Self-Closing Valve - Epson Stylus Photo RX700 Service Manual

EPSON Stylus Photo RX700

2.2.8.2 Self-closing Valve

The Valve Assy is equipped with the self-closing valve to prevent ink from flowing
back.
The self-closing valve works as a sub tank to compensate for a temporary shortage of
ink supply to the off carriage type head. When solid printing is performed with a
printhead of an off carriage type, there may be a case where an excessive volume of a
specific ink is consumed temporarily and dot missing can occur.
Use of this valve ensures a uniform print quality.
When ink in the Valve Assy is supplied to the Printhead, the pressure in the Ink Storage
Chamber drops, so that the Valve Lever is tilted by the Pressure Receiving Plate. When
the Valve Lever inclines, the ink passage from the Ink Tube to the Valve Assy opens,
so that ink is supplied to the Ink Storage Chamber.
When the Ink Storage Chamber is filled with ink, the Valve Lever tilted by the Pressure
Receiving Plate is raised, so that the Valve Lever closes the ink passage from the Ink
Tube Assy.
The capacity of each Ink Storage Chamber is equivalent to
C H E C K
P O I N T
printing of 36 pages of graphics.
Stylus Photo RX700 uses six colors, thus two chambers are left
out of use.
Operating Principles
LM
M
No ink
LC
Y
C Bk
No ink
Mechanism Operating Principles
Filter Ink Storage Chamber
To Printhead
To Printhead
Figure 2-28. Self-closing Valve
Revision A
Valve Lever
Pressure
Receiving
Plate
Valve Lever
Filter
37