Brother MFC5100C Service Manual page 25

This scanner mechanism supports a dual scanning system.
(1) If you set documents on the document guide base with their faces up and start the scanning
operation, then the ADF motor rotates to pull in those documents into the ADF unit, starting
from the top sheet to the bottom, page by page. Each document curves downwards and turns to
the right with the document feed roller so as to advance above the CCD unit, and then it is fed
out to the document tray with the document ejection roller ASSY.
This way, documents move above the CCD unit being kept in a stationary position.
(2) If you open the ADF & document tray ASSY, put a sheet of document (or put a bound book
opened) on the glass of the scanner top cover, close the ADF & document tray ASSY, and
start the scanning operation, then the CCD drive mechanism will be driven.
The CCD motor built in the CCD unit rotates. As illustrated below, the CCD drive gear and
idle pulley carry the CCD drive belt on the underside of the CCD unit, so clockwise and
counterclockwise rotations of the CCD motor move the CCD unit to the right and left,
respectively.
In this scanning system, the CCD unit moves horizontally beneath a document being kept in
stationary position.
The CCD unit contains a charge coupled device (CCD) image sensor. The cold-cathode
fluorescent lamp illuminates a document and the reflected light of the scanned image data is
transmitted via the mirrors into the lens which reduces the scanned data so as to form the image on
the CCD.
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