Ricoh G133 Service Manual page 887

Paper Height and End Detection
2.6.2 PAPER END AND BOTTOM PLATE
The paper stack raises the paper end feeler [A] and the paper end sensor [B] deactivates
if there is some paper in the paper tray.
When the paper tray runs out of paper, the paper end feeler [A] drops into the cutout in the
tray bottom plate. At this time the paper end sensor [B] activates
SM 15 B800