JPH1044385A - Liquid container applying negative pressure, ink jet cartridge integrating container and ink jet recording head and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid container being employed in the ink tank of ink jet recording in which liquid can be fed utilizing a stabilized negative pressure. SOLUTION: A cylindrical ink tank 100 has double wall structure of an outer wall 101 having a corner defined by the bottom face and the side face of the cylinder, and an inner wall 102 having outer face equivalent or similar to that of the outer wall 101 and a corner corresponding to that of the outer wall 101. The inner wall 102 defines an inner liquid containing part and it is separable from the outer wall 101. Furthermore, a section 103 for feeding liquid from the liquid containing part to the outside is provided and the inner wall 102 is deformed substantially in the center of the bottom face thereof as the liquid flows out and separated, at the corner thereof, from the corner of the outer wall 101 while retaining the shape substantially.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid storage container and an ink tank which use a negative pressure to supply a liquid to an external member of a liquid storage container such as a pen or an ink discharge unit as a recording unit or the like. The present invention relates to an ink jet cartridge and an ink jet recording apparatus in which the container and the ink jet recording head are integrated, and more specifically, to the field of ink jet recording using an epoch-making ink tank which forms the ink tank itself by blow molding.

[0002]

2. Description of the Related Art As a container for accommodating a liquid, there has been known a container for supplying a liquid while applying a negative pressure to the inside of the container when supplying the liquid to the outside. A feature of this type of container is that a proper liquid supply can be performed to a liquid using part connected to the container, such as a pen tip or a recording head, by a negative pressure applied by the container itself.

[0003] There are various types of such a theory that have been demonstrated in actual liquid storage containers, but the range of use of these various containers has been limited. The reason for this is that there is no manufacturing variation and the structure is not simple.

[0004] For example, in the field of ink jet recording which needs this negative pressure characteristic properly, there is a method in which a sponge as a negative pressure source is stored in an ink tank as a liquid storage container, or a bag of ink. Provide a spring in the storage section,
A device that forms a negative pressure by giving a force that resists inward deformation of a bag due to consumption of ink (Japanese Patent Application Laid-Open No. 56-67269,
Japanese Patent Application Laid-Open No. 6-226993) is known. The rubber ink container disclosed in U.S. Pat.No. 4,509,062 has a conical shape with a rounded conical portion, and the rounded conical portion is thinner than the thickness of the conical peripheral surface. It is a configuration of doing. The thin rubber bag structure with the rounded conical portion is a structure for the storage container to be preferentially displaced and deformed in accordance with ink consumption. These have been put to practical use as ink storage containers for ink jet recording apparatuses, and are satisfactory at present.

However, since such a negative pressure generating structure is relatively expensive, it is not suitable for a writing implement having a pen tip such as a marker or a plotter. In particular, it is not preferable to have an extra complicated negative pressure generating structure as described above as a writing implement of this kind, because the writing implement itself becomes large in size.

[0006] Incidentally, the above-mentioned writing implement adopts a form in which felt or the like capable of generating a negative pressure is used for the pen tip itself and ink is supplied while air is introduced into the liquid storage container from the pen tip. ing. The biggest problem of the gas-liquid exchange structure in this ink supply mode is ink leakage from the pen tip. In order to solve this problem, a large number of fins are stacked at a predetermined interval between the pen tip and the liquid storage container so as to intersect the ink supply direction as an ink leakage prevention mechanism. It has been proposed to provide an ink holding mechanism capable of holding the ink to be made. However, at present, this mechanism leaves unusable ink inside the writing implement.

Further, since the ink supply system of this kind of writing implement is generally open to the atmosphere, the stored ink is evaporated and the amount of used ink is reduced. Originally, it is preferable to perform ink evaporation suppression as a substantially closed type.

Here, the field of ink jet recording using a substantially closed ink supply system will be briefly summarized. In general, when a negative pressure generation source is not used as an ink supply system, an ink supply system that supplies ink by a difference in height with respect to an ink using unit (ink ejection head), which is called a “head difference”, is known. In this case, since no special conditions are required for the ink storage unit, an ink storage bag such as a normal bag is often used.

However, since the ink supply path is of a closed type, a supply pipe such as a tube is required from the ink storage bag to an ink use section (ink discharge head) located above, resulting in a large ink supply path. It becomes a device. In order to minimize or eliminate the head difference in the ink supply path, an ink tank for applying a negative pressure to the ink ejection head has been proposed and implemented. The one in which the head and the ink tank can be integrated will be referred to as an ink jet cartridge.

The ink jet cartridge can be further classified into a structure in which a recording head and an ink container are always integrated, a structure in which a recording unit and an ink container are separate, and both can be separated from a recording apparatus. It can be divided into a configuration that is sometimes used integrally. In any of the configurations, in order to increase the efficiency of use of the ink stored in the ink storage unit, the coupling portion of the ink storage unit with the recording unit is often provided below the center of the ink storage unit. For this reason, in order to stably hold the ink in the ink storage section of the ink jet cartridge and to prevent ink leakage from a discharge section such as a nozzle provided in the recording section, the back pressure against the ink flow supplied to the recording section is reduced. Is required. This back pressure is called negative pressure because the pressure at the discharge port is made negative with respect to the atmospheric pressure.

One of the easiest methods for generating a negative pressure is a method utilizing the capillary force of a porous body as described above. The ink tank in the method is
Stored inside the ink tank for the purpose of storing ink,
Preferably, the ink jet recording apparatus includes a compressed and stored porous body such as a sponge, and an air communication port through which air can be introduced into the ink storage section to smoothly supply ink during printing.

However, a problem when using a porous member as an ink holding member is that the ink storage efficiency per unit volume is low. In order to solve this problem, a configuration in which a porous body is inserted into a part of the ink tank is used instead of the configuration in which the porous member is inserted into the entire ink tank. With this configuration, the ink storage efficiency per unit volume and the ink holding capacity can be increased as compared with the configuration in which the porous body is inserted into the entire ink tank.

From the viewpoint of further improving the ink storage efficiency, a bag-like container having a combination of a bag and a spring as described above, or a rubber ink container can be used.

[0014]

With the current ink tanks as described above, the demands of the current market are at a satisfactory level. However, the present inventors have come up with the following three problems when considering ideal conditions required for a liquid container, particularly an ink-jet ink tank, from a future perspective.

The first point is that the ink storage efficiency is further improved (first problem). That is, the ink storage efficiency of the ink tank is increased by further increasing the ink storage efficiency of the ink tank occupying the same space.

The second point is that the number of constituent parts is small and the structure of the parts themselves is simple (second problem). Further, as additional effects, there are advantages such as improvement of product yield and reduction of quality control items. Can be expected.

The third point is how to deal with environmental problems that have recently become a problem (third problem). One solution to this problem is that the components of the ink tank can be recycled. For this purpose, it is desirable that the number of components of the ink tank be as small as possible and that the components can be easily separated and collected when collecting the components.

However, an ink tank containing a porous member is not sufficiently satisfactory in terms of ink storage efficiency as described above. Further, even with the current configuration using a bag-shaped container, a device having a complicated mechanism such as a spring inside the ink storage unit or between the ink storage unit and the housing has a large number of parts and is difficult to assemble. Not only that, the bag-shaped container has a multilayer structure in order to achieve both flexibility and prevention of ink evaporation, which is not satisfactory with respect to the above problems.

In the above-mentioned conical rubber ink container, since the structure limitation as described above is important,
It is not possible to provide a maximum space in the desired space. In addition, the kind of ink that can be used is restricted from a material viewpoint. Therefore, the conical rubber ink storage bag has a complicated structure and manufacturing conditions, is complicated in terms of quality control, and has a poor product yield.

The present applicant has already filed an application for an excellent polygonal column-shaped liquid storage container based on the knowledge obtained by the research by some of the present inventors and a comprehensive viewpoint as described above. On the premise of the liquid storage container described above, the present invention has been further conceived based on a more preferable idea of the present inventors.

That is, in the above-described liquid storage container, a negative pressure is generated by deforming a wall surface of the liquid storage portion as the liquid is used. By focusing on the bottom surface, it is possible to generate a stable negative pressure suitable for an ink tank of an ink jet recording apparatus or the like even with a cylindrical container.

A main object of the present invention is to provide a liquid storage container capable of supplying a liquid while utilizing a stable negative pressure as one of the constituent elements of the liquid supply system based on the above-mentioned viewpoint. It is. The main object of the present invention can be applied to a writing implement and an ink jet recording head in the recording field, and another object in the ink jet field of the present invention is, in particular, the liquid storage container which can be completely integrated with or separated from the ink jet head. It is to provide.

[0023]

The specific objects of the present invention can be understood from the following constitution.

The liquid container according to the present invention has a substantially cylindrical shape having a substantial air communication portion, an outer wall having a corner formed by an extension of the bottom surface and the side surface of the cylinder, and an inner wall which is equivalent to the inner surface of the outer wall. Or, an outer surface having a similar shape, a corner portion corresponding to a corner portion of the outer wall, an inner wall capable of forming a liquid storage portion capable of storing a liquid therein and being peelable from the outer wall, and the liquid A liquid container having a liquid supply unit that supplies liquid from a storage unit to the outside, and a pinch-off unit in which a part where the inner wall is integrated is sandwiched by the outer wall, wherein the thickness of the inner wall is substantially cylindrical. The liquid storage container is characterized in that the portion constituting the corner is thinner than the central area of the bottom surface and the height is smaller than the diameter of the column, thereby solving the above problems and stabilizing the negative pressure. It will be realized.

A liquid container according to another embodiment of the present invention comprises:
An outer wall having a substantially cylindrical shape having a substantially atmospheric communication portion and having a corner formed by an extension of the bottom surface and the side surface of the cylinder, an outer surface having a shape similar to or similar to the inner surface of the outer wall, It has a corner portion corresponding to the corner portion, forms a liquid storage portion capable of storing a liquid therein, and has an inner wall detachable from the outer wall, and is capable of supplying a liquid from the liquid storage portion to the outside. A liquid container having a liquid supply portion and a pinch-off portion in which a portion where the inner wall is integrated with the outer wall is pinched off, and with the outflow of the liquid, the vicinity of the central area of the bottom surface of the inner wall is The liquid storage container is characterized in that the liquid storage container is deformed and detached from the corresponding corner of the outer wall in a state where the corner of the inner wall maintains a substantially shape, thereby solving the above problem and stabilizing the negative pressure. Is realized.

All of the above can solve the problem of a liquid storage container using a negative pressure to supply a liquid to the outside such as a pen as a recording unit or an ink discharge unit. More preferable conditions in the present invention will be described later in detail, but are as follows.

[0027] The thickness of the inner wall is gradually reduced from the central area of each surface toward each of the corners.

The outer wall has a convex shape on the side of the liquid storage portion, and the thickness of the outer wall gradually decreases from the central region of each surface of the substantially polygonal prism toward each corner.

The corners of the inner wall and the outer wall are each a minute curved surface.

Further, in the liquid container of the present invention, the position of the pinch-off portion may be, for example, a substantially cylindrical side surface or a central portion of a pair of bottom surfaces. Further, the position of the liquid supply unit may be on the substantially cylindrical side surface, or may be on the outer peripheral portion or the central portion of one of the pair of bottom surfaces.

The liquid container of the present invention is preferably used as an ink tank in the field of ink jet recording, and is also applied to an ink jet cartridge and an ink jet recording apparatus.

[0032]

Next, embodiments of the present invention will be described in detail with reference to the drawings. In the following, description will be made by taking an ink tank for storing ink in the field of ink jet recording as an example of a liquid storage container, but it is needless to say that the present invention can be applied to a general liquid storage container using negative pressure. .

<First Embodiment> FIGS. 1A to 1C schematically show the structure of an ink tank according to a first embodiment of the present invention. FIG. 2B is a cross-sectional view, FIG. 2B is a side view as viewed from the X direction, and FIG. 1C is a perspective view.

The ink tank 100 has a substantially columnar shape, has an outer wall 101 forming an outer shell, and an inner wall 102 separable from the outer wall, and a region surrounded by the inner wall 102 (hereinafter referred to as an inner wall 102). , Referred to as an ink storage unit). The outer wall 101 is sufficiently thicker than the inner wall 102, and hardly deforms even if the inner wall 102 deforms due to the outflow of ink. This outer wall 101 is
The ink container is protected so that the ink in the ink container does not leak to the outside due to the inadvertent deformation of 2. Further, an air intake port (not shown) is provided on the outer wall 101. The air intake is for introducing air between the inner wall 102 and the outer wall 101 when the inner wall 102 is reduced in volume and deformed with consumption of ink. The air intake may be a simple opening, or a gap formed in the outer wall 101 corresponding to a welding portion (pinch-off portion) described later may be used as it is as the air intake.

An ink supply unit 103 for supplying the ink stored in the ink storage unit to the outside of the ink tank 100 is provided on the side surface of the cylinder. The ink supply unit 103 is, for example, a connection portion with an ink introduction unit of an inkjet head.

The ink tank 100 is formed on the inner wall 1 of the ink tank 100 by direct blow molding described later.
02 and the outer wall 101 are simultaneously manufactured in a single step. Inner wall 10 that partitions ink storage section
2 must naturally form a closed space, and therefore, a welding portion (pinch-off portion) 104 is provided on the inner wall 102. The welded portion 104 is formed by sandwiching a parison for forming the wall of the ink tank 100 with a mold at the time of blow molding, which will be described later, and the inner walls 102 are welded to each other.
As described later, it is also used as a support portion for supporting the inner wall 102. In the present embodiment, as shown in FIG. 1 (b), the shape of the welded portion 104 is a straight line when viewed from the side, but the ink tank can be easily extracted from the mold in a manufacturing process described later. If so, it may not be a simple linear shape.

FIG. 1 (a) is a schematic diagram
In order to make the ink supply unit 103 easy to understand, the inner wall 102 and the outer wall 1
However, since the ink supply unit actually exists at a position facing the welded portion 104 on the side surface of the ink tank, a welded portion also exists in the ink supply portion 103, and its cross section is shown in FIG. As shown in a).

FIG. 2 is a view showing a modified example of the ink tank 100 of the present embodiment. Here, a small gap 107 of about several tens μm between the outer wall and the inner wall generated near the welded portion 104 is shown. We use as air intake. This gap is easily formed by applying an external force to the welded portion 104 after the blow molding by selecting a material having low adhesiveness to the outer wall 101 for the inner wall 102 and peeling the inner wall 102 from the outer wall 101. Is done.

Here, the ink tank 100 shown in FIG. 1 will be described in detail. The ink tank 100 is composed of a pair of bottom surfaces which are cylinders and a plane, and side surfaces which are cylinder surfaces. The part 103 is added as a curved surface. Hereinafter, the vicinity of the intersection line between the bottom surface and the side surface will be referred to as a corner. In addition, you may comprise by providing a minute curved surface part in a corner part. At this time, the minute curved surface portion of the cylinder is regarded as a corner, and the surface is defined as a flat surface or a cylindrical surface excluding the minute curved surface portion.

In the ink tank 100, in the initial state, since the corners of the inner wall 102 correspond to the corners of the outer wall 101, the inner wall 102 has a similar shape to the outer wall 101, and the outer wall 101 serving as a housing is formed. The inner wall 102 can be made to follow the shape of at a predetermined interval. That is, the dead space seen when a bag-shaped container is housed in the conventional housing can be eliminated, and the amount of ink stored per unit volume in the outer wall of the ink tank can be increased (increased ink storage efficiency). be able to.

Here, the thickness of the inner wall surface is thinner at the corners than at the central area of the bottom surface, and gradually decreases from the central area of the bottom surface toward each of the corners. It has a convex shape on the side. This direction is, in other words, the same as the deformation direction of the surface, and has the effect of promoting the deformation of the ink storage section described later. Also, the corner of the inner wall,
As will be described later, since it is constituted by two surfaces and one is a cylindrical surface which is a curved surface, as a result, the strength of the entire corner of the inner wall is relatively higher than the strength of the central region. Further, when viewed from the extension of the surface, the thickness is smaller than that of the central region, so that the movement of the surface described later is permitted. It is desirable that the portions constituting the corners of the inner wall have substantially the same thickness.

The ink supply section 103 has an ink lead-out permitting member 106 having an ink leak preventing function capable of preventing ink leak when a slight vibration or external pressure is applied to the tank. Is connected to an ink lead-out tube of the ink jet recording means. The time when the ink is filled and connected to the ink outlet tube or the like is an initial state. The ink lead-out permission member 106 serving as a connection portion with the ink jet head uses a one-way fiber member made of an ink absorber, and has a meniscus holding force. Ink lead-out permission member 106
Thus, the ink container can be substantially sealed, and when the ink introduction unit on the inkjet head side is inserted, the ink in the ink container can be led out while maintaining the airtight state. Note that, depending on the combination of the ink tank 100 and the ink jet head, a rubber stopper, a porous member, a valve, a filter, a resin, or the like may be used in place of the ink lead-out permitting member 106 instead of the pressure contact body.

In the ink supply section 103, the inner wall 102 and the outer wall 101 are hardly separated from each other by providing an ink lead-out permitting member 106 as a pressing member. Further, since the substantially cylindrical ink supply portion 103 is provided on the side surface of the ink tank 100 which is a cylindrical surface so as to protrude vertically, the inner wall accompanying the discharge of the ink by the discharge of the ink from the ordinary ink jet recording means. With respect to the deformation 102, the root portion of the ink supply unit 103 (the joint portion with the side surface of the ink tank) has a characteristic that it is not easily crushed. In the ink tank 100 of the present embodiment, the ink supply section is substantially cylindrical, but the shape of the ink supply section is not limited to a substantially cylindrical shape. Even in the case of the polygonal column shape, the size of the ink supply unit is sufficiently smaller than that of the ink storage unit. Therefore,
Even when the consumption of the ink is completely completed, the inner wall 102 and the outer wall 101 of the ink supply unit 103 are maintained in the initial use state (initial state) without being deformed.

Hereinafter, ink is stored in the ink tank 100 shown in FIG.
The change in the shape of the ink tank 100 when the ink is derived from FIG. 3 will be described with reference to FIG. FIG. 3 is a schematic diagram showing this shape change in the order of (a) to (d).
1B shows a cross-sectional view taken along the line BB, and a suffix 2 shows a cross-sectional view taken along the line AA in FIG. Note that FIG. 1 and FIG. 3 to be described later are schematic diagrams, and the positional relationship between the outer wall 101 and the inner wall 102 of the ink tank 100 is drawn with a space therebetween. As long as it is possible, the inner wall 102 and the outer wall 101 may be in contact with each other, or may be configured to be arranged with a small space therebetween.
Therefore, in any case, in the initial state, the ink tank 100 is formed so that the corner of the inner wall 102 comes at least at a position corresponding to the corner of the outer wall 101 along the shape of the inner surface of the outer wall 101. (Fig. 3 (a
1), (a2)).

When the ink in the ink container starts to be consumed after the ink is ejected from the ink jet head of the ink jet recording means, the inner wall 102 is deformed from the center of the bottom surface in the direction in which the volume of the ink container is reduced. Get started. In the case of this embodiment, the bottom surface is not necessarily larger in area than the side surface, but since the bottom surface is a plane and the side surface is a cylindrical surface having a curvature, the height as a cylinder is larger than the diameter of the bottom surface. Under the condition that it is not large, the bottom starts to deform before the side.

Here, the outer wall 101 functions to suppress the displacement of the corner of the inner wall 102. In the ink tank 100, since there is almost no variation in the position of the corners described above, the ink storage unit is acted upon by the action of deformation due to ink consumption and the action of returning to the initial state, thereby stabilizing the negative pressure. Works in the direction. At this time, air intake (not shown)
Air is introduced between the inner wall 102 and the outer wall 101 from
An effect of maintaining a stable negative pressure at the time of using the ink without inhibiting the deformation of the inner wall 102 is exhibited. That is, the space between the inner wall 102 and the outer wall 101 communicates with the outside air via the air intake. After this, the inner wall 1
By balancing the force of No. 02 with the force of the meniscus at the ejection port of the recording head, ink is held in the ink storage section (FIGS. 3B1 and 3B2).

Further, when a considerable amount of ink in the ink container is led out (FIGS. 3C1 and 3C2), the ink container is deformed in the same manner as described above, and the central portion of the ink container is moved inward. A stable crushing way toward is maintained. Further, the welded portion 104 also serves as a deformation restricting portion of the inner wall 102, and on the side surface (the side surface of the cylinder) of the ink tank 100, a region farther from the pinch-off portion deforms first than a region near the pinch-off portion 104. First, it separates from the outer wall 101.

However, with only the above-described inner wall deformation restricting portion, the inner wall 102 near the ink supply unit 103 is deformed to block the ink supply unit 103, and the ink stored in the ink storage unit may be sufficiently used. It may be impossible to do so. However, a corner formed by two cylindrical surfaces whose axes are orthogonal to each other is also formed at the joint between the ink supply unit 103 and the side surface.
2 shows strong resistance to deformation. The ink supply unit 103 is provided on a side surface of the substantially cylindrical ink tank 100 at a position approximately ほ ぼ in the height direction of the ink tank 100. As described later, the height of the ink tank (the height of the cylinder) ) Is h and the diameter of the ink tank (diameter of the cylinder) is d.
<D, preferably h ≦ d / 4, the distance from the ink supply unit 103 to the bottom surface is at most half the diameter d of the bottom surface, and under preferable conditions, is less than one-eighth of the diameter of the bottom surface. Also, the inner wall 10 near the ink supply unit 103
2 is prevented from being preferentially deformed. h ≦ d / 4
At the time, since the bottom surface is a surface having the maximum area,
Deformation is performed more smoothly.

In the state shown in FIGS. 3 (c1) and 3 (c2), the corners of the inner wall 102 are located so as to be separable from the corresponding corners of the outer wall. These bottom surfaces come into contact with each other in the central region. In FIG. 3 (c1), the contact portion is hatched in a net shape. Then, this contact portion is further expanded by drawing out more ink. In other words, in the ink tank 100, when the ink is discharged, the pair of bottom surfaces contact each other before the ridge (edge) formed by the bottom surface and the side surface is bent.

Eventually, almost all of the ink stored in the ink storage section is used (hereinafter, referred to as a final state).
However, the state at this time is shown in FIGS. 3 (d1) and (d2). In this state, the contact portion of the ink storage unit covers almost the entire area of the ink storage unit, and the corner of the inner wall 102 is
Except for the corner between 3 and the side, the outer wall 101 is completely separated from the corner. Note that the corner formed by the ink supply unit 103 and the side surface is separable at the corresponding corner of the outer wall even in the final state, and serves as a deformation regulating portion of the inner wall until the end.

In this final state, the welded portion 104 may separate from the outer wall 101 depending on the thickness of the inner wall 102. In this case, since the welded portion 104 has a length component, the deformation direction is Limited. Therefore, even when the welded portion 104 comes off the outer wall 101, the deformation is not irregular, and the deformation is performed while maintaining a balance.

The change when the ink is stored in the ink storage section of the ink tank 100 of the present embodiment and the ink is drawn out from the ink supply section 103 is as described above. Before the edge formed by the bottom surface and the side surface is bent, the pair of bottom surfaces contact each other, and the corners other than the corners formed by the surface having the ink supply unit move, so that when the ink tank is deformed, The configuration has a priority of the deformation.

The ink tank 100 of the present embodiment is different from the above-described polygonal column-shaped liquid storage container by the present applicant.
Since the surface that is preferentially deformed is the bottom surface of the cylinder and is circular, the deformation of all corners when the inner wall is deformed becomes uniform, and the deformed surface (in the case of a polygonal column, the maximum area surface, this ink tank In this case, the deformation at the center of the bottom surface becomes even smoother.

In the case of the ink tank according to the present embodiment, a pair of bottom surfaces need to be in contact with each other, so that the height of the ink tank (the height of the cylinder) is d, and the diameter of the ink tank (the diameter of the cylinder). ) Is d, h <d must be satisfied. In order to ensure the smooth deformation of each corner as described above, it is preferable that h ≦ d / 4 because the bottom surface has the maximum area.

Here, the fact that at least one of the bottom surfaces of the outer walls of the ink tank, which is formed by a substantially column, which is one of the stable negative pressure generating mechanisms, is not fixed to the inner wall will be described in further detail. .

In the above configuration, when the ink in the ink storage portion is reduced by the discharge of the ink from the ink jet recording head, the inner wall of the ink tank is most likely to be deformed under the condition of the above-described structure for restricting the deformation. Try to start deformation from. In the present embodiment,
Since at least one of the pair of bottom surfaces of the outer wall of the ink tank formed by the cylinder is not fixed to the inner wall, the deformation starts from a substantially central portion of the inner wall surface corresponding to this surface.

Since this surface has a substantially planar shape, it is uniformly and continuously deformed in the direction in contact with the opposing surface in accordance with the amount of ink reduction in the ink storage portion. Therefore, there is no discontinuous large deformation of the ink storage portion during ejection and non-ejection, and more stable holding of a negative pressure, which is optimal as an ink tank used in an ink jet recording apparatus, and stable negative pressure at the time of ink ejection. Can be realized. Further, as in the present embodiment, when the pair of opposed bottom surfaces have no joint portion between the inner wall and the outer wall and can be easily peeled off, the two bottom surfaces are deformed almost simultaneously, so that the negative pressure is maintained. Further, it is possible to further stabilize the negative pressure at the time of ink ejection.

[0058] When the liquid container of the present invention is applied to an ink tank for inkjet recording, the volume of the ink tank can be up to 500 cm ^3, a commonly range used is about 5 to 100 cm ^3.

As described above, it is desirable that the inner wall 102 of the ink tank 100 is thicker near the center of the inner wall than at the corner, but from the results of experiments conducted by the present inventors, a more preferable film is formed. The thickness conditions are as follows: the thickness near the center of the inner wall surface is 100 to 250 μm, and the thickness near the corner is 2 μm.
It was found that those having a diameter of 0 to 80 μm can generate a particularly stable negative pressure.

Hereinafter, the negative pressure in the ink container will be described. The negative pressure includes a static negative pressure generated even when the ink is not drawn out to the outside, and a dynamic negative pressure generated when the ink inside is drawn out to the outside. Is the total negative pressure. Here, the following three points are required for the negative pressure in the ink storage unit.

The first point is that the ink tank has an initial static negative pressure of about +2 to -60 mm Aq., More preferably about -2 to -30 mm Aq. It is. When the internal pressure indicates a positive value at the time of product shipment, the negative pressure can be kept in a more desirable range by performing an initial recovery operation in the recording apparatus main body, for example. Here, the state at the time of product shipment is not limited to the initial state, that is, the state of FIGS. 3 (a1) and (a2). If the condition of the negative pressure with respect to the atmospheric pressure is satisfied, FIG. As shown in (b2), a state in which a slightly smaller amount of ink is injected into the ink storage unit than the maximum ink storage amount may be.

The second point is that the pressure change in the ink tank when printing is performed and when printing is not performed is small, that is, the difference between the static negative pressure and the total negative pressure is small. Is solved by minimizing as much as possible. Here, in the ink tank according to the present embodiment, the dynamic negative pressure of the ink container itself as seen when a porous body is used for the ink container can be neglected. It is a configuration that can be easily reduced.

The third point is that the change in the negative static pressure due to the change in the amount of ink existing inside the ink storage unit is small from the initial state to the final state. In the case where the ink is simply filled in the ink container, the static negative pressure changes linearly or non-linearly with respect to the amount of ink present in the ink container, and the rate of the change becomes large. The ink tank according to the present embodiment has a small rate of change in the static negative pressure from the initial state to immediately before the final state, realizes a substantially stable static negative pressure, and exhibits excellent characteristics.

Therefore, it can be said that the ink tank 100 of the present embodiment sufficiently fulfills its function with respect to generation of stable negative pressure which is a condition peculiar to the field of ink jet recording, and in particular, its volume use efficiency is high. From
It can be said that it is suitable for the current mainstream small-sized ink jet recording apparatus.

Next, a method for manufacturing the above-described ink tank 100 of the present embodiment will be described in detail.

The ink tank 100 according to the present embodiment employs a double wall structure made of a molding resin material. The outer wall 101 is made thicker to have strength, while the inner wall 102 is made of a soft material and is made thinner. By doing so, it is possible to follow the volume fluctuation of the ink stored inside. As a material used for each wall, it is desirable that the inner wall has ink resistance and the outer wall has impact resistance and the like.

In the present embodiment, as described above, as a method for manufacturing the ink tank 100, multilayer blow molding using blowing air is employed. This is because the walls (the outer wall 101 and the inner wall 102) of the ink tank 100 are formed of a resin that is not substantially stretched, so that the inner wall of the ink tank that constitutes the ink storage section is formed in any direction. It is designed to withstand a substantially uniform load. Therefore, even if the ink contained by the ink tank inner wall oscillates in any direction while the ink is consumed to some extent, the ink tank inner wall can reliably hold the ink, and the overall ink tank durability can be maintained. Improve the quality.

Examples of the blow molding method include a method using injection blow, a method using direct blow, and a method using double wall blow.

Hereinafter, the manufacturing process of the method using the direct blow molding in the present embodiment will be described in detail.

FIGS. 4 (a) to 4 (d) show the steps of manufacturing the ink tank according to the present embodiment, and FIG. 5 is a flowchart showing the procedure of manufacturing the ink tank. FIG.
Is an ink tank 100 in the ink tank manufacturing process.
FIG. 1 is a schematic view showing the state of FIG. 1, wherein the suffix 1 indicates the bottom surface of the ink tank, and the suffix 2 indicates a cross section corresponding to AA in FIG.

FIG. 6 (a) shows an accumulator head for molding a parison 207 having a double structure of an inner wall resin and an outer wall resin in order to perform multilayer blow molding. Is a main accumulator 201 for supplying the inner wall resin, a main extruder 202 for extruding the inner wall resin, and a sub accumulator 2 for supplying the outer wall resin.
03. It has a sub-extruder 204 for extruding the outer wall resin.

Using the injection nozzle as a multi-layer nozzle, an inner resin (resin for the inner wall) and an outer resin (resin for the outer wall) are simultaneously injected into a mold to prepare a unit in which the first and second parisons are integrated. In this case, the resin supply may be such that the inner resin and the outer resin are in contact, not all of them are in contact, or a structure in which a part of the resin is in contact. When two resins are in contact, select a material that does not cause the resins to weld together on the surface where the inner resin and the outer resin contact, or add a compound to one of the resins when supplying them to the mold It is necessary to form it separably. If the same type of material is required due to the wettability and shape of the ink, when the inner resin material or the outer resin material is multi-layered, the resin is supplied so that different materials are located on the contact surface. May be. It is ideal that the supply of the inner resin is uniform over the entire circumference. However, the resin may be partially thinned to make it easier to follow fluctuations in the internal pressure. The method of partially reducing the thickness is selected according to the internal structure of the ink tank, but is configured along the supply direction of the resin supplied into the mold.

The resin for the outer wall and the resin for the inner wall supplied by these are supplied to the die 206 via the ring 205 (steps 301 and 302), and the parison 207 in which the first and second parisons are integrated is formed. Is performed (step 303). Next, with respect to the integrated parison 207, a mold 208 arranged so as to sandwich the parison 207 is shown in FIG.
Is moved from the state shown in FIG. 4 to the state shown in FIG. 4C, and the parison 207 is sandwiched (step 304). Subsequently, as shown in FIG. 4C, air is injected from the air nozzle 209 and blow-molded into a shape suitable for the mold 208 (step 305). FIGS. 6A and 6A are schematic diagrams of the state of the ink tank at this time. At this time, the inner wall and the outer wall are in close contact with no gap. In addition, it is more preferable that the temperature of the mold is controlled within a range of about ± 30 ° C. with respect to the reference temperature at the time of molding because variation in individual thickness of each wall of the ink tank at the time of manufacturing can be reduced. .

Next, the inner wall 102 and the outer wall 101 other than the ink supply unit are separated (step 306). As a method of this peeling, for example, there is a method by evacuation,
FIGS. 6 (b1) and 6 (b2) are schematic views of the state of the ink tank at this time when vacuuming is performed. As a method of separating the inner wall and the outer wall other than performing the evacuation, there is a method of using materials having different thermal expansion rates (shrinkage rates) for the molding resin forming the inner wall and the outer wall. In this case, after the blow molding, the temperature of the molded product decreases, so that the molded product can be automatically peeled, and the number of steps can be reduced. Similarly, at the portion where the parison is sandwiched between the molds during blow molding, an external force is applied after molding to separate the inner wall and the outer wall, and the gap can be communicated with air to be used as an air communication port. The ink container for inkjet is more preferable because the number of steps can be reduced.

After the inner wall 102 and the outer wall 101 are separated from each other, ink is injected (step 307). At this time, before the ink is injected, the ink container is made substantially the same shape as the initial state by the pressurized air (FIGS. 6 (c1) and (c2)).
Thereafter, ink injection may be performed. Further, when the ink container is formed in the same shape as the initial state, the ink may be injected by pressurization. Further, when the amount of the ink to be injected is about 90% of the volume of the ink container,
It is possible to easily cope with a change in the environment where the ink tank 100 is placed, and it is possible to prevent the ink from leaking to the outside due to a change in external force, a change in temperature, and a change in atmospheric pressure. FIGS. 6 (d1) and 6 (d2) are schematic diagrams of the state of the ink tank 100 after the ink has been injected. Ink tank 1 at this time
00 is in a state where the inner wall and the outer wall can be separated from each other by drawing out the ink. After the ink is injected, the ink lead-out permission member 106 is attached to the ink supply unit 103 (Step 308).

In the above blow molding, since the parison 207 is processed in a viscous state, both the resin for the inner wall and the resin for the outer wall have no orientation.

In addition, resin for the inner wall before blow molding, for the outer wall
Assuming that the thickness of the resin is t and T, respectively,
Thickness t₁, T₁Are thinner than the thicknesses t and T, respectively. Outside
The relationship between the thickness of the wall resin and the thickness of the inner wall resin is determined according to the present invention.
T from purpose₁> T₁And T ₁> T₁Molded so that
Was.

The use of blow molding not only reduces the number of steps in manufacturing and improves the yield due to the reduction in the number of parts, but also improves the shape of the outer wall 101 of the ink tank as shown in FIG. The inner wall 10 such that the corner of the inner wall 102 comes to a position corresponding to the corner of the outer wall 101.
2 shapes can be made.

That is, in the initial state filled with ink,
Ink tank inner wall 10 with respect to ink tank outer wall 101
2 has a similar shape, and the inner wall 102 of the ink tank can follow the shape of the outer wall 101 of the ink tank serving as a housing at a predetermined interval, which is seen when a bag-shaped container is housed inside the conventional housing. Dead space can be eliminated, and the ink storage amount per unit volume in the outer wall of the ink tank can be increased (ink storage efficiency can be increased).

Further, by adopting the structure as in the present embodiment, the inner wall to which the ink is adhered is separated from the outer wall and is a thin layer. Therefore, it is easily taken out from the outer wall to separate and discard or separate and recycle. Is possible.

Hereinafter, a supplementary description will be given of the manufacture of the ink tank by blow molding.

The outer wall and the inner wall which can be separated from each other and which are formed by the above-described direct blow manufacturing method are substantially cylindrical molds having a cylindrical parison having an axial direction perpendicular to the axial direction of the parison. Has the same configuration by inflating uniformly by air blow using That is, the above-mentioned inner wall is formed to be thinner in the vicinity of the corner than in the vicinity of the center of the bottom surface constituting the container. Similarly, the outer wall is formed to be thinner in the vicinity of the corner than in the vicinity of the center of the bottom surface constituting the container. Furthermore, as described above, the inner wall is formed by being laminated on the outer wall having a thickness distribution that gradually decreases from the center of the bottom surface to the corners of the bottom surface, as described above. This results in the inner wall having an outer surface that matches the inner surface of the outer wall. Since the outer surface of the inner wall follows the thickness distribution of the outer wall, the outer surface protrudes toward the ink storage portion formed by the inner wall. Since the inner surface of the inner wall has the above-described thickness distribution of the inner wall, the inner surface is further convexed toward the ink storage portion. These structures perform the functions described above on both bottom surfaces of the cylindrical ink tank.
According to the present invention, such a convex shape may be present at least on the bottom surface, and the convex shape may be 2 mm as the inner wall surface.
Or less, and 1 mm or less on the outer surface of the inner wall. Although the convex shape may be within the measurement error range in the small area portion, it is one factor that gives a priority to the deformation on each surface of the substantially cylindrical ink tank. One.

Next, the molding resin constituting the ink tank in the present invention will be described.

The ink tank of the present invention has a double structure of an inner wall for containing ink and an outer wall covering the inner wall. Therefore, it is desired that the inner wall be made of a material that is flexible when thinned, has excellent liquid contact properties, and has a low gas permeability, and the outer wall is made of a material that is strong to protect the inner wall. It is.

Therefore, an ink tank having the same shape as that described in the above embodiment was molded using a polypropylene resin, a polyethylene resin, or a polyphenylene ether resin as a molding resin. Here, the polyphenylene ether resin is amorphous having almost no crystal structure, and the polypropylene resin and the polyethylene resin are at least partially crystallized and have crystallinity.

A resin having no crystal structure generally has a small heat shrinkage, and a resin having a crystal part generally has a large heat shrinkage. Examples of the amorphous material include polystyrene, polycarbonate, and polyvinyl chloride in plastics. In addition, the crystalline material forms a crystal part at a certain ratio under a predetermined environment, and examples thereof include polyacetal and polyamide. The crystalline plastic has a relatively clear melting point and a glass transition temperature (Tg: a temperature at which a molecule starts micro-Brownian motion and the property changes from a glassy state to a rubbery state). on the other hand,
In the case of amorphous plastics, there is a glass transition temperature but no clear melting point.

Since the mechanical strength, specific volume, specific heat, coefficient of thermal expansion, and the like of plastics change abruptly at the glass transition temperature and melting point, by selecting a combination of materials utilizing this property, the resin on the inner side and the outer side can be selected. Can be improved. This example has mechanical strength on the outside by using an amorphous polyphenylene ether resin on the outside and using a polypropylene resin as a crystalline resin on the inside as in the first embodiment described above. thing,
A soft material with large heat shrinkage can be selected inside.

Further, the polymer molecule has a C—C bond and a C—C bond.
In the case of a hydrocarbon structure consisting only of H bonds, generally the polarity is small and it is called a nonpolar polymer. On the other hand, a polymer containing many polar atoms such as O, S, N, and halogen is called a polar polymer. The polar polymer has a large intramolecular condensing force and a large resin binding force. Utilizing this property, it is possible to improve the releasability of the resin by combining non-polar resins with each other, or combining a non-polar resin and a polar resin.

As the material used for the inner wall of the liquid container of the present invention, polyethylene resin, polypropylene resin or the like can be applied as described above, but from the viewpoint of strength, the tensile elasticity is 15 to 3000 ( It is desirable that the condition of about kgf / cm ² ) be satisfied. Within this numerical value, a material within a desired range can be selected depending on conditions such as the shape and thickness of the container and the desired negative pressure performance.

<< Second Embodiment >> Next, a second embodiment of the present invention will be described.
An embodiment will be described. FIGS. 7A and 7B are schematic diagrams of the configuration of the ink tank according to the second embodiment, in which FIG. 7A is a cross-sectional view, FIG. 7B is a bottom view, and FIG. is there.

The difference between the ink tank 110 and the ink tank according to the first embodiment is the position of the ink supply unit 113. That is, the ink supply unit 113
Is provided in a portion near the outer periphery of one of the two bottom surfaces of the cylinder. Welding part (pinch-off part) 114a, 1
In terms of the relationship with 14b, the ink supply unit 113 is disposed at a position corresponding to a line provided on the side surface and connecting the two opposed welding portions 114a and 114b. The ink supply unit 113 is provided with an ink lead-out permission member 116. Unlike the first embodiment, the ink lead-out permission member 116 is provided so as to protrude slightly from the inner bottom surface of the inner wall 112. I have.

In the ink tank 110, similarly to the ink tank of the first embodiment, the wall of the ink tank is formed with an outer wall to prevent evaporation of ink, uniform pressure in the tank, and prevention of ink leakage. 2 of 111 and inner wall 112
The inner wall 112 is configured to be deformed by freely following the internal pressure fluctuation caused by a decrease in the amount of the ink stored therein. Further, a corner formed by the bottom surface having the ink supply unit 113 serves as a restriction unit for the movement of the inner wall 112.

In the ink tank 110, the inner wall 112
Portion 114 formed by pinching off
The gap 117 of the outer wall 111 generated near a and 114b is used as an air intake.

Further, in the present embodiment, at least one of the bottom surfaces of the outer wall 111 having the planar shape is formed on the inner wall 11.
The second embodiment is similar to the first embodiment in that the inner wall 112 has no joint portion and the inner wall 112 can be easily separated from the outer wall 111, but specifically, the bottom surface facing the ink supply unit 113. Is formed so that a joint portion between the inner wall 112 and the outer wall 111 is not formed. In the ink supply unit 113, the outer wall 111 and the inner wall 112 are joined.

In the ink tank 110, the ink in the ink storage section is used and the inner wall 11 of the ink tank is used.
When 2 is deformed, the deformation starts from the ceiling surface of the ink tank 110, that is, the bottom surface opposite to the ink supply unit 113, instead of the pair of bottom surfaces being simultaneously deformed. This deformation direction is vertically downward and the ink supply unit 1
13 and the direction of ink supply to the recording head. Therefore, also in the present embodiment, although the configuration is different, it is possible to easily realize the stable ejection of the ink and the maintenance of the negative pressure as much as the first embodiment.
FIG. 8 shows the shape change when ink is stored in the ink storage unit of the ink tank 110 and the ink is drawn out from the ink supply unit 113 in the order of (a) to (d). Here, a change in a cross section perpendicular to the ceiling surface at the center of the ink tank is shown.

FIG. 8A is a diagram showing an initial state, in which the corners of the outer wall 111 correspond to the corners of the inner wall 112 of the ink tank 110, and the inner wall 112 and the outer wall 111 are separable. It is in a state. The ink supply unit 113 exists on the lower surface in the drawing of the pair of bottom surfaces, and the other is a ceiling surface.

When the ink supply from the ink supply unit 113 is started, as shown in FIG. 8B, the deformation starts from the center of the inner wall surface corresponding to the ceiling surface of the outer wall of the ink tank. At this time, of the corners of the inner wall 112, the positions of the corners formed by the inner wall surfaces corresponding to the ceiling surface start to move away from the corresponding corners of the outer wall 111 and start moving downward along the outer wall 111. At this time, the corner where the movement has started restricts the deformation of the inner wall 112 to some extent, so that together with the corner of the outer wall 111, a force is generated that causes the inner wall corresponding to the ceiling surface to return to the initial shape. As a result, a negative pressure is generated in the ink container. At this time, similarly to the first embodiment, the inner wall 112 and the outer wall 111 extend from the gap 117 (air intake port).
The air serves to maintain a stable negative pressure when the ink is used without hindering the deformation of the inner wall 112.

When the ink is further discharged, as shown in FIG. 8C, the deformation of the inner wall surface corresponding to the ceiling surface is promoted, and the inner wall 11 formed by the inner wall surface corresponding to the ceiling surface is accelerated.
The second corner is completely separated from the corner of the outer wall 111. On the other hand, the inner wall surface corresponding to the bottom surface having the ink supply unit 113 is hardly deformed. This is similar to the case of the first embodiment.
This is because the movement of the inner wall 11 is restricted, so that the corner of the inner wall on the bottom surface on the ink supply unit 113 side is separable from the corresponding corner of the outer wall.

When the ink is further drawn out and reaches the final state shown in FIG. 8D, the ink is deformed to such an extent that the inner wall surface corresponding to the ceiling surface and the surface of the ink supply unit are in contact with each other. At this time, the corner formed by the inner wall surface corresponding to the ceiling surface is further deformed, and is completely separated from the outer wall 111 on the ceiling surface side. Here, there is a possibility that the ink supply unit 113 may be blocked from the ink storage unit side by the inner wall surface corresponding to the ceiling surface.
Reference numeral 6 is attached to the ink supply unit 113 so that its tip projects from the bottom surface of the inner wall 112. This is to prevent the opposing inner walls 112 from coming into close contact with each other around the ink supply unit 113 and interrupting the supply of ink. With such a configuration, FIG.
As shown in (d), even if the upper surface of the ink lead-out permission member 116 is blocked by the inner wall 112, the ink flows from the peripheral wall, and the supply of the ink is not interrupted. In this case, since the ink flows only from the peripheral wall, the ink supply conditions are different from those shown in FIGS. 8A to 8C, but since the negative pressure is almost constant, 8 (a)
The ink supply is performed almost uniformly in the state shown in FIGS.

As described above, the porous member or the fiber member is interposed in the ink supply section 113 as the ink derivation permitting member 116 so that a part thereof is included in the ink storage section side. The ink inside can be reliably drawn out from the gap formed between the protruding portion and the inner wall surface corresponding to the ceiling surface by the meniscus force of the ink of the porous member or the fiber member.

In this final state, the ink supply unit 1
The corner formed by the inner wall surface on the 13th side is located in a state where it can be separated from the corresponding corner of the outer wall 111. As a result, the inner wall surface of the surface having the ink supply unit 113 is hardly deformed.

As described above, by providing the ink supply unit 113 on one of the pair of bottom surfaces, it is possible to stably maintain a negative pressure from the initial state to the final state, and to achieve a configuration excellent in use efficiency. It can be. In addition,
In this embodiment, since the inner wall 112 on the ceiling surface mainly deforms and comes into contact with the bottom surface on the ink supply unit 113 side, the height of the ink tank (the height of the cylinder) is d, and the diameter of the ink tank is When the diameter of the cylinder is d, h <d /
Must be 2. In order to ensure smooth deformation as described above, it is desirable that h ≦ d / 4.

Next, a method of manufacturing the ink tank 110 according to the second embodiment will be described. The manufacturing method here is a manufacturing method by blow molding as in the case of the first embodiment. However, in the first embodiment, the ink supply section is present in the parison supply direction, and the air blowing port is provided. Is an ink supply unit, whereas in the present embodiment,
Since the ink supply section 113 is different from the parison supply direction, a step of welding the air blowing port and a step of providing the ink supply section 113 are required. The air blowing port may be any of the welded portions 114a and 114b, but in the present embodiment, the inner wall 112 is welded by the welded portion 114b after molding, using 114b as the air blowing port. This is because when the ink supply unit is made to coincide with the parison supply direction as in the first embodiment, the bottom surface of the ink tank is provided in a direction orthogonal to the parison supply direction, that is, in a direction having a welded portion. This is because the ink tank of the second embodiment can be more easily manufactured by increasing the number of steps of welding the air blowing port and providing the ink supply unit.

<< Third Embodiment >> Next, a third embodiment of the present invention will be described.
An embodiment will be described. FIGS. 9A and 9B are schematic schematic views of the configuration of the ink tank according to the third embodiment, in which FIG. 9A is a cross-sectional view and FIG. 9B is a bottom view.

The difference between the ink tank 120 and the ink tank of the first embodiment is the position of the ink supply section 123 and the positions of the welding sections 124a and 124b. That is, the welding portions 124a and 124b are respectively located at the centers of the pair of bottom surfaces of the cylindrical ink tank 120, and the ink supply portion 123 is also provided at the center of one of the pair of bottom surfaces. Therefore, one welding portion 124 a is located at the position of the ink supply unit 123. The ink supply portion 123 is provided with an ink lead-out permitting member 126. The ink lead-out permitting member 126 is provided so as to slightly protrude from the inner bottom surface of the inner wall 122, as in the case of the second embodiment. Have been.

In the ink tank 120, like the ink tank of each of the above-described embodiments, ink evaporation prevention,
In order to equalize the pressure in the tank and prevent ink leakage, the ink tank has a double structure of an outer wall 121 and an inner wall 122, and the inner wall 122 is caused by a decrease in the amount of ink contained therein. It is configured to deform freely following internal pressure fluctuations. A corner formed by a bottom surface having the ink supply unit 123;
The welded portion 124b formed on the surface corresponding to is a restricting portion for the movement of the inner wall 122. In the ink tank 120, a gap 127 of the outer wall 121 generated near the welded portion 124b formed by pinching off the inner wall 122 is used as an air intake.

In the ink tank 120, the ink in the ink container is used and the inner wall 12 of the ink tank is used.
When 2 is deformed, the deformation starts from the ceiling surface of the ink tank 120, that is, from the bottom surface facing the ink supply unit 123, instead of the pair of bottom surfaces being simultaneously deformed. This deformation direction is vertically downward and the ink supply unit 1
23 and the direction of ink supply to the recording head. Therefore, in the present embodiment as well, although the configuration is different, it is possible to easily realize stable ink ejection and negative pressure holding as in the above embodiments.

[0108] There is a welded portion 124b on the ceiling surface, which serves as a deformation restricting member for the inner wall surface. Therefore, it is difficult for the inner wall surface to suddenly deform. However, the welded portion 124b can be separated from the outer wall 121 by the presence of the gap 127.
In the direction in which the inner wall 122 can be deformed. Therefore, finally, the welded portion 124b is connected to the outer wall 1
21 and comes into contact with the inner wall surface on the ink supply unit 123 side. Rather, in the present embodiment, the presence of the welded portion 124b at the center of the ceiling surface increases the strength of the center, and as a result, more stable ink supply can be realized.

In this embodiment, since the inner wall 122 on the ceiling surface mainly deforms and comes into contact with the bottom surface on the ink supply unit 123 side, the height of the ink tank (the height of the column) is d, Let the diameter of the ink tank (the diameter of the cylinder) be d
Then, h <d / 2 must be satisfied. In order to ensure smooth deformation as described above, it is desirable that h ≦ d / 4.

Next, a method of manufacturing the ink tank 120 will be described. This ink tank can be manufactured by performing the same blow molding as in the first embodiment, since the ink supply section is provided at the welding section.
Of course, the shape of the mold needs to be changed.

<< Fourth Embodiment >> In each of the above-described embodiments, the bottom surface of the cylindrical ink tank, particularly the bottom surface that is to be deformed, is a smooth surface without fine irregularities. Was. In the fourth embodiment, an outwardly protruding rib is provided on the bottom surface of the ink tank as a convex portion, and the inner wall is used as a restricting portion against deformation. Is to occur. FIG. 10A is an enlarged sectional view of a rib portion. As for the shape of the projection forming the rib, the inner surface of the outer wall 141 and the outer surface of the inner wall 142 are equivalent or correspond to each other, and the protrusion is also formed in a trapezoidal shape protruding from the inner wall 142 toward the outer wall 141. The shape is not particularly limited, and may be a square (rectangular) shape, or may be a shape protruding from the outer wall 141 toward the inner wall 142. Such ribs are formed by providing grooves corresponding to the ribs in a desired shape in a mold in the blow molding described above.

FIGS. 10B and 10C show such a rib 143.
It is a figure showing arrangement of. In FIG. 10 (b), the ribs 14 which are considerably shorter than the circumference are formed along the circumference of the concentric circle.
3 are arranged at predetermined intervals, and those shown in FIG. 10 (c) have ribs arranged radially. By providing the ribs 143 in this manner, the local strength when the bottom surface is deformed is adjusted, the time until the bottom surfaces come into contact with each other is delayed, and the stability of the static negative pressure is further increased. I have. In particular, by forming a shape protruding from the inner wall toward the outer wall, the inner wall is less likely to bend and the inner wall is less likely to separate from the outer wall, and as a result, the strength is improved.

<< Fifth Embodiment >> FIG. 11 is a schematic sectional view of an ink tank according to a fifth embodiment of the present invention. This ink tank 150 is different from the ink tank of the first embodiment in that the shape of the corner formed by the side surface and each bottom surface is a minute curved surface shape. It is the same as the first embodiment that the ink supply unit 153 is provided and the ink lead-out permission member 156 is attached thereto, and that the length and the like are present.

By forming the parison into a small curved shape as described above, it is possible to form a thinner corner portion more stably when the parison is formed by expanding the parison in the mold. By thus forming the corners with a minute curved surface, the occurrence of pinholes can be largely prevented. Paying attention to the corners formed by the minute curved surfaces, the configuration of the present embodiment makes it possible to compare the outer wall 15 with the edge shape (the first embodiment).
1 and the inner wall 152 can be formed with a substantially uniform thickness, and stable movement of the surface can be achieved. Further, by making the film thickness at that portion uniform, it is possible to achieve stable strength. In addition, since the corner has a spherical shape (curved surface) when viewed locally when the surface is formed into a curved shape, the strength of the portion itself is increased, and the structure is hardly locally collapsed. As a result, it is possible to more stably achieve the crushing of the surface. Further, in the case of the present embodiment, the relationship of (crush control force of the surface itself) <(crush control force by corner) is established, so that the priority of the break control can be specified, and a more stable negative pressure Can be generated.

The ink tank 150 can be easily manufactured by forming a portion corresponding to a corner into a minute curved surface in a mold used for blow molding. Also,
Since the production of the mold becomes easier and the productivity is improved, the production of the ink tank can be provided at a substantially lower cost.

In each of the embodiments of the present invention described above, the outer wall and the inner wall are described as having a single layer.
These may have a multilayer structure of different materials in order to increase the impact resistance. In particular, by forming the outer wall with a multilayer structure, it is possible to prevent the occurrence of breakage during transportation or installation. The ink tank may be integrated with an inkjet head to be described later, or may be relatively replaceable with the inkjet head. Is also applicable.

Further, each of the above embodiments has been described as an ink tank in the field of ink jet recording. However, the present invention is not limited to the case where an external member or an external member of a liquid container such as a pen as a recording section or an ink discharge section is used. It is needless to say that the present invention can also be applied to a liquid storage container using a negative pressure to supply a liquid to the container. in this case,
In the liquid supply unit corresponding to the ink supply unit of the ink tank,
A liquid outflow prevention member, which is an ink lead-out permission member in the ink tank, may be provided.

In addition, the structure of the outer wall will be supplemented. As described above, one of the functions of the outer wall is to restrict the deformation of the corners of the inner wall. However, as a structure exhibiting this function, the shape can be maintained against the deformation of the inner wall, and the corners can be maintained. What is necessary is just to have a structure (corner surrounding member) that covers the periphery of the object. Therefore, the outer wall or the inner wall may be covered with a material such as plastic, metal, or cardboard. The outer wall may be the whole surface, or a surface structure only at the corners, and this surface structure may be connected with a rod of metal or the like. Further, the outer wall may have a mesh structure.

<< Inkjet Cartridge >> Next, FIG. 1 shows a case where an ink tank is connected to an inkjet head (recording head) to constitute an inkjet head cartridge. FIG. 12A is a schematic diagram of a recording head unit which is recording means connectable to the above-described ink tank 100, and FIG. 12B shows a state where the recording head unit 401 and the ink tank 100 are connected. FIG.

In FIG. 12A, a recording head unit 401 as recording means is assembled so that recording heads for black, yellow, cyan, and magenta are integrated so that full-color printing can be performed. Have been. These recording heads have a liquid flow path having an ejection port for ejecting ink, and a heating resistor element for ejecting ink from the ejection port. Reference numeral 402 denotes an ink supply tube as an ink introduction unit for introducing ink into each recording head unit. At an end of the ink supply tube 402, a filter 403 for trapping bubbles and dust is provided. ing.

When the above-described ink tank 100 is mounted on the recording head unit 401, FIG.
As shown in FIG.
00, an ink lead-out permission member (press-contact body) 106
Is connected, ink can be supplied. The recording head unit 401 is provided with four recording heads corresponding to each color of black, yellow, cyan, and magenta, so that four ink tanks 100 are mounted on the recording head unit 401. You.
The four ink tanks 100 store black, yellow, cyan, and magenta inks, respectively.

After the ink tank is mounted, the ink inside the ink tank is introduced into the recording head by a recovery means or the like provided in a recording device (not shown), and an ink communication state is formed. Thereafter, during the printing operation, ink is ejected from the ink ejection unit 404 provided on the recording head, and the ink held in the inner wall 102 of the ink tank 100 is consumed.

Here, the ink tank 100 is mounted such that the ink supply section is located below the center of the ink tank 100. As a result, the ink tank 1
It is not necessary to adjust the ejection force on the recording head side in accordance with the change in the remaining amount of ink during printing, and it is possible to increase the use efficiency of ink that can be actually used.

Further, since the ink tank in each of the above-described embodiments has the ability to generate and maintain a negative pressure in the inner package surrounded by the inner wall of the ink tank, the pressure contact member and the valve provided in the ink supply section are provided. The ink lead-out permitting member 106 such as a rubber stopper may be capable of holding the ink when separated from the recording head.

<< Inkjet Recording Apparatus >> Next, an inkjet recording apparatus which carries out recording by mounting the above-described inkjet cartridge having the ink tank shown in FIG. 1 will be described. FIG. 13 is a schematic diagram of the ink jet recording apparatus IJRA.

In FIG. 13, an ink jet head cartridge HC comprising a head unit 401 and an ink tank 100 is fixedly supported by a positioning means of a carriage (not shown) in the main body of the ink jet recording apparatus, and is detachably mounted on the carriage. Attached in a form.

The forward / reverse rotation of the drive motor 513 is transmitted to the lead screw 504 via the drive transmission gears 511 and 509 to rotate the lead screw 504, and the carriage is rotated by a pin (not shown) engaged with the spiral groove 505 of the lead screw 504. )
Having. Thereby, the carriage is reciprocated in the longitudinal direction of the apparatus.

Reference numeral 502 denotes the recording head unit 401
Are caps for capping the front surface of each recording head, and are used for performing suction recovery of the recording head through an opening in the cap by suction means (not shown). The cap 502 can be moved by the driving force transmitted via the gear 508 and the like to cover the ejection opening surface of each recording head. In the vicinity of the cap 502, a cleaning blade (not shown) is provided, and this blade is supported so as to be movable in the vertical direction in the figure. The blade is not limited to this form, and it goes without saying that a known cleaning blade can be applied to this embodiment.

The capping, cleaning, and suction recovery are performed so that desired operations can be performed at the corresponding positions by the action of the lead screw 505 when the carriage moves to the home position. If the desired operation is performed in any of the above, any of the present embodiments can be applied.

The connection pad 452 of the recording head unit 401 mounted on the carriage is connected to the connection pad 531 when the connection plate 530 provided on the carriage is rotated about a predetermined axis, and is electrically connected. You.
Since no connector is used for this connection, no unnecessary force acts on the recording head.

[0131]

As described above, according to the present invention, the height of the cylinder is made smaller than the diameter of the cylinder so that the bottom surface of the cylinder is deformed so that the ink jet recording apparatus can be used even in a cylindrical container. Therefore, there is an effect that a stable negative pressure suitable for an ink tank or the like can be generated, and a liquid container capable of supplying a liquid while using the stable negative pressure can be provided.

Further, by applying the above structure to an ink tank, a negative pressure of ink supply, a mechanical force from the outside,
Since the inner wall is deformed delicately following a change in temperature and a change in pressure, the pressure in the ink tank becomes constant, and there is an effect that the supply of ink to the ink jet head is performed smoothly.

Further, according to the present invention, the inner wall surface corresponding to at least one of the pair of bottom surfaces of the cylindrical liquid storage container has no joint with the outer wall, so that the inner wall can be easily separated from the outer wall. When the inner wall of the ink tank is deformed due to the use of the ink in the ink container, stable deformation is performed from this surface, thereby realizing stable ink ejection and holding a negative pressure. it can.

Further, in addition to the above effects, when the pinch-off portion and the ink supply portion are provided on the side surface, the degree of freedom of the height of the tank can be increased, and the pinch-off portion and the ink supply portion can be provided on the bottom surface. , The negative pressure can be further stabilized.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams schematically showing an ink tank according to a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view, FIG. 1B is a side view seen from an X direction, and FIG. It is.

FIGS. 2A and 2B are diagrams schematically showing an ink tank according to a modification of the first embodiment, in which FIG. 2A is a cross-sectional view and FIG. 2B is a side view.

FIG. 3 is a schematic diagram illustrating a deformation accompanying derivation of ink in the ink tank according to the first embodiment.

FIGS. 4A to 4D are diagrams illustrating a manufacturing process of the ink tank according to the first embodiment.

FIG. 5 is a flowchart illustrating a manufacturing procedure in a manufacturing process of the ink tank according to the first embodiment.

FIG. 6 is a schematic diagram illustrating a state of the ink tank in a process of manufacturing the ink tank according to the first embodiment.

FIGS. 7A and 7B are schematic diagrams of the configuration of an ink tank according to a second embodiment, in which FIG. 7A is a cross-sectional view, FIG. 7B is a bottom view, and FIG. 7C is a side view as viewed from the Y direction. is there.

FIG. 8 is a schematic diagram illustrating a deformation accompanying derivation of ink in an ink tank according to a second embodiment.

FIGS. 9A and 9B are schematic diagrams of the configuration of an ink tank according to a third embodiment, in which FIG. 9A is a cross-sectional view and FIG. 9B is a bottom view.

FIGS. 10A and 10B are schematic views showing an ink tank according to a fourth embodiment of the present invention, in which FIG. 10A is an enlarged cross-sectional view showing the shape of a rib portion, and FIGS. FIG.

FIG. 11 is a schematic sectional view illustrating a configuration of an ink tank according to a fifth embodiment of the present invention.

FIG. 12 (a) is a schematic perspective view showing an ink jet cartridge having an ink tank according to the present invention and an ink jet head connectable to the ink tank, and FIG. 12 (b) shows a connection between the ink jet head and the ink tank. It is a schematic sectional drawing which shows a state.

FIG. 13 is a schematic diagram illustrating an inkjet recording apparatus equipped with an inkjet cartridge having an ink tank according to the present invention.

[Explanation of symbols]

100, 110, 120, 150 Ink tank 101, 111, 121, 141, 151 Outer wall 102, 112, 122, 142, 152 Inner wall 103, 113, 123, 153 Ink supply unit 104, 114a, 114b, 124a, 124b Welding unit 106, 116, 126, 156 Ink lead-out permission member 107, 117, 127 Clearance 201 Main accumulator 202 Main extruder 203 Sub-accumulator 204 Sub-extruder 205 Ring 206 Die 207 Parison 208 Mold 209 Air nozzle 301-308 Step 401 Recording head unit 402 ink supply pipe 403 filter 404 ink discharge section

Claims (18)

[Claims] An outer wall having a substantially cylindrical shape and a substantially cylindrical shape and having a corner formed by an extension of a bottom surface and a side surface of the cylinder; and an outer surface having a shape similar to or similar to the inner surface of the outer wall. An inner wall that has a corner corresponding to the corner of the outer wall, forms a liquid storage portion capable of storing a liquid therein, and is detachable from the outer wall; And a pinch-off portion in which a portion where the inner wall is integrated with the outer wall is sandwiched by the outer wall, wherein the thickness of the inner wall is substantially the corner from the central area of the bottom surface of the column. The liquid container is characterized in that the portion constituting is thinner and has a height smaller than the diameter of the column. 2. The liquid container according to claim 1, wherein the thickness of the inner wall is gradually reduced from a central region of the bottom surface toward each of the corners. 3. An outer wall of the bottom surface has a convex shape on the liquid storage portion side, and a thickness of the outer wall gradually decreases from a central region of the substantially cylindrical bottom surface toward each corner. The liquid storage container according to claim 1, wherein 4. The liquid container according to claim 1, wherein corners of the inner wall and the outer wall are minute curved surfaces, respectively. 5. The liquid container according to claim 1, wherein a rib portion is formed on the inner wall at the bottom surface. 6. The liquid container according to claim 1, wherein the height is equal to or less than a quarter of the diameter. 7. The liquid container according to claim 1, wherein the bottom surface is a surface having a maximum area. 8. An outer wall which has a substantially cylindrical shape and has a substantially cylindrical shape, and has a corner formed by an extension of a bottom surface and a side surface of the cylinder, and an outer surface having a shape similar to or similar to the inner surface of the outer wall. And a corner portion corresponding to the corner portion of the outer wall, an inner wall which forms a liquid storage portion capable of storing a liquid therein and which can be peeled off from the outer wall, and from the liquid storage portion to the outside. A liquid container having a liquid supply portion capable of supplying a liquid, and a pinch-off portion in which a portion where the inner wall is integrated with the outer wall is sandwiched by the outer wall, wherein a bottom surface of the inner wall is formed as the liquid flows out. The liquid container is characterized in that the vicinity of the central area of the liquid container is deformed and detached from the corresponding corner of the outer wall while the corner of the inner wall maintains a substantially shape. 9. The liquid container according to claim 8, wherein the pinch-off portion is located on a side surface of the substantially cylindrical shape. 10. The liquid container according to claim 8, wherein the liquid supply section is located on a side surface of the substantially cylindrical shape. 11. The liquid supply portion is located on one of a pair of bottom surfaces of the substantially columnar shape, and a portion of the inner wall near a center area of the other surface of the pair of bottom surfaces is deformed as the liquid flows out. The liquid storage container according to claim 8, wherein 12. The liquid container according to claim 11, wherein the height of the column is lower than half the diameter of the column. 13. The liquid container according to claim 12, wherein the height is equal to or less than a quarter of the diameter. 14. The liquid container according to claim 8, wherein a rib portion is formed on the inner wall at the bottom surface. 15. The liquid container according to claim 8, wherein the bottom surface is a surface having a maximum area. 16. An outer wall having a substantially cylindrical shape having a substantially atmospheric communication portion and having a corner formed by an extension of a bottom surface and a side surface of the cylinder, and an outer surface having a shape similar to or similar to the inner surface of the outer wall. And an inner wall which has a corner corresponding to the corner of the outer wall and stores ink therein and which is detachable from the outer wall, and supplies ink to the outside from the ink housing. An ink supply portion, and a pinch-off portion in which a portion where the inner wall is integrated with the outer wall is pinched, and with the outflow of the ink, the vicinity of the central region of the bottom surface of the inner wall is deformed, An ink tank characterized in that the corners of the inner wall are separated from the corresponding corners of the outer wall while maintaining the approximate shape, and an ink jet head that is joined to the ink supply unit of the ink tank and discharges ink. Characterized by having Ink-jet cartridge. 17. An outer wall having a substantially cylindrical shape and a substantially cylindrical shape and having a corner formed by an extension of a bottom surface and a side surface of the cylinder, and an outer surface having a shape similar to or similar to the inner surface of the outer wall. And an inner wall which has a corner corresponding to the corner of the outer wall and stores ink therein and which is detachable from the outer wall, and supplies ink to the outside from the ink housing. An ink supply portion, and a pinch-off portion in which a portion where the inner wall is integrated with the outer wall is pinched, and with the outflow of the ink, the vicinity of the central region of the bottom surface of the inner wall is deformed, An ink tank portion, wherein the corner portion of the inner wall is separated from the corresponding corner portion of the outer wall while maintaining a substantially shape, and an ink jet head connected to the ink tank portion for discharging ink according to a recording signal. Inkjet with Cartridges and, equipped with the ink jet cartridge removably jet recording apparatus characterized by comprising a carriage to be scanned. 18. A liquid storage member having a substantially cylindrical shape and having a corner corresponding to an extended intersection area of two surfaces of the cylinder, and a corner of the liquid storage member being movable within a range in which the shape can be maintained. And a corner surrounding member capable of maintaining a shape with respect to deformation of the liquid storage member, wherein the thin film forming the liquid storage member has a thickness in a central region of a bottom surface thereof. On the other hand, the thickness of the corner portion is small, and the height is smaller than the diameter of the column.