JPH08258277A - Ink jet recording device - Google Patents

Abstract

PURPOSE: To provide an ink jet unit simple in constitution and capable of hermetically closing the ink passages between a recording head and an ink tank. CONSTITUTION: A joining elastic member 22 is provided to the joined part of a recording head 21 and an ink tank 1. The protruding part of a manifold 23 is inserted in the joining elastic member 22 under pressure to hold the manifold 23 and the joining elastic member 22 to a hermetically closed state. The joining elastic member 22 has an almost funnel like shape. The joint part of the ink tank 1 is pressed by the joining elastic member 22 simultaneously with the mounting of the ink tank. At this time, the funnel-shaped part of the joining elastic member 22 is elastically deformed and the joining elastic member 22 is pressed to the surface of the joint part of the ink tank 1 to become a hermetically closed state. By this constitution, ink passages hermetically closed by the joined part are formed and the leakage of ink or the penetration of air can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording unit for ejecting ink for recording, and more particularly to an ink jet recording unit in which a recording head and an ink tank are detachable.

[0002]

2. Description of the Related Art In recent years, the range of equipment to which an ink jet recording apparatus is applied has become widespread, and many ink jet recording units in which a recording head and an ink tank can be separated have been introduced into the market.

In such a construction in which the recording head and the ink tank are separable, it is necessary to seal the ink flow path from the ink tank at the joint to the recording head when the ink tank is mounted. If this ink flow path is not completely sealed, ink leakage will occur, causing a great deal of damage to general users. In particular, when a part of the ink tank has a part containing only the ink liquid that does not use the capillary member, it is necessary to completely seal and join.

In many actual products, an O-ring is used as a means for joining an ink tank and a recording head and sealing an ink flow path through which ink flows from the ink tank to the recording head. As an example, JP-A-6-210
As described in Japanese Patent Publication No. 869, etc., a structure in which a valve is provided in an ink tank and an O-ring is used to seal the recording head and the ink tank is considered.

However, if the O-ring is used to seal the recording head and the ink tank,
A high pressing force is required to shut off and seal the joint portion from the outside air. Therefore, a force is required for attachment / detachment, and operability is poor. Furthermore, since a mechanism for generating a pressing force must be added, the structure itself becomes complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simple structure and can reliably seal the ink flow path between the recording head and the ink tank. On the contrary, it is an object of the present invention to provide an inkjet recording unit that can be easily separated and replaced.

[0007]

According to the present invention, there is provided an ink jet recording unit comprising a recording head having an ink ejecting portion for ejecting ink, and a detachable ink tank for supplying ink to the recording head. A substantially funnel-shaped joining member made of an elastic body is provided at a joining portion of the ink flow path of the ink tank.

The joint member is provided on the side of the recording head as in the second aspect of the invention, and is pressed against the surface of the ink tank when the ink tank is mounted so that the joint portion of the ink flow path is formed. It can be configured to be hermetic. Alternatively, as in the invention described in claim 3,
The joining member may be provided on the ink tank side, and the joining portion of the ink flow path may be sealed by being pressed against the surface of the recording head when the ink tank is mounted. The joining member can be made of chlorinated butyl rubber as in the invention according to claim 4.

[0009]

According to the present invention, a substantially funnel-shaped joining member made of an elastic material is provided at the joining portion of the ink flow path between the recording head and the ink tank, and the joining member is used as the recording head or the ink tank. The airtightness can be obtained only by a simple structure in which the air is pressed against the surface of the ink, and it is possible to prevent ink leakage and prevent air from entering from the outside. At this time, the pressing force for pressing the joining member against the surface of the recording head or the ink tank may be small, and the ink flow path can be sealed by a simple operation. Further, since the pressing force is small, the ink tank can be easily separated and replaced.

[0010]

FIG. 1 is a sectional view showing an embodiment of an ink jet recording unit of the present invention, and FIG. 2 is an enlarged view of the vicinity of a joint portion. In the figure, 1 is an ink tank, 2 is a main ink chamber, 3 is a capillary member, 4 is an intermediate ink chamber, 5 is a communication passage, 6 is an atmosphere communication port, 7 is a communication hole, 8 is a first meniscus forming member, Reference numeral 9 is an ink supply unit, 10 is a second meniscus forming member, 11 is a joint port, 12 is a fitting protrusion, and 1 is a fitting protrusion.
3 is a convex portion, 21 is a recording head, 22 is a joining elastic member, 2
3 is a manifold, 24 is an ink supply pipe, 25 is a recording chip, 26 is a filter, 27 is a holding member, 28 is a claw part,
29 is a spring member.

The ink jet recording unit comprises an ink tank 1 and a recording head 21. The recording head 21 is fixed to, for example, a carriage of a recording device. Further, the ink tank 1 is detachably attached to the recording head 21.

The ink tank 1 is provided with a fitting projection 12 and a convex portion 13. On the other hand, the holding member 27 that constitutes a part of the recording head 21 is provided with a claw portion 28 and a spring member 29. Fitting protrusion 12 of ink tank 1
Is engaged with the claw portion 28, and the convex portion 13 is locked by the spring member 29, so that the ink tank 1 is fixed to the recording head 21. At this time, due to the elastic force of the spring member 29, the ink tank 1 has some pressing force against the recording head 21. At the time of attachment / detachment, the ink tank 1 can be removed by releasing the engagement between the spring member 29 and the convex portion 13 and disengaging the claw portion 28 from the fitting protrusion 12.

A main ink chamber 2 is provided inside the ink tank 1.
And an intermediate ink chamber 4 is provided on the side of it. A communication hole 7 is provided in the lower portion of the main ink chamber 2, and communicates with the intermediate ink chamber 4 and the joint port 11 via the communication passage 5. When the ink tank 1 is mounted, it is connected to the recording head 21 at the joint port 11, the ink in the main ink chamber 2 passes through the communication passage 5, and the joint port 11
Is supplied to the recording head 21 via the.

The bottom surface of the main ink chamber 2 is formed as an inclined surface with the communication hole 7 as the lowest portion. Further, the communication passage 5 is also configured such that the joint port 11 is the lowest portion and gradually becomes higher toward the intermediate ink chamber 4. Main ink chamber 2
A capillary member 3 is arranged inside the. This capillary member 3 holds ink by a capillary force and maintains a negative pressure in the recording head. At the upper part of the main ink chamber 2, there is provided an atmosphere communication port 6 capable of communicating with the capillary member 3 in the atmosphere. This atmosphere communication port 6 allows the capillary member 3
Communicates with the atmosphere above it and is open to atmospheric pressure.
At the time of supplying the ink to the recording head 21, the ink in the capillary member 3 is pushed by the atmospheric pressure and is drawn out from below the capillary member 3 to the communicating path 5 side by the negative pressure, so that the ink in the capillary member 3 is efficiently discharged. Can be used.
At this time, the negative pressure in the print head is kept constant by the capillary force of the capillary member 3.

A communication hole 7 provided on the bottom surface of the main ink chamber 2.
The first meniscus forming member 8 is arranged in the.
The bottom of the capillary member 3 is arranged in pressure contact with the first meniscus forming member 8. When the capillary member 3 is impregnated with ink, the ink passes through the first meniscus forming member 8 and moves to the intermediate ink chamber 4. The first meniscus forming member 8 prevents unnecessary air from entering the intermediate ink chamber 4 even when the capillary member 3 runs out of ink. When the ink is further consumed, the air that has entered from the atmosphere communication port 6 passes through the capillary member 3 and the main ink chamber 2
Due to the increase of the negative pressure in the inside, the meniscus of the ink stretched in the fine pores formed in the first meniscus forming member 8 in contact with the capillary member 3 is pushed to overcome the surface tension and pass therethrough to form bubbles. Become. The generated bubbles move to the intermediate ink chamber 4 through the communication passage 5. At this time, communication passage 5
The inclination of allows the bubbles generated in the communication hole 7 to be smoothly moved to the intermediate ink chamber 4.

The ink supply section 9 is in contact with the lower surface of the first meniscus forming member 8 and extends to the bottom surface of the communication passage 5. Alternatively, it may be configured as a part of the first meniscus forming member 8. The ink supply section 9 has a cross-sectional dimension smaller than the diameter of the communication hole 7. When air bubbles are accumulated on the lower surface of the first meniscus forming member 8 to form an air layer, or when the ink in the main ink chamber 2 is exhausted and the liquid level of the ink is lower than the height of the communication passage 7,
The ink supply unit 9 sucks the ink from the bottom of the communication path 5 and supplies the ink to the first meniscus forming member 8, so that the first meniscus forming member 8 is always kept in a wet state and the negative pressure is maintained. be able to. As a result, the best state can be maintained until the ink is used up.

The intermediate ink chamber 4 is initially filled with ink. Then, the bubbles that pass through the first meniscus forming member 8 from the main ink chamber 2 and enter the communication passage 5 are accumulated. After the ink in the main ink chamber 2 is exhausted, the accumulation of bubbles increases according to the amount of ink used,
It is also possible to detect ink shortage based on the amount of bubbles in the intermediate ink chamber 4.

The joint port 11 is provided with a second meniscus forming member 10. In a state where the ink tank 1 is removed and left to stand, the surface tension of the ink formed in the fine holes provided in the second meniscus forming member 10 causes the intermediate ink chamber 4 and the communication passage 5 to be formed.
The ink inside does not leak from the joint port 11. Further, when the ink tank 1 is attached to the recording apparatus, the air remaining in the joint port 11 due to the pressure at the time of attachment passes through the ink film of the second meniscus forming member 10 and moves to the intermediate ink chamber 4. Let for that reason,
It is possible to reduce bubbles from entering the recording head 21. Further, when the ink tank 1 is installed, vibration and impact applied to the ink tank 1, pressure fluctuation due to acceleration, and inclusion of bubbles from the nozzle side of the print head are prevented.

A joint elastic member 22 is provided at the joint of the recording head 21 with the ink tank 1. The convex portion of the manifold 23 is press-fitted into the joining elastic member 22. Thereby, the airtightness between the manifold 23 and the joining elastic member 22 is maintained. The joint elastic member 22 has a substantially funnel shape. By bringing this funnel-shaped portion into contact with the surface of the ink tank 1, the outer surface is kept sealed. The opening shape of the funnel-shaped portion can be substantially circular. Of course, other shapes such as a rectangle and an ellipse may be used. Chlorinated butyl rubber is preferable as the material of the bonding elastic member 22 because of its low air permeability, and a rubber hardness of about 60 ° is suitable for sealing. In addition, materials having various ink resistances such as silicone rubber having a rubber hardness of about 50 ° can be used. The thickness of the funnel-shaped part is
Desirably, if it is about 0.5 mm, it is easy to contact the surface of the ink tank 1. Since the sealing is performed by the funnel-shaped portion as described above, it can be easily estimated that the sealing can be performed even when the pressing force of the ink tank 1 and the recording head 21 is small. In addition, the elastic member 2 is joined to the ink tank 1 side.
Even if 2 is provided, sealing can be performed similarly.

The recording head 21 is composed of a holding member 27 of the ink tank 1 and a manifold 22 provided with a joint elastic member 22. Manifold 2
3, a print chip 25, an ink supply pipe 24 for supplying ink to the print chip 25, a filter 26 for trapping dust, and the like are integrally formed. In addition, the holding member 27 includes the claw portion 28 and the spring member 2 as described above.
9 are provided. The claw portion 28 fits with the fitting member 12 of the ink tank 1. Further, the spring member 29 locks the convex portion 13 of the ink tank 1 and applies a pressing force to the ink tank 1 by its elastic force. According to experiments, the pressing force of the spring member 29 is preferably about 200 gf to keep the airtightness.

The ink in the ink tank 1 is transferred to the recording head 2
To fill 1 into the cartridge, suction is performed from the print chip 25. At this time, since the inside of the ink supply pipe 24 has a negative pressure, a force acts on the funnel-shaped portion of the joint elastic member 22 in the direction of contacting the surface of the ink tank 1, that is, in the sealing direction.
No ink leaks.

FIG. 3 is an explanatory view of a state of using ink in one embodiment of the ink jet recording unit of the present invention. When recording is started, the ink in the main ink chamber 2 is supplied from the communication hole 7 through the communication path 5 to the recording head 21 through the joint port 11. The ink supplied to the recording head 21 passes through the joint between the ink tank 1 and the recording head 21. As described above, the joint portion has the joint elastic member 22.
Since the airtightness is maintained by, the ink does not leak out or the air does not enter. The ink that has passed through this joint passes through the filter 26 and is supplied from the ink supply pipe 24 to the recording chip 25.

As the ink moves, air gradually enters the main ink chamber 2 through the air communication port 6 and spreads inside the capillary member 3. At this time, due to the capillary force of the capillary member 3,
Ink is supplied to the recording head 21 at a stable negative pressure.
FIG. 3A shows a state in which the ink has been consumed to some extent.

When the ink held in the capillary member 3 is almost consumed, the air reaches the surface of the first meniscus forming member 8. When the ink is further consumed, a certain negative pressure value (the bubble point pressure of the ink determined by the filtration accuracy of the first meniscus forming member 8) is applied to the first meniscus forming member 8 and the first meniscus forming member 8 is formed. Air becomes bubbles through the meniscus of the ink formed on the forming member 8 and moves to the communication path 5. The bubbles that have moved to the communication passage 5 move to the intermediate ink chamber 4 along the slope of the communication passage 5 and are accumulated there. The negative pressure in the communication path 5 is alleviated by the amount of the bubbles that have moved to the intermediate ink chamber 4, and the negative pressure in the recording head 21 is maintained. This state is shown in Figure 3.
It shows in (B). This operation is repeated, and the intermediate ink chamber 4
And the ink in the communication passage 5 is consumed, and finally becomes an empty state.

In the state shown in FIG. 3B, both surfaces of the first meniscus forming member 8 are exposed to air. Further, even in the state shown in FIG. 3A, the mixed air bubbles may rarely cover the surface of the first meniscus forming member 8. In such a case, ink meniscus formation may not be formed on the first meniscus formation member 8. However, since the ink supply unit 9 is provided in contact with the first meniscus forming member 8, the ink is supplied to the first meniscus forming member 8 by the capillary force of the ink supplying unit 9. Therefore, the first meniscus forming member 8 is always in a wet state, the formation of the meniscus can be maintained, and stable negative pressure can be maintained to perform good recording.

Further, in the state of FIGS. 3A and 3B, even when the ink tank 1 is removed, the second meniscus forming member 8 having a finer opening than that of the first meniscus forming member 8 is formed.
Since the meniscus forming member 10 is provided, the ink is held by the meniscus of the second meniscus forming member 10, and the negative pressure inside the ink tank 1 is kept constant.
No ink leakage occurs. This constitutes a removable ink tank.

FIG. 4 is a perspective view in which the entire construction of a specific example of the ink jet recording head unit of the present invention is disassembled into its constituent portions, and FIG. 5 is a three-sided view of the same manifold portion. 5 (A), (B), and (C) show the states shown in the A direction, B direction, and C direction in the assembled state of the manifold portion in the configuration shown in FIG. 4, respectively. . In the figure, the same parts as those in FIG. Reference numeral 31 is a manifold member, 32 is a joint member, 33 is a printed circuit board, 34 is a front hat, 35 is an ink introducing portion, 41 is a concave portion, 42 is a claw portion, and 43 is a hole portion. In this specific example, an example in which the present invention is applied to a color printer using a plurality of colors of ink is shown. Here, three colors of ink are used. The holding member 27 is not shown in FIGS. 4 and 5.

The joint member 3 is attached to the manifold member 31.
2 are joined and attached to the printed circuit board 33. The head chip 25 is attached to the printed circuit board 33, and the front hat 34 is attached to the ink ejection surface side. The ink tank 1 is detachably attached from above the joint member 32, and the ink supplied from the ink tank 1 is supplied to the recording chip 25 through the manifold 23.

Three ink tanks 1 are provided, and ink of each color is supplied. As the colors to use,
For example, cyan, magenta, and yellow. Of course, it is not limited to this color. It is also possible to use four colors including black, or to use two colors or five or more colors. In that case, it is sufficient to use ink tanks of the number of colors. . The present invention can be similarly configured in a recording apparatus that records only one color.

The joint member 32 has three ink introducing portions 35 so as to be connected to the ink tanks of the respective colors. A filter 26 and a joint elastic member 22 are provided in each ink introducing portion 35. The joint elastic member 22 is mounted so that the convex portion of the ink introducing portion 35 is press-fitted. As a result, the ink introduction portion 35 and the joint elastic member 22 are kept sealed, and ink leakage and air intrusion at this portion are prevented. The joint elastic member 22 is mounted so that its substantially funnel-shaped opening faces the side on which the ink tank 1 is mounted.

As the three ink tanks 1 are mounted, the joint portions of each ink tank 1 are pressed against the corresponding joint elastic members 22. At this time, the funnel-shaped portion of the joining elastic member 22 is elastically deformed, the joining elastic member 22 is pressed against the surface of the joint portion of each ink tank 1 to be in a hermetically sealed state, and a sealed ink flow path is formed in the joining portion. To be done.

The manifold member 31 is provided with a recess 41 that forms an ink supply path for each color, and the joint member 32 is joined from above by an adhesive to form the ink supply path. In this embodiment, the joint member 32 is provided with the claw portion 42, and is engaged with the hole portion 43 of the manifold member 31 to generate a coupling force. Thereby, while the adhesive is solidified, the manifold member 31 and the joint member 32 can be easily coupled without being fixed from the outside. The ink supply path thus formed supplies the recording chip 25 with the ink introduced from the ink introducing section 35 via the filter 26.

The printed board 33 includes a board provided with wirings for supplying electric power and control signals to the recording chip 25, signals of images to be recorded, etc., and a heat sink for radiating heat generated by the recording chip 25. It is composed of an integrated metal substrate. A drive circuit or the like for driving the heating element may be provided in accordance with the image to be recorded. The printed board 33 and the recording chip 25 are electrically connected by, for example, wire bonding.

In the above-mentioned embodiments and concrete examples,
Although the bonding elastic member 22 is provided on the recording head 1 side, the invention is not limited to this and may be provided on the ink tank 1 side.
In this case, the joint portion on the recording head 1 side may be provided with a flat surface so as to be sealed by the pressure contact of the joint elastic member 22.

[0035]

As is apparent from the above description, according to the present invention, a funnel-shaped joining elastic member made of an elastic body is provided at the connecting portion between the recording head and the detachable ink tank. Therefore, it is possible to prevent ink from leaking from the connecting portion between the recording head and the ink tank and mixing of air with a simple operation of mounting the ink tank. Further, since the airtight connection by the joining elastic member is stable, it does not adversely affect the print quality and the like. Further, since this closed state is realized by only a small pressing force, it is easy to remove not only when the ink tank is attached, but also the ink tank can be easily replaced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an inkjet recording unit of the present invention.

FIG. 2 is an enlarged view of the vicinity of a joint portion in an embodiment of the inkjet recording unit of the present invention.

FIG. 3 is an explanatory diagram of an ink using state in an embodiment of the inkjet recording unit of the present invention.

FIG. 4 is a perspective view in which the entire configuration of a specific example of the inkjet recording head unit of the present invention is disassembled into its constituent parts.

FIG. 5 is a three-sided view of a portion of a manifold in a specific example of the inkjet recording head unit of the present invention.

[Explanation of symbols]

1 ... Ink tank, 2 ... Main ink chamber, 3 ... Capillary member,
4 ... Intermediate ink chamber, 5 ... Communication passage, 6 ... Atmosphere communication port, 7 ...
Communication holes, 8 ... First meniscus forming member, 9 ... Ink supply part, 10 ... Second meniscus forming member, 11 ... Joint port, 12 ... Fitting protrusion, 13 ... Convex part, 21 ... Recording head, 22 ... Joint elastic member, 23 ... Manifold, 24 ...
Ink supply pipe, 25 ... Recording chip, 26 ... Filter, 2
7 ... Holding member, 28 ... Claw portion, 29 ... Spring member, 31 ... Manifold member, 32 ... Joint member, 33 ... Printed circuit board, 34 ... Front hat, 35 ... Ink introduction section,
41 ... concave part, 42 ... claw part, 43 ... hole part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Takagi 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Junichi Yoshida, 2274 Hongo, Ebina City, Kanagawa Prefecture, Fuji Xerox Co., Ltd. (72) Inventor Naruo Kawauchi 1-4-25 Kita-no-cho, Atobe, Yao-shi, Osaka Prefecture Nishiki Castle Guard Co., Ltd. (72) Inventor Takehiko Noda 1-4-25, Kita-cho, Yabu-shi, Osaka Prefecture Nishiki Castle Guard Co., Ltd.

Claims (4)

[Claims] 1. An inkjet recording unit comprising a recording head having an ink ejecting section for ejecting ink and a detachable ink tank for supplying the ink to the recording head, wherein an ink flow path of the recording head and the ink tank is formed. An ink jet recording unit having a substantially funnel-shaped joining member formed of an elastic body at the joining portion. 2. The joint member is provided on the recording head side, and is pressed against the surface of the ink tank when the ink tank is mounted to seal the joint portion of the ink flow path. Item 2. The inkjet recording unit according to Item 1. 3. The joint member is provided on the ink tank side, and is pressed against the surface of the recording head when the ink tank is mounted to seal the joint portion of the ink flow path. Item 2. The inkjet recording unit according to Item 1. 4. The ink jet recording unit according to claim 1, wherein the joining member is made of chlorinated butyl rubber.