When the original set sensor detects that an original has just been placed, the pick-up roller drops (the pick-up roller HP sensor turns off), then the ADF bottom plate lift motor [A] turns ON, and the lift lever [B] lifts the bottom plate. The bottom plate HP sensor [C] (on the pick-up roller holder) detects when the bottom plate is at the correct position for original feed, and the ADF bottom plate lift motor [A] stops. When the bottom plate HP sensor [C] turns off during original feed, the ADF bottom plate lift motor [A] turns on until the bottom plate HP sensor [C] turns on again. This mechanism ensures that the top of the original is always at the correct height for feed, even when the maximum number of sheets [220 sheets (80 g/m2, 20 lbs)] is stacked in the original tray.
At the end of a job, the ADF bottom plate lift motor moves the bottom plate down until the bottom plate HP sensor detects it.
