Near End/End Detection - Ricoh B089 Service Manual

NEAR END/END DETECTION

2.4 NEAR END/END DETECTION
This tray can hold two stacks of paper, so the machine needs to monitor the status
of both these stacks. There are seven sensors to do this.
In the right tray (paper feed side), three height sensors measure the height of the
stack, and an end sensor detects when all the paper is used up. As the amount of
paper remaining in the tray decreases, the base plate rises and the actuator
activates the paper height sensors. When paper runs out in the right tray, the stack
in the left tray is moved across to the right tray.
There are also two height sensors ([F] in the diagram on the previous page) and an
end sensor in the left tray (paper storage side) ([G] in the diagram on the previous
page). When there is no paper in both trays, paper end is detected.
The machine determines the amount of remaining paper based on the sensor
outputs, as shown in the following table.
Paper end sensor 1: ❍ = Low (no paper), # = High (paper present)
Other sensors: ❍ = Low (paper present), # = High (no paper)
Paper Height Sensor 1
Paper Height Sensor 2
Paper Height Sensor 3
Paper End Sensor 1
Paper Height Sensor 4
Paper Height Sensor 5
Paper End Sensor 2
Paper Height Sensor 1
Paper Height Sensor 2
Paper Height Sensor 3
Paper End Sensor 1
Paper Height Sensor 4
Paper Height Sensor 5
Paper End Sensor 2
The following diagram is the sensor layout, as viewed from the front.
A862/B391
100% 75%
❍ ❍ ❍
❍ ❍ ❍
❍ ❍ #
# # #
❍ # ❍
❍ ❍ ❍
❍ ❍ ❍
25%
# ❍ ❍
#
– –
– – –
# # #
❍ # #
# ❍ #
❍ ❍ ❍
Paper Storage Side
Paper Height
Sensor 5
Paper Height
Sensor 4
Paper End
Sensor 2
9-8
Amount of paper
❍ ❍ ❍
❍ ❍ #
❍ ❍
# # #
# # ❍
# # ❍
❍ # ❍
Amount of paper
❍ ❍ #
❍ #
#
–
# # #
# # #
# # #
# # ❍
Paper Feed Side
Paper End
Sensor 1
Paper Height
Sensor 1
Paper Height
Sensor 2
Paper Height
Sensor 3
B391D112.WMF
50%
# ❍
❍
–
#
– –
# #
❍ #
❍ ❍
❍ ❍
Near-end End
#
–
– – –
– – –
# ❍
# #
# #
# #
❍
#
–
#
#
❍
❍
SM