This invention relates to an ink cartridge for an ink jet printing apparatus, such as an inkjet printer.
In many ink jet printers, the ink reservoir is contained in a removable ink cartridge, which may also contain the ink delivery components. Such ink cartridges typically consist of an ink reservoir, some form of pressure regulator, an ejector chip, a filter, and ink passages from the ink reservoir to the chip. With thermal inkjet technology, the chip heats the ink and jets it out through a nozzle plate. The pressure regulator keeps the ink entering the chip at a slight negative pressure.
In existing art, the ink reservoirs are often formed by walls or partitions molded into the cartridge body, and pressure regulation is accomplished by inserting a piece of foam into each of the ink reservoirs. The capillary action of the foam creates backpressure for the chip, and the pore size of the foam when compressed determines the ink backpressure.
One aspect of the cartridge design to consider is how it is filled. The standard method to fill a cartridge is to pump the ink through a needle that passes through the lid and is inserted into the foam. The needle extends down through the foam and stops just above the filter. The needle height in this process is critical as it affects the ink saturation around the filter area. It is often difficult to get good saturation when this method is used. If the needle is too close to the filter, some ink is forced through the filter and into the ink channel during ink fill. This wets part of the ink channel and allows air bubbles to remain in the ink channels during prime, preventing a complete prime. If the needle is too high off the filter the ink travels to the top of the foam and begins pooling before the foam around the filter is complete saturated. The pooling ink can contaminate the lid weld surfaces preventing a good weld and also can cause cross contamination between colors.
In one embodiment, the present invention provides an ink cartridge having an ink reservoir and a pressure-regulating material such as foam located in a pocketed lid that fits with the cartridge body. The pocket has an orifice located such that it can deliver ink to an ejection device. The entire lid, with its integral pocket constituting the ink reservoir, can be secured to the cartridge body, such as by plastic welding or other means, such that the ink reservoir pocket is contained inside the cartridge body.
In one embodiment, the location of the ink reservoirs and pressure-regulating material in open-bottom pockets in the lid can, for example, allow the foam to be filled with ink from the bottom through the same orifices through which ink flows during normal printing operations. The filling can be performed when the lid is separated from the cartridge body, thus allowing optimal saturation of the foam without wetting the filters and ink channels.
Accordingly, it is one aspect of the present invention to provide an ink cartridge for an ink jet printing apparatus that includes: a cartridge body having external walls, an open portion, and at least one outlet through which ink may pass to feed ink to an ejection device; and a lid covering the open portion of the cartridge body, where the lid has at least one ink reservoir pocket extending into the cartridge body, and where the pocket has an orifice in fluid communication with the outlet of the cartridge body. In a more detailed embodiment, the ink cartridge can include an ink filter in fluid communication with the orifice of the pocket. In an even more detailed embodiment, the ink filter can be attached to the cartridge body. In an even more detailed embodiment, the ink filter can be made of stainless steel mesh.
In an alternate detailed embodiment of the aforementioned aspect of the present invention, the ink cartridge can include a pressure-regulating material such as a foam material residing in the pocket, where the pressure-regulating material at least partially fills the volume of the pocket and is in fluid communication with the orifice of the pocket.
In an alternate detailed embodiment of the aforementioned aspect of the present invention, the cartridge body includes a plurality of outlets through which ink may pass to an ejection device, and the lid includes a corresponding plurality of the pockets, where each pocket has an orifice in fluid communication with a respective cartridge outlet. This embodiment may be practiced in such a way that each of the plurality of pockets contains a different color of ink. Additionally, this embodiment may further be practiced in the same more detailed embodiments as stated above for the aforementioned aspect of the present invention and its alternate embodiments.
It is another aspect of the present invention to provide a pocketed lid for an ink cartridge, where the pocketed lid includes at least one ink reservoir pocket extending into a cartridge body, and where the pocket has an orifice in fluid communication with an outlet of the cartridge body.
It is a further aspect of the present invention to provide a method for filling an ink cartridge with ink. The method might include the following steps: (a) providing a pocketed lid for a cartridge body, where the pocketed lid has at least one ink reservoir pocket; (b) flowing ink into the pocket of the pocketed lid; and (c) mounting the pocketed lid with a cartridge body. In a detailed embodiment, the ink can flow into the pocket of the pocketed lid from the bottom of the pocket. In a further detailed embodiment, the ink can flow into the pocket of the pocketed lid through the same orifice through which ink flows out of the pocket during normal printing operations. In yet a further detailed embodiment, the method might further include, prior to (b) flowing ink into the pocket of the pocketed lid, the step of (al) placing the pocketed lid onto an ink fill fixture, where the ink fill fixture has an ink fill nozzle in fluid communication with the pocket in the pocketed lid.
In an alternate embodiment, the pocketed lid might include a plurality of ink reservoir pockets. In a more detailed embodiment, the ink flows into each of the plurality of pockets of the pocketed lid through the same orifices through which ink flows out of the respective pocket during normal printing operations. In yet a further detailed embodiment, the method might further include, prior to (b) flowing ink into the pocket of the pocketed lid, the step of (a1) placing the pocketed lid onto an ink fill fixture, where the ink fill fixture has an ink fill nozzle in fluid communication with each of the plurality of pockets in the pocketed lid.
It is a yet another aspect of the present invention to provide an ink cartridge for an ink jet printer that includes: a cartridge base having at least one outlet through which ink may pass to feed ink to an ejection device; and a cartridge cover for coupling to the cartridge base, the cartridge cover providing a wall of the ink cartridge and including at least one ink reservoir pocket extending from the wall toward the cartridge base, the pocket having an orifice in fluid communication with the outlet of the cartridge body. In a more detailed embodiment, the outer walls of the ink cartridge are provided by cartridge base and/or the cartridge cover. In a yet a further detailed embodiment, the ink cartridge includes an ink filter in fluid communication with the orifice of the pocket. In an even more detailed embodiment, the ink filter is attached to the cartridge base.
As shown in
It is a feature of this exemplary embodiment that the cartridge body remains unchanged from existing cartridge bodies, and all the changes are contained in the lid. This is advantageous because the tooling for the body is very complex, making modifications or retooling quite expensive. Also, the body goes through many assembly steps in the manufacturing process, each being potentially negatively impacted if the body were modified. The lid, on the other hand, is a simple mold and easily changed or retooled. The attachment of the lid is also one of the last assembly steps in the manufacturing process of a cartridge, and impact on the manufacturing process is minimized by confining all changes to the lid.
Referring specifically to
A new method can be used to fill the ink reservoirs of such an exemplary embodiment, and this method eliminates difficulties present with existing ink-fill methods. In the exemplary embodiment, the foam 20 is placed into pockets in the lid. These pockets 14 are open at their bottom ends 25 providing the orifice 16, which allows them to be filled with ink through this orifice 16 prior to installation of the pocketed lid 12 into the cartridge body 10. After the foam 20 is inserted into the pockets 14 in the lid 12, the lid is placed onto an ink fill fixture 30 provided in
As shown in
During the ink fill process, the ink is pumped into the foam 20 though the ink fill nozzles 36 into the lid pockets 14 from the bottom, through the open end 16 of the pockets. This gives the optimal ink fill, one that is full saturated at the bottom (the end that will be against the filter) and does so without pre-wetting the filter and ink channels, which are located in the cartridge body 10. After the foam 20 is filled with ink, the pocketed lid 12 is removed from the ink fill fixture 30 and mated to the cartridge body 10. The pocketed lid 12 is then welded in place and the completed cartridge assembly is then primed in the conventional manner. Because the foam 20 was filled with ink when separated from the cartridge body 10, the ink channels 24 are dry prior to prime, which gives a much more consistent and complete prime, one that removes most all air from the channels. This improved prime increases first time functional test rates compared with the existing ink fill methods.
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Having described the invention with reference to the exemplary embodiment, it is to be understood that the invention is defined by the claims and it not intended that any limitations or elements describing the exemplary embodiment set forth herein are to be incorporated into the meanings of the claims unless such limitations or elements are explicitly listed in the claims. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of any claims, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein.
For example, and without limitation, it is not necessary that the cartridge body 10 be an existing cartridge, where all the changes are contained in the lid. It is therefore, within the scope of the invention that an ink cartridge includes: a cartridge base having at least one outlet through which ink may pass to feed ink to an ejection device; and a cartridge cover for coupling to the cartridge base, where the cartridge cover provides a wall of the ink cartridge and includes at least one ink reservoir pocket extending from the wall toward the cartridge base, and where the pocket has an orifice in fluid communication with the outlet of the cartridge body. In such an embodiment the outer walls of the ink cartridge may be provided by cartridge base and/or the cartridge cover.