JPH0985960A - Ink-jet recording unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink-jet recording unit which is simple in structure, closes reliably an ink flow passage between a recording head and an ink tank, facilitates mounting and demounting of them and, moreover, prevents ink from dropping when the ink tank is demounted. SOLUTION: An elastic member 22 for junction, having a substantially shade- shaped portion having an opening, is provided at a junction of a recording head 21 with an ink tank 1. Further, a recess 14 is provided at a joint of the ink tank 1. The elastic member 22 for junction is pressed against the recess 14 concurrently with the mounting of the ink tank 1. At that time, the substantially shade-shaped portion of the elastic member 22 for junction is elastically deformed inward. Accordingly, a face of the ink tank 1 is not particularly stained with ink in an ink flow passage, which is closed, and, when the ink tank 1 is demounted, the ink does not drop. Furthermore, since only the recess 14 is stained with the ink, a desk, etc., are not soiled with the ink even in the case of placing the demounted ink tank 1 on a desk, etc.

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.

[0007]

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 which can be easily separated and replaced and in which ink dripping is eliminated when the ink tank is removed.

[0008]

According to a first aspect of the present invention, in an ink jet recording unit, a recording head having an ink ejecting portion for ejecting ink and a detachable ink tank for supplying the ink to the recording head are provided. In an ink jet recording unit, the recording head is provided with a joining member made of an elastic body that joins the ink tank and the ink flow path, and the joining member has an umbrella-shaped portion having an opening at the top and a wide inside. It is characterized by having.

According to a second aspect of the present invention, in the ink jet recording unit according to the first aspect, the joint member is provided on the recording head side, and a portion of the ink tank with which the joint member abuts is outside. It is characterized by being recessed from the wall surface.

[0010]

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.

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.

Further, a concave portion 14 is formed on the outer peripheral surface of the joint port 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 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.

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. As a result, the manifold 23 and the joining elastic member 22 are
The airtightness is maintained.

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. The joining elastic member 22 has a substantially umbrella-shaped portion as shown in FIG. 3, and an opening is formed at the top. That is, the shape is such that the upper portion is narrowed so that the opening has the minimum diameter, and the cross section thereof has a substantially V-shape. The substantially umbrella-shaped portion is brought into contact with the surface of the concave portion 14 of the ink tank 1 to keep the airtightness. Since the opening is small as described above, this portion abuts the concave portion 14 of the ink tank 1,
When the ink flow path is formed, it is possible to reduce the area of the recess 14 that comes into contact with the ink. 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 it is possible to eliminate the conventional dripping of the adhered ink. The opening shape of the substantially umbrella-shaped portion may be substantially circular. Of course, other shapes such as a rectangle and an ellipse may be used.

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. Moreover, the thickness of the substantially umbrella-shaped portion is preferably 0.5 m.
If it is about m, it is easy to contact the surface of the ink tank 1.

When the recess 14 of the ink tank 1 comes into contact with the joint elastic member 22, the end of the opening of the joint elastic member 22 slides on the surface of the recess 14 of the ink tank 1 and the joint elastic member 22.
The substantially umbrella-shaped portion is elastically deformed inward and comes into close contact with the ink tank 1 in the state shown in FIG. 2 to seal the ink flow path. Such elastic deformation of the substantially umbrella-shaped portion of the joining elastic member 22 can be performed with a small force, and the ink tank 1
Even if the pressing force of the recording head 21 is small, the ink flow path can be sealed. Further, when the ink tank 1 is attached, the surface of the ink tank 1 that is wet with ink is small as shown in FIG. 2, so unnecessary ink that adheres to the ink tank 1 when the ink tank 1 is removed is minimized. The ink dripping does not occur.

FIG. 4 is an explanatory view of a state of using ink 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 atmosphere 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. 4A shows a state where the ink is 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 FIG.
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. 4B, both surfaces of the first meniscus forming member 8 are exposed to air. Also in the state shown in FIG. 4A, 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. 4A and 4B, 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. 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. 5 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. 6 is a three-sided view of the same manifold part. 6 (A), (B), and (C) show the states of the configuration shown in FIG. 5 when the manifold portion is assembled, as seen from the A direction, B direction, and C direction, 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 groove 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. 5 and 6.

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. 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 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 umbrella-shaped opening 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 substantially umbrella-shaped portion of the joint elastic member 22 elastically deforms inward, the joint elastic member 22 is pressed against the surface of the concave portion of each ink tank 1 to be in a hermetically sealed state, and the ink flow path hermetically sealed in the joint portion. Is formed.

The manifold member 31 is provided with a groove 41 for forming 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 an image 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 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 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 since the shape of the joint elastic member 22 decreases toward the opening, the ink remaining in the joint elastic member 22 can be minimized. it can. Moreover, since the opening is small, it is possible to minimize the dripping of ink.

[0038]

As is apparent from the above description, according to the present invention, a joint elastic member having a substantially umbrella-shaped portion made of an elastic body is provided at the joint between the recording head and the detachable ink tank. By providing the ink tank, the airtightness of the joint between the recording head and the ink tank can be obtained by a simple operation of mounting the ink tank, and it is possible to prevent ink leakage and air mixing from this joint. Further, since the airtight connection by the joining elastic member is stable, it does not adversely affect the print quality and the like. Furthermore, since this sealed state is achieved with only a small pressing force, not only when installing the ink tank,
It is easy to remove and the ink tank can be easily replaced.

Further, since the portion of the joint elastic member that comes into contact with the ink tank has a narrow umbrella shape, it is possible to reduce the area where ink adheres to the ink tank at this joint portion. Even when the ink is removed, the ink does not drip. Further, since the concave portion is provided in the joint portion of the ink tank with which the joint elastic member abuts, the ink tank is removed during use and, for example, even when the ink tank is placed on a desk or the like, the desk may be contaminated. Has various effects such as not occurring.

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

FIG. 5 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. 6 is a three-view drawing of a manifold portion in a specific example of an 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 ... Manifold member, 32 ... Joint member,
33 ... Printed circuit board, 34 ... Front hat, 35 ... Ink introducing section, 41 ... Groove section, 42 ... Claw section, 43 ... Hole section.

Front page continuation (72) Inventor Katsuhide Ogawa 2274 Hongo, Ebina City, Kanagawa Fuji Xerox Co., Ltd. (72) Inventor Junichi Yoshida 2274 Hongo, Ebina City, Kanagawa Fuji Xerox Co., Ltd.

Claims (2)

[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 the recording head comprises an ink tank and an ink flow path. An ink jet recording unit, comprising: a joining member composed of an elastic body for joining, the joining member having an umbrella-shaped portion having an opening formed at the top and a spread inside. 2. The ink jet recording apparatus according to claim 1, wherein the joining member is provided on the recording head side, and a portion of the ink tank with which the joining member abuts is recessed from an outer wall surface. Recording unit.