Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
1999-06-30
2001-06-12
Barlow, John (Department: 2853)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
Reexamination Certificate
active
06244697
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to ink jet printers and in particular to a filter tower structure for removing air from permanent and semi-permanent printhead assemblies.
BACKGROUND OF THE INVENTION
During the lifespan of an ink jet printhead assemblies or “pens”, air or gas bubbles develop in the ink and coalesce into larger bubbles. As the bubbles form and coalesce, they tend to accumulate in the ink feed port, filter areas and ink feed channels of the pen. If the amount of air or gas bubbles increases significantly, performance of the pen may be affected. For disposable pens, air accumulation is not typically a significant problem. However, for longer life permanent or semi-permanent pens, and for high quality, high speed pens, substantial air or gas bubble accumulation may adversely affect printhead performance by causing misfiring or ink flow blockages.
A primary source causing air or gas bubbles in the ink feed port, between the printhead and ink cartridge, arises from the removal and connection of ink cartridges with the pen. If a spent ink cartridge is allowed to run dry of ink, air will fill the ink feed port connecting the cartridge to the carrier/printhead assembly. Even if the ink cartridge is not run dry of ink, a certain amount of air is introduced into the ink feed port each time the ink cartridge is connected and/or disconnected from the carrier/printhead assembly. Some of the air or gas bubbles which make their way into the ink flow channels of the pen are removed from the printhead through ejection orifices, however, a portion of the air or gas bubbles under the action of buoyancy may migrate back through the ink feed paths into the ink feed port in the connection between the pen and the ink cartridge.
Priming the pen by ejection of ink may remove air or gas bubbles from the printhead itself, however, there may still be a substantial amount of air in the ink feed port due to cartridge replacement. This air is effectively trapped between the pen and the ink cartridge in the connection port connecting the cartridge to the pen assembly.
An object of the invention is to provide an apparatus and method for removing air and gas bubbles from an ink jet pen.
Another object of the invention is to provide a device for removing a substantial quantity of air from an ink feed port.
Still another object of the invention is to improve the operation of a permanent or semi-permanent pen.
SUMMARY OF THE INVENTION
With regard to the foregoing and other objects and advantages, the invention provides a filter tower structure for an ink jet printer pen, the filter tower structure including an elongate conduit having a first open end and a second end, the second end being closed by a filtering media and the conduit having an upper end thereof adjacent the filtering media in selective flow communication with a vacuum source.
In another aspect, the filter tower structure includes a filter tower attached to an ink reservoir for feeding ink from the reservoir to an ink jet pen. The filter tower includes a conduit having an interior in flow communication with the ink reservoir and the pen and a tube having a first end in flow communication with the interior of the conduit and a second end in flow communication with a vacuum source. Activation of the vacuum source results in the application of a reduced pressure to the interior of the conduit such that air or gas bubbles are caused to flow into the tube from the conduit and ink from the reservoir is caused to flow into the conduit.
In another aspect the invention provides an ink jet printing device including a carrier structure containing one or more permanent or semi-permanent printheads, a filtration and air removal system connected to the carrier structure in ink flow communication with the printheads, a replaceable ink cartridge containing an ink supply for supply of ink to the printheads. The ink cartridge is removably connected to the filtration and air removal system attached to the ink cartridge. The air removal device includes a conduit having an interior in flow communication with the ink cartridge and the printheads and a tube having a first end in flow communication with the interior of the conduit and a second end in flow communication with a vacuum source.
Activation of the vacuum source results in the application of a reduced pressure to the interior of the conduit such that air or gas bubbles are caused to flow into the tube from the conduit and ink from the ink cartridge is caused to flow into the conduit.
An advantage of the air or gas bubble removal system of the invention is that it is configured so that air or gas bubbles may be easily removed after a new ink reservoir has been installed on the printhead so as to avoid problems common to printing devices having replaceable cartridges. The present invention, as described below, provides a substantial improvement in the ability to remove air or gas bubbles from the ink feed port.
REFERENCES:
patent: 4015272 (1977-03-01), Yamamori et al.
patent: 4484202 (1984-11-01), Sayko
patent: 4536777 (1985-08-01), Matsumoto
patent: 5113205 (1992-05-01), Sato et al.
patent: 5489932 (1996-02-01), Ceschin et al.
patent: 5537136 (1996-07-01), Brandon et al.
patent: 5552816 (1996-09-01), Oda et al.
patent: 5631682 (1997-05-01), Takata
patent: 5742314 (1998-04-01), Hayes
patent: 5774154 (1998-06-01), Underwood
patent: 5905518 (1999-05-01), DeFilippis
patent: 94 05 723 (1994-06-01), None
patent: 2-194969 (1990-08-01), None
Powers James Harold
Russell Matthew Joe
Barlow John
Lexmark International Inc.
Luedeka Neely & Graham
Sanderson Michael T.
Stewart Jr. Charles W.
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