MX-LCX5. Service Manual - 01.05.08 - Sharp Copying Equipment Service Manual (repair manual). Page 15

MX-LCX5  DETAILED DESCRIPTIONS  4 – 3

[A] Paper Height Sensor Actuator
[B] 4th Paper Height Sensor 4
[C] 4th Paper Height Sensor 3
[D] 4th Paper Height Sensor 2
[E] 4th Paper Height Sensor 1 (Near End)
Each tray has four paper height sensors. The illustration above
shows the paper height sensors in the 4th tray. This arrangement is
duplicated in the 5th and 6th trays.
The amount of paper remaining in the tray is detected by the three
paper height photo-interrupter sensors on the left rail as the bottom
plate rises. Five states, determined by the position of the actuator
[A] are possible. 
1)

With the actuator [A] below paper height sensor 4 [B], no sen-
sor is actuated and the display indicates 100%.

2)

When the actuator passes paper height sensor 4 [B] , the dis-
play indicates 70% of the paper supply remaining.

3)

When the actuator passes paper height sensor 3 [C], the dis-
play indicates 30% of the paper supply remaining.

4)

When the actuator passes paper height sensor 2 [D], the dis-
play indicates 10% of the paper supply remaining.

NOTE: When the actuator enters the gap of the near end sensor

[E], the machine signals near end. 

Finally, when the last sheet feeds, the paper end sensor signals
that the tray is empty. 

The paper end sensor [A] detects the top sheet of the paper in the
tray by monitoring the reflected light. When the paper tray runs out
of paper, the paper end sensor does not receive the reflected light
due to the cutout [B]. Then, the tray lift motor rotates backwards 2
seconds to drop the tray bottom plate.

[A]

[B]

[C]

[E]

[D]

[A]

[B]