Flatbed document size detection Figure 51. Flatbed document size detection Sensor names Flatbed document detection sensor: SCNSIZE1S (only detects the document on the glass) Flatbed document size detection sensor (1): SCNSIZE2S size sensor Flatbed document size detection sensor (2): SCNSIZE3S size sensor Flatbed document size detection sensor (3): SCNSIZE4S size sensor The sensors send signals to the SCB. The signals are transferred through the intermediate PCB to the CPB. The CPB calculates the size of the document based on the signals from the sensors. The flatbed document sensors are located in the same positions on the 110 vdc and 220 vdc HP LaserJet 9000mfp.
To determine sizes of larger documents, the HP LaserJet 9000mfp searches the Cold Reset Paper Size. For example, it will detect ledger if it is set to letter, and it will detect A3 if it is set to A4. 84 Chapter 5 Theory of operation C8523-90921