Ink System Mechanism; Capping Mechanism - Epson Stylus PHOTO 820 Service Manual

EPSON Stylus PHOTO 810/820

2.1.5 Ink System Mechanism

The Ink system mechanism consists of Pump mechanism with Carriage lock
mechanism and Capping mechanism with Wiper mechanism. Following table lists
the function for each mechanism.
Table 2-4. Function for each mechanism
Mechanism
This is to cover the surface of the Printhead with the cap in

Capping mechanism *

order to prevent the nozzle from increasing viscosity.
This is to remove the foreign material and unnecessary ink on
Wiper mechanism
the nozzle plate of the Printhead.
This is to eject the ink from the ink cartridge, the ink cavity and
Pump mechanism
the cap to the Waste drain ink pad.
This is to lock the CR unit with the Change lever while the CR
Carriage lock mechanism
unit is at the home position.
* Like the previous printers (Stylus COLOR 480/580), this printer adopts the
valveless cap system. The air valve system used for the previous printer
(Stylus COLOR 740) have two functions by the CR position in the capping
condition as follows.
1) Valve closing condition (CL position)
By closing the air valve, the ink is forcibly absorbed from the ink cartridge or
the ink cavity by the Pump unit and is ejected to the Waste drain ink pad while
the CR unit is in the CL position.
2) Valve opening condition (Ink absorption position)
By opening the Air valve, the negative pressure is decreased and only the ink
inside the Cap is ejected while the CR unit is in the further right side than the
CL position. (the ink is not absorbed from the ink cartridge or the ink cavity.)
The following shows you the CR unit position for each condition easily.
Printing area CR home position
But, on the valveless cap system, the above 2) operation is done outside the
capping position. The CR unit moves outside the CR home position and the pump
absorbs the ink inside the Cap.
Operating Principles
Function
CL position
Ink absorption position
(valve closing condition)
(valve opening condition)
2.1.5.1 Capping Mechanism
The Capping mechanism covers the Printhead with the Cap to prevent the nozzle from
increasing viscosity when the printer is in stand-by state or when the printer is off.
Unlike the previous printers (Stylus COLOR 480/580), the Cap unit is newly designed
for this printer as follows.
1. Non porous pad in Cap
Due to this, the cap is newly designed as follows.
Figure 2-11. Cap mechanism
The Cap unit used for the previous printers (Stylus COLOR 480/580) has the porous
pad to keep the moisture in the Cap
*2
sequence . The following points are modified to get the same effects on new Cap unit
without the porous pad.
*1 : The diameter of the ink eject hole is smaller than that of Stylus COLOR 480
/580.
*2 : The cap is modified so that the ink flows with air bubbles to the ink eject hole
in the ink absorption sequence more easily.
Overview
Ink eject hole
For Stylus C60
Ink eject hole
Porous pad
For Stylus COLOR 480/580
*1
and prevent that the air bubbles occur in CL
Revision A
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