Scanning Mechanism; Printing Mechanism - Brother FAX-545 Service Manual

3.2.1 Scanning Mechanism

The scanning mechanism consists of the automatic document feeder (ADF), document separation
roller, CIS unit (scanner), document ejection roller, and document sensors. (For details about the
sensors, refer to
Document feeding and ejecting mechanism
Placing documents face down in the ADF and starting the scanning operation activate the drive
motor so that the ADF (consisting of the document separation roller and ADF parts) feeds the
documents into the machine, starting from the bottom (first page), page by page. Each document
advances with the document separation roller to the scanner, and then it is fed out of the machine
with the document ejection roller.
Document scanning mechanism
The scanner uses a contact image sensor (CIS) unit which consists of the document illumination
LED array, the self-focus lens array gathering the light reflected from the scanned image, the CIS
PCB converting the light input to picture element data output, and CIS glass on which a document
advances. When the document passes between the white-level reference film (attached to the top
cover) and the CIS glass, it is scanned.

3.2.2 Printing Mechanism

The printing mechanism consists of the paper tray, sheet feeder (SF), paper separation roller, platen,
thermal recording head, paper ejection roller, and sensors. (For details about the sensors, refer to
Section 3.2.4.)
Paper feeding and registration mechanism
Place the recording paper face down in the paper tray. When receiving operation starts, the SF
(paper separation roller and SF parts) feeds paper into the machine, a sheet at a time. After the
leading edge of paper passes through the registration sensor actuator, the paper is further fed for the
specified time length. Accordingly, the leading edge will reach the platen where the paper skew
will be eliminated.
Printing and paper ejecting mechanism
The platen feeds the paper to the printing position where the thermal recording head prints while
the thermal ink ribbon advances. Then the paper is fed out of the machine with the paper ejection
roller.
Section 3.2.4.)
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