Incremental printing of symbolic information – Ink jet – Fluid or fluid source handling means
Reexamination Certificate
1999-07-07
2001-08-07
Yockey, David F. (Department: 2861)
Incremental printing of symbolic information
Ink jet
Fluid or fluid source handling means
C347S093000
Reexamination Certificate
active
06270211
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to ink jet printers and in particular to a filter tower structure for attachment to a permanent or semi-permanent ink jet pen.
BACKGROUND OF THE INVENTION
During the lifespan of an ink jet printhead, air or gas bubbles develop in the ink and coalesce into larger bubbles. As the bubbles form and coalesce, they tend to accumulate in filter areas and ink feed channels of the ink jet 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 significantly affect printhead performance by causing misfiring or ink flow blockages.
A primary source of air or gas bubbles in the ink feed port of an ink jet pen 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 pen. 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 pen. Some of the air or gas bubbles which make there way into the ink flow channels of the pen are removed from the printhead through the ejection orifices, however, a portion of the air or gas bubbles finds its way back through the ink feed paths into the ink filter area of the pen.
Priming the pen by ejecting ink from the printhead may remove air or gas bubbles from the printhead itself, however, there may still be a substantial amount of air in the filter area of the pen or cartridge.
An object of the invention is to provide an apparatus and method with improves the operation of an ink jet pen.
Another object of the invention is to provide an apparatus and method for filtering ink for an ink jet printer.
Another object of the invention is to provide a filtration and air removal system which can be easily connected to an ink jet pen.
Still another object of the invention is to provide a method for filtering ink and removing air from the filter device of an ink jet printer.
Another object of the invention is to provide method for connecting an ink filtration system to an ink jet pen which simplifies the manufaturing steps thereof.
SUMMARY OF THE INVENTION
With regard to the foregoing and other object and advantages, the invention provides an apparatus for filtering ink for an ink jet pen which includes an elongate open-ended trough having a bottom wall, opposing end walls and opposing side walls attached to the bottom wall, a filtered ink exit port attached to the bottom wall between the opposing end walls and side walls, a filter element disposed in the open-ended trough between the end walls and the side walls and an elongate cover assembly attached to the end walls and the side walls covering the trough defining a filter chamber containing the ink filter element. The cover assembly of the apparatus contains an ink inlet valve and a gas outlet valve.
In another aspect the invention provides an ink jet printer which includes one or more permanent or semi-permanent printheads on an ink jet pen. One or more removable ink cartridges are attached to the pen, each cartridge containing an ink feed port having an ink flow path in flow communication with the one or more printheads and containing a bellows device for removing air or gas bubbles which accumulate in the ink flow path. At least one filtration and air removal system containing a filter chamber is attached to the pen between the cartridge and the pen for filtering ink flowing to the one or more printheads and for removing air and gas bubbles from filter chamber.
In yet another aspect the invention provides a method for filtering ink and removing air and gas bubbles from one or more ink feed ports of an ink jet pen. The ink jet pen contains one or more printheads disposed on one surface thereof and having an aperture on a second surface thereof for each printhead for flow of ink to the printheads. One or more removable ink cartridges is provided, each cartridge containing ink and having an ink feed port for supplying ink through the ink feed port to at least one printhead. At least one ink filtration and air removal system containing a filter chamber and a filter element in the filter chamber for filtering ink flowing from the one or more cartridges to the one or more printheads is provided. Each filtration and air removal system contains an ink inlet device, an ink inlet port, an air outlet device, an air outlet port and a filtered ink outlet port. The ink outlet ports are connected to the pen so that each outlet port is in flow communication with the aperture corresponding to the printhead. Upon attachment of each ink cartridge to the filtration and air removal system air is removed from the filter chamber.
An advantage of the ink filtration system of the invention is that it is configured to provide a filtered ink compartment having an air accumulation space therein for accumulating, coalescing and channeling unwanted air or gas bubbles in order to effectively remove such unwanted air or gas bubbles from the ink flow paths of the pen and ink cartridge. Removal of unwanted air or gas bubbles from the ink flow paths is substantially automatically activated upon replacement of an ink cartridge without any other operator intervention. Unlike priming devices or methods, the device of the invention is adapted for removal of air or gas bubbles so that only a relatively minute quantity of ink is removed or wasted from the ink cartridge or ink supply port. By “relatively minute” means from about 0 to about 1 milliliter, preferably from about 0.1 to about 0.2 milliliters. Priming devices typically only remove air from the printhead and ink paths in the printhead itself and are not effective for removing air bubbles from the ink filter chamber. The present invention, as described below, provides a substantial improvement in the ability to remove air or gas bubbles from the ink filter chamber and provides a substantially improved ink filtration system.
REFERENCES:
patent: 3708118 (1973-01-01), Keur
patent: 4153902 (1979-05-01), Kanayama
patent: 4301459 (1981-11-01), Isayama et al.
patent: 4628334 (1986-12-01), Dagna et al.
patent: 4946204 (1990-08-01), Boticki
patent: 5017941 (1991-05-01), Drake
patent: 5119115 (1992-06-01), Buat et al.
patent: 5425478 (1995-06-01), Kotaki et al.
patent: 5456248 (1995-10-01), Holian et al.
patent: 5515091 (1996-05-01), Kimura et al.
patent: 5537136 (1996-07-01), Brandon et al.
patent: 5546109 (1996-08-01), Nakano
patent: 5606988 (1997-03-01), Pawlowski, Jr.
patent: 5621445 (1997-04-01), Fong et al.
patent: 5696546 (1997-12-01), Narang et al.
patent: 5751322 (1998-05-01), Miller et al.
patent: 5767881 (1998-06-01), Geissmann
patent: 5777646 (1998-07-01), Barinaga et al.
patent: 5815182 (1998-09-01), Otis et al.
patent: 5828395 (1998-10-01), Takata
patent: 5905518 (1999-05-01), DeFilippis
patent: 0 645 244 A1 (1995-03-01), None
patent: 0 676 294 A2 (1995-04-01), None
patent: 60-99661-A (1985-06-01), None
patent: 3-258554 (1991-11-01), None
patent: 9-109405 (1997-04-01), None
Long Gregory Alan
Powers James Harold
Russell Matthew Joe
Ward David Amos
Lexmark International Inc.
Luedeka Neely & Graham
Yockey David F.
LandOfFree
Bubble elimination and filter tower structure does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bubble elimination and filter tower structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bubble elimination and filter tower structure will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2464187