JP2022158872A - Liquid discharge head and liquid discharge device - Google Patents

Abstract

To provide a liquid discharge head with high sealing reliability.SOLUTION: A liquid discharge head 2 has: a hollow housing 4 of which one end is an opening; a lid member 5 which is fixed to an end of the opening of the housing 4, and blocks the opening; and a member 15 located in the housing 4. The lid member 5 is provided with a liquid supply port 10 for supplying a liquid into the housing 4. A first liquid guiding groove 13 is formed in a top face of the member 15, the face onto which the liquid supplied via the liquid supply port 10 is dropped, and a second liquid guiding groove 14 is formed in a side wall internal surface 4a of the housing 4. The second liquid guiding groove 14 extends from the end of the opening fixed to the lid member 5 to the opposite of the opening in the side wall internal surface 4a of the housing 4, and the first liquid guiding groove 13 extends to a side face of the member 15 which contacts or closely approaches the side wall internal surface 4a of the housing 4. The first liquid guiding groove 13 and the second liquid guiding groove 14 are so positioned as to be capable of liquid-communicating with each other.SELECTED DRAWING: Figure 4

Description

The present invention relates to a liquid ejection head and a liquid ejection apparatus.

2. Description of the Related Art Among liquid ejection apparatuses that eject liquid such as ink from a liquid ejection head, there is a liquid ejection head that supplies an amount of liquid equivalent to the ejected liquid from a liquid container (liquid tank) to the liquid ejection head under negative pressure. In the liquid ejection device described in Patent Document 1, a liquid container connected to a liquid ejection head via a tube or the like is arranged vertically below the liquid ejection head, and a negative pressure is generated by a difference in water head. there is

As an example of the liquid ejection head, there is a configuration in which an element substrate for ejecting liquid is attached and a plate-shaped cover member is joined to a housing having a liquid reservoir. A tube connected to the liquid container is connected to the mounting portion of the lid member, and communicates from the mounting portion of the lid member to the liquid storage portion in the housing to form a liquid supply path from the liquid container to the liquid ejection head. . When both the housing and the lid member are resin moldings, the housing and the lid member are joined together by an ultrasonic welding method, a vibration welding method, or the like.

JP 2017-81084 A

In order to maintain the negative pressure inside the liquid ejection head in order to supply the liquid to the liquid ejection head, the airtightness of the liquid ejection head is important. If the sealing performance of the liquid ejection head is insufficient, the negative pressure inside the liquid ejection head cannot be maintained, and the liquid may return from the tube to the liquid container side, or it may become difficult to supply the liquid to the liquid ejection head. there is a possibility.
In the liquid ejection head, from the viewpoint of strengthening the rigidity of the housing and cover member (hereinafter referred to as the housing) and optimizing the linear expansion, the ratio of the filler to the resin constituting the housing is about 35%. are mixed.
In the future, it is expected that the size of the liquid ejection head will be increased for the purpose of improving the recording speed. In order to increase the size of the liquid ejection head, it is necessary to further increase the strength of the housing and the like that constitute the liquid ejection head. For that purpose, the amount of filler mixed in the material resin is increased.
However, if the mixed amount of the filler is increased, the weldability between the housing and the cover member tends to decrease, and there is a possibility that the liquid ejection head cannot be sealed to maintain a predetermined negative pressure. In addition, when the liquid ejection head is enlarged, that is, in the case of a liquid ejection head having a long element substrate, the amount of liquid ejected per unit time increases. The negative pressure (pressure difference) is large, and a more reliable seal is required.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid ejection head and a liquid ejection apparatus with high sealing reliability.

A liquid ejection head according to the present invention includes a hollow housing having an opening at one end, a cover member fixed to the end of the opening of the housing and covering the opening, and disposed inside the housing. a member;
The lid member is provided with a liquid supply port for supplying liquid to the inside of the housing,
A first liquid guide groove is formed on the upper surface of the member and onto which the liquid supplied through the liquid supply port is dropped, and a second liquid guide groove is formed on the inner surface of the side wall of the housing. is formed and
The second liquid guide groove extends from the end of the opening fixed to the lid member toward the opposite side of the opening on the inner surface of the side wall of the housing. The liquid guide groove extends to a side surface of the member that is in contact with or close to the inner surface of the side wall of the housing, and the first liquid guide groove and the second liquid guide groove are positioned so as to allow liquid communication with each other. It is characterized by

According to the present invention, it is possible to provide a liquid ejection head and a liquid ejection apparatus with high sealing reliability.

1 is a perspective view showing an example of the internal structure of a liquid ejection device of the present invention; FIG. 1 is a perspective view of a liquid ejection head according to a first embodiment of the present invention, viewed from below; FIG. 3A is a perspective view of the liquid ejection head shown in FIG. 2 as viewed from above, and FIG. 3B is a cross-sectional view taken along line BB. 3 is an exploded perspective view of the liquid ejection head shown in FIG. 2; FIG. 3 is a schematic diagram showing a liquid path of a liquid ejection device including the liquid ejection head shown in FIG. 2; FIG. 3 is a perspective view of a liquid holding member of the liquid ejection head shown in FIG. 2; FIG. 3A is a perspective view showing the internal structure of the housing of the liquid ejection head shown in FIG. 2, and FIG. 3B is an enlarged view of the portion C; FIG. 6(a) to (d) are schematic diagrams sequentially showing the liquid supply state of the liquid path shown in FIG. 5. FIG. 3A to 3D are schematic diagrams sequentially showing how the liquid moves in the housing of the liquid ejection head shown in FIG. 2; FIG. FIG. 9 is an exploded perspective view of a liquid ejection head according to a second embodiment of the invention; 11A is a perspective view of an inner lid member of the liquid ejection head shown in FIG. 10, and FIG. 11B is a sectional view thereof; FIG. (a) is a perspective view of a liquid holding member of a liquid ejection head according to a third embodiment of the present invention, and (b) is a sectional view thereof. FIG. 11 is a perspective view of a housing and a liquid holding member of a liquid ejection head according to a fourth embodiment of the invention; FIG. 11 is a perspective view of a housing and a liquid holding member of a liquid ejection head according to a fifth embodiment of the present invention; FIG. 11 is a perspective view of a housing and a liquid holding member of a liquid ejection head according to a sixth embodiment of the present invention;

Hereinafter, embodiments of the liquid ejection head according to the present invention will be specifically described with reference to the drawings. In addition, each of the following embodiments is a suitable example for carrying out the present invention, and the present invention is not limited to these configurations.

[First Embodiment]
FIG. 1 shows the internal structure of an inkjet recording apparatus, which is an example of a liquid ejection apparatus 1 according to the present invention. The liquid ejection apparatus 1 is a serial scan printing apparatus that performs printing by ejecting liquid while the liquid ejection head 2 reciprocates. The liquid ejection head 2 is mounted on the carriage 3 and connected to a joint (not shown) provided on the top of the carriage 3 . The carriage 3 can reciprocate along the guide shaft in the main scanning direction (direction A in FIG. 1) by a drive force transmission mechanism such as a carriage motor and a belt.

FIG. 2 is a perspective view of the liquid ejection head 2 according to this embodiment as seen from below. FIG. 3(a) is a perspective view of the liquid ejection head 2 as viewed from above, and FIG. 3(b) is an enlarged cross-sectional view of a portion thereof. FIG. 4 is an exploded perspective view of the liquid ejection head 2. FIG. The liquid ejection head 2 shown in FIGS. 2 to 4 includes a hollow housing 4 having an opening at one end, and an end of the opening of the housing 4 (opening end) that is fixed to block the opening and seal it. It has a lid member 5 that does. A space (liquid storage portion) for storing liquid is provided inside the housing 4, and a liquid retention member 15 (see FIG. 4) such as a porous material is accommodated in the liquid storage portion. An element substrate 6 (see FIGS. 2 and 4) for discharging liquid is attached to the housing 4 on the side opposite to the opening. Although not shown, the element substrate 6 includes a channel communicating with the liquid reservoir of the housing 4 and an energy generating element (for example, thermal energy) that imparts ejection energy (for example, thermal energy) to the liquid in the pressure chamber in the channel. For example, a heating element) is provided. The pressure chamber communicates with an ejection port 7 (see FIG. 2) that is open to the outside and ejects an energized liquid to the outside. The lid member 5 is formed with a mounting portion 9 to which one end of a connection member (for example, a tube) to be described later is mounted, and is provided with a liquid supply port 10 passing through the mounting portion 9 and communicating with the liquid reservoir. .

FIG. 3(b) is a cross-sectional view taken along line BB of FIG. 3(a), and is an enlarged cross-sectional view of a portion where the opening end of the housing 4 and the lid member 5 are fixed to each other. In this embodiment, the housing 4 and the lid member 5 are joined by vibration welding. Specifically, a melted portion 11 having a thickness of about 0.2 mm is generated by welding the housing 4 and the lid member 5 shown in FIG. 3(b). The melted portion 11 is a portion where the housing 4 and the lid member 5 are fused together, and is a joint portion where the housing 4 and the lid member 5 are actually joined.
Then, there is a possibility that a gap that causes minute leakage of liquid or gas may be generated in the fusion zone 11 or its vicinity.

FIG. 5 schematically shows the path of the liquid L in the liquid ejection device 1 including the liquid ejection head 2. As shown in FIG. One end of a flexible tube 8 which is one type of connection member is connected to a liquid container 12 fixed to the main body of the liquid ejection device 1 , and the other end of the tube 8 serves as a lid of the liquid ejection head 2 . It is attached to the attachment portion 9 of the member 5 . As a result, the liquid L in the liquid container 12 flows into the liquid reservoir of the housing 4 via the tube 8 and the liquid supply port 10 of the mounting portion 9 of the lid member 5 . The liquid L is held in the liquid holding member 15 of the liquid reservoir. The liquid L held by the liquid holding member 15 is sent to the channel of the element substrate 6, and when the energy generating element corresponding to the channel is driven to generate ejection energy, the liquid L to which the energy is applied is discharged. The droplets are discharged from the discharge port 7 onto an external recording medium or the like.

FIG. 6 is a perspective view of the liquid holding member 15 of the liquid ejection head 2 according to this embodiment. FIG. 7(a) is a perspective view showing the inside of the hollow housing 4 of the liquid ejection head 2 according to this embodiment, and FIG. 7(b) is an enlarged view showing part C of FIG. 7(a). The liquid holding member 15 of this embodiment is made of polypropylene, and as shown in FIG. 6, the first liquid guiding groove 13 is formed on the upper surface. The inner wall surface of the first liquid guide groove 13 is preferably surface-treated so that the liquid does not easily permeate. As shown in FIGS. 7(a) and 7(b), second liquid guide grooves 14 are formed in the side wall inner surface 4a of the housing 4 in which the liquid holding member 15 is accommodated. The second liquid guiding groove 14 is formed on the side wall inner surface 4a of the housing 4 from the open end fixed to the lid member 5 toward the opposite end (the end to which the element substrate 6 is attached). extended. The second liquid guiding groove 14 terminates near the center of the side wall, and this termination portion is formed in an enlarged circular shape. In addition, the first liquid guide groove 13 of the liquid holding member 15 is located on the side surface of the liquid holding member 15 that is in contact with or close to the side wall inner surface 4a of the housing 4 in the state that the liquid holding member 15 is accommodated in the liquid reservoir of the hollow housing 4. extends to A portion of the second liquid guide groove 14 (preferably an enlarged circular end portion) is positioned on the extension line of the first liquid guide groove 13 . Then, in a state in which the liquid holding member 15 is housed in the liquid reservoir of the hollow housing 4, the first liquid guide groove 13 of the liquid holding member 15 and the second liquid guide groove 14 of the housing 4 are separated from each other. It is positioned so as to allow liquid communication, and is in a so-called fluid communication state.

A liquid supply state of the liquid ejection apparatus 1 including the liquid ejection head 2 of the present embodiment described above will be described. 8(a) to 8(d) sequentially show the supply state of the liquid L in the liquid path shown in FIG. 5 when the liquid ejection device 1 is in use (during liquid suction). 8A, the liquid ejection head 2 and the liquid container 12 are connected by the tube 8, the liquid L is held inside the liquid ejection head 2 and the liquid container 12, and the liquid L is held inside the tube 8. In FIG. It is in a state where it is not. In this state, when a negative pressure is applied from the forming surface 6a of the element substrate 6 of the liquid ejection head 2 (see FIG. 2) to suck the liquid L, the inside of the liquid ejection head 2 becomes negative pressure, and the pressure inside the liquid ejection head 2 becomes negative. As shown in (b), the liquid L in the liquid container 12 moves through the tube 8 toward the liquid ejection head 2 side. 8(c), the liquid L reaches the liquid holding member 15 in the liquid reservoir of the housing 4 from the tube 8 via the liquid supply port 10 of the cover member 5. . Then, when the liquid suction from the surface 6a on which the ejection port 7 is formed is completed, the liquid L is in a stable state as shown in FIG. become. The tube 8 is filled with the liquid L at this time.

A moving state of the liquid L when the liquid L reaches the liquid holding member 15 in the housing 4 as shown in FIG. 8(c) will be described. 9(a) to 9(d) are schematic diagrams sequentially showing such movement states of the liquid L. FIG. A portion of the liquid L dropped onto the upper surface of the liquid holding member 15 from the tube 8 and the liquid supply port 10 flows into the first liquid guide groove 13 . Since the inner wall surface of the first liquid guide groove 13 is made difficult for the liquid L to permeate due to the surface treatment, the liquid L flowing into the first liquid guide groove 13 is shown by an arrow D in FIG. 9(a). , and guided to the second liquid guiding grooves 14 provided on the inner surface 4a of the side wall of the housing 4. As shown in FIG.

Note that when a large amount of liquid L flows into the first liquid guide groove 13, part of the liquid L that has flowed overflows the first liquid guide groove 13, and the surface of the liquid holding member 15 is not treated. It is absorbed inside the liquid holding member 15 from the point. The liquid L absorbed inside the liquid holding member 15 is guided to the element substrate 6 and ejected to the outside from the ejection port 7 as required.

As described above, the liquid L that has reached the second liquid guide groove 14 moves upward in the vertical direction as indicated by arrow E in FIG. , reaches the open end fixed to the lid member 5 of the housing 4 . In general, the capillary force is defined by h (m) as the liquid level in the tube, T (N/m) as the surface tension of the liquid, θ as the contact angle of the liquid with respect to the tube, and ρ (kg/m ³ ), where g (m/s ² ) is the gravitational acceleration and r (m) is the radius of the tube, h=2T cos θ/ρgr. In this embodiment, the second liquid guide groove 14 corresponds to the tube in this formula.

As described above, the liquid L reaching the open end fixed to the lid member 5 of the housing 4 is divided into four lines as indicated by arrows F in FIG. Move along the section. As shown in FIG. 3B, this movement of the liquid L is caused by a melted portion 11 (joint portion) generated in the portion where the opening end of the housing 4 and the lid member 5 are fixed to each other. It is caused by a capillary force generated in a slight gap or recess on the inner side of the body 4 . The liquid L thus moving along the edge of the opening of the housing 4 further moves as indicated by the arrow G in FIG. .

Thus, the liquid L guided by the first liquid guide groove 13 and the second liquid guide groove 14 spreads over the entire circumference of the opening end of the housing 4 fixed to the lid member 5 . When a minute gap (for example, a circular gap with a diameter of about several tens of μm) is generated in the fusion zone 11, the liquid L spreading around the entire circumference of the open end portion is formed inside the housing as shown in FIG. 3(b). The gap is closed by forming a meniscus that covers the gap of the fusion zone 11 from the inside of the body 4 . Since the meniscus of the liquid L is less likely to be broken unintentionally and easily retains its shape, minute leakage of the liquid L at the junction between the housing 4 and the lid member 5 can be suppressed. In particular, the periphery of the liquid ejection head 2 is kept at high humidity due to the presence of the ejected liquid L and the liquid L held in the tube 8 and the liquid container 12 , and is fixed to the lid member 5 . The meniscus of the liquid L formed at the open end of the liquid L tends to be retained for a long period of time. Furthermore, even if the meniscus of the liquid L is broken, the liquid suction operation shown in FIG. 8 is executed to supply the liquid L to the liquid ejection head 2, and the meniscus is formed again to close the gap.

As described above, in this embodiment, the first liquid guide groove 13 on the upper surface of the liquid holding member 15 and the second liquid guide groove 14 on the side wall inner surface 4 a of the housing 4 allow the liquid L to flow through the lid member 5 . It leads to the entire circumference of the end of the opening of the housing 4 fixed to. As a result, even if there is a small gap in the joint (melted portion 11) between the housing 4 and the lid member 5 or in the vicinity thereof, the liquid L is guided to the entire circumference of the opening end of the housing 4. The gap is closed by the meniscus of , the airtightness is maintained, and the reliability of the airtightness can be improved.

[Second embodiment]
Next, a second embodiment of the invention will be described. FIG. 10 is an exploded perspective view of the liquid ejection head 2 according to this embodiment. The liquid ejection head 2 of this embodiment has an inner lid member 16 arranged inside the housing in addition to the housing 4 and lid member 5 similar to those of the first embodiment.
FIG. 11(a) is a perspective view of the inner lid member 16 of this embodiment, and FIG. 11(b) is a cross-sectional view of the inner lid member 16 taken along a first liquid guiding groove 19, which will be described later. The inner lid member 16 is arranged on the liquid holding member 17 inside the housing 4 . The liquid holding member 17 of this embodiment does not have the first liquid guiding groove. The inner lid member 16 has a notch 18 at its end and a first liquid guide groove 19 on its upper surface. As with the first liquid guide groove 13 of the first embodiment, the first liquid guide groove 19 is housed in the liquid reservoir of the hollow housing 4 of the inner cover member 16 . extends to an end surface in contact with or close to the side wall inner surface 4a. A side wall inner surface 4a of the housing 4 is formed with a second liquid guide groove 14 similar to that of the first embodiment. The first liquid guide groove 19 of the inner lid member 16 and the second liquid guide groove 14 of the housing 4 are positioned so as to allow liquid communication with each other, and are in a so-called fluid communication state. As shown in FIG. 11(b), the first liquid guide groove 19 is provided with a protrusion 19a for guiding the liquid to the first liquid guide groove 19 at a position facing the liquid supply port 10 of the cover member 5. ing.

As in the first embodiment, when the liquid is supplied from the liquid container 12 to the inside of the housing 4 through the tube 8 and the liquid supply port 10 , the liquid drops onto the upper surface of the inner lid member 16 . Part of the liquid that has reached the upper surface of the inner lid member 16 passes through the first liquid guide groove 19 and the second liquid guide groove 14 and reaches the open end of the housing 4 fixed to the lid member 5. spreads over the entire circumference of the Even if there is a minute gap at or near the joint (melted portion 11) between the housing 4 and the lid member 5, the meniscus of the liquid guided over the entire circumference maintains the airtightness of the joint. The sealing reliability can be improved, and the same effect as in the first embodiment can be obtained. That is, in the present embodiment, the inner cover member 16, not the liquid holding member 17, is the member having the first liquid guide groove 19 formed on the upper surface thereof. Therefore, in this embodiment, the material, size, and shape of the liquid holding member 17 are highly flexible, any liquid holding member 17 can be used, and surface treatment is not required.

A part of the liquid that has reached the upper surface of the inner lid member 16 flows out of the portion other than the first liquid guide groove 19 or overflows the first liquid guide groove 19 and flows through the notch 18 into the lower liquid holding member. 17 and is absorbed. The liquid absorbed by the liquid holding member 17 is sent to the channel of the element substrate 6 . Since the configuration and steps other than those described above may be the same as those of the first embodiment, description thereof is omitted.

[Third Embodiment]
Next, a third embodiment of the invention will be described. 12A is a perspective view of the liquid holding member 20 of the liquid ejection head 2 according to this embodiment, and FIG. 12B is a cross-sectional view of the liquid holding member 20 taken along a first liquid guide groove 21, which will be described later. is. As shown in FIGS. 12(a) and 12(b), a first liquid guide groove 21 is formed in the upper surface of the liquid holding member 20 of this embodiment.
The first liquid guide groove 21 has a shape that slopes downward from a position facing the liquid supply port 10 toward the second liquid guide groove 14 on the side wall inner surface 4 a of the housing 4 . In the present embodiment, even if the liquid ejecting apparatus 1 is installed in a slightly tilted posture, the liquid dropped onto the upper surface of the liquid holding member 20 is divided into two systems in the same manner as in the state shown in FIG. 9A. Moving. That is, the movement of the liquid from the first liquid guide groove 21 to the second liquid guide groove 14 is performed with high reliability. Then, the sealing reliability can be improved as in the first embodiment. Note that the configuration and steps other than those described above may be the same as those of the first embodiment, so description thereof will be omitted.

[Fourth Embodiment]
Next, a fourth embodiment of the invention will be described. FIG. 13 is a perspective view of the housing 22 and the liquid holding member 15 of the liquid ejection head 2 according to this embodiment. The housing 22 of the present embodiment has five second grooves extending in a fan shape (radially) from a position connected to or close to the first liquid guide groove 13 of the liquid holding member 15 toward the opening end on the side wall inner surface 22a. It has a liquid guide groove 23 . In this embodiment, the movement of liquid from the first liquid guide groove 13 to the second liquid guide groove 23 is performed with higher reliability. Then, the sealing reliability can be improved as in the first embodiment. Note that the configuration and steps other than those described above may be the same as those of the first embodiment, so description thereof will be omitted.

[Fifth Embodiment]
Next, a fifth embodiment of the invention will be described. FIG. 14 is a perspective view of the housing 24 and the liquid holding member 25 of the liquid ejection head 2 according to this embodiment. The liquid holding member 25 of the present embodiment has two first liquid guiding grooves 26 formed on the upper surface thereof, the two first liquid guiding grooves 26 intersecting each other perpendicularly to form a cross shape. Four side wall inner surfaces 24a of the housing 24 are formed with second liquid guide grooves 27 extending from positions connected to or adjacent to the first liquid guide grooves 26 toward the open ends. In this embodiment, the movement of liquid from the first liquid guide groove 26 to the second liquid guide groove 27 is performed more reliably. Then, the sealing reliability can be improved as in the first embodiment. Note that the configuration and steps other than those described above may be the same as those of the first embodiment, so description thereof will be omitted.

[Sixth Embodiment]
Next, a sixth embodiment of the invention will be described. FIG. 15 is a perspective view of the housing 28 and the liquid holding member 29 of the liquid ejection head 2 according to this embodiment. The housing 28 of this embodiment has a partition wall 30 inside, and the liquid reservoir inside the housing 28 is divided into a plurality of (for example, three) compartments by the partition wall 30 . Each compartment of the liquid reservoir accommodates a liquid holding member 29 . Each liquid holding member 29 is formed with a first liquid guide groove 13 similar to that of the first embodiment. Further, on the side wall inner surface 28a of the housing 28 and the partition wall 30, second grooves similar to those in the first embodiment extend from a position connected to or adjacent to the first liquid guide groove 13 toward the opening end, respectively. A liquid guiding groove 31 is formed respectively. In the present embodiment, in the liquid ejection head 2 that ejects multicolor liquids, the liquid storage sections are separately used for each color to prevent the liquids of each color from being mixed with each other. Sealing reliability can be improved as in the embodiment. Note that the configuration and steps other than those described above may be the same as those of the first embodiment, so description thereof will be omitted.

It is also possible to arbitrarily combine the configurations of the embodiments described above. In the third to sixth embodiments, an inner cover member may be provided in the same manner as in the second embodiment, and the member forming the first liquid guide groove on the upper surface may be the inner cover member instead of the liquid holding member. can.

A more specific example of each embodiment of the present invention described above will be described.
(First embodiment)
In a first example of the present invention, the liquid ejection head 2 according to the first embodiment was manufactured. The liquid ejection head 2 of this embodiment is constructed using a material filled with a filler at a rate of 50% as the resin constituting the housing and lid member. Further, the housing accommodates a liquid holding member 15 (see FIG. 6) in which a semi-cylindrical concave first liquid guide groove 13 having a diameter of about 3.25 mm and a length of about 53 mm is formed. The inner surface of the first liquid guide groove 13 is surface-treated by heating from a hot plate of about 200° C. via a Teflon (registered trademark) sheet, and is in a state where liquid does not easily permeate. The side wall inner surface 4a of the housing 4 has a second liquid guiding groove 14 (see FIG. 7) having a width of 0.5 mm, a depth of 0.5 mm and a height of 7.5 mm.

This liquid ejection head 2 was mounted on the carriage 3 of the liquid ejection apparatus 1 shown in FIG. 1, and the tube 8 was filled with the liquid as shown in FIG. and left for 24 hours.
As a comparative example, although not shown, a liquid ejection head was constructed using a material in which a resin was filled with a filler at a rate of 50%. A liquid ejection head having a liquid holding member in which the first liquid guide groove is not formed and a housing in which the second liquid guide groove is not formed was manufactured. The liquid ejection head 2 of the comparative example was also mounted on the carriage 3 of the liquid ejection apparatus 1 shown in FIG. 1 and left for 24 hours in the state shown in FIG. 8(d). The liquid used in this example and comparative example is liquid ink with a surface tension of about 0.03 (N/m).

In the liquid ejection head of the comparative example, after being left for 24 hours, minute gas leakage occurred at the joint between the housing and the cover member, and the negative pressure inside the liquid ejection head could not be maintained. As a result, a phenomenon occurred in which the liquid in the tube moved toward the liquid container. On the other hand, in the liquid ejection head 2 of the present embodiment, minute gaps such as the joint portion (melting portion 11) are formed by the meniscus of the liquid that has reached the end portion of the opening of the housing 4 fixed to the lid member 5. The negative pressure inside the liquid ejection head 2 was maintained by being closed. Therefore, in the liquid ejection head 2 of this embodiment, printing by liquid ejection was possible by sending a drive signal to the liquid ejection device 1 . When the liquid discharge head 2 of this embodiment was horizontally cut along the edge of the opening of the housing 4 and observed, it was found that the liquid that had moved through the second liquid guide groove 14 spread over the entire circumference. was confirmed.

(Second embodiment)
In a second example of the present invention, the liquid ejection head 2 according to the second embodiment was manufactured. The liquid ejection head 2 of this embodiment is made of a material obtained by filling a resin with a filler at a rate of 50% as in the first embodiment. In addition, the housing is provided with an inner lid member 16 (see FIG. 11) in which a first liquid guide groove 19 having a width of 2 mm, a depth of 4 mm, and a length of about 53 mm is formed, and the first liquid guide groove. A liquid holding member 17 is accommodated. Other configurations were the same as those of the liquid ejection head of the first embodiment. This liquid ejection head 2 was processed in the same manner as in the first embodiment, and the maintenance of the negative pressure in the liquid ejection head 2 and the state of movement of the liquid to the joint portion were verified. good results were obtained.

(Third embodiment)
In a third example of the present invention, the liquid ejection head 2 according to the third embodiment was manufactured. The liquid ejection head 2 of this embodiment is also made of the same material as in the first embodiment. A liquid holding member 20 (see FIG. 12) in which a semi-cylindrical concave first liquid guide groove 21 having a diameter of 3.25 mm and a length of about 53 mm is formed is housed. The first liquid guide groove 21 is inclined by about 4° from a position facing the liquid supply port 10 toward the second liquid guide groove 14 on the side wall inner surface 4 a of the housing 4 . rice field. Other configurations were the same as those of the liquid ejection head of the first embodiment. This liquid ejection head 2 was processed in the same manner as in the first embodiment, and the maintenance of the negative pressure in the liquid ejection head 2 and the state of movement of the liquid to the joint portion were verified. good results were obtained.

(Fourth embodiment)
In Example 4 of the present invention, the liquid ejection head 2 according to the above-described fourth embodiment was manufactured. The liquid ejection head 2 of this embodiment is also made of the same material as in the first embodiment. Further, five second liquid guide grooves 23 are formed on the inner surface of the side wall so as to fan out (radiately) from a position connected to or close to the first liquid guide groove 13 of the liquid holding member 15 toward the open end. A housing 22 (see FIG. 13) is accommodated. Each of the five second liquid guide grooves 23 is approximately 0.5 mm wide, 0.5 mm deep, and 7.5 mm high. Other configurations were the same as those of the liquid ejection head of the first embodiment. This liquid ejection head 2 was processed in the same manner as in the first embodiment, and the maintenance of the negative pressure in the liquid ejection head 2 and the state of movement of the liquid to the joint portion were verified. good results were obtained.

(Fifth embodiment)
In Example 5 of the present invention, the liquid ejection head 2 according to the fifth embodiment was manufactured. The liquid ejection head 2 of this embodiment is also made of the same material as in the first embodiment. A liquid holding member 25 having two cross-shaped first liquid guide grooves 26 on its upper surface, and a second liquid guide extending from a position connected or adjacent to the first liquid guide groove 26 toward the opening end. It has a housing 24 with grooves 27 formed in the inner surface of its four side walls. Each of the first liquid guide grooves 26 has a semi-cylindrical concave shape with a diameter of 3.25 mm and a length of about 53 mm. The height was about 7.5 mm (see FIG. 14). Other configurations were the same as those of the liquid ejection head of the first embodiment. This liquid ejection head 2 was processed in the same manner as in the first embodiment, and the maintenance of the negative pressure in the liquid ejection head 2 and the state of movement of the liquid to the joint portion were verified. good results were obtained.

(Sixth embodiment)
In Example 6 of the present invention, the liquid ejection head 2 according to the sixth embodiment was manufactured. The liquid ejection head 2 of this embodiment is also made of the same material as in the first embodiment. It also has a housing 28 having therein a partition wall 30 that divides the liquid reservoir into three compartments (see FIG. 15). A liquid holding member 29 is accommodated in each of three compartments of the liquid reservoir of the housing 28 divided by the partition wall 30 . The upper surface of each liquid holding member 29 is formed with first liquid guiding grooves 13 each having a diameter of about 3.25 mm and extending over the entire liquid holding member 29 and having a semi-cylindrical concave shape. Each of the side wall inner surface of the housing 28 and the partition wall 30 has a width of 0.5 mm and a depth of 0.5 mm, each extending from a position connected to or adjacent to the first liquid guide groove 13 toward the opening end. A second liquid guiding groove 31 having a height of about 7.5 mm is formed. Other configurations were the same as those of the liquid ejection head of the first embodiment. This liquid ejection head 2 was processed in the same manner as in the first embodiment, and the maintenance of the negative pressure in the liquid ejection head 2 and the state of movement of the liquid to the joint portion were verified. good results were obtained.

According to the present invention, it is possible to provide a liquid ejection head and a liquid ejection apparatus having high sealing reliability, with respect to a liquid ejection head configured using a material having a large filler content. In addition, it goes without saying that the reliability of the sealing performance is further improved in a liquid ejection head constructed using a material with a low filler content.

2 Liquid ejection head 4 Housing 4a Side wall inner surface 5 Lid member 10 Liquid supply port 15 Liquid holding member (member arranged inside the housing)
13 First liquid guide groove 14 Second liquid guide groove

Claims (14)

a hollow housing having an opening at one end; a cover member fixed to an end of the opening of the housing to close the opening; and a member arranged inside the housing;
The lid member is provided with a liquid supply port for supplying liquid to the inside of the housing,
A first liquid guide groove is formed on the upper surface of the member and onto which the liquid supplied through the liquid supply port is dropped, and a second liquid guide groove is formed on the inner surface of the side wall of the housing. is formed and
The second liquid guide groove extends from the end of the opening fixed to the lid member toward the opposite side of the opening on the inner surface of the side wall of the housing. The liquid guide groove extends to a side surface of the member that is in contact with or close to the inner surface of the side wall of the housing, and the first liquid guide groove and the second liquid guide groove are positioned so as to allow liquid communication with each other. A liquid ejection head characterized by: 2. The liquid ejection head according to claim 1, wherein a part of said second liquid guide groove is positioned on an extension line of said first liquid guide groove. 3. The liquid ejection head according to claim 1, wherein said member having an upper surface on which said first liquid guide groove is formed is a liquid holding member. 4. The liquid ejection head according to claim 3, wherein an inner wall surface of said first liquid guide groove is surface-treated. A liquid holding member and an inner lid member positioned on the liquid holding member are arranged inside the housing, and the member having the first liquid guiding groove formed on the top surface is provided with the inner lid member. 3. The liquid ejection head according to claim 1, which is a lid member. 6. The liquid ejection head according to claim 5, wherein the inner lid member is provided with a notch for allowing the liquid to flow toward the liquid holding member. 7. The liquid guided from the first liquid guide groove and the second liquid guide groove to the end of the opening spreads over the entire circumference of the end of the opening. 2. The liquid ejection head according to item 1 or 2. The lid member is fixed to the end of the opening of the housing by welding, and the liquid guided to the end of the opening is melted by welding the lid member and the end of the opening of the housing. 8. The liquid ejection head according to claim 7, wherein the melted portion spreads over the entire circumference of the end portion of the opening on the inside side of the housing. 9. The liquid ejection head according to any one of claims 1 to 8, wherein an element substrate for ejecting liquid is attached to the housing on a side opposite to the opening. The first liquid guide groove has a shape that slopes downward from a position facing the liquid supply port toward the second liquid guide groove on the inner surface of the side wall of the housing. The liquid ejection head according to any one of claims 1 to 9. A plurality of the second liquid guide grooves are formed on the inner surface of the side wall of the housing so as to radially expand from a position connected to or adjacent to the first liquid guide grooves toward the end of the opening. 11. The liquid ejection head according to any one of claims 1 to 10. 2. An upper surface of said member is formed with two said first liquid guide grooves that intersect with each other, and said second liquid guide grooves are formed respectively with four side wall inner surfaces of said housing. 12. The liquid ejection head according to any one of 11 to 11. A partition wall is provided inside the housing, and the first liquid guide grooves are formed in members arranged in respective compartments divided by the partition wall, and 13. The liquid ejection head according to any one of claims 1 to 12, wherein said second liquid guide groove is formed in said wall surface and said partition wall. A liquid ejection head according to any one of claims 1 to 13, a liquid container containing liquid to be supplied to the liquid ejection head, and a connection member connecting the liquid ejection head and the liquid container. liquid ejection device.

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