed
shaft lever
Paper feed roller
3