Brother International MFC-P2000 Service Manual - Page 41

2.3 Scanner Mechanism Document ADF parts Document front sensor actuator Document rear sensor actuator Document feed roller Document pressure bar Separation roller Document eject roller Pressure roller CIS unit Pinch roller Fig. 2-31 2.3.1 Document Transfer (Feed and Eject) This mechanism consists of the document stacker, automatic document feeder (ADF), document eject roller ASSY and two document sensors (document front sensor, document rear sensor). If documents are set face down on the document stacker to start the scanning operation, the document front sensor detects the document, then the scanner motor rotates so that the ADF (which consists of the separation roller and ADF parts) feeds those documents into the equipment, starting from the bottom sheet to the top, page by page. Each document is advanced by the document feed roller ASSY to the scanner, and it is fed out of the equipment with the document eject roller ASSY. The document rear sensor detects that the document is fed out without any paper jam. 2.3.2 Scanner The scanner uses a contact image sensor (CIS) unit which consists of an LED array to illuminate the document, a self-focus lens array to collect the reflected light, a CIS to carry out photoelectric conversion to output picture element data and a cover glass on which the document advances. When the document passes between the document pressure bar and the cover glass, it is scanned. II-22