Brother MFC260C Service Manual page 59

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
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 are:
- 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) are:
- 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 an 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 caps the head nozzles
to prevent them from drying up, purges for removing air bubbles from the head/maintenance unit,
and wipes off any ink remaining on the head nozzle surface.
The carriage drive mechanism moves the head/carriage unit with a DC motor (carriage motor)
along the recording paper. It has a CR encoder sensor that 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 a single DC
motor (paper feed motor).
The major components are:
- Paper tray: Recording paper is stored in this tray.
- Paper pull-in rollers and their holder: These pull in paper into the machine.
- Bank ASSY: This separates paper, sheet by sheet to feed it into the printer section.
- Jam clear cover: Removing this cover allows the user to access paper jammed. It also guides
paper pulled in from the paper tray into the printer section.
- Paper feed roller: This roller performs paper registration and feeds paper to the printer section
precisely.
- Paper ejection roller: This roller ejects paper and keeps paper tension tight.
- Paper feed motor: This motor is the drive source for rollers.
- Clutch gear: This gear switches the transmission route of the paper feed motor rotation torque
between three gears--SF changeover gear, HS changeover gear, and purge gear, enabling the
torque to be applied to the various mechanisms.
- PF rotary encoder: This generates a signal indicating the rotation speed of the PF roller gear. The
signal is sent to the controller and used for controlling the paper feed position and speed.
(Section 3.2.2.1)
(Section 3.2.2.2)
(Section 3.2.2.3)
3-8
(Section 3.2.2.4)
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