# Patent

## Title
Method of manufacturing liquid container and liquid container

## Abstract

A method of manufacturing a liquid container, the liquid container including a liquid containing chamber in which a liquid can be contained, an air communicating passage allowing the liquid containing chamber to communicate with air, a liquid supply port for supplying the liquid contained in the liquid container to an outside, a liquid flow passage allowing the liquid container and the liquid supply port to communicate with each other, a differential pressure valve which is disposed in the liquid flow passage, which is normally urged to a closed state, and which is changed to an opened state when a differential pressure between a side of the liquid supply port and a side of the liquid containing chamber is equal to or more than a predetermined value, and a blocked portion formed by closing a bypass flow passage allowing a supply port side flow passage that is closer to the liquid supply port than the differential pressure valve to communicate with a containing chamber side flow passage that is closer to the liquid containing chamber than the differential pressure valve, so as to bypass the differential pressure valve, the method includes; opening at least a part of the blocked portion so as to form the bypass flow passage; injecting the liquid into the liquid containing chamber from the liquid supply port via the supply port side flow passage, the bypass flow passage, and the containing chamber side flow passage; and blocking the bypass flow passage after injecting the liquid.

## Background
BACKGROUND
1. Technical Field
The present invention relates to a method of manufacturing a liquid container in which a liquid containing chamber contains a liquid such as ink and a liquid container manufactured by the method.
2. Related Art
As such a kind of a liquid container, an ink cartridge mounted on a liquid jetting apparatus such as, for example, an ink jet printer is suggested (for example, see Patent Document 1). In general, the ink cartridge includes a container body having a substantially flat boxlike shape which is detachable from a cartridge holder included in the liquid jetting apparatus, and films which are attached to both the front and back surfaces of the container body.
The container body is provided with an ink supply port, which is connected to an ink receiver, such as an ink supply needle provided in the cartridge holder when the container body is mounted on the cartridge holder of the liquid jetting apparatus. In the inside of the container body, an ink containing chamber for containing ink, an air communicating passage for allowing the inside of the ink containing chamber to communicate with the air, and an ink flow passage for allowing the ink containing chamber and the ink supply port to communicate with each other are partitioned so that a plurality of partition walls and the films form wall surfaces. Further, a differential pressure valve, which is interposed in the way of the ink flow passage, is normally urged to a closed state while changed to an opened state when a differential pressure between a side of the ink supply port and a side of the ink containing chamber is equal to or more than a predetermined value
For this reason, when the ink cartridge is mounted on the cartridge holder of the liquid jetting apparatus and when the differential pressure between the side of the ink supply port and the side of the ink containing chamber is equal to or more than a predetermined value according to ink consumption of the liquid jetting apparatus, the differential pressure valve becomes the opened state. Accordingly, the ink contained in the ink containing chamber is supplied to the ink supply port via the ink flow passage so as to be consumed by the liquid jetting apparatus. Alternatively, when the ink cartridge is not mounted on the cartridge holder of the liquid jetting apparatus or the differential pressure of the side of the ink supply port and the side of the ink containing chamber is less than the predetermined value while the ink cartridge is mounted on the cartridge holder of the liquid jetting apparatus, the differential pressure valve is maintained to be in the closed state. As a result, the ink flow from the ink containing chamber to the ink supply port is blocked so that the unnecessary ink does not leak from the ink supply port.
Patent Document 1: JP-A-2003-94682
However, when the residual ink in the ink containing chamber decreases to a very small amount or zero and thus the ink supply is not satisfied, the ink cartridge that is used up is recovered, and then an individual configuration member thereof in which a method of disposing waste matters is different is usually classified to fall into dispose. For example, a film is removed from the container body. For this reason, in the known ink cartridge, when the residual ink decreases to the extent that the ink supply is poor, the used ink cartridge may be disposed. As a result, a wasteful use of the resource may happen.
Further, in the process of manufacturing the known ink cartridge, an ink injecting-only hole for injecting ink into an ink containing chamber is generally formed in the container body so as to inject the ink from the ink injecting-only hole to the ink containing chamber. However, in such a manufacturing method, it may be necessary to seal the ink injecting-only hole used to inject the ink, by attaching a sealing film after the ink is injected. Accordingly, the process of manufacturing the ink cartridge may be complicated and the number of the components may increase.
For this reason, when the ink cartridge that includes the ink containing chamber containing the ink is manufactured, there is recently a demand for a method of manufacturing the ink cartridge in which the ink can be easily and efficiently injected into the liquid containing chamber and the resources can be effectively used without using the ink injecting-only hole
SUMMARY
An advantage of some aspects of the invention is to provide a method of manufacturing a liquid container in which liquid can be easily and efficiently injected to a liquid containing chamber when the liquid container that includes the liquid containing chamber containing the liquid is manufactured and the resources can be effectively used for the liquid container in which the residual ink decreases to the extent that the ink supply is poor, and a liquid container manufactured by the method. The advantage can be attained by at least one of the following aspects:
A first aspect of the invention provides a method of manufacturing a liquid container, the liquid container comprising a liquid containing chamber in which a liquid can be contained, an air communicating passage allowing the liquid containing chamber to communicate with air, a liquid supply port for supplying the liquid contained in the liquid container to an outside, a liquid flow passage allowing the liquid container and the liquid supply port to communicate with each other, a differential pressure valve which is disposed in the liquid flow passage, which is normally urged to a closed state, and which is changed to an opened state when a differential pressure between a side of the liquid supply port and a side of the liquid containing chamber is equal to or more than a predetermined value, and a blocked portion formed by closing a bypass flow passage allowing a supply port side flow passage that is closer to the liquid supply port than the differential pressure valve to communicate with a containing chamber side flow passage that is closer to the liquid containing chamber than the differential pressure valve, so as to bypass the differential pressure valve, the method comprising; opening at least a part of the blocked portion so as to form the bypass flow passage; injecting the liquid into the liquid containing chamber from the liquid supply port via the supply port side flow passage, the bypass flow passage, and the containing chamber side flow passage; and blocking the bypass flow passage after injecting the liquid.
According to the method of manufacturing the liquid container, the bypass flow passage for bypassing the differential pressure valve is formed by opening the blocked portion. Accordingly, when the liquid is injected into the liquid containing chamber, the liquid supply port originally used for supplying the liquid to the liquid jetting apparatus can be also used for injecting the liquid without using an ink injecting-only hole. When the residual liquid in the liquid containing chamber decreases to the extent that the liquid supply is poor, the liquid container can be reused by re-injecting the liquid from the liquid supply port to the liquid containing chamber. As a result, it is unnecessary to recover/dispose the used liquid container. Moreover, since the bypass flow passage is blocked after the ink injecting process, there is also no case where an ink leaks or the like. Accordingly, when the liquid container that includes the liquid containing chamber containing the liquid is manufactured, the liquid can be easily and effectively injected into the liquid containing chamber and the resources can be also effectively used as much as possible in the liquid container in which the residual liquid decreases to the extent that the liquid supply is poor.
In the method of manufacturing the liquid container, the bypass flow passage may be formed by forming a gap between a top surface of a partition wall formed in the liquid container to partition the supply port side flow passage and the containing chamber side flow passage, and a film member attached to the top surface so as to cover both the supply port side flow passage and the containing chamber side flow passage.
According to the method of manufacturing the liquid container, the gap formed between the top surface of the partition wall and the film member serves as the bypass flow passage in which the liquid injected from the liquid supply port flows over the partition wall from the supply port side flow passage, bypasses the differential pressure valve, and then flows in the containing chamber side flow passage. As a result, the bypass flow passage can be easily formed even though a new partition wall for forming the bypass flow passage in the container body is not manufactured.
In the method of manufacturing the liquid container, an attachment portion of the film member may be detached from the top surface of the partition wall by heating the attachment portion so as to form the gap between the attachment portion and the top surface.
According to the method of manufacturing the liquid container, even when the film member is attached to the top surface of the partition wall, when the attachment portion between the top surface of the partition wall and the film member is heated, the attachment portion is easily detached upward from the top surface of the partition wall, and therefore the gap is formed between the top surface of the partition wall and the film member. As a result, the bypass flow passage can be easily and effectively formed.
The method of manufacturing the liquid container further may include a depressurization process of depressurizing the inside of the liquid containing chamber before the liquid injecting process.
According to the method of manufacturing the liquid container, since the inside of the liquid containing chamber is depressurized in the depressurization process, the liquid can be effectively injected into the ink containing chamber in the subsequent ink injecting process.
In the method of manufacturing the liquid container, the inside of the liquid containing may be depressurized through the air communicating passage in the depressurization process.
According to the method of manufacturing the liquid container, when the inside of the liquid containing chamber is depressurized and even when the depressurization-only passage is not provided in the container body, the air communicating passage can be also used as the depressurization hole. As a result, a rigidity can be satisfactorily guaranteed without configuring the complex container body.
In the method of manufacturing the liquid container, the method may further comprise removing at least a part of a valve mechanism provided in the liquid supply port before injecting the liquid.
According to the method, the injection of the liquid can be facilitated.
In the method of manufacturing the liquid container, the method may further comprise sealing the liquid supply port with a sealing film after injecting the liquid.
According to the method, the leakage of the liquid through the liquid supply port can be prevented.
In the method of manufacturing the liquid container, the method may further comprise removing a part of a sealing film attached to the liquid supply port before the at least a part of the valve mechanism is removed.
According to the method, the removal of the valve member can be facilitated.
A second aspect of the invention provides a liquid container manufactured by the method.
A third aspect of the invention provides a method of manufacturing a liquid container, the liquid container comprising a liquid containing chamber in which a liquid can be contained, an air communicating passage allowing the liquid containing chamber to communicate with air, a liquid supply port for supplying the liquid contained in the liquid container to an outside, a liquid flow passage allowing the liquid container and the liquid supply port to communicate with each other, a differential pressure valve which is disposed in the liquid flow passage, which is normally urged to a closed state, and which is changed to an opened state when a differential pressure between a side of the liquid supply port and a side of the liquid containing chamber is equal to or more than a predetermined value, and a blocked portion formed by closing a bypass flow passage allowing a supply port side flow passage that is closer to the liquid supply port than the differential pressure valve to communicate with the liquid containing chamber, so as to bypass the differential pressure valve, the method comprising; opening at least apart of the blocked portion so as to form the bypass flow passage; injecting the liquid into the liquid containing chamber from the liquid supply port via the supply port side flow passage and the bypass flow passage; and blocking the bypass flow passage after injecting the liquid.
According to the method of manufacturing the liquid container, the bypass flow passage for bypassing the differential pressure valve is formed by opening the blocked portion. Accordingly, when the liquid is injected into the liquid containing chamber, the liquid supply port originally used for supplying the liquid to the liquid jetting apparatus can be also used for injecting the liquid without using an ink injecting-only hole. When the residual liquid in the liquid containing chamber decreases to the extent that the liquid supply is poor, the liquid container can be reused by re-injecting the liquid from the liquid supply port to the liquid containing chamber. As a result, it is unnecessary to recover/dispose the used liquid container. Moreover, since the bypass flow passage is blocked after the ink injecting process, there is also no case where an ink leaks or the like. Accordingly, when the liquid container that includes the liquid containing chamber containing the liquid is manufactured, the liquid can be easily and effectively injected into the liquid containing chamber and the resources can be also effectively reused as much as possible in the liquid container in which the residual liquid decreases to the extent that the liquid supply is poor.
In the method of manufacturing the liquid container, the bypass flow passage may be formed by forming a gap between a top surface of a partition wall formed in the liquid container to partition the supply port side flow passage and the liquid containing chamber, and a film member attached to the top surface so as to cover both the supply port side flow passage and the liquid containing chamber.
According to the method of manufacturing the liquid container, the gap formed between the top surface of the partition wall and the film member serves as the bypass flow passage in which the liquid injected from the liquid supply port flows over the partition wall from the supply port side flow passage, bypasses the differential pressure valve, and then flows in the containing chamber. As a result, the bypass flow passage can be easily formed even though a new partition wall for forming the bypass flow passage in the container body is not manufactured.
In the method of manufacturing the liquid container, an attachment portion of the film member may be detached from the top surface of the partition wall by heating the attachment portion so as to form the gap between the attachment portion and the top surface.
According to the method of manufacturing the liquid container, even when the film member is attached to the top surface of the partition wall, when the attachment portion between the top surface of the partition wall and the film member is heated, the attachment portion is easily detached upward from the top surface of the partition wall, and therefore the gap is formed between the top surface of the partition wall and the film member. As a result, the bypass flow passage can be easily and effectively formed.
The method of manufacturing the liquid container further may include a depressurization process of depressurizing the inside of the liquid containing chamber before the liquid injecting process.
According to the method of manufacturing the liquid container, since the inside of the liquid containing chamber is depressurized in the depressurization process, the liquid can be effectively injected into the ink containing chamber in the subsequent ink injecting process.
In the method of manufacturing the liquid container, the inside of the liquid containing may be depressurized through the air communicating passage in the depressurization process.
According to the method of manufacturing the liquid container, when the inside of the liquid containing chamber is depressurized and even when the depressurization-only passage is not provided in the container body, the air communicating passage can be also used as the depressurization hole. As a result, a rigidity can be satisfactorily guaranteed without configuring the complex container body.
In the method of manufacturing the liquid container, the method may further comprise removing at least a part of a valve mechanism provided in the liquid supply port before injecting the liquid.
According to the method, the injection of the liquid can be facilitated.
In the method of manufacturing the liquid container, the method may further comprise sealing the liquid supply port with a sealing film after injecting the liquid.
According to the method, the leakage of the liquid through the liquid supply port can be prevented.
In the method of manufacturing the liquid container, the method may further comprise removing a part of a sealing film attached to the liquid supply port before the at least a part of the valve mechanism is removed.
According to the method, the removal of the valve member can be facilitated.
A fourth aspect of the invention provides a liquid container manufactured by the method.



BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
FIG. 1 is a perspective view illustrating the front surface of an ink cartridge according to an exemplary embodiment.
FIG. 2 is a perspective view illustrating the rear surface of the ink cartridge according to the same exemplary embodiment.
FIG. 3 is an exploded perspective view illustrating the front surface of the ink cartridge according to the same exemplary embodiment.
FIG. 4 is an exploded perspective view illustrating the rear surface of the ink cartridge according to the same exemplary embodiment.
FIG. 5 is a front (fore) view illustrating the ink cartridge according to the same exemplary embodiment.
FIG. 6 is a rear (back) view illustrating the ink cartridge according to the same exemplary embodiment.
FIGS. 7(a) and 7(b) are schematically sectional views illustrating the ink cartridge according to the same exemplary embodiment, in which FIG. 7(a) is an explanatory view of a differential pressure valve in the closed state and FIG. 7(b) is an explanatory view of the differential pressure valve in the opened state.
FIG. 8 is a block diagram illustrating an ink injecting process.
FIG. 9 is schematically sectional view illustrating the ink cartridge equipped when the ink injecting process starts.
FIGS. 10(a) to 10(d) are sectional views illustrating major portions to describe a bypass forming process, in which FIG. 10(a) is the sectional view illustrating a state at an initial injecting time, FIG. 10(b) is the sectional view illustrating a state after the initial injecting time, FIG. 10(c) is the sectional view illustrating a state before a re-injecting time, and FIG. 10(d) is the sectional view during the re-injecting time.



DESCRIPTION OF EXEMPLARY EMBODIMENTS
First Exemplary Embodiment
Hereinafter, a first exemplary embodiment of the invention embodying an ink cartridge mounted on an ink jet printer (abbreviated to a “printer”), which is a kind of a liquid jetting apparatus, will be described in detail with reference to the accompanying FIGS. 1 to 9. Moreover, in the following description of exemplary embodiments, “a front and rear direction, “a right and left direction”, and “an upward and downward direction denote the front and rear direction, the right and left direction, and the upward and downward direction, respectively indicated by arrows shown in FIGS. 1 to 4.
As shown in FIGS. 1 to 4, an ink cartridge (liquid container) 11 according to this exemplary embodiment includes a container body 12 of which the front surface (one surface) made of a synthetic resin such as, for example, polypropylene (PP) or the like is opened and which has a substantially flat rectangular shape. In the front surface of the container body 12, a front film (film member) 13 made of a material to be heat welded is attached to substantially cover the whole surface of an opening 12a, and a cover 14 is detachably attached so as to hide the opening 12a from the outside (front surface) of the front film 13. Further, in the rear surface and upper surface of the container body 12, a rear film 15 made of a material to be heat welded is attached so as to substantially cover the whole rear surface and the upper surface thereof.
As shown in FIGS. 1 and 3, in the right surface of the container body 12, an erroneous mount preventing protrusion 16 for preventing the ink cartridge 11 from being erroneously mounted on a cartridge holder (not shown) provided in the printer is extended in the upward and downward direction. The erroneous mount preventing protrusion 16 is formed of each different shape according to a kind of ink color and an erroneous mount preventing concave (not shown) having a different shape according to the kind of the ink color is provided in the cartridge of the printer so as to individually correspond to the erroneous mount preventing protrusion 16 of each ink color. That is, even when the plurality of cartridges having different colors are mounted on the cartridge holders of the printer, the ink cartridge 11 cannot be mounted on inappropriate places except a place where the erroneous mount preventing concave only fitted with the erroneous mount preventing protrusion 16 in the ink cartridge 11 is formed.
Meanwhile, as shown in FIGS. 1 to 4, an engagement lever 17 formed so as to be elastically deformed is extended obliquitously upward in the right side from the upper portion of the left surface of the container body 12. In the substantial center of the right surface which is a surface of the engagement lever 17, a locking piece 17a is protruded so as to come in a horizontal direction. Accordingly, when the ink cartridge 11 is mounted on the cartridge holder of the printer, the engagement lever 17 is elastically deformed and the locking piece 17a is locked in a part of the cartridge holder so that the ink cartridge 11 is locked to the cartridge holder
As shown in FIG. 4, in the left surface of the container body 12, a sensor accommodating chamber 18 is concavely formed below the engagement lever 17. A sensor unit 19 including a sensing mechanism (not shown) that generates vibration and outputs the residual vibration to the printer such that the printer can detect whether ink is present or not when the ink cartridge 11 is mounted on the cartridge holder of the printer and a coil spring 20 that presses the sensor unit 19 against the inner wall of the sensor accommodating chamber 18 are accommodated in the sensor accommodating chamber 18. Further, an opening of the right surface of the sensor accommodating chamber 18 is blocked by a cover member 21.
A circuit board 22 including a semiconductor storage element is provided on the surface of the cover member 21 and various kinds of information (for example, ink color information, residual ink information, and so on) on the ink cartridge 11 is stored in the semiconductor storage element. Moreover, when the ink cartridge 11 is mounted on the cartridge holder of the printer, a terminal 22a that is exposed to the surface is connected to a connecting terminal of the cartridge holder so that the circuit board 22 can send and receive the various kinds of the information to and from a control device (not shown) of the printer.
As shown in FIG. 4, an air introducing hole 23 for introducing air from atmosphere to the inside of the container body 12 and an ink supply port (liquid supply port) 24 into which an ink supply needle (not shown) provided in the cartridge holder is inserted when the ink cartridge 11 is mounted on the cartridge holder of the printer are opened in the lower surface of the container body 12. That is, the ink cartridge 11 is an ink cartridge of an open type that supplies ink (liquid) from the ink supply port 24 to the printer (that is, the container body 12 and so on) while introducing air from the air introducing hole 23 to the inside of the container body 12.
As shown in FIGS. 2 and 4, the air introducing hole 23 is sealed by a sealing film 25. Before the ink cartridge 11 is mounted on the cartridge holder of the printer to be used, the sealing film 25 is removed by a user. When the sealing film 25 is removed and then the air introducing hole 23 is exposed to the outside, the inside of the container body 12 of the ink cartridge 11 can be allowed to communicate with the air. Similarly, the ink supply port 24 is sealed by a sealing film 26. When the ink cartridge 11 is mounted on the cartridge holder of the printer, the sealing film 26 is pierced by the ink supply needle provided in the cartridge holder.
As shown in FIGS. 3 and 4, in the inside of the ink supply port 24, a valve mechanism V constituted by a ring-shaped sealing member 27 having a through hole in the middle and made of elastomer and soon, which allows the ink supply needle of the cartridge holder to be inserted into the ink supply port 24, a supply valve 28 seated on sealing member 27, and a coil spring 29 urging the supply valve 28 toward the sealing member 27 is accommodated. That is, the supply valve 28 urged by the coil spring 29 is brought in press-contact with the sealing member 27, and thus the ink supply port 24 is normally blocked so that the ink cannot drain to the container body 12 and so on. Alternatively, when the ink supply needle of the cartridge holder is inserted into the ink supply port 24, the supply valve 28 pressed by the ink supply needle resists against the urging force of the coil spring 29, moves the inside of the ink supply port 24 to be separated from the sealing member 27. Accordingly, the ink supply port 24 becomes the opened state so that the ink can be allowed to drain to the container body 12 and so on. Meanwhile, since the coil spring 29 is an example of an elastic member, the elastic member of the invention is not limited thereto as long as it urges the supply valve 28 toward the sealing member 27. In addition, a valve mechanism of the invention is not limited to the valve mechanism of this exemplary embodiment and thus known valve mechanisms, for example a valve mechanism that does not have a through hole and allows the ink supply needle of the cartridge holder to be inserted and penetrated therethrough so as to drain the ink, can be used.
Similarly, in the lower surface of the container body 12, a depressurization hole 30 for depressurizing the inside of the container body 12 by sucking air from the inside thereof before the process of injecting the ink into the ink cartridge 11 is opened in the left side of the air introducing hole 23. Further, the depressurization hole 30 is sealed by a sealing film 31. Between the air introducing hole 23 and the ink supply port 24, a concave portion 32 that constitutes a part of an ink flow passage (liquid flow passage) from an ink containing chamber 36 to the ink supply port 24 is formed. Similarly, the concave portion 32 is sealed by a sealing film 33. Further, a lower surface opening 18a of the sensor accommodating chamber 18 is formed in the right side of the ink supply port 24. The opening 18a is also sealed by a sealing film 34.
Next, an inner structure of the container body 12 of the ink cartridge 11 will be described.
As shown in FIGS. 3 and 5, in the inside of a opening 12a of the container body 12, the plurality of chambers such as the ink containing chamber (liquid containing chamber) 36 and so on and flow passages are partitioned by a plurality of ribs (partition walls) 35 provided upright from the bottom surface of the opening 12a in a thicknesswise direction of the container body 12. Meanwhile, as shown in FIGS. 4 and 6, a concavely circular differential pressure valve accommodating chamber 36 that accommodates a differential pressure valve 37 and a concavely rectangular gas-liquid separating chamber 39 are formed in the back surface (rear surface) of the container body 12.
In the inside of the differential pressure valve accommodating chamber 38, a substantial disk-shaped membrane valve (valve body) 40 that is elastically deformable, a valve cover 41 that covers the port of the differential pressure valve accommodating chamber 38, a coil spring 42 that is disposed between the valve cover 41 and the membrane valve 40 are stored. Since the differential valve accommodating chamber 38 is positioned between the ink containing chamber 36 and the ink supply port 24, the differential pressure valve 37 is interposed in the way of the ink flow passage that communicates with the ink containing chamber 36 and the ink supply port 24 each other.
In the bottom surface of the gas-liquid separating chamber 39, a rectangular ring-shaped protrusion portion 43 is formed along the inner surface thereof and a rectangular gas-liquid separating film 44 fitted into the top portion of the protrusion portion 43 is attached. The gas-liquid separating film 44 that is made of a material capable of passing gas, but blocking liquid has a function of separating gas (air) from liquid (ink). That is, the gas-liquid separating film 44 is interposed in the way of an air communicating passage 60 (see FIG. 6) that communicates with the air introducing hole 23 and the ink containing chamber 36 each other so that the ink in the ink containing chamber 36 does not drain from the air introducing hole 23 to the container body 12 and so on via the air communicating passage 60.
Next, a configuration of the ink flow passage from the ink containing chamber 36 to the ink supply port 24 will be described with reference to FIGS. 5 and 6.
As shown in FIG. 5, in the front surface of the container body 12, the ink containing chamber 36 divided into an upper ink containing chamber 45 and a lower ink containing chamber 46 by the ribs 35 is defined. Further, a substantially rectangular containing chamber side flow passage 47 that serves as a buffer chamber is partitioned to be positioned between the upper ink containing chamber 45 and the lower ink containing chamber 46. A lengthwise long supply port side flow passage 48 is partitioned to be positioned between the containing chamber side flow passage 47 and the lower ink containing chamber 46.
In the lowest position of the upper ink containing chamber 45, a through-hole 49 is formed in the thicknesswise direction (front and rear direction) of the container body 12. A through-hole 50 is formed below the through-hole 49 and in the lowest position of the lower ink containing chamber 46. As shown in FIG. 6, a communicating flow passage 51 formed in the rear surface of the container body 12 allows the through holes 49 and 50 to communicate with each other. The ink flows from the upper ink containing chamber 45 to the lower ink containing chamber 46 through the communicating flow passage 51.
As shown in FIG. 5, in the front surface of the container body 12, a communicating flow passage 52 that communicates with the lower ink containing chamber 46 through a through-hole not shown is provided in the side of the lower ink containing chamber 46. In addition, the communicating flow passage 52 communicates with the inside of the above-described sensor accommodating chamber 18 through a through-hole not shown. The communicating flow passage 52 has a three-dimensional labyrinthine structure which catches bubbles and the like in the ink so that the bubbles and so on does not flow downstream along with the ink.
As shown in FIG. 5, in the front surface of the container body 12, a through-hole 53 is formed in the containing chamber side flow passage 47. Meanwhile, as shown in FIG. 6, in the rear surface of the container body 12, a communicating flow passage 54 (see FIG. 6) that extends from the sensor accommodating chamber 18 to the above-described through-hole 53 of the containing chamber side flow passage 47 is formed. Further, in the containing chamber side flow passage 47, a through-hole 55 is formed below the through-hole 53. The through-hole 55 communicates with a valve hole 56, which is formed above the inside of the supply port side flow passage 48 and at the center of differential pressure valve accommodating chamber 38, through the differential pressure valve accommodating chamber 38.
As shown in FIG. 5, a through-hole 57 is formed below the inside of the supply port side flow passage 48 and the supply port side flow passage 48 communicates with the ink supply port 24 through the through-hole 57. As described above, in this exemplary embodiment, the ink flow passage (liquid flow passage) from the ink containing chamber 36 (lower ink containing chamber 46) to the ink supply port 24 includes the communicating flow passage 52, the communicating flow passage 54, the containing chamber side flow passage 47, and the supply port side flow passage 48 described above. Further, these ink flow passages, the ink containing chamber 36, and so on are each formed as a part of wall surfaces of the above-described front film 13 and the rear film 15 attached to the front surface and the rear surface of the container body 12.
Next, a passage structure of the air communicating passage 60 from the gas introducing hole 23 to the ink containing chamber 36 will be described with reference to FIGS. 5 and 6.
As shown in FIG. 6, in the rear surface of the container body 12, a through-hole 61 is formed to communicate with the gas introducing hole 23 in the vicinity of the gas introducing hole 23. Meandering-shaped narrow grooves 62 that communicate with the above-described gas-liquid separating chamber 39 are formed upward from the through-hole 61 and a through-hole 63 is formed in the bottom surface inside the gas-liquid separating chamber 39. The through-hole 63 communicates with the lower portion of a communicating passage 64 partitioned in the front surface of the container body 12 and a through-hole 65a is formed above the communicating passage 64. A through-hole 65h is formed immediately beside the through-hole 65a. In the rear surface of the container body 12, a communicating passage 66 including a returning portion 66a allows both of the through-holes 65a and 65b to communicate with each other.
As shown in FIG. 5, in the right corner of the front surface of the container body 12, a rectangular ink trap chamber 67 is partitioned to communicate with the above-described through-hole 65b. An L-shaped communicating buffer chamber 68 is formed below the ink trap chamber 67. Both of the chambers 67 and 68 communicate with each other through a notch 67a. A through-hole 69 is formed in the lower portion of the communicating buffer chamber 68. The through-hole 69 communicates with a through-hole 71 opened to the upper ink containing chamber 45 through a communicating passage 70 formed so as to have an L-shape in the rear surface of the container body 12. Further, in this exemplary embodiment, the narrow grooves 62, the gas-liquid separating chamber 39, the communicating passages 64 and 66, the ink trap chamber 67, the communicating buffer chamber 68, and the communicating passage 70 constitute the air communicating passage 60 formed from the air introducing hole 23 to the ink containing chamber 36 (upper ink containing chamber 45).
Next, a function of the differential pressure valve 37 will be described with reference to FIGS. 7(a) and 7(b).
As shown in FIG. 7(a), the differential pressure valve 37 is urged to the closed state in the way that the membrane valve 40 normally closes the valve hole 56 by an urging force of the coil spring 42, and thus the ink that flows from the ink containing chamber 36 to the ink supply port 24 is blocked. Alternatively, a pressure of a side of the ink supply port 24, that is a pressure inside the differential pressure valve accommodating chamber 38 (back pressure of the membrane valve 40) is lowered according to the ink supply from the ink supply port 24 to the printer. Since the ink containing chamber 36 always communicates with air, a differential pressure between the side of ink supply port 24 and the side of the ink containing chamber 36 of the differential pressure valve 37 is caused by the ink supply from the ink supply port 24 to the printer. Accordingly, as shown in FIG. 7(b), when the differential pressure between the side of ink supply port 24 and the side of the ink containing chamber 36 of the differential pressure valve 37 is equal to or more than a predetermined value, the membrane valve 40 is elastically deformed against the urging force of the coil spring 42 and separated from a valve seat 56a surrounding the valve hole 56. Then, the differential pressure valve 37 allows the ink to flow from the ink containing chamber 36 to the ink supply chamber 24. Further, in FIG. 7(b), an arrow that denotes the ink flow is indicated and the sealing member 27, the supply valve 28, and the coil spring 29 in the inside of the ink supply port 24 are not shown.
Next, a method of manufacturing the ink cartridge 11 according to this exemplary embodiment, particularly the method of manufacturing the ink cartridge 11 by injecting the ink into the ink containing chamber 36 from the outside of the container body 12 will be described below.
In the ink cartridge 11 according to this exemplary embodiment, an ink injecting hole only for injecting the ink is not provided. For this reason, when the ink is injected into the ink containing chamber 36 initially and even when the ink is re-injected to refill ink in spite of the fact that the residual ink in the ink containing chamber 36 decreases to the extent that the liquid supply is poor, the ink supply port 24 originally used for supplying ink to the printer is also used for injecting the ink.
However, when the ink is injected into the ink containing chamber 36 of the ink cartridge 11, as shown in FIG. 8, an ink injecting apparatus 85 is used. The ink injecting apparatus 85 includes an ink injecting tube 86 that is connected airtight to the ink supply port 24 of the ink cartridge 11 and a vacuum suction tube 87 that is connected airtight to the depressurization hole 30 of the ink cartridge 11. Further, an ink injecting mechanism 88 is provided in the ink injecting tube 86. A vacuum suction mechanism 89 is provided in the vacuum suction tube 87.
The ink injecting mechanism 88 includes a valve 90 for opening/closing the ink injecting tube 86, a large-scale ink tank 91 for retaining ink, and a pump 92 for sending the ink tank 91 to the ink injecting tube 86. The ink injecting mechanism 88 allows and blocks the ink to be injected by the opening/closing operation of the valve 90. Meanwhile, the vacuum suction mechanism 89 includes a valve 93 for opening/closing the vacuum suction tube 87, a vacuum pump 94 for performing vacuum sucking through the vacuum suction tube 87, and an ink trap 95, which is disposed between valve 93 and the vacuum pump 94, for trapping the ink that flows into the vacuum suction tube 87.
However, even when the ink is sent into the ink supply port 24 by using the ink injecting apparatus 85, the differential pressure valve 37 urged to the closed state is interposed between the ink supply port 24 and the ink containing chamber 36, and thus the ink flow is blocked. Accordingly, in this exemplary embodiment, the following process is performed before the ink injecting process (liquid injecting process)
First, when the ink is initially injected and when the front film 13 is attached to the front surface (one surface) of the container body 12, gaps are formed between the top surface of the rib 35 surrounding the supply port side flow passage 48 and the front film 13. That is, as shown in FIG. 5, a plurality of protrusions 35a are formed at a predetermined interval on the top surface of the rib 35 surrounding the supply port side flow passage 48 so that the top surface between the respective protrusions 35a does not come in contact with the front film 13. Accordingly, the gaps through which the ink can flow are formed in spaces between the front film 13 and the top surface that is between the respective protrusions 35a on the rib 35.
As a result, a bypass flow passage 80 that allows the ink to bypass the differential pressure valve 37 by flowing over the rib 35 from the supply port side flow passage 48 via the gaps can be formed so as to flow the ink to the containing chamber flow passage 47. Further, after the bypass forming process of forming the bypass flow passage 80 ends, the ink injecting apparatus 85 is connected to the ink cartridge 11.
That is, the ink injecting tube 86 of the ink injecting apparatus 85 is connected to the ink supply port 24 and the vacuum suction tube 87 of the ink injecting apparatus 85 is connected to the depressurization hole 30. When the connecting operations are performed, the sealing member 27, the supply valve 28, and the coil spring 29 are preferably removed from the inside of the ink supply port 24. In this case, it is necessary for the air introducing hole 23 to be sealed by the sealing film 25.
Next, the vacuum pump 94 is driven to perform depressurization process while the valve 90 of the ink injecting mechanism 88 is in the closed state and the valve 93 of the vacuum suction mechanism 89 is in the opened state. Then, the inner pressure of the ink containing chamber 36 is depressurized up to a predetermined pressure. When the depressurization process ends, the ink injecting process is performed by using the ink injecting apparatus 85.
In this case, a pump 92 of the ink injecting mechanism 88 is driven while the valve 93 of the vacuum suction mechanism 89 is in the closed state and the valve 90 of the ink injecting mechanism 88 is in the opened state. Then, the ink sent from the ink tank 91 to the ink injecting tube 86 flows into the ink supply port 24, and then is injected into the ink containing chamber 36 through the supply port side flow passage 48, the bypass flow passage 80, and the containing chamber side flow passage 47.
Next, when the ink injecting process (initial injecting process) ends, the ink supply port is sealed by the sealing film 34 and a bypass block process of blocking the bypass flow passage 80 is finally performed That is, each protrusion 35a on the rib 35 surrounding the supply port side flow passage 48 is pressure-heated from the upper portion of the front film 13 by using a jig such as heating iron. Then, the protrusions 35a on the rib 35 surrounding the supply port side flow passage 48 are melted, and therefore the front film 13 is heat-welded into the top surface of the rib 35. Further, the bypass flow passage 80 is blocked, and thus a blocked portion 81 (see FIG. 8) is formed. Accordingly, when the initial ink injecting process ends, the process of manufacturing the ink cartridge 11 by injecting the ink into the ink containing chamber 36 ends.
Meanwhile, when the ink cartridge 11 mounted on the printer is used, and afterward the residual ink in the ink containing chamber 36 decreases to the very small amount or zero, the ink re-injecting process is performed to reuse the ink cartridge 11 in the following way. That is, when the ink is re-injected, a bypass forming process of forming a gap for the bypass flow passage 80 in the above-described blocked portion 81 is performed before the ink re-injecting process.
First, as shown in FIG. 9, the sealing member 27, the supply valve 28, and the coil spring 29 that constitute the valve mechanism V are removed from the ink supply port 24 (valve mechanism removing process). At this time, as shown in FIG. 10(b), in the top surface of the rib 35 surrounding the supply port side flow passage 48, the front film 13 is attached by means of a heat welding, and thus the blocked portion 81 is formed. Moreover, each protrusion 35a of the top surface of the rib 35 is melt by means of a pressure-heat using a heating iron in the blocking process that is performed after the initial injecting process. Then, the top surface of the rib 35 becomes substantially flat. If it is necessary to remove at least a part of the sealing film 34 so as to remove the at least a part of the valve mechanism V, a sealing film removing process of removing at least a part of the sealing film 34 thermally welded to the ink supply port is performed prior to the valve mechanism removing process.
Next, in the same way as the blocking process when the ink is initially injected, a heat treatment of the blocked portion 81 is performed by using a heating jig such as a heating iron 77 as shown in FIG. 10(c). In the blocked portion 81, the attachment portion between the top surface of the rib 35 and the front film 13 is melt by performing the heat treatment. Then, the front film 13 is detached upward from the top surface of the rib 35 as shown in FIG. 10(d). In this way, a gap for the bypass flow passage 80 is formed again between the front film 13 and the top surface of the rib 35.
When the bypass flow passage 80 is formed again, the ink injecting apparatus 85 is then connected to the ink cartridge 11 in the same way as the initial injecting process. The ink injecting process is performed by using the above-described ink injecting apparatus 85 in the same way as the initial injecting process. Of course, the depressurization process is also performed in the same way as the initial injection process before the ink injecting process. Further, it is necessary for the air introducing hole 23 to be sealed by the sealing film 25 or another sealing means.
Next, when the depressurization process ends, and then the ink injecting process starts, the ink sent from the ink tank 91 of the ink injecting apparatus 85 to the ink injecting tube 86 flows into the ink supply port 24. The ink that flows to the ink supply port 24 is injected into the ink containing chamber 36 via the supply port side flow passage 48, the bypass flow passage 80, and the containing chamber side flow passage 47.
Next, when the ink injecting process (re-injecting process) ends, a bypass blocking process of blocking the bypass flow passage 80 is finally performed in the same way as the initial injecting process. That is, the front film 13 is attached to the top surface of the rib 35 surrounding the supply port side flow passage 48 by using the jig such as the heating iron by means of the heat welding. Then, the blocked portion 81 to which the front film 13 is attached is formed on the rib 35 again. In this way, when the ink re-injecting process ends, the manufacturing process of the ink cartridge 11 that includes the ink containing chamber 36 containing the ink ends.
When the ink injecting process (re-injecting process) ends, the sealing member 27, the supply valve 28, and the coil spring 29 in the ink supply port 24 returns to the original position. Further, the ink supply port is sealed with another sealing film and thereby the process of manufacturing the ink cartridge 11 ends.
Accordingly, the following effects will be achieved according to this exemplary embodiment.
(1) When the ink is injected into the ink containing chamber 36, the ink supply port 24 originally used for supplying ink to the printer can be also used for injecting the ink without depending on the ink injecting-only hole. Therefore, a simplification of the ink cartridge 11, for example, by omitting the ink injecting-only hole, can contribute to a decrease in a product cost.
(2) When the residual ink in the ink containing chamber 36 decreases to a very small amount or zero and when ink is re-injected from the ink supply port 24, the ink cartridge 11 is reusable. Accordingly, it is unnecessary for the used ink cartridge to be recovered/disposed.
(3) When the ink cartridge 11 is manufactured by initially injecting or re-injecting the ink into the ink containing chamber 36, the ink is injected by using the ink supply port 24. In this case, the troublesome manual work such as removing a sealing film or re-attachment is not required as compared with the case where the ink-injecting-only hole is used. As a result, the ink can be easily and effectively injected into the ink containing chamber 36.
(4) When the residual ink in the ink cartridge 11 decreases to the extent that the ink supply is poor, the ink cartridge 11 is reusable by injecting ink from the ink supply port 24. As a result, unnecessary dispose can be suppressed, and thus an effective use of resources is possible.
(5) The bypass flow passage 80 is formed by forming the gap between the top surface of the rib 35 surrounding the supply port side flow passage 48 and the front film 13. Accordingly, it is unnecessary for a new rib for the bypass flow passage to be formed in the container body 12, and thus the bypass flow passage 80 can be easily formed.
(6) The gap for the bypass flow passage 80 is formed by re-heating the blocked portion 81 in which the front film 13 is heat-welded on the top surface of the rib 35 so as to melt the attachment portion of the blocked portion 81. As a result, the bypass flow passage 80 can be easily and effectively in this way.
(7) Since the inside of the ink containing chamber 36 is depressurized in the depressurization process before the ink injecting process, the ink can be effectively injected into the ink containing chamber 36 in the subsequent ink injecting process.
Each above-described exemplary embodiment can be modified into various forms as follows

    
    
        In the depressurization process, the vacuum suction tube 87 is connected to the air introducing hole 23, with the depressurization hole 30 sealed, and then the inside of the ink containing chamber 36 can be depressurized by sucking the air through the air communicating passage 60 without using the depressurization hole 30. According to the above-described configuration, since it is unnecessary for the depressurization hole 30 to be formed in the container body 12, a simplified configuration of the ink cartridge 11 can be achieved.
        The depressurization process can be omitted as long as it is not difficult to inject the ink into the ink containing chamber 36 by raising the injecting pressure at the time of injecting the ink without the depressurization.
        When the gap for the bypass flow passage 80 is formed between the top surface of the rib 35 and the front film 13 by heating the blocked portion 81 in the bypass forming process, other heating methods such as a hot air ejecting method, a heat ray irradiating method, and the like as well as the heating method by the heating iron can be used to detach the front film 13 from the top surface of the rib 35.
        In order to form the gap for the bypass flow passage 80 more effectively and reliably, a pressurization process of sending a pressurization gas (air) to the inside of an ink flow passage (liquid flow passage) can be provided after the heat treatment of the blocked portion 81 is performed in the bypass forming process. For example, the pressurization gas can be input from any part such as the depressurization hole used for sucking in the depressurization process, the air communicating passage, or the ink supply port 24.
        The gap for the bypass flow passage 80 can be formed by detaching the attachment portion between the front film 13 and the top surface of the rib 35 partitioning the supply port side flow passage 48 and the lower ink containing chamber 46, as well as the means of detaching the attachment portion of the front film 13 and the top surface of the rib 35 partitioning the supply port side flow passage 48 and the containing chamber side flow passage 47.
        When the front film 13 is completely attached to the top surface of the rib 35 in advance by means of heat welding in the blocked portion 81, and then even when the ink is initially injected, the blocked portion 81 that is the attachment portion can be detached by means of the heat treatment. In this way, the bypass flow passage 80 can be formed.
        The liquid container is not limited to the ink cartridge that is mounted on the printer to be used, but can be applied to a liquid container that is mounted on, for example, a printing apparatus that is used for a facsimile or a copier or a different liquid jetting apparatus for jetting a liquid such as an electrode material or a color material that are used for manufacturing a liquid crystal display, an EL display, a plane emission display, and so on. Moreover, the liquid container can be also applied to a liquid container that is mounted on a liquid jetting apparatus for jetting bioorganic matter used for manufacturing a biochip or a sample jetting apparatus for being used as precision pipette.
    
    


The entire disclosure of Japanese Patent Application No. 2006-220737 filed on Aug. 11, 2006 is expressly incorporated by reference herein.
While this invention has been described in conjunction with the specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, preferred embodiments of the invention as set forth herein are intended to be illustrative, not limiting. There are changes that may be made without departing from the sprit and scope of the invention.

## Claims

1. A method of manufacturing a liquid container, the liquid container comprising:
a liquid containing chamber in which a liquid can be contained,
an air communicating passage allowing the liquid containing chamber to communicate with air,
a liquid supply port for supplying the liquid contained in the liquid container to an outside of the liquid container,
a liquid flow passage allowing the liquid container and the liquid supply port to communicate with each other,
a differential pressure valve which is disposed in the liquid flow passage, which is normally urged to a closed state, and which is changed to an opened state when a differential pressure between a side of the liquid supply port and a side of the liquid containing chamber is equal to or more than a predetermined value,
the liquid flow passage comprising a supply port side flow passage between the liquid supply port and the differential pressure valve,
a partitioning wall partitioning the supply port side flow passage and the liquid containing chamber,
a plurality of ribs formed on a top surface of the partitioning wall,
a film member covering the ribs, the supply port side flow passage and the liquid containing chamber, and
a bypass flow passage defined by a gap between the plurality of ribs, and communicating the supply port side flow passage and the liquid containing chamber so as to bypass the differential pressure valve,
the method comprising:
injecting the liquid into the liquid containing chamber from the liquid supply port via the supply port side flow passage and the bypass flow passage; and
melting the ribs so that the top surface of the partitioning wall is made flat and a blocked portion blocking the bypass flow passage is formed after injecting the liquid.

2. The method according to claim 1, wherein an attachment portion of the film member is detached from the top surface of the partition wall by heating the attachment portion so as to form the gap between the attachment portion and the top surface.

3. The method according to claim 1, further comprising depressurizing the inside of the liquid containing chamber before injecting the liquid.

4. The method according to claim 3, wherein the inside of the liquid containing chamber is depressurized through the air communicating passage.

5. The method according to claim 1, further comprising removing at least a part of a valve mechanism provided in the liquid supply port before injecting the liquid.

6. The method according to claim 5, further comprising removing a part of a sealing film which seals the liquid supply port before the at least a part of the valve mechanism is removed.

7. The method according to claim 1, further comprising sealing the liquid supply port with a sealing film after injecting the liquid.

8. A liquid container manufactured by the method according to claim 1.

9. A method of manufacturing a liquid container, the liquid container comprising:
a liquid containing chamber in which a liquid can be contained,
an air communicating passage allowing the liquid containing chamber to communicate with air,
a liquid supply port for supplying the liquid contained in the liquid container to an outside of the liquid container,
a liquid flow passage allowing the liquid containing chamber and the liquid supply port to communicate with each other,
a differential pressure valve which is disposed in the liquid flow passage, which is normally urged to a closed state, and which is changed to an opened state when a differential pressure between a side of the liquid supply port and a side of the liquid containing chamber is equal to or more than a predetermined value, and
the liquid flow passage comprising a supply port side flow passage between the liquid supply port and the differential pressure valve,
a partitioning wall partitioning the supply port side flow passage and the liquid containing chamber,
a film member covering the supply port side flow passage and the liquid containing chamber, the film member being attached to a top surface of the partitioning wall so that the supply port side flow passage and the liquid containing chamber are not in communication with each other,
the method comprising:
detaching the film member from the top surface of the partitioning wall to form a bypass flow passage communicating the supply port side flow passage and the liquid containing chamber while bypassing the differential pressure valve,
injecting the liquid into the liquid containing chamber from the liquid supply port via the supply port side flow passage and the bypass flow passage; and
attaching the film member to the top surface of the partitioning wall so that a blocked portion blocking the bypass flow passage is formed after injecting the liquid.

10. The method according to claim 9, wherein the bypass flow passage is formed by forming a gap between the top surface of the partitioning wall and the film member.

11. The method according to claim 10, wherein an attachment portion of the film member is detached from the top surface of the partitioning wall by heating the attachment portion so as to form the gap between the attachment portion and the top surface.

12. The method according to claim 9, further comprising depressurizing the inside of the liquid containing chamber before injecting the liquid.

13. The method according to claim 12, wherein the inside of the liquid containing chamber is depressurized through the air communicating passage.

14. The method according to claim 9, further comprising removing at least a part of a valve mechanism provided in the liquid supply port before injecting the liquid.

15. The method according to claim 14, further comprising removing a part of a sealing film which seals the liquid supply port before the at least a part of the valve mechanism is removed.

16. The method according to claim 9, further comprising sealing the liquid supply port with a sealing film after injecting the liquid.

17. A liquid container manufactured by the method according to claim 9.