Patent Description:
According to the invention, an ink refilling container is disclosed in claim <NUM>.

A cap having a slit valve and configured to be attached to a container containing liquid or the like in a dischargeable manner is disclosed in <CIT>. This cap includes a cap base, a slit valve mounted on the opening of the cap base, and a lid body for opening and closing the opening of the cap base. In this cap, in a state in which the lid body is closed, a dome-shaped convex portion provided on the lid body pushes the slit valve, thereby pushing the slit valve open slightly to prevent the content from adhering to the slit valve.

In the cap described in the above paragraph, if the dome-shaped convex portion pushes the outer-circumference-side end of the slit valve, the creep deformation of the valve occurs in a state of receiving a force toward the outer circumference, and there is a possibility that the slit will remain open undesirably. If the container is directed downward with the lid body open, the dripping of the content through the slit valve is likely to occur. If the amount of pushing the slit valve by the convex portion is decreased in order to suppress the creep deformation, even if the internal pressure of the container increases due to a rise in temperature, etc., the pressure will not be released sufficiently. Therefore, when the container is turned upside down, there is a risk that the spouting of the content of the container might occur due to the exceeding of the sum of the increased pressure and the liquid head pressure of the content over the pressure resistance of the valve.

[<NUM>] <CIT> discloses an ink container storing ink which has a bottom part closing a lower end of a trunk part constituting an outer peripheral wall. The bottom part comprises: a ground contact part formed into an annular shape; a convex part formed at a central position in the ground contact part; and an annular convex part provided between the ground contact part and the convex part.

[<NUM>] <CIT> discloses a liquid storage bottle which includes a nozzle which has an inlet through which a liquid is injected, a cylindrical cap which is mountable on the nozzle to open or close the inlet, a slit valve which is provided in the inlet and includes a plurality of slits intersecting each other, and a sealing unit which seals the inlet when the cap is mounted on the nozzle. The cap includes a protrusion which protrudes from a surface facing the inlet toward the slit valve when the cap is mounted on the nozzle, and a tip portion of the protrusion faces the slit valve at a position separated in a radial direction of the nozzle from an intersection of the plurality of slits in a state where the inlet is sealed by the sealing unit.

[<NUM>] <CIT> discloses a double pressurized container comprising an outer container, a flexible inner container and a lid body sealing both the outer and inner containers.

According to an aspect of the present invention, there is provided an ink refilling container according to claim <NUM>.

<FIG> is a schematic perspective view of an exemplary structure of a recording apparatus <NUM> according to a first embodiment, illustrated in a see-through state with omission of details. The recording apparatus <NUM> is an ink-jet printer that records an image, etc. on a medium by ejecting ink onto the medium. In <FIG>, X, Y, and Z directions, which are orthogonal to one another, are shown. The X direction and the Y direction are parallel to the horizontal direction. The Z direction is parallel to the vertical direction. The X direction will be referred to also as "leftward/rightward direction", wherein the direction toward the right is denoted as +X, and the direction toward the left is denoted as -X. The Y direction will be referred to also as "frontward/rearward direction", wherein the direction toward the front is denoted as +Y, and the direction toward the rear is denoted as -Y. The Z direction will be referred to also as "top/bottom direction", wherein the direction toward the top is denoted as +Z, and the direction toward the bottom is denoted as -Z. When two objects are described as "intersecting with each other" below, it means any of the following states: a state in which the two objects intersect with each other actually"; a state in which an extension of one of the two objects intersects with the other; and a state in which an extension of one of the two objects and an extension of the other intersect with each other.

The recording apparatus <NUM> includes a housing <NUM>. The housing <NUM> has a shape of a rectangular parallelepiped whose longitudinal direction is along the leftward/rightward direction. A platen <NUM> whose longitudinal direction is along the leftward/rightward direction is provided at a floor position closer to the rear inside the housing <NUM>, with the top surface of the platen <NUM> lying substantially along the horizontal direction. Paper P, which is an example of a medium, is transported frontward while being supported by the top surface of the platen <NUM>. A guide shaft <NUM> extending in the leftward/rightward direction is provided above the platen <NUM> inside the housing <NUM>. A carriage <NUM>, on the bottom face of which a recording head <NUM> configured to eject ink is mounted, is supported on the guide shaft <NUM>. The carriage <NUM> has a support hole <NUM> going through itself in the leftward/rightward direction. The carriage <NUM>, with the guide shaft <NUM> inserted through the support hole <NUM>, is supported in such a way as to be able to reciprocate freely along the guide shaft <NUM>.

A driving pulley <NUM> and a driven pulley <NUM> are supported rotatably at respective positions near the two ends of the guide shaft <NUM> inside the housing <NUM>. The output shaft of a carriage motor <NUM> is coupled to the driving pulley <NUM>. An endless timing belt <NUM>, a part of which is fixed to the carriage <NUM>, is stretched between the driving pulley <NUM> and the driven pulley <NUM>. The carriage <NUM> is driven by the carriage motor <NUM> via the timing belt <NUM> to reciprocate in the leftward/rightward direction, which is the direction of scan over the paper P, while being guided by the guide shaft <NUM>. When the carriage <NUM> reciprocates in this way, ink is ejected toward the paper P, which is transported on the platen <NUM> frontward, from the recording head <NUM> mounted on the bottom face of the carriage <NUM>.

A rectangular ejection port <NUM> is provided as an opening in the front face of the housing <NUM> at a position in front of the platen <NUM>. Recording is performed on the paper P by ejecting ink from the recording head <NUM> toward the paper P when the paper P is transported on the platen <NUM> inside the housing <NUM>, and then, the recorded paper is ejected frontward through the ejection port <NUM>. An ejection tray <NUM>, which has a shape of a rectangular plate and is able to support the paper P ejected from the inside of the housing <NUM>, is provided in the ejection port <NUM> such that the ejection tray <NUM> is able to be put into a drawn-out protruding position frontward, that is, in the direction of ejection, and is able to be put into a retracted position inside the housing <NUM>. A paper feed cassette <NUM>, inside which sheets of paper P to be used for recording can be housed in a stacked state, is detachably attached under the ejection tray <NUM> in the ejection port <NUM> such that the paper feed cassette <NUM> can be inserted rearward and drawn out frontward.

An openable-and-closable door <NUM> is provided on the front of the housing <NUM> at one end position in the leftward/rightward direction, specifically, at the right end position in the present embodiment. The openable-and-closable door <NUM> has a rectangular surface shape on its front, a rectangular surface shape on its top, and a right-angled triangular surface shape on its right side. The openable-and-closable door <NUM> has a pivot <NUM> extending in the leftward/rightward direction at its bottom end position. The openable-and-closable door <NUM> is able to open frontward and close rearward by turning around the pivot <NUM> freely. A window portion <NUM>, which is made of a rectangular transparent member, is formed in the front of the openable-and-closable door <NUM>. A user is able to see the inside of the housing <NUM>, in particular, the portion behind the front of the openable-and-closable door <NUM>, through the window portion <NUM>, even without opening the openable-and-closable door <NUM>.

An ink supply unit <NUM> is housed inside the housing <NUM> of the recording apparatus <NUM> at a position behind the openable-and-closable door <NUM> near the front face and near one end, specifically, near the right end in the present embodiment. The ink supply unit <NUM> supplies ink to the recording head <NUM>. The ink supply unit <NUM> includes a plurality of ink tanks, specifically, five ink tanks <NUM> to <NUM> in the present embodiment, and is configured as an integrated structure body that can be handled together. As will be described later, it is possible to refill each of the ink tanks <NUM> to <NUM> with ink.

<FIG> is a perspective view of the ink supply unit <NUM>. <FIG> is a plan view of the ink supply unit <NUM>. The ink supply unit <NUM> includes the five ink tanks <NUM> to <NUM>, each of which has an elongated box-like shape whose longitudinal direction is along the frontward/rearward direction, five ink supply tubes <NUM>, which are routed from the rear of the ink tanks <NUM> to <NUM> respectively, and an ink refilling adapter <NUM>, which has a shape of a rectangular parallelepiped and is attached to the ink tanks <NUM> to <NUM> all together. The ink refilling adapter <NUM> is integrated with the ink tanks <NUM> to <NUM> by being mounted onto a stepped portion <NUM>, which is formed as a cutout in the top-and-front part of each of the plurality of ink tanks <NUM> to <NUM>, with the ink tanks <NUM> to <NUM> arranged side by side in the leftward/rightward direction. As illustrated in <FIG>, the ink supply tubes <NUM> routed from the rear of the ink tanks <NUM> to <NUM> respectively are connected to respective non-illustrated ink flow passages formed inside the carriage <NUM>, and are connected to the recording head <NUM> via these respective ink flow passages. The ink refilling adapter <NUM> may be configured as a part of the housing <NUM> by which the ink tanks <NUM> to <NUM> are enclosed. The ink refilling adapter <NUM> may be formed integrally with the ink tanks <NUM> to <NUM>.

<FIG> is a partially-cut-away cross-sectional view taken along the line IV-IV of <FIG>. <FIG> is a partially-cut-away cross-sectional view taken along the line V-V of <FIG>. Each of the plurality of ink tanks <NUM> to <NUM> has an ink containing chamber <NUM> inside itself. The ink containing chamber <NUM> is a space inside which ink IK can be contained. In the present embodiment, black ink is contained in the ink containing chamber <NUM> of the ink tank <NUM>, which is the rightmost one of the ink tanks arranged side by side. Ink of colors other than black, for example, cyan, magenta, and yellow, etc., is contained in the respective ink containing chambers <NUM> of the ink tanks <NUM> to <NUM>, which are arranged side by side to the left of the rightmost one, that is, the ink tank <NUM>. The front wall portion, which can be seen from the outside through the window portion <NUM> formed in the front face of the housing <NUM>, of each of the plurality of ink tanks <NUM> to <NUM> has a see-through portion <NUM>. The see-through portion <NUM> is made of a transparent resin so as to enable the liquid level of the ink IK contained in the ink containing chamber <NUM> to be seen. An upper limit mark <NUM>, which approximately indicates the upper limit of the liquid level of the ink IK contained in the ink containing chamber <NUM>, and a lower limit mark <NUM>, which approximately indicates the lower limit thereof, are printed on the see-through portion <NUM>. The limit indicated by the upper limit mark <NUM> roughly shows, for example, how much refill ink can be poured without causing any overflow from an ink inlet <NUM>. The lower limit mark <NUM> roughly shows, for example, the level at which the user should refill the nearly empty ink tank with ink.

As illustrated in <FIG>, the ink inlet <NUM>, via which ink can flow into the ink containing chamber <NUM> from the outside, is provided over the horizontal part of the stepped portion <NUM> of each of the plurality of ink tanks <NUM> to <NUM>. The ink inlet <NUM> includes a needle <NUM>. The needle <NUM> has flow passages <NUM> and <NUM> and extends upright. The inside and the outside of the ink containing chamber <NUM> are in communication through the flow passages <NUM> and <NUM>. The flow passages <NUM> and <NUM> of the needle <NUM> are two flow passages arranged adjacently such that their respective end openings are configured in radiating directions, with the center of the needle <NUM> located at the center of the radiating configuration. The flow passage <NUM>, which is one of the two flow passages <NUM> and <NUM>, is the rear-side flow passage in the present embodiment. The flow passage <NUM>, which is the other, is the front-side flow passage in the present embodiment. In the present embodiment, the height of the rear-side flow passage <NUM> measured at its end opening is less than that of the front-side flow passage <NUM>, and the cross-sectional area size of the rear-side flow passage <NUM> is larger than that of the front-side flow passage <NUM>. A remaining amount sensor <NUM> for detecting the amount of the ink IK left in the ink containing chamber <NUM> is provided at a position closer to the rear near the bottom inside the ink containing chamber <NUM>. The remaining amount sensor <NUM> may be omitted. The tip of the needle <NUM> may be configured as a level plane such that the flow passages <NUM> and <NUM> have an equal height. Further, the flow passages <NUM> and <NUM> may have the same cross-sectional area as each other.

As illustrated in <FIG>, the upper surface <NUM> of the ink refilling adapter <NUM> is a horizontal plane that intersects with, preferably, is orthogonal to, the direction in which the needle <NUM> extends. Through holes <NUM> going vertically down from the upper surface <NUM> to the lower surface <NUM> of the ink refilling adapter <NUM> are formed as an example of an ink inlet forming portion. The through hole <NUM> is made up of the ink inlet <NUM>, which has a circular hole shape with the needle <NUM> arranged at its center, and front-and rear rectangular hole portions constituting a pair, the front one of which is continuous from and is located in front of the ink inlet <NUM>, and the rear one of which is continuous from and is located behind the ink inlet <NUM>. The bottom-side opening of the ink refilling adapter <NUM> is closed by the horizontal part of the stepped portion <NUM>, with the needle <NUM> protruding upright, in each of the plurality of ink tanks <NUM> to <NUM>.

In the through hole <NUM>, at areas located outside the ink inlet <NUM> in the radiating directions from the ink inlet <NUM>, which lies at the center, front-and rear recesses <NUM> which constitute a pair and have their respective openings open upward, that is, in the direction in which the needle <NUM> extends, are formed respectively, as defined by the above-mentioned front-and rear rectangular hole portions which constitute the pair and whose bottom-side opening is closed. The recesses <NUM> are point-symmetric with respect to the ink inlet <NUM>, the center of point symmetry. The depth direction of the recesses <NUM> goes vertically downward. That is, at the areas located outside the ink inlet <NUM> including the needle <NUM> in the ink refilling adapter <NUM> integrally attached to the ink tanks <NUM> to <NUM>, the plurality of recesses <NUM>, specifically, two recesses made up of the front one and the rear one constituting the pair in the present embodiment, are formed in a point-symmetric layout, with the ink inlet <NUM> located at the center of point symmetry. In this configuration, the tip of the needle <NUM> arranged at the center of the ink inlet <NUM> having a circular hole shape is located at a relatively-recessed position toward the ink containing chamber <NUM> in comparison with the upper surface <NUM> of the ink refilling adapter <NUM>, at which the opening of the through hole <NUM>, including the ink inlet <NUM> and including the recesses <NUM>, is exposed. That is, the upper surface <NUM> of the ink refilling adapter <NUM> extends in the direction intersecting with the direction in which the needle <NUM> extends, at a height position that is more outside than the tip of the needle <NUM> as viewed in the direction in which the needle <NUM> extends. On the other hand, the lower surface <NUM> of the ink refilling adapter <NUM> serves as a tank engagement portion configured to be brought into engagement, from above, with the ink tanks <NUM> to <NUM> arranged side by side in the leftward/rightward direction by a single engaging operation all together.

A peripheral portion located around the upper edge of the opening of each of the plurality of through holes <NUM> in the upper surface <NUM> of the ink refilling adapter <NUM> is painted in a predetermined color, specifically, painted in the same color as that of ink having flowed in through the ink inlet <NUM> of the through hole <NUM> and contained in the ink containing chamber <NUM> of the ink tank <NUM> to <NUM>. In this respect, the peripheral portion located around the upper edge of the opening of each of the plurality of through holes <NUM> of the ink refilling adapter <NUM> plays a role of a first portion that offers, to the outside, information about the ink contained inside the ink tank <NUM> to <NUM> in which the ink inlet <NUM> of the through hole <NUM> is in communication with the ink containing chamber <NUM>. For example, black is the paint color of the peripheral portion located around the upper edge of the opening of the through hole <NUM> in which the ink inlet <NUM> that is in communication with the ink containing chamber <NUM> of the ink tank <NUM> containing black ink is arranged.

On the inner surface of the recess <NUM>, specifically, on the inner side surface along the top/bottom direction, at a position that is closer to the bottom than the upper edge of the opening of the recess <NUM> is, that is, at a position that is closer to the horizontal part of the stepped portion <NUM>, a first concave-and-convex portion <NUM> having a characteristic concave-and-convex shape in the horizontal direction is provided in such a way as to extend in the depth direction of the recess <NUM>, or in other words, extend in the direction of the central axis of the ink inlet <NUM>. Another name of the first concave-and-convex portion <NUM> is a first key structure portion. As illustrated in <FIG>, the first concave-and-convex portion <NUM> is provided individually for the ink inlet <NUM> of each of the plurality, five in the present embodiment, of ink tanks <NUM> to <NUM>. Therefore, the first concave-and-convex portion <NUM> is formed in the rectangular recess <NUM> of each of the plurality of through holes <NUM> formed at positions corresponding to the ink tanks <NUM> to <NUM> respectively in the top/bottom direction in the ink refilling adapter <NUM>, wherein the first concave-and-convex portion <NUM> formed in each one through hole <NUM> is different from the first concave-and-convex portion <NUM> provided on the inner surface of the recesses <NUM> of the other through holes <NUM>. That is, each first concave-and-convex portion <NUM> of them serves as an identifier portion that makes it possible to identify an ink refilling container <NUM> that has an ink outlet <NUM> configured to be coupled to the ink inlet <NUM> of the through hole <NUM> in which this first concave-and-convex portion <NUM> is formed. In the description above, the "position that is closer to the bottom than the upper edge of the opening of the recess <NUM> is" means that any position suffices as long as it is set back toward the bottom, even if slightly, in comparison with the edge of the opening.

<FIG> is a side view of the ink refilling container <NUM>, with a cap <NUM> put thereon. The ink refilling container <NUM> and the ink tank <NUM> to <NUM> constitute an ink replenishment system. The ink refilling container <NUM> is a container from which refill ink is supplied to the ink tank <NUM> to <NUM> whose ink is running low. The ink refilling container <NUM> includes a bottle <NUM> and the cap <NUM>. The cap <NUM> is configured to be put on the bottle <NUM> detachably. With regard to the ink refilling container <NUM>, the bottom direction is defined as the direction from the cap <NUM> toward the bottle <NUM> when the ink refilling container <NUM> is placed on a table, etc., and the top direction is defined as the opposite direction, namely, from the bottle <NUM> toward the cap <NUM>.

<FIG> is a perspective view of the bottle <NUM>. <FIG> is a plan view of the bottle <NUM>. <FIG> is a longitudinal sectional view of the bottle <NUM>. As illustrated in <FIG>, the bottle <NUM> includes a container body portion <NUM>, an ink outlet forming portion <NUM>, and a container annexation portion <NUM>. The container body portion <NUM> is a cylindrical portion having a bottom. This cylindrical portion with a bottom is the main part of the bottle <NUM>. As illustrated in <FIG>, the container body portion <NUM> has an ink containing portion <NUM>, inside which ink can be contained. The ink outlet forming portion <NUM> is provided at the top-side end of the container body portion <NUM>, the opposite of the bottom of the container body portion <NUM>. The ink outlet forming portion <NUM> is a portion where the ink outlet <NUM> is formed as an opening at its end. Ink is able to flow out through the ink outlet <NUM> from the inside of the ink refilling container <NUM>. The container annexation portion <NUM> is a portion annexed to the ink outlet forming portion <NUM> in such a way as to interpose at least a part of the ink outlet <NUM>. In the present embodiment, the ink outlet forming portion <NUM> and the container annexation portion <NUM> are formed integrally. That is, the container annexation portion <NUM> is a part of the ink outlet forming portion <NUM>. Among components that constitute the ink refilling container <NUM>, at least the container body portion <NUM> is made of a transparent or semitransparent material. As such a material, for example, polypropylene can be used. The ink outlet forming portion <NUM> and the container annexation portion <NUM> may be configured as distinct parts that are not formed integrally.

The ink outlet <NUM> is in communication with the ink containing portion <NUM> illustrated in <FIG>. As illustrated in <FIG>, in the present embodiment, a groove <NUM> is formed in the end face of the ink outlet <NUM>. In addition, as illustrated in <FIG>, an annular convex portion <NUM> is formed along the outer circumference of the ink outlet forming portion <NUM> at a position between the end of the ink outlet <NUM> and a positioning portion <NUM>. The positioning portion <NUM> will be described later. Since the groove <NUM> is provided, it is possible to reduce the risk of dripping of ink from the ink outlet <NUM> when the ink refilling container <NUM> is put into an upright position after the ink tank <NUM> to <NUM> is refilled with ink. Moreover, since the annular convex portion <NUM> is provided, even if ink drips down from the ink outlet <NUM>, it is possible to stem the dripping ink.

As illustrated in <FIG>, the ink outlet forming portion <NUM> and the container annexation portion <NUM> are provided above the container body portion <NUM>. The ink outlet <NUM> formed by the ink outlet forming portion <NUM>, together with the container annexation portion <NUM> annexed around it, is covered by the cap <NUM> and therefore cannot be seen from the outside when the ink refilling container <NUM> is in a storage state. A first thread portion <NUM> is formed on the outer circumferential portion <NUM> of a cylindrical lower-end part of the ink outlet forming portion <NUM>.

<FIG> is a perspective view showing an inner shape of the cap <NUM>. A second thread portion <NUM> is formed on the inner circumferential surface of the cap <NUM>. The second thread portion <NUM> formed in the cap <NUM> is configured to be brought into thread engagement with the first thread portion <NUM> of the bottle <NUM>. By this thread engagement, the cap <NUM> is attached onto the bottle <NUM> in such a way as to enclose the ink outlet <NUM> at the mouth portion of the ink refilling container <NUM>. A state in which the cap <NUM> is attached to the bottle <NUM> by the thread engagement of the first thread portion <NUM> of the bottle <NUM> and the second thread portion <NUM> of the cap <NUM> will be hereinafter referred to as "cap-on state".

As illustrated in <FIG>, the cap <NUM> includes a barrel portion <NUM>, a top portion <NUM>, and a protruding portion <NUM>.

The barrel portion <NUM> has a cylindrical shape. The barrel portion <NUM> includes an inner circumferential portion <NUM> on which the second thread portion <NUM> configured to engage with the first thread portion <NUM> is formed. On the inner circumferential portion <NUM>, the second thread portion <NUM> is formed near an opening-side end that is the opposite of a top-end end located closer to the top portion <NUM>.

In a cap-on state, the top portion <NUM> faces the ink outlet <NUM> of the bottle <NUM>. The top portion <NUM> is provided on the barrel portion <NUM> in such a way as to close the top of the barrel portion <NUM>.

The protruding portion <NUM> is provided at the center of the inner surface of the top portion <NUM>. In the present embodiment, the protruding portion <NUM> has a substantially cylindrical shape. The protruding portion <NUM> extends in the direction of the central axis CX2 of the barrel portion <NUM>. In addition, in a cap-on state, the protruding portion <NUM> extends in the direction of the central axis CX of the ink outlet <NUM>. This means that, in a cap-on state, the central axis CX of the ink outlet <NUM> of the bottle <NUM> is in alignment with the central axis CX2 of the barrel portion <NUM> of the cap <NUM>. As illustrated in <FIG>, the radius of the protruding portion <NUM> is set to be less than the length of each slit <NUM> formed in a valve <NUM> provided inside the ink outlet <NUM>. More specifically, the radius of the protruding portion <NUM> is set to be less than the length of the slit <NUM> as viewed in the direction of the central axis CX of the ink outlet <NUM> when the valve <NUM> is closed. The valve <NUM> and the slits <NUM> will be described in detail later.

Small protrusions <NUM> are provided at the tip end of the protruding portion <NUM>. In the present embodiment, the small protrusions <NUM> are provided as a part of the protruding portion <NUM> and constitute the tip end of the protruding portion <NUM>. The small protrusions <NUM> protrude in the direction of the central axis CX2 of the barrel portion <NUM>. In addition, in a cap-on state, the small protrusions <NUM> protrude in the direction of the central axis CX of the ink outlet <NUM>. It is preferable if the protruding portion <NUM> has a plurality of small protrusions <NUM>. It is more preferable if the number of the small protrusions <NUM> which the protruding portion <NUM> has is less than the number of the valve segments <NUM> provided in the valve <NUM>. In the present embodiment, the number of the valve segments <NUM> is six, and the number of the small protrusions <NUM> is two. The small protrusions <NUM> are provided at equal intervals in the circumferential direction along the outer circumference of the protruding portion <NUM>. The small protrusions <NUM> can be described as having a structure formed by cutting away some parts of a ring wall, which would be annularly continuous if no part were cut away, of the protruding portion <NUM> having a cylindrical shape.

An annular sealing portion <NUM> is provided on the top portion <NUM> outside the protruding portion <NUM> in the radial direction. In a cap-on state, the sealing portion <NUM> seals the ink outlet <NUM> tightly. In the present embodiment, the sealing portion <NUM> includes a first sealing portion <NUM> and a second sealing portion <NUM>. The second sealing portion <NUM> is located at an outer position relative to the first sealing portion <NUM>. As illustrated in <FIG>, in a cap-on state, the outer circumferential surface of the first sealing portion <NUM> is in contact with the inner circumferential surface of the ink outlet <NUM> to seal the ink outlet <NUM> tightly. In addition, in a cap-on state, the inner circumferential surface of the second sealing portion <NUM> is in contact with the outer circumferential surface of the ink outlet <NUM> to seal the ink outlet <NUM> tightly. That is, in the present embodiment, the ink outlet <NUM> is sealed tightly by both of the first sealing portion <NUM> and the second sealing portion <NUM>. Instead of providing both of the first sealing portion <NUM> and the second sealing portion <NUM>, either one of them may be provided, and the ink outlet <NUM> may be sealed tightly by the one provided.

In the present embodiment, in a cap-on state, the protruding portion <NUM> provided on the cap <NUM> is inserted into the bottle <NUM> through the slits <NUM> formed in the valve <NUM>. In a state in which the protruding portion <NUM> is inserted through the valve <NUM>, the gap between each valve segment <NUM> and the protruding portion <NUM> is very small. For this reason, even if the ink refilling container <NUM> is turned upside down, the leakage of ink from the bottle <NUM> into the cap <NUM> does not occur easily because an ink meniscus is formed at the gap between the valve segment <NUM> and the protruding portion <NUM>. A detailed explanation of a positional relationship between the protruding portion <NUM> and the valve <NUM> in a cap-on state will be given later.

The whole of the outer surface of the container annexation portion <NUM> illustrated in <FIG> is painted in a predetermined color. Specifically, it is painted in the same color as that of ink contained in the container body portion <NUM> to which the container annexation portion <NUM> is annexed. In this respect, the container annexation portion <NUM> of the ink refilling container <NUM> plays a role of a second portion that offers, to the outside, information about the ink contained inside the ink refilling container <NUM>. For example, the outer surface of the container annexation portion <NUM> of the ink refilling container <NUM> containing black ink is painted in black. It is not always necessary for the container annexation portion <NUM> to be painted in the same color as that of the ink, and the container annexation portion <NUM> may be made of a transparent or semitransparent material. The ink outlet forming portion <NUM> may be made of a transparent or semitransparent material. If the ink outlet forming portion <NUM> is made of a transparent or semitransparent material, it becomes easier to recognize the color of ink adhering to the inside of the ink outlet <NUM> when seen from the outside. Moreover, for example, the container body portion <NUM> of the ink refilling container <NUM> containing black ink may be configured to be thicker than the container body portion <NUM> of the ink refilling container <NUM> containing ink of any other color. In this configuration, the thickness and shape of the ink outlet forming portion <NUM> for black ink may be configured to be the same as the thickness and shape of the ink outlet forming portion <NUM> for any other color.

As illustrated in <FIG>, a convex portion <NUM> is provided on at least a part of periphery around the ink outlet <NUM>, wherein the convex portion <NUM> is configured to fit into the recessed portion <NUM> provided for each of the plurality of ink tanks <NUM> to <NUM> to which refill ink is supplied. More specifically, the convex portion <NUM> is formed above the cylindrical lower-end part on which the first thread portion <NUM> is formed on the outer circumferential surface of the container annexation portion <NUM> at areas located outside the ink outlet <NUM> in the radiating directions from the ink outlet <NUM>, which lies at the center, in such a way as to protrude upward in the direction of the central axis CX of the ink outlet <NUM>. The convex portion <NUM> serves as a second mating portion that is able to mate with a first mating portion, specifically, mate with the recessed portion <NUM> formed in the upper surface <NUM> of the ink refilling adapter <NUM>, when the tip of the needle <NUM> of the ink inlet <NUM> is inserted into the ink outlet <NUM>. Similarly to the pair of recesses <NUM> made up of the front one and the rear one between which the ink inlet <NUM> is located, the convex portion <NUM> is configured as a pair made up of the front one and the rear one between which the ink outlet <NUM> is located. As illustrated in <FIG>, the convex portion <NUM> is located at an inner position relative to the external wall <NUM> of the container body portion <NUM> in the radiating directions from the ink outlet <NUM>, which lies at the center, in the ink refilling container <NUM>.

In the present embodiment, the tip end of the convex portion <NUM> of the ink refilling container <NUM> protrudes beyond the ink outlet <NUM> in the direction of the central axis CX of the ink outlet <NUM>. For this reason, it is possible to prevent the risk of staining the user's finger(s) and/or the peripheral portion of the ink refilling container <NUM> with ink due to the touch contact of the ink outlet <NUM> with it during an ink refilling process. In another embodiment, the tip end of the convex portion <NUM> may be configured not to protrude beyond the ink outlet <NUM> in the direction of the central axis CX of the ink outlet <NUM>.

A second concave-and-convex portion <NUM>, which is able to be brought into engagement with the first concave-and-convex portion <NUM> formed on the inner surface of the corresponding recessed portion <NUM> of the ink refilling adapter <NUM>, is formed in the outer surface of each convex portion <NUM> in the leftward/rightward direction. Another name of the second concave-and-convex portion <NUM> is a second key structure portion. The second concave-and-convex portion <NUM> extends in the direction in which the convex portion <NUM> protrudes. In other words, the second concave-and-convex portion <NUM> extends in the direction of the central axis CX of the ink outlet <NUM>. When the convex portion <NUM> mates with the recessed portion <NUM>, accompanied by engagement of the second concave-and-convex portion <NUM> with the first concave-and-convex portion <NUM>, the ink outlet <NUM> of the ink refilling container <NUM> is coupled to the ink inlet <NUM> for the ink tank <NUM> to <NUM>. The convex portion <NUM>, including the second concave-and-convex portion <NUM>, is provided in a point-symmetric layout, with the ink outlet <NUM> located at the center of point symmetry. In the present embodiment, the pair constituting the convex portion <NUM> is arranged with <NUM>° point symmetry. Therefore, when one of the pair constituting the convex portion <NUM> is positioned to face one of the pair constituting the recessed portion <NUM>, the other of the pair constituting the convex portion <NUM> will inevitably face the other of the pair constituting the recessed portion <NUM>. This structure makes mating and engagement easier.

Between the cylindrical lower-end part, of the container annexation portion <NUM>, on which the first thread portion <NUM> is formed and the convex portion <NUM> in which the second concave-and-convex portion <NUM> is formed, as illustrated in <FIG>, the positioning portion <NUM> that has a plane shape intersecting with, or preferably orthogonal to, the central axis CX of the ink outlet <NUM> is provided outside the ink outlet <NUM> in the radiating directions when viewed in the direction of the central axis CX of the ink outlet <NUM>. Moreover, the positioning portion <NUM> is provided so as to sandwich the ink outlet <NUM> and the convex portion <NUM> in directions of +X and -X when the convex portion <NUM> is positioned to be in +Y and -Y directions. The positioning portion <NUM> constitutes a part of the exterior face of the container annexation portion <NUM> that is a part of the exterior face of the ink refilling container <NUM>. As illustrated in <FIG>, the positioning portion <NUM> is provided at a position closer to the container body portion <NUM> than the tip end of the convex portion <NUM> is, as viewed in the direction of the central axis CX of the ink outlet <NUM>.

As illustrated in <FIG>, the bottle <NUM> is configured by assembling a spout portion <NUM>, the valve <NUM>, and the container body portion <NUM> together. The spout portion <NUM> is integrally made up of the ink outlet <NUM>, the ink outlet forming portion <NUM>, and the container annexation portion <NUM>.

A third thread portion <NUM> is formed on the outer circumferential surface of a neck portion <NUM>, which is provided at the upper end of the container body portion <NUM>. On the other hand, a fourth thread portion <NUM> is formed on the inner circumferential surface of the lower portion of the spout portion <NUM>. By thread engagement of the fourth thread portion <NUM> with the third thread portion <NUM> formed on the neck portion <NUM> of the container body portion <NUM>, the spout portion <NUM> is attached onto the upper portion of the container body portion <NUM>.

The valve <NUM> made of an elastic material, for example, a silicon membrane, for sealing the ink outlet <NUM> in such a way that the ink outlet <NUM> can be opened and closed is provided inside the ink outlet <NUM> formed in the ink outlet forming portion <NUM>. As illustrated in <FIG>, the valve <NUM> is provided at a position closer to the mouth end than the positioning portion <NUM> is, as viewed in the direction of the central axis CX of the ink outlet <NUM>.

As illustrated in <FIG>, the valve <NUM> includes the valve segments <NUM> segmented by at least one slit <NUM> extending in the radial direction from the center of the ink outlet <NUM> toward the outer circumference. In the present embodiment, six slits <NUM> are provided. Therefore, the number of the valve segments <NUM> is six. These valve segments <NUM> are pushed by the needle <NUM> to give way in a widening manner into the inside of the ink outlet <NUM> from the outside, and the valve <NUM> is configured to open in this way. The valve <NUM> is called also as a slit valve. When the needle <NUM> is removed from the ink outlet <NUM>, the valve <NUM> returns to its original state due to its elastic resilience and thus closes, with the gap of the slits <NUM> made narrower than in a valve-open state.

When the valve <NUM> opens due to the insertion of the tip of the needle <NUM> of the ink inlet <NUM> into the ink outlet <NUM>, the positioning portion <NUM> is placed in contact with the upper surface <NUM> of the ink refilling adapter <NUM>, in which the through holes <NUM> including the ink inlets <NUM> and the recesses <NUM> are formed, thereby positioning the valve <NUM> relative to the ink tank <NUM> to <NUM> in the direction of the central axis CX of the ink outlet <NUM>. In this respect, the upper surface <NUM> of the ink refilling adapter <NUM> serves as a receiving surface constituting a part of the ink-tank-side structure with which the positioning portion <NUM> of the ink refilling container <NUM> is placed in contact and configured to receive the positioning portion <NUM> having a plane shape when the valve <NUM> of the ink outlet <NUM> of the ink refilling container <NUM> opens for the purpose of allowing the supply of refill ink to the ink tank <NUM> to <NUM>.

<FIG> is a partially-cut-away side view showing a state of an ink replenishment system immediately before ink refilling is performed. <FIG> is a partially-cut-away side view showing a state during ink refilling. <FIG> is a partially-cut-away side view showing a state in which the positioning portion of the ink refilling container is placed in contact with the ink-tank-side receiving surface. The operational behavior of an ink replenishment system having the structure described above will now be explained, with a focus on operation in refilling the ink tank <NUM> to <NUM> of the ink supply unit <NUM> with ink by using the ink refilling container <NUM>. As a premise of the description below, as illustrated in <FIG>, it is assumed here that the level of ink contained in the ink tank <NUM> corresponding to black ink and located at the rightmost position among the plurality of ink tanks <NUM> to <NUM> arranged side by side has become low to reach the lower limit mark <NUM> printed at the lowest part of the see-through portion <NUM>. Therefore, in the description below, it is assumed that there is a need to refill the ink tank <NUM> with ink. It is further assumed that the ink refilling container <NUM> used for ink refilling contains a sufficient amount of black ink, and the cap <NUM> has been removed in advance from the ink refilling container <NUM>. It is further assumed that the shape of the second concave-and-convex portion <NUM> formed in the outer surface of the convex portion <NUM> of the ink refilling container <NUM> matches the shape of the first concave-and-convex portion <NUM> formed on the inner surface of the recessed portion <NUM> located in front of and behind the ink inlet <NUM> toward the ink tank <NUM>, and, because of the matching shape, the second concave-and-convex portion <NUM> is able to come into engagement with the first concave-and-convex portion <NUM> when the convex portion <NUM> is inserted into the recessed portion <NUM>. In <FIG>, <FIG>, and <FIG>, the ink outlet <NUM> is illustrated as if it protrudes beyond the convex portion <NUM> for the sake of illustrative convenience. However, the operational behavior of an ink replenishment system described below will be the same even if the convex portion <NUM> protrudes beyond the ink outlet <NUM>.

To refill the ink tank <NUM> with ink, first, the user opens the openable-and-closable door <NUM> of the housing <NUM> by rotating it frontward around the pivot <NUM> from a closed state illustrated in <FIG>. As a result, the upper surface <NUM> of the ink refilling adapter <NUM>, in which the ink inlets <NUM> communicating to the ink tanks <NUM> to <NUM> respectively are formed, of the ink supply unit <NUM> becomes exposed to the outside of the housing <NUM>. In this top-exposed state, the user is able to couple the ink outlet <NUM> of the bottle <NUM> from above to the target ink inlet <NUM>, which is the one corresponding to the ink tank which the user wants to refill.

Then, as illustrated in <FIG>, the user turns the bottle <NUM> containing black ink to be used for refilling upside down, and holds it such that the ink outlet <NUM> is positioned over the rightmost one of the through holes <NUM> of the ink refilling adapter <NUM>. That is, the user positions the central axis CX of the ink outlet <NUM> of the bottle <NUM> in alignment with the central axis of the ink inlet <NUM> for the ink tank <NUM>, namely, the one which the user wants to refill. When the user performs this positioning, the user visually checks the paint color of the container annexation portion <NUM> of the bottle <NUM> held in the user's hand against the paint color of the periphery around the upper edge of the opening of the through hole <NUM> in which the ink inlet <NUM> for the ink tank <NUM>, namely, the one which the user wants to refill, is provided. If the colors of the two match, the user is able to confirm that the bottle <NUM> held in the user's hand is suitable one for the current ink refilling. After the confirmation, the user proceeds to the next step.

Next, the user lowers the bottle <NUM> from the state illustrated in <FIG> to insert the convex portion <NUM> of the bottle <NUM> into the recessed portion <NUM> of the ink refilling adapter <NUM> integrally attached to the ink tank <NUM>. The insertion of the convex portion <NUM> into the recessed portion <NUM> ensures that the central axis of the ink outlet <NUM> is in alignment with the central axis of the ink inlet <NUM>. Since the pair constituting the recessed portion <NUM> is point symmetric with respect to the needle <NUM> located at the center of the ink inlet <NUM>, the convex portion <NUM> is able to be inserted into whichever one of the recessed portion <NUM>. Therefore, there is no need for the user to confirm whether the recessed portion <NUM> and the convex portion <NUM> are in a suitable positional relationship or not by rotating the bottle <NUM> around the central axis CX of the ink outlet <NUM> again and again. The user is able to insert the convex portion <NUM> into the recessed portion <NUM> easily.

In the process of inserting the convex portion <NUM> into the recessed portion <NUM> downward, which is the depth direction of the recessed portion <NUM>, from a state in which the convex portion <NUM> is slightly inserted in the recessed portion <NUM>, the second concave-and-convex portion <NUM> formed in the outer surface of the convex portion <NUM> comes into engagement with the first concave-and-convex portion <NUM> formed on the inner surface of the recessed portion <NUM>. Then, when the user further inserts the convex portion <NUM> into the recessed portion <NUM> toward the bottom, that is, in the depth direction of the recessed portion <NUM>, while keeping the engaged state, the tip of the needle <NUM> of the ink inlet <NUM> reaches the position of the valve <NUM> of the ink outlet <NUM> and causes the valve <NUM> to open.

That is, as illustrated in <FIG>, the tip of the needle <NUM> pushes the valve <NUM> to widen the slits <NUM> upward from below, or in other words, from the outside to the inside of the ink outlet <NUM>, thereby putting the valve <NUM> into an open state. As a result, the ink outlet <NUM> of the bottle <NUM> becomes coupled to the needle <NUM> of the ink inlet <NUM> for the ink tank <NUM>, and black ink for a refill is supplied from the inside of the bottle <NUM> into the ink tank <NUM>. When this refilling is performed, one of the two flow passages <NUM> and <NUM> of the needle <NUM> of the ink inlet <NUM> serves as an ink flow passage, through which the ink flows, and the other serves as an air flow passage, through which air flows. Specifically, of the two flow passages <NUM> and <NUM>, the one whose end opening comes into contact earlier than the other with the ink that has flowed out from the ink outlet <NUM> by opening the valve <NUM> serves as the ink flow passage, and the other serves as the air flow passage. For example, if the user attempts to couple the ink outlet <NUM> to the ink inlet <NUM> with the bottle <NUM> tilted, which one of the two flow passages <NUM> and <NUM> serves as the ink flow passage depends on which direction the bottle <NUM> is tilted in.

If the second concave-and-convex portion <NUM> does not come into engagement with the first concave-and-convex portion <NUM> after starting the insertion of the convex portion <NUM> into the recessed portion <NUM>, the user is able to know at that point in time that the user is mistakenly attempting to attach a wrong bottle <NUM> corresponding to a color other than black. In such a case of wrong bottle attachment, if the upper end of the first concave-and-convex portion <NUM> were located at the same height level as the edge of the opening of the recessed portion <NUM>, not only the engagement of the second concave-and-convex portion <NUM> with the first concave-and-convex portion <NUM> but also the insertion of the convex portion <NUM> into the recessed portion <NUM> would be impossible. Therefore, the user might spend fruitless time trying to insert the convex portion <NUM> into the recessed portion <NUM> again and again in vain. In this respect, in the present embodiment, since the upper end of the first concave-and-convex portion <NUM> is located below the edge of the opening of the recessed portion <NUM>, when the convex portion <NUM> is inserted into the recessed portion <NUM>, it is easier for the convex portion <NUM> to be guided toward the bottom in the depth direction of the recessed portion <NUM>. Moreover, the user will not spend time in a vain attempt.

Moreover, as illustrated in <FIG> and <FIG>, when the needle <NUM> of the ink inlet <NUM> for the ink tank <NUM> opens the valve <NUM> provided inside the ink outlet <NUM> of the bottle <NUM>, the positioning portion <NUM> of the bottle <NUM> is placed in contact with the upper surface <NUM> of the ink refilling adapter <NUM> constituting a part of the ink-tank-side structure. That is, the bottle <NUM> is held such that the valve <NUM> is opened in a state of being positioned with respect to the needle <NUM>, which is provided on the side where the ink tank <NUM> is provided, in the direction of the central axis of the ink outlet <NUM> due to the contact of the positioning portion <NUM> with the upper surface <NUM> of the ink refilling adapter <NUM>.

Moreover, in this process, the bottle <NUM> is held stably with good coupling of the ink outlet <NUM> to the ink inlet <NUM> because the positioning portion <NUM> is provided outside the ink outlet <NUM> in the radiating directions. Furthermore, when the positioning portion <NUM> of the bottle <NUM> is placed in contact with the upper surface <NUM> of the ink refilling adapter <NUM>, there is a gap between the bottom-side surface of the ink inlet <NUM> at which the base end of the needle <NUM> of the ink inlet <NUM> is located and the end of the ink outlet <NUM> of the bottle <NUM>. Therefore, ink is prone to form a pool on the bottom-side surface of the ink inlet <NUM> at which the base end of the needle <NUM> of the ink inlet <NUM> is located; however, the disclosed structure makes it possible to prevent the bottle <NUM> from being stained due to the contact of such a pool of ink with the end of the ink outlet <NUM>.

If the level of ink contained in the ink tank <NUM> is still lower than the upper limit mark <NUM> of the see-through portion <NUM> when the refilling of the ink tank <NUM> with ink from the bottle <NUM> has finished, the ink tank <NUM> may be further refilled up to the level of the upper limit mark <NUM> by using another bottle <NUM> containing ink of the same color, that is, black. The ink refilling described above can be performed for the ink tanks <NUM> to <NUM> corresponding to ink of colors other than black in the same manner as done for the ink tank <NUM> corresponding to black ink.

<FIG> is a cross-sectional view showing a positional relationship between the protruding portion <NUM> and the valve <NUM> in a cap-on state. <FIG> is a view of the positional relationship between the protruding portion <NUM> and the valve <NUM> in a cap-on state, seen from the inside of the spout portion <NUM>. As illustrated in these drawings, in a cap-on state, that is, in a sealed state in which the cap <NUM> is in thread engagement with the bottle <NUM> and in which the sealing portion <NUM> seals the ink outlet <NUM> tightly, the protruding portion <NUM> is inserted in the inside of the bottle <NUM> through the slits <NUM> at the center region as viewed in the direction of the central axis CX of the ink outlet <NUM>. This means that, in a cap-on state, the protruding portion <NUM> is inserted into the slits <NUM> to protrude through the valve <NUM> downward in the direction of the central axis CX. Therefore, in a cap-on state, the tip end of the protruding portion <NUM> protrudes into the bottle <NUM> significantly more than the protrusion of the ink-outlet-center-side end of the valve segments <NUM> into the bottle <NUM>. In the process of putting the cap <NUM> on the bottle <NUM>, the protruding portion <NUM> pushes the middle portion located closer to the center of the ink outlet <NUM> than the outer-circumference-side end of the valve segments <NUM> is. That is, the protruding portion <NUM> is arranged in such a way as to push the middle portion of the valve segments <NUM> that does not include the outer-circumference-side end of the valve segments <NUM> and is located closer to the center of the ink outlet <NUM> than the outer-circumference-side end is. Therefore, in a cap-on state, each valve segment <NUM> deforms in such a way that the ink-outlet-center-side end of the valve segment <NUM> is located deeper into the bottle <NUM> in the direction of the central axis CX than the outer-circumference-side end of the valve segment <NUM> is. The middle portion of the valve segment <NUM> is an area that is located at an inner region than the portion corresponding to the outer circumference of the protruding portion <NUM> as indicated by broken-line illustration in <FIG> and does not include the outer-circumference-side end of the valve segment <NUM>.

<FIG> is a cross-sectional view showing a state in which the protruding portion <NUM> is being pulled out from the valve <NUM>. <FIG> depicts a state of the protruding portion <NUM> and the valve <NUM> immediately before the seal provided by the sealing portion <NUM> is unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to relative rotation of the first thread portion <NUM> and the second thread portion <NUM>. The sealing of the ink outlet <NUM> by the sealing portion <NUM> is unsealed when, in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation, the disengagement further advances from the state illustrated in <FIG>. In the present embodiment, in a state in which the sealing of the ink outlet <NUM> by the sealing portion <NUM> has been unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation, the tip end of the protruding portion <NUM> is still inserted inside the bottle <NUM> through the valve segments <NUM>. Then, upon the disengagement of the cap <NUM> and the bottle <NUM> from each other, the protruding portion <NUM> is pulled out from the valve segments <NUM>.

In the present embodiment, in the process of detachment of the cap <NUM> from the bottle <NUM>, due to the screw rotation, the protruding portion <NUM>, including the small protrusions <NUM>, is in contact with each valve segment <NUM> while rotating. Due to this rotation, the state of contact of each valve segment <NUM> and the protruding portion <NUM> changes. Even if the internal pressure of the ink containing portion <NUM> has become high due to a rise in temperature, etc., such a change in the state of contact makes it easier for air inside the ink containing portion <NUM> to escape through the gap between each valve segment <NUM> and the protruding portion <NUM>. Therefore, air inside the ink containing portion <NUM> escapes toward the cap <NUM>. This results in a decrease in the internal pressure of the ink containing portion <NUM>. In the present embodiment, it is easier to form a gap between each valve segment <NUM> and the protruding portion <NUM> especially because the protruding portion <NUM> has a plurality of small protrusions <NUM> at its tip end. Therefore, it is easier to decrease the internal pressure of the ink containing portion <NUM>.

In the present embodiment, as described above, the protruding portion <NUM> provided on the cap <NUM> is inserted into the bottle <NUM> through the slits <NUM> at the center region of the ink outlet <NUM> in a sealed state in which the cap <NUM> is in thread engagement with the bottle <NUM>. For this reason, as compared with a case where the protruding portion <NUM> pushes the outer-circumference-side end of each valve segment <NUM>, each valve segment <NUM> is less susceptible to creep deformation. Therefore, the slits <NUM> are less likely to remain open when the cap <NUM> is detached from the bottle <NUM>, and staining due to spilling of ink is unlikely to occur even if the ink outlet <NUM> of the bottle <NUM> without the cap <NUM> is directed downward. In particular, in the present embodiment, since the protruding portion <NUM> is provided on the cap <NUM> in such a way as to push the middle portion of the valve segments <NUM>, which is located closer to the center of the ink outlet <NUM> than the outer-circumference-side end is, it is easier for the protruding portion <NUM> to push the valve segments <NUM> at the center region of the ink outlet <NUM>. Therefore, it is possible to prevent the creep deformation of the valve segments <NUM> more effectively, thereby reducing the risk of staining due to spilling of ink from the ink outlet <NUM>.

Moreover, in the present embodiment, the tip end of the protruding portion <NUM> is configured to be inserted into the slits <NUM> in a state in which the seal provided by the sealing portion <NUM> is unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation. Because of this configuration, the degree of entry of air and/or the ink IK into the gap between the protruding portion <NUM> and the valve segments <NUM> varies due to the screw-rotating operation when the cap <NUM> is detached from the bottle <NUM>. Therefore, it is easier to release the pressure that has increased inside the bottle <NUM>. Therefore, it is possible to prevent the content of the bottle <NUM> from spouting due to the exceeding of the sum of the increased pressure and the liquid head pressure of the content over the pressure resistance of the valve <NUM> when the bottle <NUM> is turned upside down.

Furthermore, in the present embodiment, the protruding portion <NUM> has, at its tip end, the small protrusions <NUM> protruding in the direction of the central axis CX2 of the barrel portion <NUM>. Therefore, the small protrusions <NUM> push and release the valve segments <NUM> in turns due to the screw-rotating operation when the cap <NUM> is detached from the bottle <NUM>. For this reason, a gap is formed by relative displacement of the valve segments <NUM> in the top/bottom direction, and the gap makes it easier for the internal pressure of the container body portion <NUM> to be released gradually. Therefore, it is possible to more effectively prevent the content of the bottle <NUM> from spouting due to the exceeding of the sum of the increased pressure and the liquid head pressure of the content over the pressure resistance of the valve <NUM> when the bottle <NUM> is turned upside down.

Furthermore, in the present embodiment, the number of the small protrusions <NUM> provided at the tip end of the protruding portion <NUM> is less than the number of the valve segments <NUM>. If many small protrusions <NUM> were inserted into the valve segments <NUM>, the whole of the valve segments <NUM> would be pushed. This would make it difficult to form a gap by relative displacement of the valve segments <NUM>. In this respect, since the number of the small protrusions <NUM> is less than the number of the valve segments <NUM>, it is easy to form a gap, and air passes easily. Therefore, it is possible to release the pressure inside the bottle <NUM> smoothly.

<FIG> is a perspective view showing an inner shape of a cap 68b according to a second embodiment. <FIG> is a cross-sectional view showing a positional relationship between the protruding portion <NUM> and the valve <NUM> according to the second embodiment. <FIG> is a view of the positional relationship between the protruding portion <NUM> and the valve <NUM> in a cap-on state according to the second embodiment, seen from the inside of the spout portion <NUM>.

In the first embodiment, the number of the small protrusions <NUM> provided on the protruding portion <NUM> of the cap <NUM> is two. By contrast, the cap 68b according to the second embodiment has four small protrusions <NUM> at the tip end of the protruding portion <NUM>. The small protrusions <NUM> are provided at equal intervals in the circumferential direction along the outer circumference of the protruding portion <NUM>. Even with this modified configuration, the small protrusions <NUM> push and release the valve segments <NUM> in turns due to the screw-rotating operation when the cap 68b is detached from the bottle <NUM>. For this reason, a gap is formed by relative displacement of the valve segments <NUM> in the top/bottom direction, and the gap makes it easier for the internal pressure of the container body portion <NUM> to be released gradually. Therefore, it is possible to effectively prevent the content of the bottle <NUM> from spouting due to the exceeding of the sum of the increased pressure and the liquid head pressure of the content over the pressure resistance of the valve <NUM> when the bottle <NUM> is turned upside down.

In the foregoing embodiments, the tip end of the protruding portion <NUM> is configured to be inserted in the inside of the bottle <NUM> through the slits <NUM> in a state in which the seal provided by the sealing portion <NUM> is unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation. However, the tip end of the protruding portion <NUM> may be configured to be not inserted into the inside of the bottle <NUM> through the slits <NUM> in a state in which the seal provided by the sealing portion <NUM> has been unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation, and may be in a state of push-widening the slits <NUM>. The tip end of the protruding portion <NUM> may be configured to be not in contact with the valve segments <NUM> in a state in which the seal provided by the sealing portion <NUM> has been unsealed in the process of disengagement of the cap <NUM> and the bottle <NUM> from each other due to the screw rotation.

In the foregoing embodiments, the protruding portion <NUM> provided on the cap <NUM> has the small protrusions <NUM>. However, the protruding portion <NUM> may be configured not to have the small protrusions <NUM>.

In the foregoing embodiments, the number of the small protrusions <NUM> is two or four. However, the number of the small protrusions <NUM> is not limited to two or four. The number of the small protrusions <NUM> may be one, three, or five or more depending on the number of the valve segments <NUM>. The number of the small protrusions <NUM> may be equal to or greater than the number of the valve segments <NUM>.

Claim 1:
An ink refilling container (<NUM>), comprising:
a bottle (<NUM>); and
a cap (<NUM>) configured to be put on the bottle detachably;
the bottle including
an ink outlet forming portion (<NUM>) that includes an ink outlet (<NUM>), a valve (<NUM>) provided inside the ink outlet and an outer circumferential portion (<NUM>), the ink outlet having a cylindrical shape, the outer circumferential portion having a first thread portion (<NUM>), wherein the valve is made of an elastic material and includes valve segments (<NUM>) segmented by at least one slit (<NUM>) extending in a radial direction from a center of the ink outlet toward an outer circumference;
the cap including
a barrel portion (<NUM>) having a cylindrical shape and including an inner circumferential portion on which a second thread portion (<NUM>) configured to engage with the first thread portion is formed; and
a top portion (<NUM>) configured to face the ink outlet when the cap is put on the bottle; wherein
a protruding portion (<NUM>) extending in a direction of a central axis of the barrel portion is provided at a center of the top portion,
a sealing portion (<NUM>) having an annular shape is provided on the top portion outside the protruding portion in the radial direction,
a radius of the protruding portion is set to be less than a length of the slit as viewed in a direction of a central axis of the ink outlet when the valve is closed, and
in a sealed state in which the cap is in thread engagement with the bottle and in which the sealing portion seals the ink outlet, a tip end of the protruding portion is inserted in an inside of the bottle through the slit at a center region of the ink outlet as viewed in the direction of the central axis of the ink outlet, and characterized in that
the protruding portion has a plurality of small protruding portions (<NUM>) that constitute the tip end thereof, the small protruding portions axially extending in the direction of the central axis of the barrel portion from a cylindrical wall of the protruding portion and arranged at equal intervals in the circumferential direction, the protruding portion pushes down the valve segments and the tip end of the protruding portion is located more inside of the bottle than ink-outlet-center-side ends of the pushed valve segments in the sealed state.