Ink storage container

Abstract

The present application provides an ink storage container having an ink storage unit that stores ink therein and an ink filling unit that communicates with the ink storage unit, in which the ink storage unit is a region in which the surface free energy of the inner wall is lower than the surface tension of the ink, and the ink filling unit communicates with the ink storage unit. And the ink filling unit is a region in which the surface free energy of an inner wall portion in contact with the ink is higher than the surface tension of the ink when the ink is poured from the ink storage unit.

Description

Technical Field

[0001] The present disclosure relates to ink storage containers. Background Art

[0002] Heretofore, ink storage containers for replenishing ink in ink tanks of inkjet devices such as inkjet printers are known. Functions required of ink storage containers include visibility of contents, ease of pouring ink, and storage reliability (see Japanese Patent Laid-Open JP_H10-245080 (hereinafter referred to as Patent Document 1), etc.). For example, poor visibility of contents may cause the user to misunderstand that there is more ink remaining than there actually is when the user visually checks the ink storage container being used. Therefore, it is desirable to ensure transparency of the container so that the contents can be seen at a glance.

[0003] At the same time, ease of pouring is also important. For example, there are various concepts such as providing a bottle with a tapered nozzle that can be inserted into the tank of the printer, providing a filling pin at the front end of the bottle that can be inserted into the tank of the printer, and providing a slot for the bottle while providing a pin on the tank side of the printer.

[0004] Patent Document 1 also mentions improving the visibility of the remaining amount and the convenience of filling ink.

[0005] A variety of inks have been developed recently, and their properties vary. Examples include inks for printing on materials other than paper, some of which are even for materials that are difficult for ink to penetrate (such as vinyl chloride).

[0006] In order to ensure print fixability on water-impermeable materials, such inks may use more organic solvents than typical inks used for printing on paper. Such inks containing a large amount of organic solvents tend to have low surface tension. Therefore, in some cases, even in an ink storage container made of the material described in Patent Document 1, the ink may infiltrate and spread on the inner wall.

[0007] Furthermore, in order to facilitate pouring, the bellows structure described in Patent Document 1 is a movable component and therefore may be worn and broken if repeatedly used. Summary of the invention

[0008] The present disclosure provides an ink storage container having an ink storage unit storing ink therein and an ink filling unit communicating with the ink storage unit, wherein the ink storage unit is a region where the surface free energy of an inner wall is lower than the surface tension of the ink, and the ink filling unit is a region where the surface free energy of an inner wall portion contacting with the ink when the ink is poured from the ink storage unit is higher than the surface tension of the ink.

[0009] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1A It is the appearance of an inkjet printer;

[0011] Figure 1B It is a schematic diagram of an ink tank;

[0012] Figure 1C is a diagram showing how ink is filled into an ink tank from an ink storage container according to an exemplary embodiment of the present disclosure;

[0013] Figure 2A An ink storage container suitable for use in the present disclosure and an exploded view thereof are shown;

[0014] Figure 2B is a cross-sectional view of an ink storage container suitable for the present disclosure taken along line IIB-IIB';

[0015] Figure 2C yes Figure 2B A partial enlarged view of the ink storage unit;

[0016] Figure 2D yes Figure 2B A partial enlarged view of the ink filling unit in FIG.

[0017] Figure 3A The state of the ink droplet is shown in the case where the surface free energy of the substrate 101 is less than the surface tension of the ink 111;

[0018] Figure 3B The state of the ink droplet is shown in the case where the surface tension of the ink 111 is less than the surface free energy of the substrate 102;

[0019] Figure 4A is a schematic diagram showing an ink storage container 150;

[0020] Figure 4B is a schematic diagram showing an ink storage container 155;

[0021] Figure 5 is a schematic diagram showing the relationship between haze value and visibility;

[0022] Fig. 6A is a cross-sectional view of an ink storage container according to Exemplary Embodiment 3;

[0023] Figure 6B is a cross-sectional view of an ink storage container according to Exemplary Embodiment 3;

[0024] Figure 6C is a cross-sectional view of an ink storage container according to Exemplary Embodiment 3;

[0025] Fig. 7A is an exploded view of the ink storage container 200;

[0026] Figure 7B is a cross-sectional view of the ink storage container 200;

[0027] Fig. 8A are a sectional view and an enlarged view of an upper portion of the ink storage container 200 in a state where the cap unit 30 is attached to the ink filling unit 20;

[0028] Figure 8B are a sectional view and an enlarged view of an upper portion of the ink storage container 200 in a state where the cap unit 30 is not attached;

[0029] Figure 8C is in the cover unit 30 from Fig. 8A A sectional view and an enlarged view of the upper portion of the ink storage container 200 in a state where the state in which the cover unit 30 is attached to the ink filling unit 20 begins to be opened;

[0030] Fig.9A is a cross-sectional view of an ink filling unit 20 of an ink storage container 300 provided with a slit valve as a valve mechanism;

[0031] Fig. 9B Is set in Fig.9A A top view of a slit valve in the ink filling unit 20 is shown;

[0032] Fig.10 is an enlarged cross-sectional view of the ink filling unit 20 and the cap unit 30 of the ink storage container 300;

[0033] Fig.11A is a cross-sectional view showing the relationship between the slit valve and the protrusion in a state where the cover is opened;

[0034] Fig. 11B is a cross-sectional view showing the relationship between the slit valve and the protrusion in a state where the cover is opened;

[0035] Fig. 11C is a cross-sectional view showing the relationship between the slit valve and the protrusion in a case where the cover is closed;

[0036] Fig.11D is a cross-sectional view showing the relationship between the slit valve and the protrusion in a case where the cover is closed;

[0037] Fig. 12A is a cross-sectional view of an ink filling unit 420 of the ink storage container 400; and

[0038] Fig. 12B is a cross-sectional view of the ink filling unit 520 of the ink storage container 500 . DETAILED DESCRIPTION

[0039] Preferred exemplary embodiments of the present disclosure will be described. Note that in all the following exemplary embodiments, shapes and structures are not limited to those illustrated as exemplary embodiments, and a designer may arbitrarily change, add, or omit them within the scope of the claims.

[0040] <Exemplary Embodiment 1>

[0041] (Inkjet equipment)

[0042] First, the configuration of an inkjet device to which the ink storage container according to the present embodiment can be applied will be described. In the present embodiment, the inkjet device will be described as an inkjet printer, but the ink storage container according to the present embodiment can be used for other inkjet devices. Figure 1A A general inkjet printer 1 is shown. Reference numeral 2 denotes an ink tank provided in the printer, and ink is supplied from the ink tank via a tube 3 to an inkjet print head (not shown) housed in 4 to perform printing. Hereinafter, reference numeral 4 will be referred to as a head unit, and the inkjet print head will be referred to as a print head.

[0043] The inkjet printer 1 repeats the reciprocating motion of the print head (main scanning) and the conveyance of a print sheet such as general printing paper, special paper, OHP film, etc. at a predetermined interval (sub scanning). The inkjet printer 1 according to the present embodiment is a serial inkjet printer that forms characters, symbols, images, etc. by selectively ejecting ink as an example from the print head while being synchronized with the main scanning and the sub scanning and depositing the ink on the print sheet.

[0044] exist Figure 1A In the embodiment, the head unit 4 is slidably supported by the guide rail 5, and is reciprocated along the guide rail 5 by a driving unit such as a motor (not shown). The print sheet is conveyed by the conveying roller in a direction intersecting the moving direction of the head unit 4 while facing the ink ejection surface of the print head and keeping a constant distance from the ink ejection surface.

[0045] The print head has a plurality of ejection port arrays, each ejecting ink of a different color. The print head is equipped with a printing element unit. In the printing element unit, a plurality of electrothermal conversion elements (heaters) or piezoelectric elements are arranged as ejection energy generating elements for ejecting ink. The ejection energy generating element causes the ink supplied via the ink supply path (tube 3, etc.) to be ejected from the ejection port. For example, in the case of using an electrothermal conversion element as the ejection energy generating element, the heater generates heat to generate bubbles in the ink, and the bubble generation energy is used to eject the ink from the ejection port.

[0046] Figure 1B A simplified cross-sectional view of the ink tank 2 is shown. After opening the tank cover 2-1 and removing the plug 6, as shown in FIG. Figure 1CAs shown, the user inserts the ink filling unit 20 of the ink storage container into the joint 8, thereby filling the ink into the ink tank 2. Generally speaking, when the ink in the ink tank 2 is reduced, the user can replenish any amount of ink from the ink storage container at any time.

[0047] The ink tank 2 has a gas-liquid exchange membrane 7 which can always keep the pressure inside the ink tank 2 equal to the atmospheric pressure even if the ink in the ink tank is consumed with the plug 6 attached to the ink tank.

[0048] (Ink storage container)

[0049] Next, the configuration of the ink storage container 100 will be described. Figure 2A An ink storage container applicable to the present disclosure and its exploded view are shown. The ink storage container 100 is a storage container for filling ink into the ink tank 2. The ink storage container 100 has an ink storage unit 10 capable of containing and storing ink during storage and logistics, and an ink filling unit 20 protruding from the ink storage unit 10 and serving as an ink pouring unit. The ink storage unit 10 and the ink filling unit 20 are in fluid communication, so that when the ink storage unit 10 and the ink filling unit 20 are connected, the ink storage unit 10 and the ink filling unit 20 are connected. Figure 1C In the case where ink is filled into the ink tank 2, the ink flows from the ink storage unit 10 to the ink tank 2 via the ink filling unit 20. In another exemplary embodiment, the ink storage container 100 may be used to replenish ink to an inkjet device other than an inkjet printer.

[0050] The ink storage container 100 may have a cap unit 30 to prevent ink from leaking or drying. If necessary, a packing or the like (not shown) may be interposed between the ink storage unit 10 and the ink filling unit 20 to improve their sealing properties.

[0051] In the present embodiment, an example is described in which the ink storage unit 10 and the ink filling unit 20 are plugged by a threaded structure and the cap unit 30 and the ink filling unit 20 are plugged by fitting, but the present disclosure is not limited thereto, and any form or combination may be used as long as the ink does not overflow.

[0052] Figure 2B Shown along Figure 2A Cross-sectional view taken along line IIB-IIB'. Figure 2C Shows Figure 2B A partially enlarged view of the ink storage unit 10 in FIG. Figure 2D Shows Figure 2B A partially enlarged view of the ink filling unit 20 in FIG.

[0053] In this embodiment, the entire inner surface area of ​​the ink storage unit 10 is referred to as the ink storage unit inner wall. Figure 2C Similarly, the entire inner area of ​​the ink filling unit 20 that can come into contact with ink during ink filling is referred to as the ink filling unit inner wall. Figure 2D 2 , the threaded portion 22 does not contact the ink during the ink filling and is therefore not included in the ink filling unit inner wall 21 .

[0054] In the present embodiment, the surface free energy of the ink storage unit inner wall 11 is lower than the surface tension of the ink contained therein. On the other hand, the surface free energy of the ink filling unit inner wall 21 is higher than the surface tension of the ink contained therein. For the threaded portion 22, the surface free energy is not particularly specified, but may be the same as or different from the surface free energy of the ink filling unit inner wall 21.

[0055] For example, in the case of using ink having a surface tension of about 25 mN / m, it is preferred that the ink storage unit inner wall 11 is made of a material having a surface free energy less than or equal to about 18 mN / m, and the ink filling unit inner wall 21 is made of a material having a surface free energy greater than or equal to about 29 mN / m.

[0056] Here, the relationship between the surface tension of ink and the surface free energy of a solid in contact with the ink will be described. FIG3 shows how the state of an ink droplet changes depending on the relationship between the surface tension of ink and the surface free energy of a solid in contact with the ink when an ink droplet so small that the influence of gravity can be ignored falls on a certain solid surface.

[0057] Figure 3A The shape of the ink droplet in the case where the surface free energy of the substrate 101 is less than the surface tension of the ink droplet 111 is shown, and θ is defined as the angle between the tangent line of the ink droplet near the solid surface and the solid. This θ is the so-called contact angle, and is defined in the present disclosure by measuring the measured value of the dynamic receding contact angle θ relative to the ink using a micro contact angle meter (product name: DropMeasure, manufactured by Microjet Co., Ltd.). In the present disclosure, a state in which the angle θ is greater than or equal to about 70 degrees is defined as a state in which the ink droplets are easily aggregated (liquid repellency). If the angle is preferably greater than or equal to 90 degrees, the ink droplets tend to be more easily aggregated.

[0058] Figure 3B is an image diagram of the state of ink droplets when the surface free energy of the substrate 102 is approximately equal to or greater than the surface tension of the ink droplets 111. In the present disclosure, this state refers to a state where θ is less than about 70 degrees and is defined as a state where ink easily infiltrates and spreads (lyophilicity).

[0059] For example, if the ink dries as it infiltrates and spreads on the wall surface 11 of the ink storage unit 10, ink components remain on the wall surface, resulting in poor visibility. Therefore, it is preferable that the ink shows a tendency to aggregate in the ink storage unit 10 so that the user can visually confirm the contents accurately. On the other hand, during ink filling, the ink flows into the ink tank along the ink filling unit inner wall 21. Therefore, if the ink infiltrates and spreads as much as possible, filling becomes easy.

[0060] The surface free energy of a solid is generally defined as a value measured using a method generally referred to as the OWRK method. The OWRK method is a method in which two or more types of ink reagents having known physical properties are used to measure the contact angle of each reagent with a solid, and the surface free energy is calculated based on the physical property values ​​of the ink and the measured value of the contact angle.

[0061] The surface tension of ink is defined as a value measured using the Wilhelmy method (also called the plate method). The Wilhelmy method is a method of calculating surface tension by inserting a solid platinum plate into the ink to be measured and measuring the force generated in the direction in which the ink pulls the plate.

[0062] In addition, there are generally multiple ways to adjust the surface tension of the ink, but the present disclosure does not limit the adjustment method. For example, there is a method of adjusting the surface tension by adjusting the amount of surfactant in the ink. Examples of surfactants include acetylene glycol surfactants, polyoxyethylene alkyl ethers, and the like.

[0063] In the present embodiment, the surface tension of the ink (about 25 mN / m) exceeds the surface free energy (about 18 mN / m) of the inner wall 11 of the ink storage unit. This increases the aggregation force of the ink on the inner wall surface of the ink storage unit 10, preventing the infiltration and diffusion of the ink. It is important that the surface free energy of the inner wall 11 of the ink storage unit is lower than the surface tension of the ink. It is preferable to select the material based on the condition that the surface free energy of the inner wall 11 of the ink storage unit is less than the surface tension of the ink by 5 mN / m or more as described above.

[0064] The surface free energy (about 29 mN / m) of the ink-filled cell inner wall 21 exceeds the ink surface tension (about 25 mN / m), so the ink tends to infiltrate and spread.

[0065] Therefore, in the present embodiment, it is possible to promote smooth filling of ink into the printer while maintaining good visibility by preventing the ink from infiltrating and spreading on the inner wall 11 of the ink storage unit. Since the ink can be smoothly filled into the printer while preventing the ink from infiltrating and spreading on the inner wall 11 of the ink storage unit, the amount of ink remaining in the used, discarded, or reused ink storage container 100 is reduced. That is, the amount of ink to be discarded in the case of remaining in the ink storage container 100 can be reduced. In addition, in the case of cleaning the inside of the used ink storage container 100 and reusing the ink storage container 100, if the amount of ink remaining in the ink storage container 100 is reduced, the amount of liquid such as water required for cleaning can also be reduced. This can reduce the cost of reusing the ink storage container 100, thereby promoting the reuse of the ink storage container 100. That is, the technology described in the present specification can contribute to the realization of a sustainable society, such as a decarbonized, circular society.

[0066] The material forming the ink storage unit 10 and the ink filling unit 20 may be any material that can satisfy the above-mentioned surface free energy.

[0067] Examples of materials having a surface free energy of about 18 mN / m include resins having a perfluoroalkyl group in the molecular structure, such as PTFE. Perfluoroalkyl groups, also known as carbon fluoroalkyl groups, in which all hydrogen atoms in the alkyl chain are replaced by fluorine atoms, are characterized by extremely small intermolecular forces. Examples of materials having a surface free energy of about 29 mN / m include PP. These materials can be surface-modified using methods such as plasma irradiation, light irradiation, a surface modifier, or a coating. In an ink storage container made of a single material, for example, a region A having a surface free energy higher than the surface tension of the ink stored in the nozzle portion can be provided as the ink filling unit 20. In Figure 4A In the ink storage container 150 shown, the area A is provided at the bottleneck, so that the bottleneck serves as the ink filling unit 20. Figure 4B In the illustrated ink storage container 155 , the region A is provided not only at the neck of the bottle but also at the shoulder, so that the neck of the bottle and the shoulder function as the ink filling unit 20 .

[0068] It is preferable to adjust the thickness of the ink storage container 100 according to the present embodiment so that the haze value of the substrate forming the ink storage unit 10 is 30% or less, more preferably 10% or less.

[0069] The haze value is defined as a value measured by a method based on JIS K7136. The haze value can be obtained by cutting the test piece into a suitable size (e.g., 3×3 cm) and fixing it on a movable measuring table and by using a haze meter NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd. as a measuring instrument. The haze value is a value related to the visibility of the contents, indicating the degree of scattering when light passes through a certain member. Regarding the measurement principle of the haze value, light is incident on the test piece in a straight line, and a photodetector installed at a position away from the incident line of light is used to detect the scattered light. The degree of scattering is defined by measuring the proportion of scattered light. Even for the same substance, the thicker the thickness through which the light passes, the higher the probability of collision with the molecules, and the haze value tends to be higher.

[0070] Figure 5 Graph showing the relationship between haze value and visibility. Figure 5 As shown, if the container has a high haze value, the interface of the content looks blurry, or in some cases the interface cannot be accurately identified. Specifically, it is preferred that the haze value of the storage unit is 30% or less, so that the amount of the content can be accurately identified. It is more preferred that the haze value is 10% or less, so that visibility can be expected to reach a level that the color of the content can be roughly identified.

[0071] <Exemplary Embodiment 2>

[0072] As a second exemplary embodiment, an example is given in which, using ink having a surface tension of about 35 mN / m, the ink storage unit inner wall 11 is made of a resin having a surface free energy of about 29 mN / m or less, and the ink filling unit inner wall 21 is made of a resin having a surface free energy of about 42 mN / m. In addition, the thickness is adjusted so that the haze value of the ink storage unit 10 is 30% or less. In exemplary embodiment 2, the relationship between the surface free energy of the ink storage unit inner wall 11, the surface tension of the stored ink, and the surface free energy of the ink filling unit inner wall 21 is also as follows: ink storage unit inner wall 11 < ink < ink filling unit inner wall 21.

[0073] Examples of resins having a surface free energy of about 29 mN / m include PP. Examples of resins having a surface free energy of about 42 mN / m include ABS resin.

[0074] The main difference between Exemplary Embodiment 1 and Exemplary Embodiment 2 is that the surface tension of the stored ink is 35 mN / m in Exemplary Embodiment 2, which is higher than 25 mN / m in Exemplary Embodiment 1. Therefore, in the case where the ink of Exemplary Embodiment 1 and the ink of Exemplary Embodiment 2 are dropped onto PP having a surface free energy of about 29 mN / m, the ink of Exemplary Embodiment 1 tends to infiltrate and spread, while the ink of Exemplary Embodiment 2 tends to aggregate.

[0075] Although PP is described as a material suitable for the filling unit in Exemplary Embodiment 1, PP is more suitable as a material for the storage unit than for the filling unit for the ink of Exemplary Embodiment 2. Therefore, even the same resin material has different preferred forms depending on the physical properties of the ink to be stored.

[0076] Of course, using PTFE as the storage unit in Exemplary Embodiment 2 as in Exemplary Embodiment 1 does not contradict the intention of the present disclosure, and there is no problem in using ABS resin as the filling unit in Exemplary Embodiment 1. In addition, metals such as SUS can be used for the filling unit. The surface free energy of metals is generally 400 mN / m or more, so the ink tends to infiltrate and spread.

[0077] Materials that can be used for the ink storage container 100 according to the present disclosure, including substances not described in the exemplary embodiment, may be used in any appropriate combination within the scope of the claims of the present disclosure.

[0078] <Exemplary Embodiment 3>

[0079] In the ink storage container according to the present disclosure, the ink storage unit 10 and the ink filling unit 20 may be composed of a plurality of members. In this case, as in Exemplary Embodiment 1 and Exemplary Embodiment 2, the relationship between the surface free energy of the ink storage unit inner wall 11, the surface tension of the stored ink, and the surface free energy of the ink filling unit inner wall 21 is as follows: ink storage unit inner wall 11 < ink < ink filling unit inner wall 21. Even if the ink storage container is composed of a plurality of members, the haze value of the ink storage container is preferably 30% or less.

[0080] exist Fig. 6A In the illustrated ink storage container 110, the ink storage unit 10 has an inner storage portion 41 and an outer storage portion 43. This leads to an advantage that the inner side and the outer side of the ink storage unit 10 can have different functions.

[0081] For example, a combination of using a material having low surface free energy for the inner storage portion 41 and using a material having excellent impact resistance for the outer storage portion 43 can be considered. In this case, even if there is a concern about the impact resistance of the member for the inner storage portion 41, the reinforcing effect of the member for the outer storage portion 43 can be expected. There is also an advantage that surface free energy is not a problem because the member for the outer storage portion 43 does not come into direct contact with the ink.

[0082] exist Figure 6B In the ink storage container 120 shown, the ink storage unit 10 has an inner storage portion 41 and an outer storage portion 43, and the ink filling unit 20 has an inner filling portion 42 and an outer filling portion 44. The ink storage unit 10 may have a Fig. 6A Same construction as shown.

[0083] As one of the combinations of the ink filling unit 20 of the ink storage container 120, an example is given in which a substance having a high surface free energy is used for the inner filling portion 42, and a porous member into which ink easily penetrates is used for the outer filling portion 44. In such a structure, the surface free energy of the inner filling portion 42 is increased to maintain the ease of pouring the ink. At the same time, such a structure can be expected to minimize the effect of the contamination range by absorbing the ink flowing down and leaking from the front end of the filling portion by the porous material when the user finishes pouring the ink into the ink tank 2.

[0084] Figure 6C The illustrated ink storage container 130 has a configuration in which the ink storage unit 10 and the ink filling unit 20 are respectively covered with a common member 45 made of a common material. With this structure, it is possible to ensure impact resistance by the common member 45 while using a material of appropriate surface free energy for the inner storage portion 41 and the inner filling portion 42. This makes it possible to divide the functions while reducing the types of materials used for the ink storage container 100.

[0085] There are various manufacturing methods and techniques that can be used to realize the configuration of this embodiment, but the method is not limited. The components can be created separately and assembled or combined, whether they are for inner members or outer members. In addition, the film can be formed by coating, etc., and also includes a method of attaching a separately prepared film or film. Examples of coating methods include a method in which a solvent dissolved with the desired resin is sprayed or applied, and then the solvent is evaporated.

[0086] Such a coating method and a method of applying a film or thin film have the advantage of reducing the thickness of the member, thereby expecting an effect of reducing the material cost. For the ink storage unit 10, a thinner member has the advantage of being easier to set a lower haze value. The reason why a thinner member makes it possible to set a lower haze value has been described in Exemplary Embodiment 1.

[0087] (Valve mechanism)

[0088] The ink storage container according to the present embodiment may also have a valve mechanism in the ink filling unit 20 .

[0089] 7 shows an ink storage container 200 in which a valve mechanism having a valve spring structure is provided in an ink filling unit 20. Inside the ink filling unit 20, a seal 24 having an opening, a valve 25 opening and closing the opening of the seal 24, a spring 26 biasing the valve 25, and a retainer 27 fixing the spring 26 are provided.

[0090] In the case of supplying ink from the ink storage container 200 to the ink tank 2, the communication flow path of the ink tank 2 is inserted into the opening of the ink filling unit 20 of the ink storage container 200. The ink filling unit 20 of the ink storage container 200 is provided with a recessed portion, which engages with the protrusion of the socket of the inkjet printer 1. When the communication flow path is inserted into the opening of the ink filling unit 20, the ink storage container 200 is positioned. The ink in the ink storage container 200 is supplied to the storage chamber of the ink tank body via the communication flow path by the water head difference.

[0091] The ink storage container 200 has two sealable parts (hereinafter referred to as sealing parts). FIG. 8 is a schematic diagram showing the sealing parts of the ink storage container 200. In the first sealing part, the cover unit 30 and the ink filling unit 20 cooperate to perform sealing, such as Fig. 7A In the second sealing portion, sealing is performed by the valve structure inside the ink filling unit 20, as shown in FIG. Figure 7B Each sealing portion will be described below.

[0092] Will refer to Fig. 8A The first seal is described. Fig. 8A 20 is a cross-sectional view of the upper portion of the ink storage container 200 in a state where the cap unit 30 is attached to the ink filling unit 20, and an enlarged view thereof is also shown. By attaching the cap unit 30 to the ink filling unit 20, the first sealing portion makes the cap sealing portion 30b of the cap unit 30 and the sealing portion 20d which is a part of the nozzle 10a of the ink filling unit 20 cooperate. An example of a method of attaching the cap unit 30 to the ink filling unit 20 includes screwing the ink filling unit 20 and the cap unit 30 together. Specifically, as shown in FIG. Fig. 7A , Figure 7B and Fig. 8A As shown, the threaded portion 20b with a male thread structure formed on the outside of the ink filling unit 20 and the cap threaded portion 30a with a female thread structure formed on the inside of the lower portion of the cap unit 30 are used to screw the two together. Conversely, the cap unit 30 with a male thread portion and the ink filling unit 20 with a female thread portion can also be used.

[0093] Will refer to Figure 8B The second seal is described. Figure 8B2 is a cross-sectional view of the upper portion of the ink storage container 200 in a state where the cover unit 30 is not attached, and an enlarged view thereof is also shown. The second sealing portion is a part of a liquid shutoff valve structure (valve structure) provided inside the ink filling unit 20 of the ink storage container 200. Figure 8B As shown in FIG. 1 , the ink filling unit 20 is provided with a seal 24 which is an orifice portion having an opening at its front end (upper end) into which the communication flow path is inserted. A valve 25 as a valve body of a liquid shutoff valve is biased toward the opening side by a spring 26, a gap between the seal 24 and the valve 25 is closed, and the ink storage container 200 is sealed. In the present embodiment, the spring 26 is used as a biasing mechanism, and the spring 26 is held by a holder 27 fixed in the internal space of the ink filling unit 20. The seal 24 is made of a flexible member such as rubber or an elastomer.

[0094] By this liquid shutoff valve structure, the valve 25 is biased against the opening of the seal 24 by the spring 26, so that the interior of the ink storage container 200 can be kept sealed even if the cap unit 30 is removed from the ink filling unit 20. In the case of supplying ink from the ink storage container 200 to the ink tank 2, the communication flow path is inserted into the ink filling unit 20 via the opening of the seal 24, and the valve 25 is opened. As described above, due to the water head difference, the ink in the ink storage container 200 is supplied to the storage chamber of the ink tank body via the communication flow path.

[0095] In the present embodiment, the two sealing portions are configured to be temporarily opened simultaneously when the cover unit 30 is opened from the ink filling unit 20 and when the cover unit 30 is closed relative to the ink filling unit 20. Therefore, the interior of the ink storage container 200 is communicated with the atmosphere, and the internal pressure of the ink storage container 200 can be made equal to the external pressure. This will be described in detail below.

[0096] First, in the closed state of the cover unit 30, the first sealing portion is in a sealed state, such as Fig. 8A On the other hand, in the second sealing portion, when the cover unit 30 is closed, the protrusion 30f provided in the cover unit 30 is pushed in the direction opposite to the biasing direction of the valve 25, thereby forming a gap between the seal 24 and the valve 25. Fig. 8A That is, in the closed state of the cover unit 30, the first sealing portion is sealed and the second sealing portion is opened.

[0097] Figure 8C is in the cover unit 30 from Fig. 8A The cap unit 30 shown is a cross-sectional view of the upper portion of the ink storage container 200 in a state where the cap unit 30 is attached to the ink filling unit 20 and an enlarged view thereof is also shown. Fig. 8A The closed state shown is as follows Figure 8CAs the cover unit 30 moves, the cover seal 30b and the seal 20d are separated to open the first seal. When the first seal is opened, the protrusion 30f provided in the cover unit 30 is still in a position to push the valve 25 in, as shown in FIG. Figure 8C In other words, the second sealing portion remains open. Figure 8C As shown, the second sealing portion can also be opened while the first sealing portion is opened. As the cover unit 30 moves further upward, as the cover unit 30 moves, the protrusion 30f is completely separated from the valve 25, thereby sealing the second sealing portion, as shown in FIG. Figure 8B As shown. When the cover unit 30 is closed from the open state, as the cover unit 30 moves, the protrusion 30f of the cover unit 30 pushes the valve 25 to open the second sealing portion. In this case, the first sealing portion is in the pre-sealing state and is therefore kept open. Afterwards, the cover unit 30 is closed to put the first sealing portion in a sealed state. Note that opening the first sealing portion and the second sealing portion at the same time means opening them substantially at the same time. If the second sealing portion is opened as the first sealing portion is opened, both are opened at the same time.

[0098] By the above configuration, the first sealing portion and the second sealing portion are temporarily opened simultaneously when the cover unit 30 is opened, so that the interior of the ink storage container 200 is communicated with the atmosphere, thereby enabling the internal pressure of the ink storage container 200 to be equal to the external pressure. This prevents the ink from being ejected due to the increase in the internal pressure of the ink storage container 200 when the cover unit 30 is opened to replenish the ink from the ink storage container 200 to the ink tank body. In addition, it is possible to suppress the ink from overflowing from the ink tank body. Even if the cover unit 30 is opened, the interior of the ink storage container 200 is kept sealed by the second sealing portion. This makes it possible to prevent ink leakage even if the ink storage container 200 is turned upside down.

[0099] FIG. 9 shows an ink storage container 300 equipped with a slit valve as a valve mechanism. Fig.9A is a cross-sectional view of the ink filling unit 20 according to the present embodiment. Fig. 9B is a top view of a slit valve provided in the ink filling unit 20 according to the present embodiment. Fig.10 2 is an enlarged cross-sectional view of the ink filling unit 20 and the cap unit 30 according to the present embodiment.

[0100] The ink filling unit 20 has a filling port 122c for filling ink and a sealing portion 122d made of an annular rib and provided along the periphery of the filling port 122c. The filling port 122c is provided with a slit valve 124 that opens and closes depending on the internal pressure of the ink storage container 300. The slit valve 124 has a valve body 124a made of a flexible material and three mutually intersecting slits 124b formed in the valve body 124a. The slit valve 124 is capable of sealing the filling port 122c in a closed state. The valve body 124a has six segmented pieces 124c formed by three slits 124b. Note that the number of slits 124b is not limited to this, and may be two, or four or more. In this case, the plurality of slits 124b are preferably formed as follows: Fig. 9B The illustrated embodiment has 2n symmetry with respect to the center of the circular valve body 124a, where n is the number of slits. Therefore, the partition pieces 124c can be opened equally, and the ink in the ink storage container 300 can be smoothly filled.

[0101] On the bottom surface (surface facing the filling port 122c) of the cap unit 30, a cap seal portion 123b made of an annular rib and a protrusion 123c protruding toward the slit valve 124 are provided. The cap seal portion 123b is fitted into the seal portion 122d as the cap unit 30 is attached to the ink filling unit 20, and thus serves as a sealing unit for sealing the filling port 122c together with the seal portion 122d. In a state where the filling port 122c is sealed by the cap seal portion 123b and the seal portion 122d, the front end of the protrusion 123c faces the valve body 124a of the slit valve 124 at a position away from the intersection 124d of the plurality of slits 124b in the lateral direction (radial direction of the ink filling unit 20). By such a configuration of the protrusion 123c, as will be described later, in the case where the internal pressure of the ink storage container 300 is higher than the external pressure as the cap unit 30 is opened, the internal pressure can be released. In the present embodiment, the protrusion 123 c is provided integrally with the cover unit 30 , but may also be provided separately from the cover unit 30 .

[0102] Fig.11A and Fig. 11B is a cross-sectional view showing the relationship between the slit valve and the protrusion with the cover opened.

[0103] In a state where the cover unit 30 is attached to the ink filling unit 20 and the filling port 122c is sealed, as described above, the protrusion 123c faces the valve body 124a at a position laterally away from the intersection 124d of the slit 124b, and the protrusion 123c does not contact the valve body 124a. Here, as the cover unit 30 starts to open (starts to move in the direction of the arrow), the fit between the cover sealing portion 123b and the sealing portion 122d is released, and the seal of the filling port 122c is released. In this case, if the internal pressure of the ink storage container 300 is higher than the external pressure, the valve body 24a of the slit valve 124 expands outward and deforms under the internal pressure of the ink storage container 300, as shown in FIG. Fig.11A When the expanded valve body 124a contacts the protrusion 123c, the slit 124b opens to release the pressure inside the ink storage container 300, thereby stopping the expansion of the valve body 124a. Thereafter, when the cover unit 30 is removed, the slit 124b closes and the filling port 122c is sealed again, as shown in FIG. Fig. 11B When ink is filled from the ink storage container 300 into the ink tank 2, the pressure difference between the inside and outside of the ink storage container 300 is eliminated, and the filling port 122c is in a sealed state. Therefore, by simply tilting the bottle body, the pressure required to open the slit 124b can be prevented from acting on the slit valve 124, so that ink leakage through the filling port 122c can be prevented.

[0104] Fig. 11C and Fig.11D is a cross-sectional view showing the relationship between the slit valve and the protrusion in a state where the cover is closed.

[0105] When the internal pressure of the ink storage container 300 increases in a state where the cap unit 30 is not attached to the ink filling unit 20, the valve body 124a of the slit valve 124 is deformed by expanding outward, as shown in FIG. Fig. 11C Here, as the cover unit 30 begins to close, before the cover sealing portion 123b and the sealing portion 122d are fitted together, the protrusion 123c contacts the expanded valve body 124a, as shown in FIG. Fig.11D As shown. As a result, the slit 124b opens to release the pressure inside the ink storage container 300, thereby stopping the expansion of the valve body 124a, and then the slit 124b closes to seal the filling port 122c. As the cap unit 30 continues to close, the cap seal portion 123b and the seal portion 122d cooperate together to seal the filling port 122c. In this case, since the expansion of the valve body 124a stops, the protrusion 123c faces the valve body 124a at a position laterally away from the intersection 124d of the slit 124b and does not contact the valve body 124a.

[0106] With this configuration, even if the internal pressure of the ink storage container 300 increases, the internal pressure can be released to the outside by making the protrusion 123c contact the slit valve 124 as the cover unit 30 is opened or closed. Note that the length of the protrusion 123c is not particularly limited, and can be set to an optimal length depending on the actual deformation amount of the valve body 124a due to the increase in the internal pressure of the ink storage container 300. Therefore, for example, when the deformation amount of the valve body 124a is relatively small, in a state where the filling port 122c is sealed by the cover sealing portion 123b and the sealing portion 122d, the front end of the protrusion 123c can contact the valve body 124a to such an extent that the valve body 124a is not deformed.

[0107] In order to make the protrusion 123c only contact with the expanded valve body 124a, it is also possible to consider Fig.10 The cap unit 30 shown is attached to the ink filling unit 20 (the filling port 122c is sealed) in a state where the front end of the protrusion 123c faces the intersection 124d of the slits 124b. However, in this case, depending on the thickness of the protrusion 123c, as the valve body 124a expands, the protrusion 123c may be inserted into the gap between the slits 124b near the intersection 124d. Even if the protrusion 123c is inserted in this way, the slit 124b can remain closed. As a result, even if the protrusion 123c contacts the expanded valve body 124a, the pressure in the ink storage container 300 may not be released. From this point of view, it is preferred that, in a state where the filling port 122c is sealed, the front end of the protrusion 123c faces the valve body 124a of the slit valve 124 at a position laterally away from the intersection 124d of the plurality of slits 124b.

[0108] The ink filling unit 20 may have one flow path or may have two flow paths. Fig. 12A 4 is a cross-sectional view of the ink filling unit 420 of the ink storage container 400. Fig. 12A As shown, the filling unit front end (nozzle) 410 protrudes from the outer surface of the bottom wall 411 of the ink filling unit 420 in the first direction 434. That is, in a case where the ink filling unit 420 is attached to the ink storage unit (not shown), the nozzle 410 protrudes from the ink storage unit via the ink filling unit 420 in the first direction 434. The nozzle 410 may also protrude from the bottom wall 411 in the second direction 435 as well as in the first direction 434. In this case, the nozzle 410 is provided to penetrate the bottom wall 411.

[0109] The nozzle 410 is generally cylindrical. The nozzle 410 has an outer peripheral surface 412 having a circular cross section. An outer peripheral surface 413 as a part of the outer peripheral surface 412 has a tapered shape and is inclined in a direction in which the diameter of the outer peripheral circle decreases from the bottom wall 411 toward the first direction 434. Such a shape enables smooth operation in the case where the nozzle 410 is sequentially inserted into the tank from the distal end side away from the ink storage unit. However, the nozzle 410 may have the same outer peripheral circle diameter from the bottom wall 411 to the front end, and its outer peripheral surface may extend in the vertical direction. In addition, in addition to the cylindrical shape, the shape of the nozzle 410 may be, for example, a quadrangular prism.

[0110] The nozzle 410 has a flow path 490 through which ink or gas flows. The flow path 490 passes through the ink filling unit 420 along the first direction 434. Although the flow path 490 extends along the first direction 434, the flow path 490 is not limited thereto and may be curved. The cross-sectional shape of the flow path 490 may be circular or a shape other than a circular shape. In a state where the ink filling unit 420 is attached to the ink storage unit, one end of the flow path 490 communicates with the ink storage unit through an opening 493. The other end of the flow path communicates with the outside of the ink filling unit 420 through an opening 494 on the distal end side of the nozzle. The opening 493 has a circular shape. Note that the opening 493 may have a shape other than a circular shape. The opening 493 may be formed at the base end of the nozzle 410, and its position is not limited to the base end surface 414. The opening 494 is formed in the front end surface 415, which forms the end of the nozzle 410 facing the first direction 434. The opening 494 has a circular shape. Note that the opening 494 may have a shape other than a circular shape.

[0111] like Fig. 12BAs shown, in another embodiment, the nozzle 510 of the ink storage container 500 may have two flow paths 590, namely a first flow path 591 and a second flow path 592. The first flow path 591 and the second flow path 592 may have the same length or different lengths along the ink flow direction. The first flow path 591 and the second flow path 592 may also have the same cross-sectional shape and cross-sectional area, or may have different cross-sectional shapes and cross-sectional areas. The number of flow paths 590 may be more than two. In the case where the nozzle 510 has more than one flow path 590, the length and shape of each flow path 590 may be the same or different. In the case where the nozzle 510 has two flow paths 590, the openings 593 and 595 formed at the base end are formed on the same surface. However, these openings may be formed on different surfaces. The first opening 594 and the second opening 596 are formed in the front end surface 515, which forms the end of the nozzle 510 facing the first direction 534. However, the first opening 594 and the second opening 596 may be formed at the front end of the nozzle 510, and their positions are not limited to the front end surface 515. The first opening 594 and the second opening 596 have a circular shape. Note that the first opening 594 and the second opening 596 may have shapes other than a circle.

[0112] For example, the front end of the nozzle 510 is a part of the nozzle 510 formed by the front end surface 515 and the outer peripheral surface 512. The nozzle 510 has a recess 516 on the outer peripheral surface 512. The recess 516 is defined by the front end surface 515 and the inner peripheral surface 518 (one side surface) of the annular rib 517 protruding from the outer edge of the front end surface 515 toward the first direction 534. That is, the front end surface 515 is recessed from the front end of the nozzle 510 (the front end of the annular rib 517). The inner peripheral surface 518 extends from the front end surface 515 toward the outer edge of the front end surface 515 in the first direction 534. In other words, the inner peripheral surface 518 extends in the first direction 534 while being inclined in the direction in which the diameter of the recess 516 increases. Note that the inner peripheral surface 518 may extend along the first direction 534 without being inclined. In addition, the nozzle 510 does not necessarily have to have the recess 516. In other words, the front end of the nozzle 510 does not necessarily have to be recessed.

[0113] 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 and equivalent structures and functions.

Claims

1. An ink storage container, comprising: An ink storage unit that stores ink therein; and an ink filling unit in communication with the ink storage unit, wherein The ink storage unit is a region where the surface free energy of the inner wall is lower than the surface tension of the ink, and The ink filling unit is a region where the surface free energy of the inner wall portion that comes into contact with the ink when the ink is poured from the ink storage unit is higher than the surface tension of the ink.

2. The ink storage container according to claim 1, wherein: The ink is ink for an inkjet printer, and the ink storage container is used to inject the ink into the inkjet printer.

3. The ink storage container according to claim 1, wherein: A contact angle of the ink with respect to an inner wall of the ink storage unit is greater than or equal to 70 degrees.

4. The ink storage container according to claim 1, wherein: A contact angle of the ink with respect to an inner wall of the ink filling unit is less than or equal to 40 degrees.

5. The ink storage container according to claim 1, wherein: The ink has a surface tension of 25 mN / m to 40 mN / m.

6. The ink storage container according to claim 1, wherein: A haze value of a member included in the ink storage unit is less than or equal to 30%.

7. The ink storage container according to claim 1, wherein: The material of the inner wall of the ink storage unit includes a compound having a perfluoroalkyl group.

8. The ink storage container according to claim 1, wherein: The difference between the surface free energy of the inner wall of the ink storage unit and the surface tension of the ink is greater than or equal to 5 mN / m.

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