6.5.2 ORIGINAL SIZE DETECTION
The machine uses five sensors on three APS boards to detect the size of the
original on the exposure glass.
[A]: APS1. (W1 and W2) detects original width
[B]: APS2. (L1 and L2) detects original length
[C]: APS3. (L3) detects original length
[D]: ARDF position sensor. Detects whether the ARDF is open or closed.
[E]: APS start sensor. Triggers automatic paper size detection.