Ink System; Pump, Carriage Lock, Head Cleaner Mechanism - Epson STYLUS Scan 2500 Service Manual

EPSON Stylus Scan 2500

2.2.5 Ink System

Ink system mechanism consists of 1) cap mechanism, 2) pump mechanism, 3)
carriage lock mechanism, 4) waste ink absorber and 5) ink sequence. Out of
these mechanisms, 1) to 4) are physical mechanism and parts which are
mounted on the printer mechanism and 5) the ink sequence is performed
automatically by the firmware. The EPSON Stylus Scan 2500 has no engage/
disengage mechanism, meaning the pump and platen are always at work
when the PF motor operates. The figures below show printhead positions
when the ink system and various ink-pumping sequences are performed.
Eject roller
drive gear
Eject roller
PF (pump)
transmission
motor pinion
gear
gear
Figure 2-13. Ink System Mechanism
Operating Principles
PF roller drive
gear
Carriage lock
lever
Cleaner blade
Pump roller
Cap unit
Printer Mechanism Operation
Printable Area
2976 dots (360-dpi)
A
B
Figure 2-14. Major Ink Sequence Positions on Carriage
2.2.6 Pump, Carriage Lock, Head Cleaner
Mechanism
In the EPSON Stylus Scan 2500, there is no switch or mechanism to switch
between the ink pump and paper feed operations. Therefore, whenever the
paper feed/pump motor rotates, the pump-drive roller inside the pump unit
rotates. However, the rotational direction of the rollers determines whether or
not the pump sucks ink. Also, even if the pump rotates in the ink-absorption
direction, ink is not absorbed if the carriage is in the false-absorption position.
Figure 2-13 shows process of conveying motive power to the pump drive
roller.
The process of conveying the motive power to the paper eject roller is shown
in Figure 2-15. This motive power is conveyed to Gear C through Gear B. The
lever that drives Gear C, the carriage lock, and the head-cleaner mechanism is
shown separately but it is constructed as one unit. Since the engagement of
these parts depends on the tension of the compression spring, if the lever is
burdened, only Gear C and the pump roller rotate and no more motive power
is conveyed to the lever part.
Revision A
C
D E F
A. ASF Pick-up position
B. Flushing position
C. Wiping/rubbing position
D. Flushing position
E. Ink Discharge position
F. Cap cleaning position
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