43967002TH Rev.1 47 /Oki Data CONFIDENTIAL 2. Theory of Operation2.3.1.4 Document detectionDocument present/absent detectionDocument present/absent detection on the document tray is performed by the document setsensor (PI11). When a document is placed on the document tray, the detection lever movestogether with the light-shielding plate so that the photo interrupter that has been shuttingdown the light, passes the light. Thus, the document set sensor (PI11) issues the documentdetection signal (EMPTY) telling that a document is set, to the connected equipment via theADF driver circuit PCB.Detection of final documentThe final document detection sensor (PI3) and the document set sensor (PI11) detect if thedocument that has started scanning is the final document or not. If the final document isfed, and the rear end of the final document has passed the final document detection lever ofthe document tray, the detection lever moves together with the light-shielding plate so thatthe photo interrupter that has been shutting down the light, passes the light. Thus, the finaldocument detection sensor (PI3) issues the final document detection signal (LAST). Whenthe final document has passed the document sensor (PI11), the no document signal (EMPTY)is issued telling that the document under feeding is the final document, to the connectedequipment via the ADF driver circuit PCB.ADF driver circuit PCBDocumentDetection leverPI11EMPTY ADF driver circuit PCBDocumentDetectionleverLASTEMPTYPI11PI3
