JPH0985961A - Ink-jet recording unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording unit which is simple in structure and closes reliably an ink flow passage between a recording head and an ink tank, facilitates mounting and demounting of them, and improves reliability by reducing residual air in a junction and improving filling properties of ink. SOLUTION: An elastic member 22 for junction, having a plate part and a substantially shade-shaped part having an opening, is provided at a junction of a recording head 21 with an ink tank 1. The shade-shaped part of the elastic member 22 for junction is pressed inward to be elastically deformed concurrently with the mounting of the ink tank 1. With this arrangement, a closed ink flow passage is formed. In this course, the shade-shaped part abuts against the plate part, and the stay of air in the ink flow passage can be prevented. A protrusion or a groove is provided in advance at the portion between the shade-shaped part and the plate part, whereby at the time when the shade-shaped part abuts against the plate part, both the parts can also be prevented from being junctioned.

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 that ejects 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.

To solve such a problem, for example,
In Japanese Patent Application No. 7-60456, it has been proposed to join the recording head and the ink tank by using an approximately funnel-shaped joining elastic member. However, for example, when the joining elastic member is attached to the recording head side and the ink tank is pressed and attached, since the area of the connection portion between the substantially funnel-shaped joining elastic member and the ink tank is large, the joining surface of the ink tank is A large amount of ink adheres. Therefore, when the ink tank is removed before the ink tank is empty, there is a problem that the ink attached to the joint surface of the joint elastic member of the ink tank drips.

In order to solve this, it has been considered that the joining elastic member is formed in an inverted funnel shape, that is, in a substantially umbrella shape in which the opening extends from the bottom. This reduces the area where the joint surface of the ink tank is exposed to the ink flow path, reduces the amount of ink that adheres to the ink tank when the ink tank is removed, and prevents ink dripping. But,
If only such a shape is used, air will remain in the wide portion formed inside the substantially umbrella-shaped portion of the joining elastic member when the ink tank is attached, and if printing is continued in this state, the remaining air will remain. As a result, there is a problem in that the nozzle is clogged and a printing defect occurs.

[0008]

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 ink jet recording unit that can be easily separated and replaced and that has improved reliability by reducing the air remaining in the joint portion and improving the ink filling property. .

[0009]

According to a first aspect of 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 the ink to the recording head. In the above, a joining member formed of an elastic body is provided at a joining portion of the ink flow path of the recording head and the ink tank, and the joining member has an umbrella-shaped portion having an opening formed at the top and a central portion at the center. A flat plate portion having an opening is formed, and the umbrella-shaped portion and the flat plate portion are configured to have a substantially ∠-shaped cross section.

According to a second aspect of the present invention, in the ink jet recording unit according to the first aspect, a plurality of protrusions are provided on one of opposing surfaces of the umbrella-shaped portion and the flat plate portion of the joining member. It is characterized by that.

According to a third aspect of the present invention, in the ink jet recording unit according to the first aspect, a plurality of groove portions are provided on one of opposing surfaces of the umbrella-shaped portion and the flat plate portion of the joining member. It is characterized by that.

According to a fourth aspect of the invention, in the ink jet recording unit according to any one of the first to third aspects, the joint member is provided on the recording head side, and the joint member and the ink tank are provided. At the time of joining, the corner portions of the peripheral edge of the opening formed in the umbrella-shaped portion of the joining member come into contact with the ink tank.

[0013]

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 portion, 10 is a second meniscus forming member, 11 is a joint port, 12 is a fitting protrusion, 13 is a convex portion, 14 is a concave portion, 21 is a recording head, 22 is a joining elastic member, 23 is a manifold, 24 is an ink supply pipe, 25 is a recording chip, 26 is a filter, 2
Reference numeral 7 is a holding member, 28 is a claw portion, and 29 is a spring member.

This 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.

Inside the ink tank 1, the main ink chamber 2
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 recess 14 is formed on the outer surface of the joint opening 11. When the ink tank 1 is mounted, the joint elastic member 22 comes into contact with the recess 14 to form an ink flow path. Therefore, the recess 14 gets wet with the ink with the ink tank 1 attached. When the ink tank 1 is removed, ink is attached to the concave portion 14, but the removed ink tank 1
However, even if the ink is placed on a desk or the like, since the recess 14 does not allow the ink to come into contact with the desk or the like, a problem such as stain on the desk or the like does not occur.

The recording head 21 is composed of a holding member 27 of the ink tank 1 and a manifold 23 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.

A joint elastic member 22 is provided at the joint of the recording head 21 with the ink tank 1. The joint elastic member 22 is press-fitted into the convex portion of the manifold 23. Thereby, the manifold 23 and the joining elastic member 2
The two seals are kept.

FIG. 3 is a sectional view showing an example of the joining elastic member in the embodiment of the ink jet recording unit of the present invention. In the figure, 31 is an umbrella portion, 32 is a flat plate portion, 3
3 is a corner portion and 34 is a protrusion. The joint elastic member 22 has a substantially umbrella-shaped umbrella-shaped portion 31 having an opening formed at the top and a wide inside, and a flat plate portion 22 having an opening at the center. The umbrella-shaped portion 31 has a shape in which the upper portion is narrowed so that the opening has the smallest diameter, and the cross section thereof has a substantially V-shape.
The corner portion 33 at the peripheral edge of the opening of the umbrella-shaped portion 31 abuts on the surface of the concave portion 14 of the ink tank 1 to maintain a hermetic seal with the outside. Since the opening is small, the concave portion 14 of the ink tank 1
When this part abuts and an ink flow path is formed,
The area of the recess 14 that comes into contact with ink can be reduced. Therefore, when the ink tank 1 is removed, the amount of ink that adheres to the recess 14 can be kept to a small amount, and the ink that adheres to the ink tank 1 can be prevented from dripping. The opening shape of the umbrella-shaped portion 31 may be substantially circular. Of course, other shapes such as a rectangle and an ellipse may be used.

The flat plate portion 32 is a donut-shaped plate-like portion having an opening serving as an ink flow path in the center thereof. The flat plate portion 32 is provided near the base of the umbrella-shaped portion 31,
The umbrella-shaped portion 31 and the umbrella-shaped portion 31 are formed so as to have a substantially ∠-shaped cross section. In the case of only the umbrella-shaped portion 31, air may stay inside the umbrella-shaped portion 31 when the ink tank 1 is attached, which may cause a printing defect. To prevent.

When the concave portion 14 of the ink tank 1 comes into contact with the joint elastic member 22, the corner portion 33 of the opening of the joint elastic member 22.
Slips on the surface of the concave portion 14 of the ink tank 1, and the umbrella-shaped portion 31 of the joint elastic member 22 elastically deforms inward so that the ink tank 1
And close the ink flow path. The elastic deformation of the umbrella-shaped portion 31 of the joint elastic member 22 can be performed with a small force, and the ink flow path can be sealed even if the pressing force of the ink tank 1 and the recording head 21 is small.
Further, when the ink tank 1 is mounted, the umbrella-shaped portion 31 is deformed inward and comes into contact with the ink tank 1 as shown in FIG. It is possible to minimize unnecessary ink that adheres to the ink tank 1 when the ink is removed. Therefore, dripping of ink does not occur when the ink tank 1 is removed.

When the ink tank 1 is mounted, the umbrella-shaped portion 31 and the flat plate portion 32 are in contact with each other as shown in FIG. This eliminates the extra space inside the umbrella-shaped portion 31, and the air remaining inside the umbrella-shaped portion 31 is pushed out. Therefore, defective ejection of ink due to air can be avoided, and good image quality can be maintained.

By mounting the ink tank 1, the umbrella-shaped portion 31
After the flat plate portion 32 and the flat plate portion 32 come into contact with each other, the minute gap is filled with ink. Then, the capillarity of the ink may join the umbrella-shaped portion 31 and the flat plate portion 32. In such a case, when the ink tank 1 is removed or the ink tank 1 is attached, the umbrella-shaped portion 31 does not return after being pressed. In such a state, the umbrella-shaped portion 3
It becomes impossible to obtain a sufficient elastic force of 1 to contact the surface of the ink tank 1, and the adhesion between the ink tank 1 and the umbrella-shaped portion 31 deteriorates, which causes ink leakage and the like. In this example, as shown in FIG. 3, a protrusion 34 is provided on the umbrella-shaped portion 31 to avoid joining of the umbrella-shaped portion 31 and the flat plate portion 32.

Further, since the projection 34 is also elastically deformable, when the ink tank 1 is pressed against the joining elastic member 22 when the ink tank 1 is attached or detached, the projection 34 is projected together with the umbrella-shaped portion 31 and the flat plate portion 32. 34 can also be elastically deformed so that the ink tank 1 can be easily attached to and detached from the locking mechanism. Even if a large pressure is applied when the ink tank 1 is mounted, the umbrella-shaped portion 3
1, the flat plate portion 32, and the protrusion 34 function as a damper, so that a sudden pressure applied to the recording head 21 can be relieved. As a result, it is possible to prevent positional deviation of the recording head 21.

The material of the joint elastic member 22 is desired to have low air permeability and high surface smoothness. When the surface smoothness is high, when it comes into contact with the concave portion 14 of the ink tank 1, it slips on the surface and good elastic deformation is possible. From this, for example, chlorinated butyl rubber is suitable,
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 wall thickness of the umbrella-shaped portion 31 is preferably 0.5 mm.
If the degree is small, the surface of the ink tank 1 is easily contacted.

FIG. 4 is a sectional view showing another example of the joining elastic member in the embodiment of the ink jet recording unit of the present invention. In the figure, 35 is a groove. Instead of the protrusion 34 shown in FIG. 3, a groove 35 may be provided as shown in FIG. The groove portion 35 weakens the capillary force of the ink that has entered between the umbrella-shaped portion 31 and the flat plate portion 32, so that the umbrella-shaped portion 31 and the flat plate portion 32 can be easily separated.

Although the projection 34 or the groove 35 is provided on the umbrella-shaped portion 31 side in FIGS. 3 and 4, the invention is not limited to this.
It may be provided in a portion of the flat plate portion 32 with which the umbrella-shaped portion 31 abuts.

FIG. 5 is an explanatory view of the ink use state in the 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. This joint portion is the joint elastic member 2 as described above.
Since the airtightness is maintained by 2, the ink does not leak 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 into 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. 5A 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 5.
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. 5B, both surfaces of the first meniscus forming member 8 are exposed to air. Even in the state shown in FIG. 5A, 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. 5A and 5B, even if the ink tank 1 is removed, the second meniscus forming member 8 having a finer opening than 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. Further, since the joint elastic member 22 has a substantially umbrella shape and is elastically deformed inward,
Less ink adheres to the concave portion 14 of the ink tank 1,
Ink dripping does not occur. Further, since the joining elastic member 22 and the ink tank 1 are joined in the recess 14, even when the removed ink tank 1 is placed on, for example, a desk or the like, the ink attached to the recess 14 does not affect the desk or the like. There is no stain. Thereby, the ink tank can be attached and detached favorably.

FIG. 6 is a perspective view in which the entire structure of a specific example of the ink jet recording head unit of the present invention is disassembled into its constituent parts, and FIG. 7 is a three-sided view of the same manifold part. 7 (A), (B), and (C) show states of the configuration shown in FIG. 6 as viewed from the A direction, B direction, and C direction in the assembled state of the manifold portion. . In the figure, the same parts as those in FIG. Reference numeral 41 is a manifold member, 42 is a joint member, 43 is a printed circuit board, 44 is a front hat, 45 is an ink introducing portion, 51 is a groove portion, 52 is a claw portion, and 53 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. 6 and 7, the holding member 27 is not shown.

The joint member 4 is attached to the manifold member 41.
2 are joined and attached to the printed circuit board 43. The head chip 25 is attached to the printed circuit board 43, and the front hat 44 is attached to the ink ejection surface side. The ink tank 1 is detachably attached from above the joint member 42, 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. The colors used are:
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. . When black is used, the ink flow path for black can be made larger than that for other colors due to the difference in the amount used with other colors. The present invention can be similarly configured in a recording apparatus that records only one color.

The joint member 42 has three ink introducing portions 45 so as to be connected to the ink tanks of the respective colors. A filter 26 and a joining elastic member 22 are provided in each ink introducing portion 45. The joint elastic member 22 is mounted so that the convex portion of the ink introducing portion 45 is press-fitted. As a result, the ink introducing portion 45 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 the opening of the umbrella-shaped portion 31 faces the side on which the ink tank 1 is mounted.

When the three ink tanks 1 are mounted, the recesses provided in the joint portions of the respective ink tanks 1 are pressed by the corresponding joint elastic members 22. At this time, the corner portion 33 of the joint elastic member 22 abuts the surface of the recess of each ink tank 1 and the umbrella-shaped portion 31 elastically deforms inward, forming a sealed ink flow path at the joint portion.

The manifold member 41 is provided with a groove 51 for forming an ink supply path for each color, and the joint member 42 is joined from above by an adhesive to form the ink supply path. In this embodiment, the joint member 42 is provided with the claw portion 52, which engages with the hole portion 53 of the manifold member 41 to generate a coupling force. Accordingly, while the adhesive is solidified, the manifold member 41 and the joint member 42 can be easily coupled without being fixed from the outside. The ink supply path formed in this manner supplies the ink introduced from the ink introduction unit 45 to the recording chip 25 via the filter 26.

The printed board 43 includes a board provided with wirings for supplying electric power and control signals to the recording chip 25, signals of images to be recorded, and the like, and a heat sink for radiating heat generated by the recording chip 25. It is composed of an integrated metal substrate. A driving circuit or the like for driving the heating element in accordance with an image to be recorded may be provided. The printed board 43 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 having a high circumference so as to be sealed by the pressure contact of the joint elastic member 22. Even with such a configuration, the ink flow path can be sealed, and the umbrella-shaped portion 31 and the flat plate portion 32 can be sealed.
The close proximity to each other can prevent air from staying. Further, since the shape of the joint elastic member 22 is reduced toward the opening, the ink remaining in the joint elastic member 22 can be minimized and the ink dripping can be minimized.

[0047]

As is apparent from the above description, according to the present invention, the joint elasticity having the umbrella-shaped portion and the flat plate portion made of the elastic body is provided at the joint portion of the recording head and the detachable ink tank. Since a member is provided, the airtightness of the joint between the recording head and the ink tank can be obtained with a simple operation of mounting the ink tank, and it is possible to prevent ink leakage and air mixing from this joint and It is possible to prevent air from staying in the elastic member, prevent defective ink ejection, and always obtain good image quality. At this time, by providing a protrusion or a groove between the umbrella-shaped portion and the flat plate portion, it is possible to prevent the umbrella-shaped portion and the flat plate portion from being joined to each other, and to stabilize the hermetic coupling between the ink tank and the joining elastic member. it can.
Furthermore, 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 the joint portion in the embodiment of the inkjet recording unit of the present invention.

FIG. 3 is a cross-sectional view showing an example of a joining elastic member in an embodiment of the inkjet recording unit of the present invention.

FIG. 4 is a cross-sectional view showing another example of the joining elastic member in the embodiment of the inkjet recording unit of the present invention.

FIG. 5 is an explanatory diagram of an ink using state in the embodiment of the inkjet recording unit of the present invention.

FIG. 6 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. 7 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 portion, 10 ... Second meniscus forming member, 11 ... Joint port, 12 ... Fitting protrusion, 13 ... Convex portion, 14 ... Recessed portion, 2
DESCRIPTION OF SYMBOLS 1 ... Recording head, 22 ... Joining elastic member, 23 ... Manifold, 24 ... Ink supply pipe, 25 ... Recording chip, 26 ...
Filter, 27 ... Holding member, 28 ... Claw portion, 29 ... Spring member, 31 ... Umbrella portion, 32 ... Flat plate portion, 33 ... Corner portion, 34 ...
Projection, 35 ... Groove portion, 41 ... Manifold member, 42 ... Joint member, 43 ... Printed circuit board, 44 ... Front hat, 45 ... Ink introducing section, 51 ... Groove section, 52 ... Claw section,
53 ... hole.

Front Page Continuation (72) Inventor Katsuyuki Fujii 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72) Inventor Katsuhide Ogawa 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72) Inventor Yoshida Junichi 2274 Hongo, Ebina City, Kanagawa Prefecture Fuji Xerox Co., Ltd. (72) Inventor Naruo Kawauchi 1-4-25, Kita-no-cho, Ruins of Yao City, Osaka Pref. Nishiki Castle Guards Co., Ltd. (72) Takehiko Noda Yao, Osaka Prefecture 1-4-25, Kitanomachi, Ruins of City

Claims (4)

[Claims] 1. An ink jet recording unit comprising a recording head having an ink ejection portion 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. A joint member formed of an elastic body is provided at the joint portion, and the joint member has an umbrella-shaped portion having an opening formed at the top and a wide inside, and a flat plate portion having an opening formed at the center. An ink jet recording unit, wherein the section and the flat plate section have a substantially ∠-shaped cross section. 2. The inkjet recording unit according to claim 1, wherein a plurality of protrusions are provided on one of opposing surfaces of the umbrella-shaped portion and the flat plate portion of the joining member. 3. The inkjet recording unit according to claim 1, wherein a plurality of groove portions are provided on one of opposing surfaces of the umbrella-shaped portion and the flat plate portion of the joining member. 4. The joining member is provided on the recording head side, and when joining the joining member and the ink tank, a corner portion of a peripheral edge of an opening formed in the umbrella-like portion of the joining member is formed. The ink jet recording unit according to claim 1, wherein the ink jet recording unit is in contact with the ink tank.