Brother 1920CN - Color Inkjet - Fax, Service Manual

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III
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This scanner mechanism supports a dual scanning system.
(1) If you set documents with their faces up on the document chute and start the scanning
operation, the ADF motor rotates so that the document feed roller ASSY feeds 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 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 scanner unit, put a sheet of document (or put a bound book opened) on the
glass of the scanner top cover, close the scanner unit, and start the scanning operation, then
the CCD drive mechanism will be driven. That is, the CCD motor rotates and its rotation will
be transmitted via the gear train to the CCD drive belt.
The CCD unit, which is supported and guided by the CCD rail, is secured to the CCD drive
belt. 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.