Paper Height And End Detection - Ricoh D129 Service Manual

Paper Feed

2.2.3 PAPER HEIGHT AND END DETECTION

Paper Height
The amount of the paper in the tray is detected by combination of high (1)/low (0) outputs from
three sensors (paper height sensor 1 [A], 2 [B], 3 [D] and sub paper height sensor [C]).
Amount of paper
100%
70%
30%
10%
End
0: No interruption (low), 1: Interruption (high), -: No checking
PH S: Paper Height Sensor
Paper End
The paper end sensor [E] monitors the light reflected by each sheet on top of the
stack.
When the last sheet feeds, the cutout [F] is exposed, and the paper end sensor receives no
reflected light from below because there is no paper. As a result, this signals paper end.
D631
PH S-1 PH S-2
0 0
0 0
0 0
0 1
1 -
- -
PH S-3 Sub PH S
0 0
1 -
0 1
- -
- -
- -
18
Indicator on the
operation panel
Four lines
Three lines
Two lines
One line
No line
SM