Liquid container

1. Field of the Invention

The present invention relates to liquid containers and particularly to a liquid container for supplying ink to an inkjet recording head of an inkjet recording apparatus.

2. Description of the Related Art

Replaceable ink tanks are conventionally used as ink tanks for inkjet printers. Such a replaceable ink tank has a problem in that while the tank is being replaced, ink leaks out of the tank toward a joint where the tank is attached to the printer and, for example, makes the user's hands dirty or drips onto the printer main body.

FIG. 16 illustrates an exemplary configuration of an ink tank disclosed in Japanese Patent Laid-Open No. 09-300646 (corresponding to U.S. Pat. No. 6,082,852). An ink tank T 2000 includes a main ink reservoir T 2003 and an intermediary reservoir T 2006 under the main ink reservoir T 2003 . A capillary member T 2004 inside the main ink reservoir T 2003 holds ink and maintains a negative pressure therein. The intermediary reservoir T 2006 is provided with an ink supply port T 2002 at the bottom to which a recording head is to be connected. The ink supply port T 2002 is provided with a meniscus forming member (filter) T 2009 .

FIG. 17 is a cross-sectional view illustrating an exemplary configuration of an ink tank for pigment ink disclosed in Japanese Patent Laid-Open No. 2003-080730 (corresponding to U.S. Pat. No. 6,722,762).

To ensure a uniform concentration of ink inside the tank where a concentration gradient often occurs, an ink reservoir T 2001 , an ink channel T 2014 , and an ink supply port T 2002 of the ink tank are arranged to form a complex structure. The ink supply port T 2002 is provided with a ball valve, with which the ink reservoir T 2001 is closed.

FIG. 18 illustrates an exemplary configuration of an ink tank disclosed in Japanese Patent Laid-Open No. 08-216424 (corresponding to U.S. Pat. No. 6,000,790). Unlike the intermediary reservoir T 2006 illustrated in FIG. 16 , an intermediary reservoir T 2006 in FIG. 18 has the form of a narrow channel and is provided with an ink supply port T 2002 at an end thereof.

FIG. 19 illustrates an exemplary configuration of an ink tank disclosed in Japanese Patent Laid-Open No. 2005-067075. An intermediary reservoir T 2006 having the form of a narrow channel is provided with an ink supply port T 2002 at a bottom end thereof. The intermediary reservoir T 2006 communicates with a main ink reservoir T 2003 through an opening T 2014 .

In the ink tank T 2000 illustrated in FIG. 16 , the intermediary reservoir T 2006 filled with ink is disposed over the meniscus forming member T 2009 for the ink supply port T 2002 . Therefore, external shocks applied to the ink tank T 2000 when it is dropped may cause the ink inside the intermediary reservoir T 2006 to break a meniscus formed at the meniscus forming member T 2009 and further, to spatter from inside the ink tank T 2000 to the outside.

In the ink tank illustrated in FIG. 17 , the ball valve for the ink supply port T 2002 can prevent ink from spattering. However, the ink tank, which is closed with the ball valve, suffers the disadvantages of having a complicated structure and the reduced amount of ink that can be stored in the ink tank.

Like the ink tank illustrated in FIG. 16 , the ink tank in either FIG. 18 or FIG. 19 is configured such that the intermediary reservoir T 2006 , which is filled with ink, extends toward the ink supply port T 2002 . Therefore, if, for example, the ink tank T 2000 is dropped and subjected to external shocks, the pressure of the ink may be easily and directly transmitted to the ink supply port T 2002 . This may cause a meniscus at the meniscus forming member to be broken and the ink to spatter.

The present invention is directed to a liquid container that does not cause ink to easily spatter even when the container is dropped or subjected to force or shocks. The present invention is also directed to a cartridge and recording apparatus incorporating the liquid container.

According to an aspect of the present invention, a liquid container includes a housing; a flexible film; a liquid reservoir configured to directly store liquid therein, the housing defining one side of the liquid reservoir and the flexible film defining another side of the liquid reservoir; a liquid supply port provided in the liquid reservoir and configured to supply liquid to a recording head; and a first overhang protruding from the housing, and located in the liquid reservoir and substantially near the liquid supply port.

In one embodiment of the present invention, the first overhang includes an absorbing member configured to absorb the inertial force of liquid being generated in liquid in the liquid reservoir by an external force applied to the housing and being directed to the liquid supply port.

According to another embodiment of the present invention, the first overhang may be located in the liquid reservoir and opposite the liquid supply port, and configured to hide the liquid supply port when viewed from the liquid reservoir.

According to another embodiment of the present invention, the liquid container may further include a second overhang located adjacent to the first overhang and configured to surround the liquid supply port.

According to another embodiment of the present invention, the first overhang includes at least one adjacent channel, and a liquid communication path may be formed between the liquid supply port and the liquid reservoir by the flexible film and the channel that are in contact with each other.

According to another embodiment of the present invention, the first overhang includes at least one channel, and a liquid communication path may be formed between the liquid supply port and the liquid reservoir by the flexible film and the channel that are in contact with each other.

According to another embodiment of the present invention, the flexible film may be arranged to be in contact with the first overhang and the second overhang, and includes a third overhang that is adjacent to the liquid supply port and is configured to absorb the inertial force of liquid, the inertial force being generated in liquid in the liquid reservoir by an external force applied to the housing.

According to another embodiment of the present invention, the liquid supply port includes a meniscus forming member, or a capillary force generating member in fabric form on the side to which the recording head is to be connected.

According to another embodiment of the present invention, a liquid container includes a housing; a liquid reservoir configured to directly store liquid therein, the liquid reservoir being located in the housing; a liquid supply port provided in the liquid reservoir and configured to supply liquid to a recording head; and an overhang protruding from the housing, and located in the liquid reservoir so as to absorb the inertial force of liquid being generated in liquid in the liquid reservoir by an external force applied to the housing and being directed to the liquid supply port.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

FIG. 1 is a cross-sectional view illustrating an exemplary liquid container according to a first exemplary embodiment of the present invention.

FIG. 2 is an external perspective view of the liquid container illustrated in FIG. 1 .

FIG. 3 is an exploded perspective view of the liquid container illustrated in FIG. 2 .

FIG. 4 is an enlarged view of section “IV” in FIG. 3 .

FIG. 5 is a cross-sectional view taken along line V-V in FIG. 2 .

FIG. 6 is a cross-sectional view illustrating an exemplary liquid container according to a second exemplary embodiment of the present invention.

FIG. 7 is a perspective view illustrating an exemplary internal configuration of the liquid container in FIG. 6 .

FIG. 8 is a cross-sectional view illustrating an exemplary liquid container according to a third exemplary embodiment of the present invention.

FIG. 9 is a perspective view illustrating an exemplary internal configuration of the liquid container in FIG. 8 .

FIG. 10 is a cross-sectional view illustrating an exemplary liquid container according to a fourth exemplary embodiment of the present invention.

FIG. 11 is a perspective view illustrating an exemplary internal configuration of the liquid container in FIG. 10 .

FIG. 12 is a cross-sectional view illustrating an exemplary liquid container according to a fifth exemplary embodiment of the present invention.

FIG. 13 is a perspective view illustrating an exemplary internal configuration of the liquid container in FIG. 12 .

FIG. 14 is a perspective view illustrating an exemplary inkjet recording apparatus on which a liquid container of the present invention is mounted.

FIG. 15 is a perspective view illustrating an exemplary internal configuration of the inkjet recording apparatus in FIG. 14 .

FIG. 16 illustrates an exemplary configuration of a known ink tank.

FIG. 17 illustrates an exemplary configuration of another known ink tank.

FIG. 18 illustrates an exemplary configuration of another known ink tank.

FIG. 19 illustrates an exemplary configuration of another known ink tank.

Exemplary embodiments of the present invention will now be described with reference to the drawings.

First Exemplary Embodiment

First, an inkjet recording apparatus on which a liquid container of the present invention is mounted will be described.

An inkjet recording apparatus is a non-impact recording apparatus capable of recording at high speed, with little noise, and on various types of recording media. The inkjet recording apparatus is widely used as a device capable of performing the recording functions of printers, word processors, facsimiles, and copiers.

FIG. 14 illustrates a basic configuration of an inkjet recording apparatus. As illustrated, the inkjet recording apparatus includes a main body M 1000 , a feeder M 3022 for feeding recording media such as paper, and an ejection tray M 1004 .

FIG. 15 illustrates an internal configuration of the inkjet recording apparatus in FIG. 14 . As illustrated, the inkjet recording apparatus includes a chassis M 3019 and other components for recording operations. A recording head cartridge (not shown) for performing recording, as intended, on a recording sheet conveyed to a recording position is removably mounted on a carriage M 4001 . The recording head cartridge includes a recording head for ejecting liquid, and an ink tank removably attached to the recording head. The recording head is configured to heat ink with an electrothermal transducer having a heating element so as to allow ink droplets to be ejected from nozzles by film boiling.

(Overall Configuration)

Next, a general configuration of a liquid container of the present invention, the liquid container being mounted on the above-describe inkjet recording apparatus, will be described with reference to FIG. 1 to FIG. 5 .

FIG. 1 illustrates an ink tank according to the first exemplary embodiment of the present invention. FIG. 1 is an enlarged view of section “I” in FIG. 5 , which illustrates the ink tank in which a negative pressure is generated by a spring. FIG. 2 is an external perspective view of the ink tank illustrated in FIG. 1 . FIG. 3 is an exploded perspective view of the ink tank illustrated in FIG. 2 . FIG. 4 is an enlarged view of section “IV” in FIG. 3 . FIG. 5 is a cross-sectional view taken along line V-V in FIG. 2 .

An ink tank T 2000 is a liquid container for storing ink. As illustrated in FIG. 2 , a housing T 2017 and a lid T 2018 constitute the exterior of the ink tank T 2000 , which is internally provided with an ink reservoir. The ink tank T 2000 is provided with an ink supply port T 2002 , at the bottom thereof, for supplying ink to a recording head (not shown).

As illustrated in FIG. 3 , the ink tank T 2000 includes the housing T 2017 , a spring T 2028 , a plate member T 2022 , a flexible film T 2027 , the lid T 2018 , a meniscus forming member T 2020 , an ink inducing member T 2016 , and a retainer T 2021 .

The housing T 2017 can be made of polypropylene. As illustrated in FIG. 3 and FIG. 5 , at the point where the ink supply port (T 2002 ) communicates with the main body of the ink tank T 2000 , the meniscus forming member T 2020 , the ink inducing member T 2016 , and the retainer T 2021 are attached to the housing T 2017 in this order.

The meniscus forming member T 2020 of the present exemplary embodiment can be a stainless mesh filter with a pore diameter of about 15 to 30 μm. The meniscus forming member T 2020 forms an ink meniscus to prevent bubbles from entering an ink reservoir T 2001 (described below). The meniscus forming member T 2020 is not limited to the mesh filter described above, but may be a high-density felt fabric or the like that can achieve similar effects.

The ink inducing member T 2016 of the present exemplary embodiment can be a capillary member having a capillary force and made of polypropylene fabric.

The flexible film T 2027 is welded to an opening frame T 2015 of the housing T 2017 so as to form the ink reservoir T 2001 , in which ink is contained. The flexible film T 2027 can be a film member which has a thickness of about 20 to 100 μm and includes a polypropylene thin film.

In the ink reservoir T 2001 , the spring T 2028 biases the flexible film T 2027 toward the outside of the ink tank T 2000 , with the plate member T 2022 interposed between the spring T 2028 and the flexible film T 2027 , so as to generate a negative pressure in the ink tank T 2000 . The spring T 2028 and the plate member T 2022 can be made of a stainless material. The lid T 2018 is attached to the main body of the ink tank T 2000 at the opening thereof so as to protect the flexible film T 2027 , which has been bent into a convex shape toward the outside of the ink tank T 2000 .

In the configuration described above, as ink in the ink reservoir T 2001 is consumed by being supplied to the recording head, the spring T 2028 shrinks, the flexible film T 2027 bends, and the capacity of the ink reservoir T 2001 gradually decreases.

(Configuration of Ink Supply Section)

FIG. 1 and FIG. 4 are an enlarged cross-sectional view and an enlarged perspective view, respectively, of an ink supply section of the ink tank T 2000 . The ink tank T 2000 of the first exemplary embodiment is provided with an obstacle T 2019 that is located opposite the meniscus forming member T 2020 at the bottom of the ink reservoir T 2001 . The obstacle T 2019 absorbs the inertial force of ink, the inertial force being generated by external shocks to the ink tank T 2000 . In the present exemplary embodiment, the obstacle T 2019 is formed in the shape of an overhang protruding from the inner wall of the main body of the ink tank T 2000 . The obstacle T 2019 is positioned such that the meniscus forming member T 2020 is hidden behind the obstacle T 2019 when viewed in the direction of arrow “E” in FIG. 1 . In the present exemplary embodiment, the distance between the obstacle T 2019 and the meniscus forming member T 2020 is about 0.5 to 1.5 mm (which is normally expected to be smaller) in view of the dimensions of molds for plastic molding. Additionally, there are channel-like alternative paths T 2023 adjacent to the obstacle T 2019 . The alternative paths T 2023 are partially formed in a direction different from that of the meniscus forming member T 2020 , and then bent to communicate with the meniscus forming member T 2020 . The obstacle T 2019 and the flexible film T 2027 are configured to surround the meniscus forming member T 2020 .

(Operation)

FIG. 5 is a cross-sectional view taken along line V-V in FIG. 2 and illustrates the position of the ink supply port T 2002 in the overall view of the ink tank T 2000 .

Since the obstacle T 2019 in the ink reservoir T 2001 is located near the meniscus forming member T 2020 in the ink supply section, the inertial force of ink toward the meniscus forming member T 2020 can be reduced when the ink tank T 2000 is subjected to force or shocks.

In other words, the obstacle T 2019 prevents the inertial force of ink attempting to move through the ink reservoir T 2001 from easily being transmitted directly to the meniscus forming member T 2020 . Moreover, as indicated by arrow “D” in FIG. 4 , the obstacle T 2019 diverts the flow of ink to the alternative paths T 2023 . This can prevent the ink from easily spattering from the ink supply port T 2002 . After flowing through the alternative paths T 2023 , the ink passes through the meniscus forming member T 2020 and is supplied via the ink supply port T 2002 to the recording head.

As illustrated in FIG. 4 , second obstacles T 2024 may also be provided, at curves of the alternative paths T 2023 , so as to surround the meniscus forming member T 2020 . This allows the inertial force of ink to be reduced even when the ink tank T 2000 is dropped at an angle. The inertial force of ink is the flowing force of ink trying to move from an ink reservoir toward an ink supply port.

Moreover, part of the flexible film T 2027 , which is located to surround the meniscus forming member T 2020 , serves as a third obstacle.

By using the simple configuration described above, it is possible to provide an ink tank that is capable of preventing ink from easily spattering from the ink supply port even when the ink tank is accidentally dropped by the user or is subjected to force or shocks.

Second Exemplary Embodiment

FIG. 6 is a cross-sectional view illustrating an exemplary ink tank according to the second exemplary embodiment of the present invention. FIG. 7 is a perspective view illustrating an exemplary internal configuration of the ink tank in FIG. 6 .

The ink tank of the second exemplary embodiment has basically the same configuration as that of the first exemplary embodiment except that an ink channel T 2026 is provided between an ink reservoir T 2001 for storing ink and a meniscus forming member T 2020 for an ink supply port T 2002 .

The ink channel T 2026 has an opening T 2025 at the bottom of the ink reservoir T 2001 . The ink tank of the present exemplary embodiment is provided with an obstacle T 2019 that is located near and opposite the opening T 2025 . When the ink tank is subjected to external shocks, the obstacle T 2019 absorbs the inertial force of ink, the inertial force being generated by the external shocks. After flowing through alternative paths T 2023 , the ink passes through the ink channel T 2026 and is supplied via the ink supply port T 2002 to the recording head.

In the ink tank configured as described above, the obstacle T 2019 in the ink reservoir T 2001 is located near the opening T 2025 of the ink channel T 2026 which communicates with the ink supply section. This has the effect of reducing the inertial force of ink toward the ink supply port T 2002 , the inertial force being generated by external force or shocks applied to the ink tank. The ink tank capable of preventing ink from easily spattering can thus be achieved.

Third Exemplary Embodiment

FIG. 8 is a cross-sectional view illustrating an exemplary ink tank according to the third exemplary embodiment of the present invention. FIG. 9 is a perspective view illustrating an exemplary internal configuration of the ink tank in FIG. 8 .

In the ink tank of the present exemplary embodiment, an obstacle T 2019 and sidewalls T 2029 of respective channel-like alternative paths T 2023 are substantially equal in height. The alternative paths T 2023 are provided on respective sides of the obstacle T 2019 .

In the ink tank with this configuration, a large cross-sectional area of the alternative paths T 2023 can be secured. At the same time, the sidewalls T 2029 can serve as second obstacles T 2024 that surround an opening T 2025 of an ink channel T 2026 .

Therefore, it is possible to reduce not only the inertial force of ink directed linearly from an ink reservoir to an ink supply port T 2002 , but also that applied from either side of the obstacle T 2019 . The effect of preventing ink from easily spattering can thus be achieved.

Additionally, slopes T 2030 are provided at points where the sidewalls T 2029 are in contact with a flexible film T 2027 . As described above, the obstacle T 2019 and the sidewalls T 2029 are substantially equal in height. This configuration facilitates the contact of the flexible film T 2027 with the sidewalls T 2029 and obstacle T 2019 , and further enhances the function of the sidewalls T 2029 as the second obstacles T 2024 .

As illustrated in FIG. 8 , the flexible film T 2027 extends from an end of the obstacle T 2019 along the slopes T 2030 and covers a small chamber T 2031 defined by the ink reservoir, the obstacle T 2019 , and the second obstacles T 2024 . With respect to the small chamber T 2031 , the area of the opening T 2025 of the ink channel T 2026 may be reduced, or the ink channel T 2026 may be divided into sub-channels.

This configuration creates resistance to the flow of ink, reduces the inertial force of ink generated by the external shocks, and thus can prevent ink from easily spattering. In the present exemplary embodiment, the ink channel T 2026 is divided into three sub-channels T 2025 - 1 , T 2025 - 2 , and T 2025 - 3 (or T 2026 - 1 , T 2026 - 2 , and T 2026 - 3 ).

Fourth Exemplary Embodiment

FIG. 10 is a cross-sectional view illustrating an exemplary ink tank according to the fourth exemplary embodiment of the present invention. FIG. 11 is a perspective view illustrating an exemplary internal configuration of the ink tank in FIG. 10 .

As illustrated in FIG. 10 and FIG. 11 , in the ink tank of the present exemplary embodiment, an ink supply port T 2002 , an ink inducing member T 2016 , a meniscus forming member T 2020 , an ink channel T 2026 , and an obstacle T 2019 are provided on the opening side of a housing T 2017 . Specifically, as indicated by arrow T 2032 in FIG. 10 , a portion of the obstacle T 2019 at the bottom of an ink reservoir T 2001 , the portion extending from an end to the upper part of the obstacle T 2019 , is covered with a flexible film T 2027 .

In the ink tank with this configuration, part of alternative paths T 2023 , as well as the obstacle T 2019 , is consistently covered with the flexible film T 2027 , which constitutes a part of the ink reservoir T 2001 . Specifically, a dotted line in FIG. 10 represents the bottom surface of one of the alternative paths T 2023 in the housing T 2017 and indicates that the upper side of the alternative path T 2023 is partially covered with the flexible film T 2027 .

The flexible film T 2027 , which covers the alternative paths T 2023 , can thus further reduce ink pressure generated by external force or shocks, and can regulate the flow of ink to ensure a reliable flow of ink along the alternative paths T 2023 . The effect of preventing ink from easily spattering from the ink supply port T 2002 can thus be achieved.

Fifth Exemplary Embodiment

FIG. 12 is a cross-sectional view illustrating an exemplary ink tank according to the fifth exemplary embodiment of the present invention. FIG. 13 is a perspective view illustrating an exemplary internal configuration of the ink tank in FIG. 12 .

As illustrated in FIG. 12 and FIG. 13 , in the ink tank of the present exemplary embodiment, channel-like alternative paths T 2023 are provided on the upper surface of an obstacle T 2019 , which has the shape of an overhang and protrudes from inside a housing T 2017 .

Thus, the alternative paths T 2023 can be created not only on respective sides of the obstacle T 2019 , but also in other areas near an ink supply port. Even if a flexible film T 2027 bends to cover the obstacle T 2019 , an ink channel can be secured.

By using the configuration described above, it is possible to reduce ink pressure generated by external force or shocks, and to regulate the flow of ink to ensure a reliable flow of ink along the alternative paths T 2023 . The effect of preventing ink from easily spattering from the ink supply port T 2002 can thus be achieved.

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 modifications, equivalent structures and functions.

This application claims the benefit of Japanese Application No. 2005-255092 filed Sep. 2, 2005, which is hereby incorporated by reference herein in its entirety.