Patent Application
20070273735
An ink tank for an ink jet recording device of the present invention is directed to an ink tank for an ink jet recording device having an ink storage section made of a plastic. The ink storage section has a coating layer including a liquid retaining member capable of retaining ink on an inner surface thereof or an impregnated member which can be impregnated with a liquid. Alternatively, the ink storage section has a coating layer including a liquid retaining member capable of retaining the liquid on an outer surface thereof.
There is not any special restriction on the ink tank for the ink jet recording device of the present invention as long as the ink tank includes the ink storage section made of the plastic and having the coating layer including the liquid retaining member capable of retaining the ink on the inner surface thereof or the liquid retaining member capable of retaining the liquid on the outer surface thereof. Examples of a constitution of the ink tank include a constitution having the ink storage section and a guiding section. The guiding section guides the ink stored in this ink storage section to a channel which supplies the ink to an ink jet recording head of the ink jet recording device. When the ink storage section is a bag having flexibility, the ink tank may have an exterior material which supports this bag.
The ink storage section is made of the plastic, and a configuration of the section may be a vessel or a bag, but the section can be the bag having the flexibility because it is easy to apply a negative pressure to the ink. A material of the plastic which forms the ink storage section may be a thermoplastic resin or a thermosetting resin. Specific examples of the material include polypropylene, polyethylene, nylon and ethylene vinyl copolymer.
There is not any restriction on the liquid retaining member or the impregnated member included in the coating layer disposed on the inner surface of the ink storage section, as long as the ink can be retained on the inner surface of the ink storage section. The member has flexibility and chemical stability with respect to the ink. Specific examples of the member include a foam material such as urethane foam, a fabric such as a natural or synthetic fiber, a fiber material such as a non-woven cloth and a gel-like substance such as a protein film. When the liquid retaining member includes the foam material or the fiber material and water included in the ink is volatilized or the ink is consumed, an inner space is formed in the ink storage section. An ink liquid is raised by a capillary function of a liquid retaining member such as the foam material or the fiber material included in a portion of the coating layer which comes into contact with this inner space. The ink liquid forms an ink layer on the inner surface of the ink storage section in an inner space portion. This ink layer can inhibit inflow and outflow of a gas between the inner space of the ink storage section and outside air.
Moreover, even when the liquid retaining member included in the coating layer includes the gel-like substance and the inner space is formed in the ink storage section, the ink retained by the gel-like substance can inhibit the inflow and outflow of the gas between the inner space of the ink storage section and the outside air in the same manner as described above. Examples of the gel-like substance included in the liquid retaining member include a protein, and such a substance may be included in the fiber material or the foam material for use.
In a case where the coating layer is disposed on the outer surface of the ink storage section, examples of the liquid retaining member for use in this layer especially include a moisture adsorbent which adsorbs a moisture from the outside air in addition to the foam material, the fiber material and the gel-like substance described above. When the liquid retaining member included in the coating layer disposed on the outer surface of the ink storage section include the foam material, the fiber material and the gel-like substance, the moisture is supplied to these materials to form a liquid layer on the outer surface of the ink storage section. In consequence, the inflow and outflow of the gas between the inner surface of the ink storage section and the outside air can be inhibited. Examples of the moisture adsorbent for use in the liquid retaining member of the coating layer disposed on the outer surface of the ink storage section include a polymer containing sodium polyacrylate as a main component and calcium chloride. These materials may be attached to the fiber material and the foam material for use. Since these materials efficiently adsorb the moisture from the outside air, a water layer can be formed on the outer surface of the ink storage section without supplying any moisture to the liquid retaining member. In consequence, the inflow and outflow of the gas between the inner surface of the ink storage section and the outside air can be inhibited.
An ink tank for an ink jet recording device of the present invention will hereinafter specifically be described in detail with reference to the drawings, but the technical scope of the present invention is not limited to these embodiments.
As one example of the ink tank for the ink jet recording device of the present invention,
The ink bag 104 of such an ink cartridge is formed of a composite material 202 having a coating layer 205 including a liquid retaining member capable of retaining the ink. The coating layer is bonded to an inner side of a plastic film 203 through a bonding layer 204. In this case, the bonding layer can be omitted in a case where the coating layer can be fused to the plastic film 203. Examples of the plastic film 203 include a molded material of polypropylene, polyethylene, nylon or an ethylene vinyl copolymer. A thickness of the plastic film can appropriately be selected in relation to a material of the film and the ink to be stored. Specifically, when priority is given to flexibility, a combination of 15 μm of polyethylene/20 μm of nylon may be used. In consideration of a gas barrier property and tenacity, a combination of 10 μm of polyethylene/10 μm of polyethylene terephthalate may be used. As a combination in which the flexibility and the gas barrier property are well balanced, a combination of 15 μm of polyethylene/10 μm of polypropylene may be used. In addition, various films may be combined and selected according to a size and a shape of the ink bag.
The coating layer 205 includes the liquid retaining member capable of retaining the ink and an impregnated member which can be impregnated with a liquid. Examples of the liquid retaining member and the impregnated member include a fiber material such as a non-woven cloth or fabric made of polyethylene fiber of about 1 to 4 deniers. The coating layer having such a fiber material can retain the ink with a capillary force. In addition, as the liquid retaining member and the impregnated member, a foam material and a gel-like substance may be included as described above.
In such a coating layer, a large amount of the ink 109 is retained by the liquid retaining member. In such a coating layer, when a gas phase 200 is present in the ink bag 104, the ink is supplied to a portion of the coating layer corresponding to a gas phase 200 through the coating layer of a portion present under the surface of the ink with the capillary force. Therefore, the plastic film 203 is separated from the gas phase 200 present in the ink bag through an ink layer between the film and the phase. Since the film does not directly come into contact with the phase, a gas can be inhibited from penetrating the plastic film.
A mechanism which inhibits inflow and outflow of the gas between an inner space of the ink bag of the present invention and the outside air will hereinafter be described. As shown in
After elapse of time t (T=t [hr]), as shown in
Next, the same injector syringe as described above is used. As shown in
As described above, a metal layer of aluminum heretofore disposed for a purpose of preventing the penetration of the gas is not required. A flexible plastic film can be used without using any evaporation film such as a metal. The flexible ink bag is deformed with consumption of the ink. Therefore, the negative pressure can easily and stably be applied to the ink stored in the bag, the ink is used up well, and a use efficiency of the ink in the ink tank improves. In general, the ink for the ink jet recording device is expensive. In consequence, a running cost can be reduced.
It has been described above that the coil spring is disposed, but in the ink tank for the ink jet recording device of the present invention, the coil spring may be replaced with a measure for appropriately applying the negative pressure if necessary. The measure may appropriately be selected. Alternatively, the measure for applying the negative pressure does not have to be disposed.
As another example of the ink tank for the ink jet recording device of the present invention,
The ink bag 511 of such an ink cartridge is formed of a composite material 508 having a coating layer 505 including a liquid retaining member capable of retaining the ink or an impregnated member which can be impregnated with a liquid. The coating layer is bonded to an outer side of a plastic film 507 through a bonding layer 504. In this case, the bonding layer can be omitted in a case where the coating layer can be fused to the plastic film 507. Specific examples of the plastic film 507 include a film formed of the same material as that described above in the plastic film 203 and having a thickness equal to that of the above plastic film.
The coating layer 505 includes the liquid retaining member capable of retaining a moisture or the impregnated member which can be impregnated with the liquid. Specific examples of the liquid retaining member and the impregnated member include members formed of the same material described above in the coating layer 205. As the moisture retained in the coating layer 505 including such a liquid retaining member or impregnated member, water can be used, but a part or all of waste ink generated at the start of the use of the ink jet recording device may be used. A measure for supplying the moisture and the waste ink to be retained in the coating layer 505 may be disposed. Moreover, a aperture diameter of an outside air communication port 500 and the number of the ports are adjusted, when the port is disposed at the exterior material 501. Furthermore, a volatilized amount of the moisture retained in the coating layer is adjusted, so that the coating layer 505 can constantly retain a wetted state.
Furthermore, as the liquid retaining member or the impregnated member included in the coating layer 505, a moisture adsorbent can be used. As the moisture adsorbent, the same adsorbent as described above may be used. Since the moisture adsorbent can adsorb the moisture from outside air, a measure for supplying the moisture does not have to be disposed in the coating layer in which this moisture adsorbent is used.
In such a coating layer, a layer of water or waste ink included in the liquid retaining member or the impregnated member is formed on an outer surface of the plastic film 507. Therefore, the plastic film 507 is separated through the layer of the water or the waste ink interposed between the film and the outside air, and does not come into direct contact. Therefore, even when a gas phase 512 is present in the ink bag 511, a gas can be inhibited from penetrating the plastic film. In the present embodiment, the water may be absorbed beforehand in the liquid retaining member, but the water or the waste ink may appropriately be introduced from the outside of the ink tank, and absorbed in the liquid retaining member. In consequence, the liquid retaining member constantly retains the water and the ink, and the penetration of the gas can securely be inhibited.
It has been described above that any negative pressure measure is not disposed in the ink bag, but a measure such as a coil spring for applying a negative pressure to the ink bag may be disposed if necessary.
Moreover, in the above embodiment, the ink bag is used as the ink storage section, but the present invention is not limited to this embodiment, and a vessel having a specific shape may be used.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2006-144164, filed May 24, 2006, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-144164 | May 2006 | JP | national |
