JPH11240171A - Ink storage container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sustaining the negative pressure in a container for storing ink at a constant level. SOLUTION: A spring 5 is provided in the ink bag 3 of an ink storage container 1. The spring 5 urges the opposite side faces of the ink bag 3 outward. Coupling deformation part 5c of the spring 5 couples a force receiving part 5a and a link part 5b partially through a plurality of stripe pieces. Since the coupling deformation part 5c is less rigid than the force receiving part 5a and the link part 5b, each coupling deformation part 5c is deformed concentrically when a force is applied in the direction for bringing the opposite force receiving parts 5a close to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink storage container for holding ink while maintaining the inside thereof at a negative pressure.

[0002]

2. Description of the Related Art Conventionally, in an ink storage container (hereinafter simply referred to as a container) provided in an on-demand type ink jet printer, various methods have been proposed for keeping the inside of the container at a negative pressure within a predetermined range. The most efficient method of using the volume of the container is, for example, a method in which an ink occluding body is provided in the container and the negative pressure of the ink occluding body is not used. This is a method of holding ink by negative pressure (negative pressure type container).

One of the important characteristics among the various characteristics required for the container is a change characteristic of a negative pressure for holding the ink. The negative pressure in the container changes depending on the amount of ink in the container and the external environment (temperature change, pressure change, etc.). Various structures have also been proposed for negative pressure containers.

[0004] For example, a liquid ink cartridge disclosed in Japanese Patent Application Laid-Open No. 6-226993, entitled "Ink Storage Container for Ink Cartridge", has an ink storage container having a pair of flexible side walls. A structure has been proposed in which a metal spring or the like that pushes the inside of the side wall of the container in a direction of expanding the inside of the container is used to hermetically close the inside of the container and reduce the pressure. In such a container, the flexible container side wall is deformed (or displaced) in accordance with the ink supply accompanying the printing operation and is pressed in a direction to compress the spring, thereby reducing the volume of the container. Therefore, since no outside air enters the container,
The influence on the negative pressure in the container due to changes in the environment (temperature and pressure) can be considerably reduced.

[0005]

In the container disclosed in the above document, the spring only elastically deforms. Therefore, when the spring receives a force in the direction of contraction due to the deformation of the side wall, the side wall is expanded. The force of the spring that pushes back in the direction increases in proportion to the spring constant, and the negative pressure in the container increases accordingly. That is, when the negative pressure in the container changes according to the amount of ink in the container, if the amount of change is large, the negative pressure in the container may exceed the allowable range, and the ink may be pulled in the container direction. As a result, the ink ejection is unstable or impossible in the ink jet printer.

It is also conceivable to reduce the negative pressure change due to the amount of ink by lowering the spring constant.
In order to obtain the initial negative pressure of the container, the flexible side wall must be deformed excessively, and the container volume cannot be used efficiently.

[0007]

Means for Solving the Problems To solve the above-mentioned problems, a solution taken by the present invention is to provide an ink storage container which holds ink while keeping the inside at a negative pressure, wherein the ink is contained in the ink storage container, A flexible member that is displaced in accordance with an operation of supplying the outside to the outside, and an elastic member that presses the flexible member in a direction opposite to the displacement direction, and the elastic member includes:
It is mainly used in the plastic deformation region.

According to the above solution, when the flexible member is displaced by the supply of ink to the outside, the elastic member is pressed by the flexible member and deformed, and the elastic member undergoes plastic deformation. . Then, even if the ink is further reduced from this state and the deformation of the elastic member proceeds, the negative pressure in the ink storage container is kept substantially constant because of plastic deformation.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals.

First Embodiment FIG. 1 is an exploded perspective view of an ink storage container according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the ink storage container according to the first embodiment, showing a state before the ink storage container is attached to the inkjet head. FIG. 3 is a cross-sectional view of the ink storage container according to the first embodiment, showing a state where the ink in the ink storage container is used after being attached to the ink jet head.

Ink storage container 1 (hereinafter referred to as container 1)
Is provided with a tank cover 2, an ink bag 3 built therein, and a tank base 4.

The ink bag 3 is formed by attaching three sides around the ink bag materials 3a and 3b by heat welding or the like, and a plate-shaped spring 5 is provided inside the ink bag. Ink bag material 3a,
3b is made of, for example, a film obtained by evaporating aluminum on a film or a film layer containing a plurality of aluminum, and has flexibility. As will be described in detail later, the spring 5 comes into contact with the ink bag 3 and presses in a direction in which both side surfaces of the ink bag 3 are expanded (expanded) by their spring properties. Ink bag 3
The other side around which is not attached is the tank base 4
Joined to.

When the tank base 4 is joined to the ink bag 3, the tank inner surface 4 a is disposed inside the ink bag 3.
And a flow path coupling surface 4 b exposed outside the ink bag 3. On the inner surface 4a of the container, an ink bag joint 4c shown in FIG.
d is provided. Further, a hole 4e shown in FIG.
Is provided. The ink flow path 7 of the ink jet head shown in FIG. 3 and connected to the hole 4e is joined to the flow path coupling surface 4b. The hole 4e is provided so that the flow path coupling surface 4b is
Before joining, the packing 8 is closed by a packing 8 having a tab 8a formed therein.
Fixed inside. The ink 9 is sealed in the ink bag 3 and is supplied to the ink flow path 7 through the filter 6.

When the packing 8 is removed by pulling the tab 8a, the hole 4e is opened.

As shown in FIG. 1, a tank cover joining portion 4f to be joined to the tank cover 2 is formed between the inner surface 4a of the container and the passage connecting surface 4b. On one side surface of the tank cover 2, a communication hole 2 a for taking in outside air into the tank cover 2 as the ink bag 3 contracts is formed.

Here, the structure of the spring 5 will be described in detail with reference to FIGS. FIG. 4 is an explanatory view showing a developed shape of a spring incorporated in the ink storage container of the first embodiment. FIG. 5 is an explanatory view showing an assembled shape of the spring incorporated in the ink storage container of the first embodiment. FIG.

Since the spring 5 is built in the ink bag 3 together with the ink 9 as described above, the spring 5 is made of stainless steel or the like which does not make the volume of the ink bag 3 unnecessarily small and has high corrosion resistance. . The spring 5 is provided with two force receiving portions 5a that receive the external air pressure and push the ink bag 3 in opposition thereto.
And the linking portion 5b, to which the movement of the force receiving portion 5a is transmitted, and the three portions (5a) of the connecting and deforming portion 5c which combine the force receiving portion 5a and the link portion 5b and deform with the consumption (decrease) of the ink 9. , 5b, 5c). Then, the spring 5 is bent by the joint deforming portion 5c and assembled as shown in FIG. 5, and the spring joining portion 5d, which is a part of the force receiving portion 5a, is joined by spot welding or laser welding or the like.

The deforming portion 5c partially connects the force receiving portion 5a and the link portion 5b with a plurality of strip-shaped short pieces.
Accordingly, the coupling deforming portion 5c includes the receiving portion 5a and the link portion 5b.
The rigidity is weaker than that of. In a state where the spring 5 is assembled, when a force is applied in a direction in which the opposing force-receiving portions 5a approach each other, the deformation concentrates on each of the coupling deformation portions 5c.

FIGS. 6 and 7 are diagrams for explaining the characteristics of the spring according to the first embodiment. In addition to FIGS.
Will be described. 6 is an explanatory view showing a state in which one force receiving portion of the spring is fixed and a force F is applied to the other force receiving portion. FIG. 7 is a diagram illustrating a force F applied to the spring 5 and a displacement (deformation) δ.
FIG.

When a force F for pressing the spring 59 shown in FIG. 6 is applied to the spring 5, a characteristic consisting of a straight line A and a curve B shown in FIG. In the straight line A, the spring 5 is elastically deformed, and the force F and the displacement δ are proportional to each other by the spring constant (F = k
Δ k: spring constant). In curve B, spring 5
Is plastically deformed, so that even if the force F is reduced to zero, the spring 5 does not return to the original state.

As shown by the curve B, in the plastic deformation region,
The force F is almost constant regardless of the displacement δ. When the force F is gradually removed at the point B1 in the middle of the plastic deformation region, the dashed line C
However, even if the force F becomes zero, the displacement does not return to the original state, and the plastic deformation D remains. That is,
The dashed-dotted line C indicates that the spring property is not completely eliminated even when the spring 5 is plastically deformed.

Further, in the plastic deformation region, near the point B1, the force F tends to decrease (the amount of change is small) as the displacement δ increases. This is because, as described above, the deformation is concentrated on each joint deforming portion 5c, so that the deformation of the joint deforming portion 5c increases as the displacement δ advances, thereby forming the adjacent link portion 5b. Angle θ
6 (see FIG. 6), and therefore, the degree of force applied to each part 5a to 5c of the spring 5 changes as compared with the case where elastic deformation occurs.

In the spring 5 having the shape shown in the present embodiment, the displacement amount δ that shifts from elastic deformation to plastic deformation and the force F at that time depend on the material of the spring 5, the plate thickness, the length and the width of the coupling deformation portion 5c. Can be changed freely. For example, in order to increase the inclination of the straight line A, that is, to shift from elastic deformation to plastic deformation with a small displacement, the spring 5 may be formed of a thicker spring material.

The operation of the container 1 and the change in negative pressure when the ink 9 of the container 1 is used by using the spring 5 having the above-described characteristics will be described with reference to FIG. FIG. 8 is a diagram illustrating a change in negative pressure in the container that changes according to the amount of ink used in the embodiment.

When the ink 9 is injected into the ink bag 3 containing the spring 5, the spring 5 is not displaced.
In this embodiment, before using the container 1, the ink 9 is slightly removed from the ink bag 3, thereby deforming the ink bag 3 in the contracting direction and displacing the spring 5, and then setting the container 1 to a usable state. I have. The initial displacement at this time is slightly before the transition from the elastic deformation to the plastic deformation, as shown in FIG. Further, the initial negative pressure in the container 1 at this time is within an ink dischargeable range as shown by a straight line E in FIG.

When printing is performed by joining the container 1 to the ink flow path 7, the ink bag 3 is deformed in the contracting direction as the ink 9 is reduced (see FIG. 3). 5a are pressed toward each other. The spring 5 presses the ink bag 3 in a direction to expand the ink bag 3 by its spring property, and maintains the negative pressure in the container 1. When the ink 9 is reduced by continuing printing, and the ink bag 3 is further deformed, the spring 5 undergoes plastic deformation (transition from the straight line A to the curve B in FIG. 7).

At the time of transition to the curve B, the pressing force of the spring 5 becomes smaller than that in the elastic deformation region, and furthermore, due to the above-mentioned characteristics (the force F is substantially constant irrespective of the displacement δ), the negative pressure in the container 1 is reduced. The pressure is kept almost constant irrespective of the amount of the ink 9 (see the straight line E in FIG. 8).

A straight line G in FIG. 8 shows a case where the inside of the container 1 is maintained at a negative pressure by utilizing the property shown by the straight line A of the spring 5 (see FIG. 7). As the contraction of the ink bag 3 progresses, the pressing force of the spring 5 also increases in proportion to the spring constant, so that in the case shown by the straight line G, the change in the negative pressure in the container 1 is larger than the straight line E. Therefore, before the ink 9 in the ink bag 3 is used up, the negative pressure in the container 1 exceeds the allowable range, and the amount of unusable ink increases.

In the first embodiment, since the spring 5 is mainly used in the plastic deformation region, when the spring 5 is plastically deformed with the use of the ink 9, the negative pressure in the container 1 is reduced due to the spring characteristic. The change becomes small, and the negative pressure in the container 1 can be kept almost constant.

In general, the force F by the ink bag 3 and the magnitude of the negative pressure in the container 1 change depending on the volume (size) of the container 1 and the external environment (change in temperature, change in air pressure, etc.). According to the present embodiment, the coupling deformation portion 5
The width and length of c, the thickness of the material of the spring 5 and the like are changed, that is, the stiffness of the spring 5 is changed so that the optimal negative pressure for the container 1 is maintained.

The shape and material of the spring 5 are not limited to this embodiment as long as the shape and the material have the above-mentioned characteristics and water resistance.

Second Embodiment Next, a second embodiment of the present invention will be described. 9 is an exploded perspective view of an ink storage container according to the second embodiment, FIG. 10 is an explanatory view of a developed shape of a spring according to the second embodiment, FIG. 11 is a three-view drawing of the spring according to the second embodiment, FIG.
2 and 13 are explanatory diagrams of characteristics of the spring according to the second embodiment. Note that each member in FIG. 9 has a shape before the ink storage container 51 is assembled.

In FIG. 9, an ink storage container 51 (hereinafter, referred to as a container 51) is composed of a plurality of members, and one of the members is a frame 52 for forming a peripheral side wall of the container 51. . The frame 52 has a pair of opposed opening surfaces, and an ink supply hole 53 is formed at a position corresponding to an ink flow path on the side of an inkjet printer (not shown). Further, a fixing claw 54 for fixing the ink storage container 51 when the ink jet printer is mounted is formed on an outer peripheral portion 57 of the frame 52.

A flexible side wall 55 (hereinafter referred to as a side wall 55) which forms one side surface of the ink container is provided on one opening side of the frame 52, and the side wall 55 is a peripheral portion (fixed portion). 56 is fixed to the outer peripheral portion 57 of the frame 52 by welding or the like so as to maintain the hermeticity. And this side wall 55 is made of polypropylene, aluminum vapor-deposited layer,
It has a layer structure. The portion of the side wall 55 other than the peripheral portion 56 (non-fixed portion) is set to a size that can cover the inner surface along the frame 52 when almost all of the ink in the container 51 is sucked out. An outside air opening 58 is formed in a part of the outer peripheral portion 57 of the frame 52 on the side where the side wall 55 is fixed. The side wall 55 before assembly shown in FIG.
Is the same as the shape of the side wall 55 shown in FIG.

A spring 59, which is an elastic member, is provided on the other opening side of the frame 52.
10 and 11 are provided at positions facing the opening surface of the frame 52, and a spring flat portion 60 for pressing the side wall 55 and a spring fixing hole used for fixing the spring 59. A spring fixing portion 62 formed with 61; a spring connecting portion 63 connecting the spring flat portion 60 and the spring fixing portion 62;
It comprises a spring flat portion 60 and a spring connecting portion 63, and a spring deforming portion 64 connecting the spring fixing portion 62 and the spring connecting portion 63, respectively.

The spring 59 has the shape shown in FIG.
The spring 59 is formed into the shape shown in FIG.
0, spring fixing hole 61, spring fixing part 62, spring connecting part 6
3. Among the spring deformable portions 64, the spring deformable portion 64 constituted by a plurality of strip-shaped short pieces has the lowest rigidity,
In addition, when a force in the direction of bending the spring 59 is applied to the spring flat portion 60 in the assembled state, the spring deforming portion 64
The deformation is concentrated on Note that the spring deformable portion 64 may be formed by being processed to be thin or thin.

The above-mentioned spring fixing hole 61 is provided on the spring fixing post 6 of the fixing side wall 65 provided further outside the spring 59.
The spring 59 is built in the container 51 by being fixed to 6. A positioning rib 67 is formed on the fixed side wall 65, and is positioned with respect to the other opening surface side of the frame 52, and is fixed so as to maintain airtightness.

Here, the characteristics of the spring 59 will be described. FIG. 12 is an explanatory view showing a state in which one force receiving portion of the spring 59 is fixed and a force F is applied to the other force receiving portion.
3 is a diagram for explaining the relationship between the force F applied to the spring 59 and the displacement (deformation) δ.

When the spring 59 is assembled as shown in FIG. 12, the spring 59 has the characteristics shown in FIG. 13, that is, the characteristics consisting of the straight line E, the curve G, and the straight line J. In the straight line E, the spring 5 is elastically deformed, and a force F (hereinafter simply referred to as a force F) for pressing the spring 59 and a displacement δ are proportional to each other by a spring constant (F = k · δ k: spring constant). ing. In the curve G, the spring 5 is plastically deformed, and therefore, even if the force F is reduced to zero, the spring 59 does not return to the original state.
Further, in the straight line J, the spring 64 is crushed to the limit.

As shown by the curve G, in the plastic deformation region, the force F is almost constant regardless of the displacement δ. When the force F is gradually removed at the point G3 in the plastic deformation region, the displacement decreases as indicated by a dashed line H. However, even if the force F becomes zero, the displacement does not return to the original state, and the plasticity does not return. The deformation L remains. That is, the dashed line H indicates that the spring 5 is not completely lost even if the spring 5 is plastically deformed.

When the force F shown in FIG. 12 is applied to the spring flat portion 60, the spring deformable portion 64, which has sufficiently low rigidity as compared with other portions, is easily deformed. This spring deformation part 6
Reference numeral 4 denotes a small elastic deformation region, and the force F increases with the displacement δ (see FIG. 13 (point 0)-(G1 point)). When a force is further applied to the spring deforming portion 64, the force F easily enters the plastic deformation region. [FIG. 13 (point G1)-(point G2)-(point G3)-(G4
Point). When the force is further applied and the spring deformable portion 64 is crushed to the limit, the force F rises rapidly [FIG.
(See point G4)-(point J1)].

In FIG. 7 of the first embodiment, the force F tends to decrease as the displacement δ increases in the plastic deformation region, whereas in FIG. 13 of the second embodiment. , In the plastic deformation region, the force F tends to increase as the displacement δ increases. This is because the shape of the spring is different between the first embodiment and the second embodiment.

With the above configuration, a sealed ink storage portion of the container 51 is formed.

A cover 68 is provided outside the side wall 55 to protect the side wall 55 of the container 51.
The cover 68 is attached to the outer peripheral portion 5 of the frame 52 by welding or the like.
7. In a state where the cover 68 and the side wall 55 are fixed to the frame 52, the cover 68 and the side wall 55 are fixed.
The outside air opening 58 is provided in a space between the outside air and the outside air. The side opening 55 is formed by the outside air opening 58.
The outside air can enter and exit in response to the change of.

Next, the ink supply section of the container 51 will be described. FIGS. 14 and 15 are cross-sectional views illustrating an ink supply unit according to the second embodiment.

In the ink supply section 69 shown in FIG. 9, as shown in FIGS. 14 and 15, the filter 70, the packing 71, and the cap 72 holding both of them maintain airtightness corresponding to the ink supply holes 53 of the frame 52. As described above, it is configured by being fixed to the frame 52 by welding or the like. Before opening the container 51 shown in FIG.
9 to seal the cap 72
The seal film 73 is peeled off when the container 51 shown in FIG. 15 is used, and the container 51 is connected to the ink passage 7 on the ink jet head side.
4

The container 51 is constituted by the above members and configuration.

Next, the operation of the container 51 and the change in negative pressure when the container 51 supplies ink (not shown) using the spring 59 having the above-described characteristics will be described with reference to FIGS. 16, 17, 18, and 19. explain. FIGS. 16, 17, and 18 are cross-sectional views showing the operation of the ink storage container according to the second embodiment during ink supply. The amount of ink 89 in the container 51 decreases from FIG. 16 to FIG. doing. FIG. 19 is a diagram for explaining a change in the negative pressure in the container that changes with the amount of ink used in the second embodiment.

In FIG. 19, the ink 89 can be supplied from the container 51, that is, the usable range of the ink 89 is from the point g1 to the point g4, and the pressure range in the container capable of supplying the ink 89 is g1. From point to g5 point. In FIG. 8 of the first embodiment, the horizontal axis indicates the amount of ink used, which corresponds to the portion described as “ink usable range” in FIG. The "initial negative pressure point M" in FIG.
9 corresponds to the g1 point. That is, FIG. 8 shows a graph from the time when the ink 89 can be supplied, while FIG. 19 shows a graph from the state where no negative pressure has yet been generated.

The spring 59 is mounted in a state where the spring 59 is sufficiently extended with respect to the thickness of the container 51. Since the cover 68 is fixed to the frame 52 thereafter, the spring 59 is
At 0, the side wall 55 is pressed against the cover 68. At this time, the state of the spring 59 is changed from the point G1 in FIG.
In this state, the spring 59 is already in a plastically deformed state. Here, it is not always necessary to be in a plastic deformation state.
Or from point G1 to the point G1. Then, the ink 89 is injected from an injection port (not shown) provided in a part of the frame 52 of the container 51 until substantially no air remains inside, and the injection port is sealed with a stopper or a film or the like. At this time, the inside of the container 51 is in a state where the negative pressure for keeping ink balanced with the external atmospheric pressure is zero (point 0 in FIG. 13).

In order to raise (generate) a negative pressure for holding ink from here, the ink supply hole 5 shown in FIG.
A negative pressure is raised by removing a certain amount of ink 89 from 3 (points G2 in FIGS. 16 and 13). When the ink removing jig is removed in this state, the ink filled in the ink supply unit 69 is sucked back to the filter 70 shown in FIG. 14 by the internal negative pressure, and the surface tension of the filter 70 and the internal negative pressure are balanced. In this state, the ink 89 is held. Here, the container 51 is sealed with the seal film 73.

As a procedure for injecting the ink 89, the cover 68 is not fixed to the frame 52, and the spring 59 is
Alternatively, the cover 89 may be fixed to the frame 52 after the ink 89 is injected and drained as described above while the ink 89 is sufficiently extended beyond the width of 1, and the negative pressure for holding the ink is raised.

When supplying the ink 89 from the container 51, the operator peels off the sheet film 73,
As shown in FIG. 15, the ink 89 in the container 51 is supplied by being connected to the ink flow path 74 and sucking from the ink flow path 74 side.

According to the supply operation of the ink 89, the spring force of the spring 59 is plastically deformed along the points G2-G3-G4 shown in FIG. 13, and the negative pressure characteristic in the container 51 during that time is shown in FIG.
It changes along points g2 -g3 -g4 shown in FIG. Further, as shown in FIG. 17, the state in the container 51 is such that the side wall 55 is displaced as the amount of the ink 89 decreases, whereby the spring 59 is displaced.

When the spring 59 is further displaced, whereby the spring deforming portion 64 is bent and the spring 59 is crushed to the limit (the state shown in FIG. 18), the force F for pressing the spring 59 is changed from the point G4 to the point J1 shown in FIG. 19, the negative pressure characteristic of the container 51 becomes g4 in FIG.
The point changes from the point to the point j1, exceeding the required pressure range, making it impossible to supply ink and making the container 51 unusable. In addition,
At this time, almost no ink 89 remains in the container 51.

Further, since the spring 59 is plastically deformed and contracted with the supply of the ink, the negative pressure of the container 51 cannot be regenerated even if the ink 89 is injected into the container 51 again.

In the second embodiment, since the spring 59 during the supply of ink is in a plastically deformed state, a change (decrease) in the amount of ink inside the container 51 is made,
It is possible to suppress the change in the negative pressure within 1. Therefore, the negative pressure in the container 51 can be kept substantially constant until the ink supply operation is completed. Further, the negative pressure can be easily set by the shape of the spring 59, and the container 51 having high ink use efficiency with respect to the initial ink amount can be provided.

Further, once the container 51 is used, the ink 89 is used.
Since it is impossible to re-inject the ink, it is possible to prevent the use of the defective ink 89 and the like, and to prevent a print head failure due to the use of the defective ink.

Further, since the container 51 of the present embodiment can be formed by assembling each member sequentially, it is easier to manufacture than the container 1 of the first embodiment.

In the second embodiment,
Before starting the first ink supply operation, the spring 59
Is in a plastically deformed state.
As long as the negative pressure can be held inside, the spring 59 may still be in an elastically deformed state at the time when the ink supply operation is started as in the first embodiment.

Third Embodiment Next, a third embodiment of the present invention will be described. The same parts as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 20 is an explanatory view showing a part of the ink storage container according to the third embodiment, and FIG. 21 is a sectional view showing the ink storage container according to the third embodiment.
In FIG. 21, the cover 68 has been removed.

Here, in the container 51 shown in the second embodiment, the material of the side wall 55 which is originally a flat sheet is formed three-dimensionally as shown in FIG. And so on. For this reason, a wrinkle 75 is formed at the corner of the side wall 55, and the wrinkle 75 becomes a resistance when the side wall 55 is displaced as shown in FIGS. 16 to 18, and causes a change in negative pressure. So wrinkles 75
In order to reduce the effect of the above, the distance between the inner wall 88 of the frame 52 and the spring flat portion 60 may be increased, but the ink capacity decreases.

Therefore, in the third embodiment, the corner radius R2 of the spring plane portion 60 is set so as to satisfy the following equation 1 with respect to the corner radius R1 of the inner wall 88 of the frame 52.

R2 ≧ R1 (1) By doing so, the distance between the edge 60a of the spring flat portion 60 and the edge 52a of the frame 52 facing the edge 60a shown in FIG. 21 is increased. Can be.

The other structure is the same as that of the second embodiment.

Next, the operation of the above-described configuration when supplying ink to the side wall 55 will be described.

When the ink 89 in the container 51 is supplied and the capacity is reduced, the side wall 55 is displaced as shown in FIGS. At this time, the wrinkles 7
Since the area where the 5 is deformed can be widened, the influence of the deformation of the wrinkles 75 on the negative pressure change can be reduced.

In the third embodiment described above, the corner radius R2 of the spring plane portion 60 is set so as to satisfy the above-mentioned formula 1 with respect to the corner radius R1 of the inner wall 88 of the frame 52, thereby obtaining the edge of the frame 52. The wrinkles 7 generated at the corners of the side wall 55 without particularly widening the distance between the edge 52a and the edge 60a of the spring flat portion 60 opposed thereto.
5 can be reduced.

Further, as a structure for obtaining the same effect, the corner shape of the spring flat portion 60 may be a chamfered shape instead of an arc, or may be a shape combining obtuse angles. Further, a combination of these may be used.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described. The same parts as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 22 is an exploded perspective view of an ink storage container according to the fourth embodiment, FIG. 23 is an explanatory view of a developed shape of a spring according to the fourth embodiment, and FIG. 24 is a three-view drawing of the spring according to the fourth embodiment. .

In the container 51 shown in the second embodiment, since the side wall 55 is pressed against the peripheral edge of the spring flat portion 60 and the edge of the spring deforming portion 64 by the internal negative pressure, the side wall 55 is vibrated or stored for a long period of time. 55 may be torn.

Therefore, in the fourth embodiment, the spring 7
The shape of No. 6 is the shape shown in FIGS. 22, 23 and 24. That is, in the spring 76, the first spring deformation portion 78 connected to the spring flat portion 77 and the first spring deformed portion 78 enter the inner side of the outer periphery of the spring flat portion 77 as shown in FIG. A spring deformation part 78 is formed.
Therefore, when the spring 76 is bent and formed, when the spring deformed portion 77 is viewed from the plane side of the spring flat portion 77, the first spring deformed portion 78 enters inside the outer peripheral ridge line of the spring flat portion 77.

In addition, a sag 79 for supporting the side wall 55 is formed on the peripheral edge of the outer peripheral portion of the spring flat portion 77 by drawing or the like. The spring 76 is further provided with a spring fixing hole 80, a spring connecting portion 81, a second spring deforming portion 82, and a spring fixing portion 83, which are the same as the structure of the spring 59 of the second embodiment. The description is omitted because it is the same.
In addition, the other configuration of the container 51 is the same as that of the second embodiment, and the description is omitted.

Next, the operation of the container 51 when supplying ink will be described. FIGS. 25, 26, and 27 are cross-sectional views showing the operation of the ink storage container according to the fourth embodiment when supplying ink. Only the differences between the operation at the time of ink supply and the second embodiment will be described.

As shown in FIGS. 25, 26 and 27, the side wall 55 is supported by the sag 79 of the spring 76 from the start of the supply of the ink 89 to the end thereof. It will not be pressed. At this time, since the edge of the first spring deforming portion 78 is inside the spring flat portion 77, the side wall 55 is not pressed against the edge of the spring deforming portion 78.

As described above, in the fourth embodiment, when the spring 76 is viewed from the plane side of the spring flat portion 77, the first spring deforming portion 78 is located inside the outer peripheral ridge line of the spring flat portion 77. Spring flat part 77 and first spring deformation part 78
Is formed, and a sag 79 for supporting the side wall 55 is formed on a peripheral edge of an outer peripheral portion of the spring flat portion 77. By supporting the side wall 55 with the sag 79, the peripheral edge of the spring flat portion 77 and the first spring are formed. Since the side wall 55 is not pressed against the edge of the deformed portion 78, the side wall 55 can be prevented from being broken due to vibration or long-term storage.

Fifth Embodiment Next, a fifth embodiment will be described. The same parts as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted. FIG. 28 is an exploded perspective view showing an ink storage container according to the fifth embodiment, and FIG. 29 is a sectional view showing an ink supply unit according to the fifth embodiment.

In the container 51 shown in the second embodiment, the ink 89 decreases depending on the width of the container 51 and the position of the ink supply hole 53, and the side wall 55 is displaced as shown in FIG. When the inside is covered, the ink supply hole 53 is also covered at the same time, and there is a possibility that the ink supply is hindered.

Therefore, in the fifth embodiment, FIG.
8. As shown in FIG. 29, a plurality of ribs 86 extending in the displacement direction of the side wall 55 are formed around the ink supply holes 85 in the frame 84, and a step is formed in the frame 84.

The shape of the spring 76 is the fourth embodiment, and the corner radius R2 of the spring flat portion 77 with respect to the corner radius R1 of the inner wall 88 of the frame 52 is expressed by the following equation (1). The other configuration is the same as that of the second embodiment, and the description is omitted.

Next, the operation of the container 51 in supplying ink in the above configuration will be described. As shown in FIG. 29, the side wall 55 is displaced with the ink supply operation, and the ink supply holes 85 are displaced.
, The side walls 55 are supported by the ribs 86 formed therearound, so that the passage of the ink 89 is ensured. Thus, the ink 89 inside the container 51 smoothly reaches the ink supply hole 85 to the end and is supplied to the outside of the container 51.

In the fifth embodiment, since the plurality of ribs 86 extending in the direction of displacement of the side wall 55 are formed around the ink supply hole 85, the ink can be smoothly supplied to the end. It is possible to perform reliable ink supply.

Further, instead of the rib 86, a groove extending in the direction of displacement of the side wall 55 or a plurality of protrusions may be provided to form a passage for the ink 89 to the ink supply hole 85.

Although the first to fifth embodiments have been described assuming an ink storage container of an ink jet head mainly used in an ink jet printer, a liquid is stored and held inside. The present invention can be applied to a liquid storage container used for a container that supplies a liquid in response to a liquid suction operation from the outside.

[0085]

As described in detail above, the present invention provides
A flexible member that is built into the ink storage container and that is displaced in accordance with an operation of supplying ink to the outside, and an elastic member that presses the flexible member in a direction opposite to the displacement direction, wherein the elastic member is By being mainly used in the plastic deformation region, the ink is continuously supplied to the outside of the container, and the pressing force of the elastic member does not increase even if the deformation of the elastic member increases with the displacement of the flexible member. Therefore, since the negative pressure in the container can be kept constant, the ink can be stably discharged when the ink jet printer is provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an ink storage container according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the ink storage container according to the first embodiment.

FIG. 3 is a sectional view of the ink storage container according to the first embodiment.

FIG. 4 is an explanatory view of a developed shape of a spring according to the first embodiment.

FIG. 5 is an explanatory view of an assembled shape of the spring according to the first embodiment.

FIG. 6 is an explanatory diagram of characteristics of a spring according to the first embodiment.

FIG. 7 is an explanatory diagram of characteristics of a spring according to the first embodiment.

FIG. 8 is an explanatory diagram of a negative pressure change in the container according to the first embodiment.

FIG. 9 is an exploded perspective view of the ink storage container according to the second embodiment.

FIG. 10 is an explanatory diagram of a developed shape of a spring according to the second embodiment.

FIG. 11 is a three-view drawing of a spring according to the second embodiment.

FIG. 12 is an explanatory diagram of characteristics of a spring according to the second embodiment.

FIG. 13 is an explanatory diagram of characteristics of a spring according to the second embodiment.

FIG. 14 is a cross-sectional view illustrating an ink supply unit according to a second embodiment.

FIG. 15 is a cross-sectional view illustrating an ink supply unit according to the second embodiment.

FIG. 16 is a cross-sectional view illustrating an operation of the ink storage container according to the second embodiment.

FIG. 17 is a cross-sectional view illustrating an operation of the ink storage container according to the second embodiment.

FIG. 18 is a cross-sectional view illustrating an operation of the ink storage container according to the second embodiment.

FIG. 19 is an explanatory diagram of a negative pressure change in the container according to the second embodiment.

FIG. 20 is a diagram illustrating a part of an ink storage container according to a third embodiment.

FIG. 21 is a cross-sectional view illustrating an ink storage container according to a third embodiment.

FIG. 22 is an exploded perspective view of an ink storage container according to a fourth embodiment.

FIG. 23 is an explanatory diagram of a developed shape of a spring according to the fourth embodiment.

FIG. 24 is a three-view drawing of a spring according to the fourth embodiment;

FIG. 25 is a sectional view showing the operation of the ink storage container according to the fourth embodiment.

FIG. 26 is a cross-sectional view illustrating an operation of the ink storage container according to the fourth embodiment.

FIG. 27 is a cross-sectional view illustrating an operation of the ink storage container according to the fourth embodiment.

FIG. 28 is an exploded perspective view of an ink storage container according to a fifth embodiment.

FIG. 29 is a cross-sectional view illustrating an ink supply unit according to a fifth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink storage container 3 Ink bag 5 Spring 9 Ink 51 Ink storage container 52 Frame 55 Flexible side wall 59 Spring 60 Spring flat part 64 Spring deformation part 76 Spring 78 First spring deformation part 79 Drip 84 Frame 86 Rib 89 Ink

Claims (8)

[Claims] 1. An ink storage container that holds ink while maintaining the inside at a negative pressure, a flexible member that is built in the ink storage container and that is displaced in accordance with an operation of supplying ink to the outside. An elastic member for pressing the member in a direction opposite to the displacement direction, wherein the elastic member is mainly used in a plastic deformation region. 2. An ink storage container for holding ink by keeping the inside at a negative pressure, a flexible ink bag built in the ink storage container and storing the ink therein, and an ink bag inside the ink bag. And an elastic member for abutting the ink bag in a direction to inflate the ink bag, wherein the elastic member is mainly used in a plastic deformation region. 3. The ink storage container according to claim 2, wherein said elastic member is a plate-like spring, and a part of the elastic member has a reduced rigidity so that a spring deformation due to contraction of said ink bag is concentrated. 4. An ink storage container for holding ink while keeping the inside at a negative pressure, comprising: a frame built in the ink storage container, having an open side surface, and holding the ink inside, and fixed to the open side surface of the frame. A flexible side wall that is displaced in accordance with an operation of supplying ink to the outside, and an elastic member that abuts on the flexible side wall in the frame and presses the flexible side wall in a direction opposite to the direction of displacement. An ink storage container comprising: an elastic member that is mainly used in a plastic deformation region. 5. The ink storage container according to claim 4, wherein the elastic member is a plate-shaped spring, and a part of the elastic member has a reduced rigidity, so that a spring deformation due to the displacement of the flexible side wall is concentrated. . 6. The ink storage container according to claim 4, wherein a radius of a corner of the elastic member is equal to or larger than a radius of a corner of the frame corresponding to the corner. 7. The ink storage container according to claim 4, wherein the shape of the edge of the elastic member with which the flexible side wall abuts when the flexible side wall is displaced is a curved shape. 8. A supply hole for supplying ink to the outside is formed in the frame, and the frame extends in a direction of displacement of the flexible side wall to form a step between the supply hole and another portion. 5. The ink storage container according to claim 4, wherein a step portion is formed.