Printing Mechanism - Brother DCP6690CW Service Manual

3.2.2 Printing Mechanism

The printing mechanism consists of the following.
Ink supply and ink jet mechanism
Head maintenance mechanism
Carriage drive mechanism
Paper pulling-in, registration, feeding and ejecting mechanisms
Duplex print mechanism
The ink supply mechanism supplies ink to the head/carriage unit, in which the ink jet
mechanism sprays ink droplets from the head nozzles onto paper.
The major components of the ink supply mechanism (shown on
- Ink refill assembly: This secures the ink cartridges and connects them to the corresponding
ink supply tubes.
- Ink supply tubes: These supply the head/carriage unit with ink fed from the ink cartridges via
the ink refill assembly.
The major components of the ink jet mechanism (head/carriage unit shown on
- Front end: This is an ink-jet head consisting of piezoelectric plate (PZT), metal plates, nozzle
plate, and head driver.It jets out ink to produce images on paper.
- Back end: This consists of damper assemblies and air vent unit. Each damper assembly
dampens the ink pressure fluctuations in the corresponding ink supply tube and collects air
bubbles that result from pressure changes on the ink.
To keep the optimum head performance, the head maintenance mechanism (shown on
35) uses the rotational torque of the ASF motor
them from drying up. It also uses the rotational torque of the paper feed motor to purge for
removing air bubbles from the head/carriage unit and wipe off any ink remaining on the head
nozzle surface.
The carriage drive mechanism (shown on
carriage motor (DC motor) along the recording paper. The CR encoder sensor mounted on the
head/carriage unit scans the CR encoder strip and monitors the current head position relative to
the home position and the current travel speed.
The paper pulling-in, registration, feeding and ejecting mechanisms are driven by the ASF
*1
motor and paper feed motor (both are DC motors).
The major components are:
- Paper trays #1
- Paper pull-in rollers and LT paper pull-in rollers (shown on
- Bank ASSY and LT bank ASSY (shown on
(Section
(Section
(Section
(Section 3.2.2.5) (for duplex print models)
*2
and #2: This machine supports two paper trays, allowing different
sizes or types of paper to be loaded.
These pull in paper into the machine. The paper pull-in
rollers are for paper tray #1
rollers for paper tray #2.
These separate paper, sheet by sheet to feed it into the
printing section. The bank ASSY is for paper tray #1
the LT bank ASSY for paper tray #2.
3.2.2.1)
3.2.2.2)
3.2.2.3)
*1
to cap the head nozzles in order to prevent
page 3-37) moves the head/carriage unit with a
pages 6-93 and
ASF motor: Auto Sheet Feeder motor
*1
DX paper tray #1 for duplex print models
*2
3-8
(Section 3.2.2.4)
page 3-11) are:
page
page 3-42):
*2
, and the LT paper pull-in
6-94):
3-13) are:
page 3-
*2
, and
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