JPH0957997A - Inkjet head connection unit, inkjet cartridge and method of assembling the same - Google Patents

Abstract

(57) Abstract: An ink jet head connection unit in which an ink supply path is formed by adhering a substrate constituting an ink jet head to another member does not cause ink ejection failure and does not cause ink leakage. reliable,
An inkjet head connection unit that is easy to manufacture. SOLUTION: A first case member 40 sandwiches a side surface of an inkjet head 10 and a first case member 40 having an opening 42 having a supply port 57 for supplying ink to the inkjet head 10 at a bottom portion thereof. Combined with the member 40,
The second case 30 covers the bottom surface and the side surface of the inkjet head 10 together with the first case 40, and when the first case member 40 and the second case member 30 are combined, The space filled with the adhesive that joins the first and second case members 30 and 40 is
Formed in a joined case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for ejecting ink from an ink jet head to record on a recording medium, and more particularly to an ink jet head for connecting an ink supply path for supplying ink to the ink jet head. Regarding connection unit.

[0002]

2. Description of the Related Art Conventionally, as a method of connecting an ink jet head to an ink supply path, a substrate forming the ink jet head and a member forming the supply path are joined with an adhesive to form an ink supply path. A method of supplying ink to an inkjet head has been used.

[0003] For example, Japanese Utility Model Laid-Open No. 4-17043 discloses that
Ink is supplied to a jetting mechanism (a mechanism for applying a propulsive force to the ink) by bonding a glass or ceramic substrate having an opening to a recess of a plastic back plate having a groove and an opening by using an adhesive. An example in which an ink supply path is configured is disclosed.

A plurality of thin-film thermal inkjet resistors are formed on the surface of the substrate, and a supply port to the inkjet resistor portion is opened through the substrate. Further, a groove is provided in the recess of the back plate at a position corresponding to the supply port of the substrate, and further, an opening is provided in the back plate so as to communicate with the groove and the ink reservoir of the elastic body. . Then, by bonding the substrate and the back plate, a capillary supply path for supplying ink from the ink reservoir to the ink jet resistance portion is formed.

[0005]

However, the above-mentioned prior art has the following problems.

[0006] It is difficult to apply an appropriate amount of adhesive thinly and uniformly to a substrate or a back plate constituting an ink jet head. Particularly, when the amount of adhesive applied is large, the adhesive flows into the ink flow path. There is a possibility that the capillary supply path will be blocked and ink supply to the ejection mechanism will be obstructed, and as a result, ejection of ink droplets will not be performed. Conversely, when the amount of the adhesive applied is small, a gap is formed in the joint surface, and there is a potential functional problem that ink leaks from the gap.

In addition, during the process of assembling the ink jet, since the surface on which the adhesive is applied is exposed, dust and the like may adhere to the bonding surface, and a gap may be formed on the bonding surface as described above. Further, since the substrate on which the ejection mechanism is formed is adhered to the surface on which the adhesive is applied, it is difficult to accurately determine the position with respect to the back plate and adhere the substrate.

The present invention has been made to solve the above drawbacks, and an object of the present invention is to supply an ink to an ink jet head by adhering a substrate constituting the ink jet head to another member. It is an object of the present invention to provide a highly reliable inkjet head connection unit or an inkjet cartridge that does not cause ink leakage or ink leakage in an inkjet head connection unit in which a supply path is formed.

Another object of the present invention is to provide an ink jet head connection unit which can be easily manufactured, is inexpensive and has high quality.

[0010]

An ink jet head connecting unit of the present invention is an ink jet head for connecting an ink jet head for ejecting ink droplets according to recording contents and an ink supply path for supplying ink to the ink jet head. In the head connection unit, an inkjet head having a first surface on which a nozzle for ejecting an ink droplet is formed and a second surface on which an inlet for supplying ink to the nozzle is formed, and the inkjet head. A first case member having a supply port for supplying ink to the head and having an opening formed at the bottom, and a side surface of the inkjet head are sandwiched between the first case member and the first case member, and the first case member is connected to the first case member. And a second case that covers the second surface and the side surface of the inkjet head, and the second surface is 1 is inserted into the opening of the case member, and when the first case and the second case are coupled, an adhesive agent for joining the inkjet head and the first and second case members is filled. Is formed in the joined case.

Further, the ink jet cartridge of the present invention is an ink jet cartridge which includes an ink jet head for ejecting ink droplets according to recording contents and an ink holding means for holding ink to be supplied to the ink jet head. An inkjet head having a first surface on which a discharge nozzle is formed and a second surface on which an inlet for supplying ink to the nozzle is formed; and an ink for supplying the ink to the inkjet head. A first case member having a supply port having an opening formed at the bottom and a side surface of the inkjet head are sandwiched between the first case member and the first case member. A second case that covers the second surface and the side surface, and the second surface is the first case member. A space filled with an adhesive that joins the inkjet head and the first and second case members when the first case and the second case are inserted into the mouth part It is formed in the formed case.

In a further preferred form of the ink jet head connecting unit or the ink jet cartridge, the first or second case member is provided with a hole for injecting the adhesive into the space inside the case combined with the adhesive. Has been. In addition, the second case is provided with a claw portion that sandwiches the side surface of the inkjet head with an appropriate pressure. Further, it is preferable that the size of the opening of the first case member is substantially the second surface of the inkjet head.

The adhesive used in the present invention preferably has a Young's modulus after curing of 36.0 kgf / mm ² or less.

Further, in the method of assembling the ink jet head connecting unit or the ink jet cartridge of the present invention, the second surface of the ink jet head is inserted into the opening of the first case member, and the second case is inserted. After being externally fitted to the inkjet head, the second case is pressed in the direction of the first case, fitted into the first case, and inserted into the space formed in the combined case. It is characterized by injecting an adhesive from the.

In the method of injecting the adhesive, it is preferable to inject the adhesive using an injection needle through a hole communicating with the space inside the case.

[0016]

In the above construction or method of the present invention,
By connecting a first case member having an opening formed at the bottom with a supply port for supplying ink to the inkjet head and a second case member that holds the side surface of the inkjet head, The surface and side surface of the inkjet head on which the ink inlet is formed is covered, and an adhesive is injected into the space inside the combined case from the outside of the case to form an ink supply path for supplying ink to the inkjet head. At this time, the adhesive satisfactorily penetrates into the gap between the inkjet head and the head case member, and the ink supply path is blocked from the outside.

As described above, since the adhesive is injected into the case from the outside and the adhesive is not exposed to the outside in the process of assembling, the ink jet head connecting unit or the ink jet cartridge which is very easy to assemble is used. Can be provided. Further, according to the present invention, there is almost no problem such as adhesion failure, which has been always caused by adhesion of dust or the like to the adhesion surface when assembling using an adhesive.

Further, the ink jet head is positioned with respect to the case by inserting the head into the case itself, and then the ink jet head is fixed with an adhesive, so that the ink jet head can be positioned more accurately than in the conventional method. It is possible.

Further, according to the present invention, after the second case is fitted onto the ink jet head, the second case is pressed toward the first case while the first case member and the second case are pressed. The case member is joined. Therefore, the surface of the inkjet head on which the ink intake port is formed is pressed against the bottom surface of the opening of the second case member on which the ink supply port is formed during assembly. For this reason, since there is almost no gap on the surface where the ink supply port and the ink intake port are joined, the adhesive injected into the space inside the case does not block the ink supply path.

As described above, according to the present invention, a strong adhesive joint which does not leak ink, does not block the ink supply path, is easy to assemble, and is inexpensive can be achieved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The details of an ink jet head connecting unit in an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an inkjet cartridge will be described as an example, but the present invention is not limited to the cartridge type and can be applied to any inkjet head connection unit that supplies ink to the inkjet head.

FIG. 1 is an exploded perspective view showing the construction of an ink jet cartridge according to an embodiment of the present invention.
FIG. 3 is a front view of the same as seen from the nozzle side of the inkjet cartridge, and FIG. 3 is a cross-sectional view (partial cross-sectional view taken along the line AA of FIG. 2) of the inkjet head connection unit that is also a part of the ink cartridge.

An ink jet head connecting unit comprising a first case member 40 (hereinafter referred to as a head case for convenience), a second case member 30 (hereinafter referred to as a nozzle case 30) and an ink jet head 10, and an ink bag 50.
And an ink supply section including an ink case 60.

The nozzle case 30 is made of AS, ABS, PSF.
A nozzle plate portion 31 having an opening portion 31a in which the nozzle 4 of the inkjet head 10 is mounted when the inkjet head 10 is mounted is provided in the central portion, which is made of a resin member such as (polysulfone), and the peripheral portion thereof is provided. An ink stop groove 32 is provided. This ink stop groove 32 is
Recovery processing operation when ejection failure occurs due to nozzle clogging, generation of bubbles in the ink flow path, etc. (for example, operation of ejecting ink and bubbles thickened by pressing the ink bag 50 from the outside (also called priming)) ), The ink discharged from the nozzle is stopped by its surface tension, and the ink discharged at that time is held inside the groove with the surface tension. And
The user performs priming by observing the amount of the ejected ink. That is, the area inside the groove is preset so that an appropriate amount of priming is performed when the ink is completely discharged inside the groove.

A protrusion wall 36 for forming an adhesive groove, which will be described later, is formed on the outer periphery of the opening on the back surface of the nozzle case 30. Further, two pins 33 are provided on the back surface of the nozzle case 30 for coupling with the head case. An adhesive injection port 3 is provided on the lower front of the nozzle case 30.
4 (shown in FIG. 2) is provided, and the adhesive injection port 34 thereof communicates with an adhesive groove described later. The head case 40 is made of a transparent material such as PSF (polysulfone), PC (polycarbonate), ABS, etc., and an engaging hole 43 is formed on the side facing the nozzle case 30. The pin 33 is press-fitted to join the nozzle case 30 and the head case 40. An opening 41 into which the projection wall 36 of the nozzle case is inserted is formed substantially at the center of the front surface of the head case 40, and the opening 31 of the nozzle case is formed at the center of the opening.
An opening 42 (shown in FIG. 3) having the same shape as that of FIG. In the opening 42, the inkjet head 1
The ink intake port 27 side of 0 is stored.

A nozzle 4 is formed at one end of the ink jet head 10, and an ink intake port 2 is provided at the other end.
7 are formed. And the inkjet head 1
0 and a head FPC 101 for sending a signal to pressure generating elements arranged in a row in the inkjet head.
The (flexible printed circuit) is inserted into the groove 49 of the head case 40, and is connected to the terminal portion 102 of the FPC.
Is fixed to the lower surface of the ink case 60. When the ink cartridge is mounted on the carriage (not shown), the terminals provided on the carriage and the FPC terminals 102
Are electrically connected.

As described above, the nozzle case 30 is joined to the head case 40 in which the ink jet head 10 is housed so as to cover the head case 40. Projection wall 3 of nozzle case 30
A pair of claws 37 for sandwiching the ink jet head are provided on the inner side of 6, and these act so as to press the ink jet head 10 against the bottom surface of the opening 42 of the head case 40 when the case is coupled. As a result, the surface of the inkjet head 10 on the ink intake port 27 side is brought into close contact with the bottom surface of the opening 42 of the head case 40,
In addition, the inkjet head 10 is supported inside the case in a state where the ink intake port 27 of the inkjet head 10 and the ink supply port 57 of the head case 40 communicate with each other. The claw 37 also has a function of determining the position of the inkjet head 10 with respect to the case.

As shown in FIG. 3, inside the combined cases, a band-like space is formed around the outer peripheral portion near the ink supply port 27 of the ink jet head 10 by the opening 41 of the head case and the projection wall 36 of the nozzle case. (Adhesive groove 48) is formed.

The nozzle case 30 has an adhesive injection port 34.
And an injection pipe 35 is provided. The adhesive groove 48 is provided with an adhesive injected from the adhesive injection port 34 through the injection pipe 35 using, for example, a dispenser equipped with a syringe needle. Is filled. As a result, the periphery of the ink supply port 27 of the inkjet head 10 is sealed with the adhesive, and the inkjet head 10 is fixed to the case.

FIG. 4 is an explanatory view showing a state where the adhesive groove 48 is filled with the adhesive.

The area of the adhesive groove 48 filled with the adhesive is a hatched portion shown in FIG. 4, and is filled so as to surround the outer circumference of the ink jet head 10. The adhesive filled in the adhesive groove 48 is guided by the capillary force into the gap between the inkjet head 10 and the head case 40 and uniformly permeates.

However, as described above, the surface of the ink jet head 10 on the ink intake port 27 side is the bottom surface of the opening 42 of the head case 40 in a state where the ink intake port 27 and the ink supply port 57 are in communication with each other. Since the ink jet head 10 is supported by the claws 37 so as to be in close contact with each other, the adhesive only permeates into a gap that is slightly generated between these surfaces, and the ink intake port 27 and the ink supply port 5
It does not penetrate into 7.

The ink jet head connecting unit is joined in this way, and a complete communication state from the ink supply portion to the nozzle can be obtained. That is, the ink supplied from the ink supply pipe 47 formed on the back surface of the head case 40 passes through the case reservoir 56 of the head case 40, does not leak to the other, and is blocked by the protruding adhesive or the like. Without being supplied, the ink is supplied to the ink intake port 27 of the inkjet head 10 and is ejected as ink droplets 104 from the nozzle 4 by driving the pressure generating means inside the head.

The ink jet head connecting unit of the present invention thus constructed has a good ink jet head and a head case which holds the ink jet head and supplies ink only by injecting a fixed amount of adhesive from one injection port. The joint of is obtained. Thereby, strong and stable adhesive bonding without ink leakage is achieved.

An ink injection port 44 is provided in the upper part of the front surface of the head case, and a plug 47 is press-fitted when the ink is not injected. The plug 47 is designed to prevent dust from coming out when it is press-fitted, and is made of, for example, a nylon member, but may be made of a soft resin such as polyimide or a metal ball. An ink supply pipe 47 (shown in FIG. 3) is formed on the back surface of the head case, and a filter 55 (shown in FIG. 3) is heat-welded to the inlet of the ink supply pipe 47. In addition, a plurality of pins 45 for coupling with the ink case 60 are provided on the back surface of the head case.

The ink bag 50 is made of, for example, butyl rubber, has a circular opening 51 at the tip, and a packing 52 at the edge of the opening 51. The packing 52 is sandwiched between the head case 40 and the ink case 60 to form a seal structure.

In order to prevent the ink from leaking from the nozzle 4 of the ink cartridge which is in a standby state where the printing operation is not performed or which has been detached from the printer and left to stand, the ink formed in the ink cartridge is prevented. It is necessary to always apply a pressure (negative pressure) that works in the direction of returning the ink from the inkjet head 10 into the path. In this embodiment, the negative pressure is obtained by the spring characteristic (shape recovery) of the ink bag 50.

Like the head case 40, the ink case 60 is made of a transparent material such as PSF (polysulfone), PC (polycarbonate), ABS, etc., and an opening 61 is formed on the side facing the head case 40. The ink bag 50 is housed therein. Also,
An engagement hole 62 is formed, and a pin 45 of the head case is press-fitted and fixed in the engagement hole 62, so that the head case 40 and the ink case 60 are coupled.

An example of the ink jet head of the present invention will be described in detail below with reference to FIGS. 5 and 6.

FIG. 5 is a perspective view of the entire head jet head connected to the ink supply means by the ink jet head connecting unit in the embodiment of the present invention. Figure 6
FIG. 3 is a sectional side view of an ink flow path portion of an inkjet head.

The ink jet head 10 of the present invention has a laminated structure in which three substrates 1, 2, and 3 having the structure described in detail below are laminated and joined.

The intermediate first substrate 1 is a silicon substrate, and the third substrate 3 is bonded to the upper surface thereof to form a plurality of nozzles 4 and a pressure generating portion having a diaphragm 5 as a bottom wall. Chamber 6 and orifice 7 provided at the rear of discharge chamber 6
And a reservoir 8 serving as an ink supply unit for supplying ink to each ejection chamber 6, and a groove that forms an ink intake port 27 provided at a rear portion of the reservoir 8.

Borosilicate glass is used for the lower second substrate which is bonded to the lower surface of the first substrate 1.
The vibrating chamber 9 is formed by joining the second substrate 2 provided with the concave portion 15 which is to form the vibrating chamber 9 for mounting the electrode on the lower portion of the vibrating plate 5. IT at each position corresponding to the diaphragm 5 on the 2
The O conductive film is sputtered to form the individual electrode 21. The individual electrode 21 has a lead portion 22 and a terminal portion 23.

The upper third substrate 3 bonded to the upper surface of the first substrate 1 is made of borosilicate glass similarly to the second substrate 2. The nozzle 4, the ejection chamber 6, the orifice 7, the reservoir 8, and the ink inlet 27 are formed by joining the third substrate 3.

The ink jet head 10 thus assembled is further assembled as an ink jet cartridge, and then, as shown in FIG. 6, the common electrode 17 is formed.
And the individual electrode 21 are connected to the drive circuit 80 via the head FPC 101. The ink 103 is the ink supply port 2
7 is supplied to the inside of the first substrate 1 through the reservoir 8,
The discharge chamber 6 and the like are filled.

When a voltage is applied between the common electrode 17 and the individual electrode 21 by the drive circuit 80, the electrostatic actuator composed of the vibrating plate 5 and the individual electrode 21 facing each other with a predetermined gap is charged, and the voltage is applied to the electrostatic actuator. The diaphragm 5 is bent toward the individual electrode 21 by the generated electrostatic force. This allows
The pressure in the ejection chamber 6 decreases, and ink is drawn into the ejection chamber 6 from the reservoir 8. After that, stop charging and suddenly discharge the charge stored in the electrostatic actuator,
The diaphragm 5 is restored to its original shape by the elastic force of the diaphragm itself. At this time, the pressure in the discharge chamber 6 rapidly rises, the ink droplets 104 are discharged from the nozzles 4, and printing is performed on the recording paper 105.

In this embodiment, an electrostatic actuator, which is a kind of electro-mechanical conversion means for converting an electric signal into vibration of a vibrating plate to eject ink droplets, is used as the pressure generating means for ejecting ink droplets. However, the present invention is not limited to this in view of the gist of the present invention. For example, a piezoelectric element may be used as the pressure generating means to configure the electro-mechanical conversion means, or a so-called electro-thermal conversion element that applies heat to the ink and ejects ink droplets by bubbles generated in the ink is used. You may use.

[0048]

EXAMPLES Preferred materials for members constituting the ink jet head connecting unit of the present invention and their linear expansion coefficients are shown below.

(1) Material for head case material Material linear expansion coefficient (/ ° C.) PSF (polysulfone) 5.5 × 10 ^-5 ABS 8.0 × 10 ^-5 (2) Material for head member Material linear expansion Coefficient (/ ° C) Borosilicate glass 3.25 × 10 ^-6 Si (silicon) 2.33 × 10 ^{-6 When the} inkjet head and head case are joined, the adhesive is exposed at the part that directly contacts the ink. ,
As the characteristics of the adhesive used in the place where it is directly contacted with the ink, excellent ink resistance and gas barrier property are required. As an adhesive satisfying such characteristics, a thermosetting epoxy adhesive is generally used.

However, when a material having a low stress resistance such as borosilicate glass is used for the member forming the ink jet head, the head receives stress due to the difference in thermal expansion at the joint with the case member, and the ink jet head is Cracks may occur in the constituent members.

When the above materials are used and an adhesive having a low Young's modulus after curing, such as a silicone-modified resin, is used, the above-mentioned phenomenon of cracking does not occur.

This is because the soft adhesive reduces the stress generated due to the difference in thermal expansion between the ink jet head and the case member and prevents the occurrence of cracks. As a result of detailed experiments, it was found that cracks and the like did not occur in an inkjet head using borosilicate glass if the Young's modulus after curing was 36.0 kgf / mm ² or less.

[0053]

As described above, according to the ink jet head connecting unit of the present invention, the adhesive flows into the ink flow passage to block the ink flow passage, thereby hindering the ink supply to the ink jet head. There is no possibility of causing a problem that ink droplets cannot be ejected.

In addition, there is no risk of ink leakage due to defective bonding due to non-uniform application of the adhesive or adhesion of dust or the like to the adhesive application surface during the assembly process.

Further, in the process of assembling the ink jet head connecting unit or the ink jet cartridge, the bonding surface for bonding the members constituting them is not exposed to the outside, so that the assembly is very easy.

As described above, it is possible to inexpensively manufacture the ink jet head connecting unit which is easy to join and is highly reliable, and the ink jet cartridge including the unit.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of an inkjet cartridge according to an embodiment of the present invention.

FIG. 2 is a front view of the inkjet cartridge shown in FIG.

FIG. 3 is an A- of the inkjet cartridge shown in FIG.
A sectional drawing.

FIG. 4 is an explanatory view showing a state in which an adhesive is filled in an adhesive groove in the ink jet cartridge shown in FIG. 1;

FIG. 5 is an exploded perspective view of an inkjet head according to an embodiment of the present invention.

6 is a sectional view of the inkjet head shown in FIG.

[Explanation of symbols]

 4 Nozzles 10 Inkjet Head 27 Ink Intake Port 30 Nozzle Case 40 Head Case 49 Head FPC 50 Ink Bag 60 Ink Case

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Yamazaki 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation

Claims (14)

[Claims] 1. A nozzle for ejecting an ink droplet is formed in an ink jet head connecting unit for connecting an ink jet head for ejecting an ink droplet according to a recorded content and an ink supply path for supplying ink to the ink jet head. And an ink jet head having a second surface formed with an inlet for supplying ink to the nozzle, and a supply port for supplying ink to the ink jet head at the bottom. A first case member having a formed opening, and a side surface of the inkjet head that is sandwiched between the first case member and the first case member, and the first case member and the second surface and the side surface of the inkjet head. A second case that covers the first case member and the second surface is inserted into the opening of the first case member. A space filled with an adhesive that joins the inkjet head and the first and second case members when the second case is joined is formed in the joined case. Inkjet head connection unit. 2. The ink jet head connection unit according to claim 1, wherein the first or second case member is provided with a hole for injecting the adhesive into a space inside the case combined with the adhesive. . 3. The inkjet head connection unit according to claim 1, wherein the Young's modulus after curing of the adhesive is 36.0 kgf / mm ² or less. 4. The ink jet head connection unit according to claim 1, wherein the second case is provided with a claw portion that sandwiches a side surface of the ink jet head with an appropriate pressure. 5. The inkjet head connection unit according to claim 1, wherein the size of the opening of the first case member is substantially the second surface of the inkjet head. 6. A nozzle for ejecting ink droplets is formed in an ink jet cartridge containing an ink jet head for ejecting ink droplets according to the recorded content and an ink retaining means for retaining ink to be supplied to the ink jet head. An inkjet head having a first surface and a second surface on which an intake port for supplying ink to the nozzle is formed, and a supply port for supplying ink to the inkjet head is formed on a bottom portion. A first case member having an opening and a side surface of the inkjet head, and is coupled to the first case member to cover the second case and the side surface of the inkjet head together with the first case. A second case, wherein the second surface is inserted into the opening of the first case member, and An inkjet characterized in that when the two cases are joined, a space filled with an adhesive for joining the inkjet head and the first and second case members is formed in the joined case. cartridge. 7. The ink jet cartridge according to claim 6, wherein the first or second case member is provided with a hole for injecting the adhesive into a space inside the case combined with the adhesive. 8. The ink jet cartridge according to claim 6, wherein the Young's modulus of the adhesive after curing is 36.0 kgf / mm ² or less. 9. The ink jet cartridge according to claim 6, wherein the second case is provided with a claw portion that sandwiches a side surface of the ink jet head with an appropriate pressure. 10. The ink jet cartridge according to claim 6, wherein the size of the opening of the first case member is substantially the second surface of the ink jet head. 11. The method for assembling an inkjet head connecting unit according to claim 1, wherein the second surface of the inkjet head is inserted into an opening of the first case member, and the second case is attached. After being externally fitted to the inkjet head, the second case is pressed in the direction of the first case, fitted into the first case, and is inserted into the space formed in the combined case, and the case outside A method for assembling an inkjet head connection unit, which comprises injecting an adhesive from 12. The method for assembling an inkjet cartridge according to claim 6, wherein the second surface of the inkjet head is inserted into an opening of the first case member, and the second case is used for the inkjet. After being externally fitted to the head, the second case is pressed in the direction of the first case, fitted into the first case, and bonded to the space formed in the combined case from the outside of the case. A method for assembling an inkjet cartridge, which comprises injecting an agent. 13. The method for assembling an inkjet head connection unit according to claim 11, wherein the adhesive is injected from a hole communicating with the space in the case using an injection needle. 14. The method of assembling an ink jet cartridge according to claim 12, wherein the adhesive is injected from a hole communicating with the space in the case using an injection needle.