JP2003145796A - Ink tank structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink tank structure for reducing the quantity of ink remaining in an ink tank. SOLUTION: An ink channel 27 communicating with the ink chamber 30 of an ink tank 1 and an ink take-out hole 7 is provided with a protrusion 36 projecting into the ink chamber 30 wherein a take-out side interconnecting opening is provided at the forward end of the protrusion 36. Furthermore, a cup-like cap 31 is provided to cover the protrusion 36. A gap 45 for sucking ink is formed between the cup-like cap 31 and the protrusion 36. Even if ink in the ink chamber 30 is decreased and the ink level drops below the take-out side interconnecting opening at the forward end of the protrusion 36, ink in the ink chamber 30 can be sucked entirely up to the bottom face of the ink chamber 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink tank structure for reducing the residual ink amount of ink taken out from an ink chamber by an ink suction force acting on an ink taking-out hole.

[0002]

2. Description of the Related Art As an ink tank of an ink jet printer, an atmosphere communicating hole communicating with an ink chamber, an ink taking-out hole for taking out ink from the ink chamber, and an ink communicating between the ink chamber and the ink taking-out hole are provided. The passage has a structure in which a protruding portion protruding into the ink chamber is provided, and an ink outlet side communication port is formed at the tip of the protruding portion,
When the ink surface is above the communication port on the ink extraction hole side, the ink in the ink tank is extracted by the ink suction force acting on the ink extraction hole. However, the ink below the ink outlet hole-side communication port structurally remains in the ink tank.

[0003]

However, when the structure of the ink tank is configured so that the ink take-out hole for taking out the ink into the ink chamber does not project, the following problems occur. Inside the protruding portion, a valve body that can close the ink outlet hole and a spring member that presses the valve body against the ink outlet are arranged, so that the ink outlet hole partly extends from the bottom surface of the ink chamber. It has a protruding shape. In that case, a wasteful space is formed between the ink tank mounting member and the amount of ink packed in the ink tank is lost.

On the other hand, in order to reduce a wasteful space between the ink tank mounting member and the ink tank mounting member, an ink passage communicating between the ink chamber and the ink take-out hole must be projected into the ink chamber. Ink that cannot be taken out remained inside, resulting in waste of ink.

In view of the above points, an object of the present invention is to
Compact ink tank and with respect to outer diameter volume,
An object of the present invention is to propose an ink tank that suppresses the protrusion of the ink take-out hole from the bottom surface and reduces the residual ink in the ink chamber in order to pack more ink.

[0006]

In order to solve the above-mentioned problems, the present invention provides an ink chamber containing ink,
An ink tank having an atmosphere communication hole communicating with the ink chamber, an ink discharge hole for discharging ink from the ink chamber, and an ink passage communicating between the ink chamber and the ink discharge hole. The ink passage includes a protruding portion that protrudes into the ink chamber, the outlet hole side communication port is formed at the tip of the protruding portion, and a cap member that covers the protruding portion is provided and acts on the ink outlet hole. It is characterized in that the ink suction force pulls out the ink below the communication hole side communication port.

Here, between the projecting portion and the cap member, from the communication port formed at the tip of the projecting portion,
You may form the gap for ink suction which extends in the opposite direction to the protrusion direction of the said protrusion part. By appropriately setting the width of the gap and the like, a large amount of ink can be sucked up. In this case, if protrusions are formed on the outer surface of the protruding portion and / or the inner surface of the cap member to form the gap for sucking the ink, a gap having an appropriate width can be formed only by mounting the cap member. Can be formed.

Further, it is desirable that the projection functions as a positioning projection for the cap member with respect to the protruding portion.

Further, the cap member may be a cup-shaped cap, and in this case, between the opening end surface of the cup-shaped cap and the bottom surface of the ink chamber facing the opening end surface, A communication part may be formed so as to communicate with the ink suction gap. It is preferable to form a plurality of protrusions for forming the communication portion on the opening end surface of the cup-shaped cap, because the communication portion can be automatically formed when the cup-shaped cap is attached to the protruding portion.

Further, in order to properly perform the ink sucking operation, it is desirable that the outer peripheral surface of the cup-shaped cap is separated from the inner surface of the ink chamber.

Next, a valve body capable of sealing the ink take-out hole is provided inside the protruding portion protruding into the ink chamber.
If a spring member that presses this valve body against the ink outlet is arranged, these parts can be compactly incorporated.

Further, the ink tank of the present invention includes a foam in which ink is absorbed and held, a foam storage chamber in which the foam is stored, an atmosphere communication hole communicating with the foam storage chamber, and the foam storage. An ink take-out hole for taking out ink from the chamber, and an ink chamber is defined between the foam storage chamber and the ink take-out hole;
By the ink suction force acting on the ink outlet,
Bubbles are introduced into the ink chamber from the side of the foam storage chamber to prevent the bubbles from advancing from the ink chamber to the ink extraction hole.

In this case, the first filter for partitioning the foam side communication port that communicates the foam storage chamber and the ink chamber with the ejection hole side communication that communicates the ink chamber and the ink ejection hole with each other. A second filter partitioning the mouth, wherein the first filter is formed of a porous material through which air bubbles can pass by an ink suction force acting on the ink outlet.
The filter may be formed of a porous material having a pore size smaller than that of the first filter.

Here, there is an ink passage communicating between the ink chamber and the ink take-out hole, and the take-out hole side communication port is between the ink passage and the ink chamber.
It may be partitioned by the filter of.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an ink tank for an ink jet printer of the present invention will be described below with reference to the drawings using a foam type ink tank. The following embodiments are examples in which the present invention is applied to an ink tank that is detachably attached to an ink tank attachment portion of an inkjet printer. Furthermore, the present invention can be similarly applied to an ink tank that is previously arranged in an inkjet printer.

1 (a) and 1 (b) are a plan view and a front view showing a foam type ink tank to which the present invention is applied, and FIG. 2 is a perspective view of the ink tank as seen from the bottom side. Yes, FIG. 3 is an exploded perspective view of the ink tank.

The ink tank 1 of this embodiment is detachably attached to a tank attachment portion (not shown) formed in an ink jet printer (not shown) for use.
The ink tank 1 has a box-shaped container body 2 having an upper opening, and a container lid 4 that closes the upper opening 3, and a foam storage section 5 is formed inside the container lid 4.
Here, the rectangular parallelepiped form 6 in which the ink is absorbed and held is housed.

An ink take-out hole 7 is formed on the bottom surface of the container body 2. A disk-shaped rubber packing 8 is attached to the ink take-out hole 7, and a through hole 8a opened at the center thereof takes out the ink. It is said to be a mouth. A valve 9 capable of closing the ink outlet 8a is arranged in a portion of the ink outlet 7 that is deeper than the rubber packing 8, and the valve 9 is constantly pressed by the coil spring 10 against the rubber gasket 8 to remove the ink. The mouth 8a is closed.

As will be described later in detail, the foam storage section 5 communicates with the ink extraction hole 7 via the first filter 11 and the second filter 12. Further, the foam storage portion 5 is open to the atmosphere through an atmosphere communication hole 13 formed in the container lid 4. When the ink absorbed and held in the foam 6 mounted in the foam container 5 is sucked through the ink outlet 7, air corresponding to the sucked ink is discharged from the atmosphere communication port 13 to the foam container. 6
Get in.

The atmosphere communication hole 13 of the container lid 4 is connected to a curved groove 13a formed on the surface of the container lid, and the end 13b of the groove 13a extends to the vicinity of the edge of the container lid 4. . At the time of shipping the ink tank 1, a seal 14 is attached to a portion of the container lid 4 where the atmosphere communication hole 13 and the groove 13a are formed.
A part 1 of the seal 14 along the cutting line 14a of 4
By cutting out 4b, the end 13b of the groove 13a is exposed and the atmosphere communication hole 13 is opened to the atmosphere.

Further, the ink tank 1 is mounted so that the ink supply needle mounted on the tank mounting portion of the ink jet printer is inserted into the ink outlet 8a (see FIG. 4 (b)). ). At this time,
The seal 15 attached to the ink outlet port 8a on the bottom surface of the container is broken and opened by the tip of the ink supply needle.

FIGS. 4A and 4B are IV-I of FIG.
FIG. 5 is a cross-sectional view and a partial cross-sectional view of the ink tank 1 when cut along the line V, FIG. 5 is a cross-sectional view of the ink tank 1 when cut along the line VV of FIG. 1, and FIG. FIG. 6 is a cross-sectional view of the ink tank 1 when cut along the line VI-VI.

Referring to these drawings, the ink take-out hole 7
The structure of the ink passage portion formed between the foam storage portion 6 and the foam storage portion 6 will be described. In the bottom plate portion 21 of the container body 2,
A tubular frame 22 having a rectangular cross section penetrates the bottom plate portion 21 and extends vertically vertically. An upper tubular frame portion 23 of the tubular frame 22 which stands upright in the foam storage portion 6
A rectangular communication port 25 is formed at the upper end of the. The communication port 25 is closed by the rectangular first filter 11.

The lower end opening of the lower tubular frame portion 24 vertically projecting downward from the container bottom plate portion 21 of the tubular frame 22 is closed by a frame bottom plate portion 24a formed integrally therewith. A cylindrical projecting portion 26 is integrally formed in a substantially central portion of the frame bottom plate portion 24a so as to extend vertically upward. The central hole of the protruding portion 26 is an ink passage 27 communicating with the ink take-out hole 7. The rubber packing 8, the valve 9 and the coil spring 10 are attached to the ink passage 27, and the spring bearing 28 of the coil spring 10 is attached. It is integrally formed on the inner peripheral surface of the protruding portion 26.

The protruding portion 26 extends to a position lower than the first filter 11 by a predetermined distance,
The circular communication port 29 formed at the upper end is closed by the second filter 12.

Thus, in the ink tank 1 of this example,
An ink chamber 30 is formed between the foam container 5 and the ink outlet 7 by a cylindrical frame 22 having a rectangular cross section integrally formed with the container body bottom plate portion 21 and a cylindrical protruding portion 26 integrally formed inside thereof. It is compartmentalized. The ink chamber 30 communicates with the foam storage section 5 through a communication port 25 to which the first filter 11 is attached.
Further, the ink chamber 30 communicates with the ink passage 27 through a communication port 29 to which the second filter 12 is attached, and the lower end side of the ink passage 27 is connected to the ink extraction hole 7.

Thus, in the ink tank 1 of this example,
An ink chamber 30 is formed between the foam container 5 and the ink outlet 7 by a cylindrical frame 22 having a rectangular cross section integrally formed with the container body bottom plate portion 21 and a cylindrical protruding portion 26 integrally formed inside thereof. It is compartmentalized. The ink chamber 30 communicates with the foam storage section 5 through a communication port 25 to which the first filter 11 is attached.
Further, the ink chamber 30 communicates with the ink passage 27 through a communication port 29 to which the second filter 12 is attached, and the lower end side of the ink passage 27 is connected to the ink extraction hole 7. The first filter 11 of this example is made of a porous material that allows air bubbles to pass therethrough by the ink suction force acting on the ink extraction holes 7 while allowing the ink to pass therethrough. That is, it is made of a porous material having a pore size that causes a capillarity to destroy the meniscus by the ink suction force. The first filter 11 is formed of, for example, a non-woven fabric or a mesh filter.

On the other hand, the second filter 12 is made of a porous material having a pore size smaller than that of the first filter 11. The second filter 12 has a pore size capable of capturing foreign matter mixed in the ink. This second filter 12 can also be formed from a non-woven fabric or a mesh filter.

Here, the ink suction force is due to the ink suction force acting on the ink extraction hole 7 or the suction force of the ink pump due to the ink discharge pressure of the ink jet head (not shown) to which the ink is supplied.

Next, a cup-shaped cap 31 for sucking ink is arranged in the ink chamber 30 of this example. The cup-shaped cap 31 sucks up the ink accumulated at the bottom of the ink chamber 30 to the communication port 29 to which the second filter 12 located above is attached.

7A and 7B are a perspective view and a sectional view showing the cup-shaped cap 31. Explaining with reference to FIGS. 4 to 7, the cup-shaped cap 31 includes a cylindrical body portion 32 and a top plate portion 33 that closes the upper end opening, and the lower end opening 34 has a circular shape. On the end surface 35, a plurality of protrusions formed at predetermined angular intervals vertically project. In this example, four protrusions 36 having the same height are formed at intervals of 90 degrees. The inner peripheral surface of the cylindrical body portion 32 has a lower end-side inner peripheral surface portion 37 and a tapered inner peripheral surface portion 3 which continuously protrudes inward from the upper peripheral portion 37.
8 and a small-diameter upper end side inner peripheral surface portion 39 continuous to the upper side.

The cup-shaped cap 31 of this shape is attached to the cylindrical protruding portion 26 formed in the ink chamber 30 in a capped state from the upper side. The outer peripheral surface of the projecting portion 26 has a slightly larger large diameter outer peripheral surface portion 41 on the lower end side, and a smaller diameter outer peripheral surface portion 42 on the upper end side, and an annular step surface 43 is formed therebetween. There is. As shown in FIG. 6, the small-diameter outer peripheral surface portion 4
Ribs 44 protruding outward are formed at 2 at predetermined angular intervals. In this example, four ribs 44 are formed at intervals of 90 degrees, and these ribs 44 have the same protrusion amount and have a predetermined length in the vertical direction. The amount of protrusion of these ribs 44 is such that they are cup-shaped caps 31.
It is set so as to fit exactly into the outer peripheral surface portion 39 of the upper end.

When the cup-shaped cap 31 is capped on the projecting portion 26, the cup-shaped cap 31 is positioned by the four ribs 44, and four cups are provided between the inner peripheral surface of the cup-shaped cap 31 and the outer peripheral surface of the projecting portion 26. A gap 45 having an arcuate cross section for ink suction is formed. Further, the height dimension from the lower surface of the protrusion 36 formed on the circular end surface 35 at the lower end of the cup-shaped cap 31 to the back surface of the top plate portion 33 is set to be larger than the height dimension of the protruding portion 26 by a predetermined amount. . Therefore, in the capping state, a gap 46 for ink passage is formed at a predetermined interval between the second filter 12 attached to the upper end of the protruding portion 26 and the back surface of the top plate portion 33 of the cup-shaped cap 31. The gap 46 communicates with the gap 45. Further, in the capping state, four gaps 47 having a constant width and having an arc-shaped cross section are formed between the four protrusions 36 formed at the lower end of the cup-shaped cap 31. This arcuate cross section gap 4
7 communicates with the above-mentioned gap 45 having an arcuate cross section.

Here, by setting the gaps 45, 46, and 47 to appropriate widths, ink is sucked up from the gap 47 through the gap 45 and passes through the gap 46 and the second filter 12. As a result, an ink suction passage reaching the communication port 29 at the upper end of the protruding portion can be formed. By doing so, even when the amount of ink accumulated in the ink chamber 30 decreases and the liquid level becomes lower than that of the second filter 12, the ink in the ink chamber is sucked up to the position of the second filter 12. The ink can be supplied from the ink passage 27 to the ink outlet 7.

Further, in this example, the outer peripheral surface 32a of the cup-shaped cap 31 forms the ink chamber 30 and the cylindrical frame 22.
The inner side surface 22a is separated from the inner side surface 22a by a predetermined width. When the outer peripheral surface 32a of the cup-shaped cap 31 comes into contact with the inner side surface 22a of the cylindrical frame 22, the inside of the ink chamber is divided into the left and right with the contact position as a boundary, and the ink accumulated in the ink chamber can be efficiently sucked up. You may not be able to. In this example, the cup-shaped cap 31 can efficiently suck up the ink accumulated in the ink chamber.

Next, when the ink cartridge 11 is mounted on the tank mounting portion of the ink jet printer, as shown in FIG.
As shown in, the tip portion of the ink supply needle 61 arranged on the ink jet printer side is
Of the valve 9 located in the ink passage 27 through the through hole 8a of the rubber packing 8 attached to the ink take-out hole 7 of
Is pushed up.

As a result, since the ink take-out hole 7 is opened, the ink absorbed and held in the foam 6 in the foam container 5 of the ink tank 1 passes through the first filter 11 and the ink chamber 30. Flow into the ink passage 27, pass through the ink supply needle 61, and can be supplied to the inkjet head on the inkjet printer side. Since such an ink supply mechanism is known, further description will be omitted. Next, when the inkjet head is driven and ink is ejected, an ink suction force acts on the ink ejection hole 7 by the ink ejection pressure, and the ink is supplied toward the inkjet head. When the ink is supplied and the amount of the ink held in the foam 6 is reduced, air is introduced into the foam housing portion 5 through the atmosphere communication port 13 accordingly. As shown by the alternate long and short dash line in FIG. 4A, the ink impregnated in the foam 6 gradually decreases as the ink is consumed, and instead, bubbles enter the foam 6. When the amount of ink remaining in the foam 6 becomes small, air bubbles enter the ink chamber 30 through the first filter 11. Here, the second filter 12 partitioning between the ink chamber 30 and the side of the ink outlet 7 does not allow air bubbles to pass through. Therefore, air bubbles gradually accumulate inside the ink chamber 30.

When the amount of remaining ink is further reduced, the liquid level of the ink stored in the foam storage section 5 and the ink chamber 30 is gradually lowered. In the present invention, the cup-shaped cap 3
1 is used to form an ink suction mechanism for sucking up the ink accumulated in the bottom portion of the ink chamber 30 to the position of the second filter 12. Substantially all of the ink that has accumulated in the ink chamber 30 is sucked up and supplied to the inkjet head from the ink outlet hole 7, so that it is possible to take out the ink until there is substantially no ink in the ink chamber 30.

As described above, in the ink tank 1 of this embodiment, the cup-shaped cap 31 is used for the gap for sucking the ink to the second filter 12 located above the bottom of the ink chamber 30. To form a compartment.
Since such a gap for sucking ink is formed, the amount of ink remaining in the ink chamber 30 can be reduced and the efficiency of ink use can be improved.

In the above embodiment, since the capillary force of the ink absorber is not used, it is possible to suck up a large amount of ink, and it is possible to avoid running out of ink when ink is sucked. . Further, it is also possible to suppress variations in the ink suction amount due to variations in the ink supply amount (flow velocity) to the inkjet head side and the negative pressure condition in the ink tank. Further, in this example, the ink passage 27 communicating with the ink outlet hole 7 is projected inside the ink chamber 30, so that the components for detecting the ink end, which are formed therein, are made compact. There is an advantage that the increase of the installation space can be suppressed. Further, since the valve 9 and the coil spring 10 that close the ink outlet 7 are arranged in the ink passage 27, the ink outlet can be made compact.

Furthermore, although the ink tank structure of this example is an ink tank mounted in the ink jet printer, the head unit integrated with the head is also provided integrally with the ink jet printer. It can also be applied to things.

Further, in this example, the second filter 12 is provided, but when the ink tank is arranged at a position lower than the position of the ink jet head or when air bubbles enter the ink chamber 127. First filter 1
The second filter 12 can be omitted if the meniscus of No. 1 is restored by a slight ink of the foam.

Furthermore, if only the lower end of the cup-shaped cap 31 is dug deeper than the frame bottom plate portion 24a to form the bottom portion, the residual ink left behind in the bottom portion of the ink chamber can be further reduced.

[0044]

As described above, according to the present invention,
By forming the protruding portion inside the ink chamber and forming the ink passage communicating with the ink outlet hole inside this, there is an advantage that it can be formed without increasing the outer dimension of the ink tank.

Further, in the present invention, the ink suction gap is formed so that the ink accumulated in the bottom portion of the ink chamber is sucked up to the position of the second filter located above. Therefore, the residual ink in the ink chamber can be reduced, and the ink utilization efficiency can be improved.

[Brief description of drawings]

1A and 1B are a plan view and a front view showing an ink tank to which the present invention is applied.

FIG. 2 is a perspective view of the ink tank of FIG. 1 when viewed from the bottom side.

FIG. 3 is an exploded perspective view of the ink tank of FIG.

4A is a cross-sectional view of the ink tank when cut along line IV-IV in FIG. 1, and FIG. 4B is a partial cross-sectional view showing a state in which an ink supply needle is inserted.

5 is a cross-sectional view of the ink tank when cut along the line VV in FIG.

FIG. 6 is a cross-sectional view of the ink tank when cut along line VI-VI in FIG.

7A and 7B are a perspective view and a cross-sectional view showing a cup-shaped cap arranged in the ink chamber of the ink tank of FIG.

[Explanation of symbols]

1 ink tank 2 container body 3 Upper opening of container body 4 container lid 5 foam storage 6 forms 7 Ink removal hole 8 rubber packing 9 valves 10 coil spring 11 First filter 12 Second filter 13 atmosphere communication hole 21 Bottom plate of container body 27 ink passage 30 ink chamber 31 cup-shaped cap 32 torso 33 Top plate part 36 Protrusion 44 ribs 45 Gap for ink suction 46 Communication 47 Gap 61 Ink supply needle

Claims (11)

[Claims] 1. An ink chamber containing ink, an atmosphere communication hole communicating with the ink chamber, an ink take-out hole for taking out ink from the ink chamber, the ink chamber and the ink take-out hole. In the ink tank having an ink passage communicating with the ink passage, the ink passage includes a protruding portion protruding into the ink chamber, the leading end of the protruding portion is formed with the communication hole side communication port, and the protruding portion Equipped with a cap member for covering
By the ink suction force acting on the ink outlet,
An ink tank structure characterized in that the ink below is taken out from the communication hole side communication port. 2. The method according to claim 1, wherein a space between the projecting portion and the cap member extends in a direction opposite to a projecting direction of the projecting portion from the communication hole side communication port formed at a tip of the projecting portion. An ink tank structure characterized in that a gap for sucking ink is formed. 3. The ink tank according to claim 2, wherein a protrusion for forming the gap for sucking the ink is formed on an outer surface of the protruding portion and / or an inner surface of the cap member. Construction. 4. The ink tank structure according to claim 3, wherein the projection is a positioning projection for the cap member. 5. The ink according to claim 4, wherein the cap member is a cup-shaped cap, and the ink is provided between an opening end surface of the cup-shaped cap and a bottom surface of the ink chamber facing the opening end surface. An ink tank structure, characterized in that a communication portion that communicates with a suction gap is formed. 6. The ink tank structure according to claim 5, wherein the opening end surface of the cup-shaped cap is provided with a plurality of protrusions for forming the communication portion. 7. The ink tank structure according to claim 5, wherein an outer peripheral surface of the cup-shaped cap is separated from an inner surface of the ink chamber. 8. The valve body according to claim 1, wherein a valve body capable of closing the ink take-out hole and a spring member for pressing the valve body against the ink take-out port are arranged inside the protruding portion. Ink tank structure featuring. 9. The foam according to claim 1, wherein the foam absorbs and holds ink, the foam storage chamber in which the foam is stored, the atmosphere communication hole communicating with the foam storage chamber, and the foam storage chamber. An ink take-out hole for taking out ink, an ink chamber is defined by the foam storage chamber and the ink take-out hole, and by an ink suction force acting on the ink take-out hole,
An ink tank structure, wherein bubbles are introduced into the ink chamber from the side of the foam storage chamber to prevent the bubbles from advancing from the ink chamber to the ink outlet. 10. The first filter that partitions a foam-side communication port that communicates the foam storage chamber and the ink chamber with the ink chamber and the ink outlet hole according to claim 9. A second filter partitioning the outlet port side communication port, wherein the first filter is formed of a porous material through which air bubbles can pass by the ink suction force acting on the ink outlet port, The ink tank structure, wherein the second filter is formed of a porous material having a pore size smaller than that of the first filter. 11. The ink passage according to claim 10, further comprising an ink passage communicating between the ink chamber and the ink take-out hole, wherein the take-out hole side communication port is provided between the ink passage and the ink chamber. Ink tank structure characterized by being separated by a filter.