Epson Stylus PHOTO 950 Service Manual page 42

EPSON Stylus PHOTO 950
Following figure shows the overview of the pump mechanism operation.
CW
Tube
Roller
Pressure on tube
Figure 2-24. Pump mechanism
1. When the pump unit is operating in the clockwise (CW) direction by means of the
pump motor, the rollers apply pressure to the tube, so that the ink from the cap unit
is sent in the waste ink pad direction.
2. When the pump unit is operating in the counterclockwise (CCW) direction, the
rollers release the tube so that no pressure is applied to the tube, and the ink is not
recovered.
OPERATING PRINCIPLES
2.2.4.2 Capping Mechanism
The capping mechanism covers the printheads with the cap holder to prevent the nozzle
CCW
from increasing viscosity when the printer is in stand- by mode or when the printer is
off. This product has valveless cap system. Air valve function used for the previous
models pumps and ejects ink only inside the cap by absorbing ink with the valve open.
By opening the Air valve, the negative pressure is decreased and only the ink inside the
cap is ejected. (the ink is not absorbed from Ink cartridge or head cavity.)
But, valveless cap system, this operation is done out side of the capping area. The CR
moves to left side of the Cap assembly and the pump absorbs the ink inside the cap.
1.
2.
Pressure released
3.
Printer Mechanism
Due to rationalization, there is no sponge inside the cap.
Previously the sponge was provided to prevent frothing during cleaning.
Now, since the shape of new cap prevents frothing by its- self, it is not necessary
to attach a sponge on the cap.
<Front side>
Carriage unit
Slider cap
Cap
Printhead
Figure 2-25. Cap Mechanism
Revision A
Slide up
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