CN107433777B

CN107433777B - Liquid ejecting head and liquid ejecting apparatus

Info

Publication number: CN107433777B
Application number: CN201710384419.5A
Authority: CN
Inventors: 浜野勇一郎; 本乡丰
Original assignee: SII Printek Inc
Current assignee: SII Printek Inc
Priority date: 2016-05-27
Filing date: 2017-05-26
Publication date: 2020-05-12
Anticipated expiration: 2037-05-26
Also published as: CN107433777A

Abstract

The invention provides a liquid ejecting head and a liquid ejecting apparatus capable of suppressing mixing of ink ejected from each head module on an ejection surface. Specifically, the device is provided with: head chips each having discharge channels filled with ink and arranged in parallel in the Y direction; a nozzle plate (32) which is fixed to each head chip together and in which nozzle holes (131A-131D) that communicate with the channels of each head chip are formed; and a second adhesion region (151) that is located on a-Z-direction end face of the nozzle plate (32) and that partitions between the second nozzle holes (131B) and the second nozzle holes (131C).

Description

Liquid ejecting head and liquid ejecting apparatus

Technical Field

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

Background

Conventionally, there is an ink jet printer including an ink jet head as a device for ejecting ink in a droplet form onto a recording medium such as recording paper to record an image or a character on the recording medium. The ink jet head is configured by mounting a plurality of head modules corresponding to respective colors on a carriage, for example (for example, patent document 1 listed below).

The head module includes a head chip having a channel filled with ink. The nozzle plate is bonded to the head chip.

In the inkjet head, ink in the channel is discharged through the nozzle hole formed in the nozzle plate by a change in volume in the channel.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2015-120265.

Disclosure of Invention

Problems to be solved by the invention

Therefore, in the ink jet head, the nozzle holes corresponding to the respective head modules are formed in one nozzle plate, and the one nozzle plate is bonded to the head chips of the plurality of head modules at a time. With this configuration, it is considered that the positional accuracy of the nozzle holes between the head modules can be improved as compared with the case where the nozzle plates are joined to the head modules, respectively.

However, in the above configuration, among the inks discharged from the respective head modules, there is a risk that the inks adhering to the discharge surface of the nozzle plate (the surface on which the nozzle holes are opened) are mixed on the discharge surface.

The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting head and a liquid ejecting apparatus capable of suppressing mixing of ink ejected from each head module on an ejection surface.

Means for solving the problems

In order to solve the above problem, a liquid ejecting head according to an aspect of the present invention includes: a first head chip and a second head chip, which are respectively formed with channels filled with liquid and are arranged in parallel along a first direction; an injection orifice plate which is fixed to the first head chip and the second head chip together, and which is formed with a first injection hole communicating with the passage of the first head chip and a second injection hole communicating with the passage of the second head chip; and a partition portion that is located on an ejection surface of the ejection orifice plate facing a side opposite to the first head chip and the second head chip and partitions the first ejection hole and the second ejection hole.

According to this configuration, the liquid adhering to the ejection surface of the ejection orifice plate is blocked by the partition between the first ejection orifices and the second ejection orifices. This can prevent the liquid ejected from the first ejection orifices and the liquid ejected from the second ejection orifices from mixing on the ejection surface and leaking to the outside of the liquid ejecting head. As a result, a liquid ejecting head having excellent reliability can be provided.

In the above aspect, the injection orifice plate may be bonded and fixed to the first head chip and the second head chip, and a slit that penetrates the injection orifice plate in a direction normal to the injection surface may be formed in a portion of the injection orifice plate that is located between the first injection hole and the second injection hole.

According to the above aspect, after the ejection orifice plate is attached to the head chip, when the ejection orifice plate expands and contracts with a temperature change at the time of curing the adhesive, the slits expand and contract, and thereby deformation of the ejection orifice plate can be absorbed. This can ensure the positional accuracy of the ejection orifice plate with respect to the head chip, and can suppress the ejection orifice plate from peeling off or the like.

In the above aspect, the present invention may further include: a base unit that supports the first head chip and the second head chip, and to which the ejection orifice plate is adhesively fixed; and an injection hole guard that is formed with an exposure hole exposing the first injection hole and the second injection hole, and covers the injection hole plate from an opposite side of the base unit with the injection hole plate interposed therebetween, wherein the partition is an adhesive that fixes the base unit and the injection hole guard via the slit.

According to the above aspect, the base unit and the jet hole guard are bonded through the slit, and the jet hole guard can be bonded even when the water repellent treatment is performed on the ejection surface of the ejection orifice plate. In addition, since the base unit and the ejection hole guard are connected by the adhesive, it is possible to reliably suppress the liquid ejected from the first ejection hole and the liquid ejected from the second ejection hole from being mixed on the ejection surface.

In the above aspect, the present invention may further include: a first manifold that is disposed adjacent to the first head chip in the first direction, supports the first head chip with a support surface facing the first direction, and has a liquid flow path communicating with the channel; a first driving substrate supported by the supporting surface of the first manifold and electrically connected to the first head chip; a second manifold which is disposed adjacent to the second head chip in the first direction, supports the second head chip by a support surface facing the first direction, and has a liquid flow path communicating with the channel; and a second driving substrate supported by the supporting surface of the second manifold and electrically connected to the second head chip.

According to the above aspect, the head chip and the drive substrate are supported by the support surface of the manifold having the liquid flow path. Therefore, for example, the liquid ejecting head can be downsized in the first direction as compared with a configuration in which the head chip and the drive substrate are supported by the two surfaces of the manifold in the first direction.

In addition, since the head chip and the drive substrate are supported by the manifold, heat generated in the head chip and the drive substrate is dissipated to the outside through the manifold. This ensures heat dissipation performance of the head chip and the drive substrate.

Further, since the head chip and the drive substrate are supported by the manifold having the liquid flow path, the liquid flowing through the liquid flow path can be heated by the heat of discharge generated in the head chip and the drive substrate and transferred to the manifold. Thus, the liquid can be supplied to the head chip at a desired temperature (viscosity), and excellent printing characteristics can be obtained.

A liquid ejecting apparatus according to an aspect of the present invention includes the liquid ejecting head according to the above aspect.

According to the above aspect, a liquid ejecting apparatus having excellent reliability can be provided.

Effects of the invention

According to one embodiment of the present invention, a liquid ejecting head and a liquid ejecting apparatus can be provided which can suppress mixing of ink ejected from each head module on an ejection surface and have excellent reliability.

Drawings

Fig. 1 is a schematic configuration diagram of an inkjet printer according to an embodiment;

fig. 2 is a perspective view of an ink jet head according to an embodiment;

fig. 3 is a perspective view showing a state where a part of the inkjet head according to the embodiment is detached;

fig. 4 is a perspective view of a first head module according to the embodiment;

fig. 5 is an exploded perspective view of a head chip according to the embodiment;

fig. 6 is an exploded perspective view of a manifold according to an embodiment;

fig. 7 is an exploded perspective view of a base member, a nozzle plate, and a nozzle guard according to an embodiment;

FIG. 8 is a partial bottom view of the ink jet head according to the embodiment viewed from the-Z direction;

fig. 9 is a cross-sectional view of an ink jet head according to a modification of the embodiment.

Detailed Description

Embodiments according to the present invention will be described below with reference to the drawings. In the following embodiments, an ink jet printer (hereinafter, simply referred to as a printer) that records on a recording medium with ink (liquid) will be described as an example. In the drawings used in the following description, the scale of each member is appropriately changed so that each member can be recognized.

[ Printer ]

Fig. 1 is a schematic configuration diagram of the printer 1.

As shown in fig. 1, the printer 1 of the present embodiment includes a pair of

transport mechanisms

2 and 3, an ink supply mechanism 4,

inkjet heads

5A and 5B, and a scanning mechanism 6. In the following description, an orthogonal coordinate system of X, Y, Z will be used as necessary. In this case, the X direction coincides with a conveyance direction (sub-scanning direction) of the recording medium P (e.g., paper). The Y direction (first direction) coincides with the scanning direction (main scanning direction) of the scanning mechanism 6. The Z direction (normal direction) represents a height direction orthogonal to the X direction and the Y direction. In the following description, the arrow direction in the drawings is referred to as the plus (+) direction and the direction opposite to the arrow is referred to as the minus (-) direction among the X direction, the Y direction and the Z direction.

The

transport mechanisms

2 and 3 transport the recording medium P in the + X direction. Specifically, the conveying mechanism 2 includes a grid roller (grid roller)11 extending in the Y direction, a pinch roller (pinch roller)12 extending parallel to the grid roller 11, and a driving mechanism (not shown) such as a motor for rotating the grid roller 11 around the shaft. Similarly, the conveyance mechanism 3 includes a grid roller 13 extending in the Y direction, a pinch roller 14 extending parallel to the grid roller 13, and a drive mechanism (not shown) for rotating the grid roller 13 around the shaft.

The ink supply mechanism 4 includes an ink tank 15 containing ink, and an ink pipe 16 connecting the ink tank 15 and the inkjet heads 5A and 5B.

In the present embodiment, a plurality of ink tanks 15 are arranged in the X direction. Each ink tank 15 contains, for example, four colors of yellow, magenta, cyan, and black.

The ink pipe 16 is, for example, a flexible hose having flexibility. The ink pipes 16 connect the ink tanks 15 and the ink jet heads 5A and 5B.

The scanning mechanism 6 reciprocally scans the inkjet heads 5A, 5B in the Y direction. Specifically, the scanner unit 6 includes a pair of

guide rails

21 and 22 extending in the Y direction, a carriage 23 movably supported by the pair of

guide rails

21 and 22, and a drive mechanism 24 for moving the carriage 23 in the Y direction.

The drive mechanism 24 is disposed between the guide rails 21, 22 in the X direction. The drive mechanism 24 includes a pair of

pulleys

25, 26 arranged at intervals in the Y direction, an endless belt 27 wound around the pair of

pulleys

25, 26, and a drive motor 28 for driving and rotating the one pulley 25.

The carriage 23 is connected to an endless belt 27. The plurality of inkjet heads 5A and 5B are mounted on the carriage 23 in a state of being aligned in the Y direction. The inkjet heads 5A and 5B are configured to be able to discharge two-color ink for each of the inkjet heads 5A and 5B. Therefore, in the printer 1 of the present embodiment, the ink jet heads 5A and 5B are configured to discharge two different colors of ink, and to be able to discharge four colors of ink, i.e., yellow, magenta, cyan, and black.

< ink jet head >

Fig. 2 is a perspective view of the ink-jet head 5A. The inkjet heads 5A and 5B are configured similarly except for the color of the supplied ink. Therefore, in the following description, the inkjet head 5A will be described, and the description of the inkjet head 5B will be omitted.

As shown in fig. 2, the ink jet head 5A of the present embodiment is configured such that head modules 30A to 30D, a buffer 31, a nozzle plate (ejection orifice plate) 32, a nozzle guard (ejection orifice guard) 33, and the like are mounted on a base member (base unit) 38. In fig. 2, a cover or the like covering the head modules 30A to 30D, the buffer 31, and the like is not shown.

(base member)

Fig. 3 is a perspective view showing a state where a part of the inkjet head 5A is detached.

As shown in fig. 3, the base member 38 is formed in a plate shape having the Z direction as the thickness direction and the X direction as the longitudinal direction. The base member 38 includes a module holding portion 41 for holding the respective head modules 30A to 30D, and a carriage fixing portion 42 for fixing the base member 38 to the carriage 23 (see fig. 1). In addition, in the present embodiment, the base member 38 is integrally formed of a metal material.

The module holding portion 41 is formed in a frame shape in a plan view seen from the Z direction. That is, a mounting opening 44 that penetrates the base member 38 in the Z direction is formed in the module holding portion 41 at the center portion on the XY plane. Insertion grooves 46 are formed in a pair of short side portions 45 positioned on both sides in the X direction in the module holding portion 41. In the insertion grooves 46 of the present embodiment, the insertion grooves 46 that face each other in the X direction among the insertion grooves 46 formed in the short side portions 45 are formed as one set, and a plurality of sets (for example, four sets) are formed at intervals in the Y direction.

Each insertion groove 46 is recessed in the X direction with respect to the inner peripheral surface of the short side portion 45, and penetrates the short side portion 45 in the Z direction. That is, the insertion groove 46 communicates with the mounting opening portion 44. The head modules 30A to 30D can be inserted into the respective sets of insertion grooves 46 facing each other in the X direction. In each of the groups of insertion grooves 46, a first acting member (not shown) that acts on the head modules 30A to 30D to one side in the X direction is disposed on the inner surface of one insertion groove 46 and toward the other insertion groove 46. In the present embodiment, the first acting member is formed in a leaf spring shape.

The carriage fixing portion 42 extends from the + Z direction end of the module holding portion 41 toward the XY plane. The carriage fixing portion 42 is formed with a mounting hole or the like for mounting the base member 38 to the carriage 23 (see fig. 1).

(head Module)

As shown in fig. 2, the head modules 30A to 30D are configured to discharge ink supplied from the ink tank 15 (see fig. 1) to the recording medium P. A plurality of head modules 30A to 30D are mounted on the base member 38 at intervals in the Y direction. In the present embodiment, four head modules, i.e., the first head module 30A, the second head module 30B, the third head module 30C, and the fourth head module 30D, are mounted on the base member 38.

In the ink jet head 5A of the present embodiment, two of the four head modules 30A to 30D discharge ink of one color. Specifically, the first head module 30A and the second head module 30B are configured to be able to discharge ink of the same color, and the third head module 30C and the fourth head module 30D are configured to be able to discharge ink of the same color. The number of the head modules 30A to 30D mounted on the base member 38, the type of ink discharged from the head modules 30A to 30D, and the like can be changed as appropriate. In addition, since the head modules 30A to 30D include the corresponding structures, the first head module 30A will be described as an example in the following description.

Fig. 4 is a perspective view of the first head module 30A.

As shown in fig. 4, the first head module 30A mainly includes a head chip 51, a manifold 52, and a drive substrate 53.

(head chip)

Fig. 5 is an exploded perspective view of the head chip 51.

As shown in fig. 5, the head chip 51 is of a so-called edge shooter type (edge shooter type) that ejects ink from an end of an extension direction (Z direction) of an ejection channel 57 described later. Specifically, the head chip 51 is configured by overlapping the actuator plate 55 and the cover plate 56 in the Y direction.

The actuator plate 55 is a so-called unipolar substrate in which the polarization direction is set in one direction in the thickness direction (Z direction). Further, the actuator plate 55 preferably uses, for example, a ceramic substrate including PZT (lead zirconate titanate) or the like. In addition, the actuator plate 55 may also be formed by laminating two piezoelectric substrates whose polarization directions are different in the Y direction (a so-called chevron (chevron) type).

On a surface (hereinafter referred to as "surface") of the actuator plate 55 facing the + Y direction, a plurality of

channels

57 and 58 are arranged in parallel at intervals in the X direction. Each of the

passages

57, 58 is formed linearly in the Z direction. Each

channel

57, 58 opens on the-Z-direction end face of actuator plate 55 and terminates at the + Z-direction end of actuator plate 55. Furthermore, the

channels

57, 58 may also extend obliquely with respect to the Z-direction.

The plurality of

channels

57 and 58 are discharge channels 57 filled with ink and non-discharge channels 58 not filled with ink. The discharge channels 57 and the non-discharge channels 58 are alternately arranged in the X direction. Each of the

passages

57, 58 is partitioned in the X direction by a drive wall 61 formed by the actuator plate 55, respectively. Further, driving electrodes, not shown, are formed on the inner surfaces of the

channels

57 and 58.

The cover 56 is formed in a rectangular shape in a front view seen from the Y direction. The cover plate 56 is joined to the surface of the actuator plate 55 in a state where the + Z direction end of the actuator plate 55 is projected.

The cover 56 has a common ink chamber 62 formed on a surface facing the + Y direction (hereinafter referred to as "front surface") and a plurality of slits 63 formed on a surface facing the-Y direction (hereinafter referred to as "rear surface").

The common ink chamber 62 is formed at a position equal to the + Z direction end of the discharge passage 57 in the Z direction. The common ink chamber 62 is recessed from the surface of the cover 56 toward the-Y direction, and is provided extending in the X direction. The ink flows into the common ink chamber 62 through the manifold 52.

The slit 63 is formed in the common ink chamber 62 at a position facing the ejection passage 57 in the Y direction. The slits 63 communicate the inside of the common ink chamber 62 with the inside of each discharge passage 57 individually. On the other hand, the non-discharge path 58 does not communicate with the inside of the common ink chamber 62.

As shown in fig. 4, a heat transfer plate 65 is attached to a surface (hereinafter referred to as "rear surface") of the actuator plate 55 facing in the-Y direction. The heat transfer plate 65 is formed of a material (for example, aluminum or the like) having excellent thermal conductivity. Heat transfer plate 65 is provided on the back surface of actuator plate 55 so as to cover the entire range of each of

channels

57, 58. The size and position of the heat transfer plate 65 can be changed as appropriate.

(manifold)

As shown in fig. 3, the manifold 52 has an ink flow path 71 (see fig. 6) through which ink flows toward the head chip 51. The manifold 52 is formed in a plate shape with the Y direction as the thickness direction as a whole. The manifold 52 is held by the base member 38 in a state of rising in the + Z direction by being inserted into a pair of insertion grooves 46 facing each other in the X direction among the insertion grooves 46. As shown in fig. 4, at both ends in the X direction, at the-Z direction end portions of the manifold 52, second acting members 70 are provided. The second acting member 70 is interposed between the inner surface of the insertion groove 46 and the manifold 52 within the insertion groove 46, and acts on the first head module 30A in the-Y direction. In the present embodiment, the second acting member 70 is formed in a leaf spring shape.

Fig. 6 is an exploded perspective view of the manifold 52.

As shown in fig. 6, the manifold 52 includes a flow path member 72 and a flow path cover 73 overlapping the flow path member 72 in the Y direction.

The flow path member 72 is integrally formed of a material having excellent thermal conductivity. In the present embodiment, among the materials of the flow path member 72, a metal material (for example, aluminum or the like) is preferably used.

The flow path member 72 includes a flow path plate 75 and an inlet port 76.

The flow path plate 75 is formed in a rectangular plate shape with the Y direction as the thickness direction. An ink flow path 71 is formed on a surface of the flow path plate 75 facing the-Y direction. The ink flow path 71 is formed in a groove shape recessed in the + Y direction. Specifically, the ink flow path 71 includes the meandering portion 79 and the communication portion 80.

The meandering portion 79 meanders in the X direction and extends in the Z direction. The + Z direction end of the meandering portion 79 communicates with the inside of the inflow port 76. On the other hand, the-Z direction end of the meandering portion 79 communicates with the communication portion 80 at the X direction central portion of the flow channel plate 75. The meandering direction of the meandering portion 79 can be appropriately changed if it meanders so as to lengthen a straight line connecting a communication portion between the meandering portion 79 and the inlet port 76 and a communication portion between the meandering portion 79 and the communication portion 80. For example, the meandering portion 79 may be configured to meander in the Z direction and extend in the X direction.

The communication portion 80 extends in the X direction at the-Z direction end of the flow path plate 75. The communicating portion 80 is configured in a shape equivalent to the common ink chamber 62 in a front view seen from the Y direction.

In the first head module 30A, the inflow port 76 is provided at an end in the-X direction among the + Z direction end surfaces of the flow path plate 75. The inflow port 76 is formed in a cylindrical shape protruding in the + Z direction from the flow path plate 75. the-Z direction end of the inflow port 76 communicates with the above-described meandering portion 79.

The flow path cover 73 has an outer shape equivalent to the flow path plate 75 in a front view seen from the Y direction, and is formed in a rectangular plate shape having a thickness in the Y direction smaller than the flow path plate 75. The flow path cover 73 is fixed to a surface of the flow path plate 75 facing the-Y direction to close the ink flow path 71 from the-Y direction. A communication hole 82 for opening the communication portion 80 is formed in the flow path cover 73 at a position overlapping the communication portion 80 when viewed in the Y direction. The communication hole 82 is formed in the same shape as the communication portion 80 in a front view seen in the Y direction.

In the present embodiment, the flow path cover 73 is formed of a metal material (for example, stainless steel) having excellent thermal conductivity. In the present embodiment, the description has been given of the case where the groove-shaped ink flow path 71 is formed only in the flow path member 72, but the present invention is not limited to this configuration, and an ink flow path may be formed at least in at least one of the flow path member 72 and the flow path cover 73. In this case, for example, grooves may be formed in the flow path member 72 and the flow path cover 73, respectively, and the ink flow path may be formed by overlapping the grooves of the flow path member 72 and the flow path cover 73.

An insulating sheet 86 is provided on the surface of the channel cover 73 facing the-Y direction. The insulating sheet 86 is formed in a frame shape in a front view seen from the Y direction. The insulating sheet 86 surrounds the periphery of the communication hole 82 on the surface of the passage cover 73 facing the-Y direction. The insulating sheet 86 is fixed to the surface of the flow path cover 73 facing the-Y direction by bonding or the like. In the present embodiment, for example, polyimide is preferably used for the insulating sheet 86. However, the material of the insulating sheet 86 can be appropriately changed if it is formed of a material (for example, a resin material or a rubber material) having a property of sufficiently reducing the stray capacitance (such as a material having a low dielectric constant ( change rate) or a material having a low dielectric constant at a small spatial distance), ink resistance (dissolution resistance), and is relatively soft (having a young's modulus (ヤング rate)).

As shown in fig. 4 and 6, the head chip 51 is fixed to a surface (support surface) of the flow path cover 73 facing the-Y direction with the insulating sheet 86 interposed therebetween. Specifically, the head chip 51 is fixed to the insulating sheet 86 by bonding or the like in a state where the surface of the cover plate 56 (the surface facing the manifold 52) faces the insulating sheet 86. At this time, the common ink chamber 62 of the cover 56 communicates with the communicating portion 80 through the communicating hole 82. Thereby, the ink flowing through the ink flow path 71 is supplied to the head chip 51. The head chip 51 protrudes in the-Z direction with respect to the manifold 52 in a state of being fixed to the manifold 52. In the example shown in fig. 4, the length of the head chip 51 in the X direction is shorter than the length of the manifold 52 in the X direction.

As shown in fig. 2, a heater 85 is disposed on a surface of the passage member 72 (passage plate 75) facing in the + Y direction. The heater 85 heats the inside of the ink flow path 71 by the flow path member 72, and thereby maintains (keeps) the ink flowing through the ink flow path 71 within a predetermined temperature range.

As shown in fig. 4, the drive substrate 53 is a so-called flexible printed board, and is configured by mounting a wiring pattern and various electronic components on a base film. The drive substrate 53 has a module control portion 88 supported by the manifold 52, and a chip connection portion 89 connecting the module control portion 88 and the head chip 51. In addition, when at least the chip connection portion 89 of the driving board 53 is formed of a flexible board, a rigid board may be used for the module control portion 88.

The module control portion 88 is formed in a rectangular shape in a front view seen from the Y direction. Electronic components such as a driver IC are mounted on the module control section 88. The module control unit 88 is fixed to the manifold 52 with the support plate 90 interposed therebetween at a portion located in the + Z direction with respect to the head chip 51 on the surface of the passage cover 73 facing the-Y direction. The support plate 90 is formed of a material (for example, a metal material) having excellent thermal conductivity. Further, the support plate 90 may not be provided. That is, the module control unit 88 may be directly fixed to the manifold 52.

As shown in fig. 2, the drive board 53 is electrically connected to the external connection board 92 via a lead portion 91 led out in the + Z direction from the module control portion 88. The external connection board 92 relays control signals and drive voltages for the head modules 30A to 30D (driver ICs) output from a main control board (not shown) mounted in the printer 1. The drive board 53 drives the head chip 51 based on the control signal and the drive voltage relayed by the external connection board 92.

As shown in fig. 4, the chip connection portion 89 extends from the module control portion 88 in the-Z direction with a gap in the Y direction with respect to the flow path cover 73. the-Z direction end of the chip connection portion 89 is fixed to the + Z direction end of the actuator plate 55 by crimping or the like. Thereby, the drive substrate 53 and the drive electrodes of the head chip 51 are electrically connected.

The drive substrate 53 includes a sensor connection portion 93 led out from the + X direction end of the module control portion 88. The sensor connection portion 93 extends to a position overlapping the heat transfer plate 65 as viewed in the Y direction. A temperature sensor 94 (e.g., a thermistor) for detecting the temperature of the ink in the discharge passage 57 is attached to a distal end portion of the sensor connecting portion 93. The temperature sensor 94 is disposed with the heat transfer plate 65 sandwiched between the back surfaces of the actuator plates 55.

As shown in fig. 3, the first head module 30A is inserted into the mounting opening portion 44 in a state where the manifold 52 is inserted into the insertion groove 46 as described above. At this time, the first head module 30A is held by the base member 38 such that the head chip 51 faces the-Y direction and the-Z direction end face of the head chip 51 is flush with the-Z direction end face of the base member 38 (module holding portion 41).

As shown in fig. 2 and 3, the second head module 30B is inserted into the mounting opening 44 in a state of being inserted into the insertion groove 46 adjacent to the insertion groove 46 into which the manifold 52 of the first head module 30A is inserted in the-Y direction. At this time, the second head module 30B is held by the base member 38 in a state where the head chips 51 face the head chips 51 of the first head module 30A in the Y direction. The inlet ports 76 of the first head module 30A and the second head module 30B are arranged at the same position in the X direction.

The head chips (first head chips) 51 of the second head module 30B are arranged with the arrangement pitch of the discharge channels 57 shifted by half pitch (staggered) with respect to the head chips 51 of the first head module 30A. Thus, the head chips 51 of the first head module 30A and the second head module 30B cooperatively eject ink of one color, thereby realizing high-density recording of characters and images recorded on the recording medium P. In the first head module 30A and the second head module 30B, the arrangement pitch of the ejection channels 57 of the head chips 51 can be changed as appropriate.

As shown in fig. 2, the third head module 30C and the fourth head module 30D are held by the base member 38 in the same manner as the first head module 30A and the second head module 30B described above, with the respective head chips (second head chips) 51 facing each other. Each of the head modules 30A to 30D is fixed to the base member 38 via a support column, not shown, provided upright in the + Z direction from the base member 38. The inflow ports 76 of the third head module 30C and the fourth head module 30D are located on the opposite side in the X direction (end in the + X direction of the flow path plate 75) from the inflow ports 76 of the first head module 30A and the second head module 30B.

(buffer)

The buffer 31 is provided in the + Z direction with respect to the head modules 30A to 30D in accordance with the color of the ink. That is, the buffer 31 of the present embodiment is provided for every two head modules (for example, the

head modules

30A and 30B). The buffers 31 are arranged in the Y direction. Each buffer 31 has the same configuration except for the color of the supplied ink. Therefore, in the following description, one of the buffers 31 (buffers for the

head modules

30A and 30B) will be described, and the description of the other buffer 31 will be omitted.

The buffer 31 is attached to the

head modules

30A and 30B in the + Z direction via a support column, not shown, fixed to the base member 38. The damper 31 has an inlet port 100, a pressure buffer 101, and an outlet port 102. Further, the buffer 31 may be provided separately from the inkjet heads 5A.

The inlet port 100 is formed in a cylindrical shape protruding from the pressure buffer 101 in the + Z direction. The ink pipe 16 (see fig. 1) is connected to the inlet port 100. The ink in the ink tank 15 flows into the inlet port 100 through the ink pipe 16.

The pressure buffer portion 101 is formed in a box shape. The pressure buffer 101 is configured by housing a movable film and the like therein. The pressure buffer 101 is disposed between the ink tank 15 (fig. 1) and the

head modules

30A, 30B to absorb pressure fluctuations of the ink supplied to the buffer 31 through the inlet port 100.

The outlet port 102 is formed in a cylindrical shape protruding from the pressure buffer 101 in the-X direction. The ink discharged from the pressure buffer 101 flows into the outlet port 102.

A filter unit 110 is connected to the outlet port 102. The filter unit 110 houses a filter, not shown, therein. The filter unit 110 removes bubbles, foreign substances, and the like contained in the ink discharged from the buffer 31 by a filter. The filter unit 110 has

branch portions

111 and 112 that branch the ink discharged from the buffer 31 into two. One branch portion 111 is connected to the inflow port 76 of the first head module 30A via a connection pipe 113. The other branch portion 112 is connected to the inflow port 76 of the second head module 30B via a connection pipe 114. The filter unit 110 is fixed to the base member 38 via a support column not shown. The external connection substrate 92 is disposed between the buffers 31 facing each other in the Y direction.

Fig. 7 is an exploded perspective view of the base member 38, the nozzle plate 32, and the nozzle guard 33.

As shown in fig. 7, a spacer (base unit) 120 is fixed to a-Z-direction end face of the module holding portion 41 of the base member 38. The spacer 120 is formed of polyimide or the like. The spacer 120 is bonded to the-Z-direction end face of the module holding portion 41 with a soft adhesive. Further, as the soft adhesive, a silicone adhesive (e.g., 1211, manufactured by ThreeBond (スリーボンド)) or the like is preferably used.

The spacer 120 covers the-Z-direction end face of the module holding portion 41 from the-Z direction. A spacer opening 121 is formed in the spacer 120 at a position overlapping the head chip 51 of each of the head modules 30A to 30D when viewed from the Z direction, so as to expose the head chip 51 in the-Z direction. In the present embodiment, the spacer opening 121 exposes the head chips 51 (for example, the head chips 51 of the first head module 30A and the second head module 30B) together for each color. The spacer opening 121 may expose the head chips 51 of the head modules 30A to 30D together, or may expose the head chips 51 individually.

(nozzle plate)

The nozzle plate 32 is made of a resin material such as polyimide. The + Z-direction end face of the nozzle plate 32 (the face facing the base member 38) is fixed to the spacer 120 and the-Z-direction end face of the head chip 51 by a hard adhesive. The hard adhesive is formed of a material harder than the soft adhesive, for example, according to shore hardness. As such a material, an epoxy resin adhesive (e.g., 931-1T1N1 manufactured by Ablestik (エイブルスティック)) or the like is preferably used. The nozzle plate 32 may be directly bonded to the base member 38 with a soft adhesive.

As shown in fig. 2 and 7, the nozzle plate 32 covers the head chips 51 of the head modules 30A to 30D from the-Z direction. A plurality of nozzle rows (first to fourth nozzle rows 130A to 130D) extending in the X direction are formed in the nozzle plate 32 at intervals in the Y direction.

The nozzle rows 130A to 130D are formed in the nozzle plate 32 at positions facing the head chips 51 of the corresponding head modules 30A to 30D in the Z direction.

Fig. 8 is a partial bottom view of the ink-jet head 5A viewed from the-Z direction.

As shown in fig. 8, each of the nozzle rows 130A to 130D has nozzle holes (first nozzle holes 131A to fourth nozzle holes 131D) penetrating the nozzle plate 32 in the Z direction. For example, the first nozzle holes 131A are formed individually in positions in the nozzle plate 32 that face the ejection channels 57 of the head chips 51 in the first head module 30A in the Z direction. That is, the first nozzle holes 131A are linearly formed at intervals in the X direction to form the first nozzle array 130A.

Similarly to the first nozzle holes 131A, the second nozzle holes (first nozzle holes) 131B, the third nozzle holes (second nozzle holes) 131C, and the fourth nozzle holes 131D are formed in positions of the nozzle plate 32 that face the discharge channels 57 of the head chips 51 in the corresponding head modules 30B to 30D in the Z direction, respectively.

As shown in fig. 7, a slit 135 penetrating the nozzle plate 32 in the Z direction is formed in a portion of the nozzle plate 32 between the second nozzle row 130B and the third nozzle row 130C in the Y direction. In the present embodiment, the slits 135 are formed in two rows at intervals in the Y direction. The slits 135 extend in parallel with the nozzle rows 130A to 130D in the X direction. The length of the slit 135 in the X direction is longer than the nozzle rows 130A to 130D. However, the length of the slit 135 can be appropriately changed if it is shorter than the length of the nozzle plate 32 in the X direction. The number of slits 135 is not limited to two, and can be changed as appropriate.

The nozzle plate 32 is not limited to a resin material, and may be formed of a metal material (stainless steel or the like), or may have a laminated structure of a resin material and a metal material. However, the nozzle plate 32 is preferably made of a material having a thermal expansion coefficient equivalent to that of the spacer 120. Further, a liquid repellent treatment is applied to the-Z direction end face (ejection face) of the nozzle plate 32. In the present embodiment, the configuration in which the head modules 30A to 30D are collectively covered with one nozzle plate 32 has been described, but the configuration is not limited to this configuration, and the head modules 30A to 30D may be individually covered with a plurality of nozzle plates 32.

(nozzle guard)

The nozzle guard 33 is formed by press working a plate material such as stainless steel. The nozzle guard 33 covers the module holding portion 41 from the-Z direction with the nozzle plate 32 and the spacer 120 interposed therebetween.

Exposure holes 141 for exposing the nozzle rows 130A to 130D to the outside are formed in the nozzle guard 33 at positions facing the nozzle rows 130A to 130D in the Z direction. The exposure hole 141 is formed in a slit shape that penetrates the nozzle guard 33 in the Z direction and extends in the X direction. The exposure holes 141 of the present embodiment are formed in two rows at intervals in the Y direction corresponding to the nozzle rows 130A to 130D that discharge the same color ink. That is, one exposure hole 141 exposes the first nozzle row 130A and the second nozzle row 130B to the outside. The other exposure hole 141 exposes the third nozzle row 130C and the fourth nozzle row 130D to the outside.

As shown in fig. 8, the nozzle guard 33 is fixed to the spacer 120 by bonding or the like. Specifically, the nozzle guard 33 is bonded to a portion of the spacer 120 that is located outside the nozzle plate 32 in a plan view as viewed from the Z direction (hereinafter referred to as a "first bonding region 150"). The first adhesive region 150 is formed in a frame shape surrounding the nozzle plate 32 over the entire periphery. The first adhesive region 150 may be adhered to the outer periphery of the nozzle plate 32, if it is adhered to the spacer 120 at least outside the nozzle plate 32.

The nozzle guard 33 is bonded to a portion of the spacer 120 exposed through the slit 135 of the nozzle plate 32 (hereinafter referred to as a "second bonding region (partition) 151"). That is, the second adhesive regions 151 extend in parallel to the nozzle rows 130A to 130D in the X direction. Thus, the second bonding region 151 separates the nozzle rows of different colors (between the second nozzle row 130B and the third nozzle row 130C) from each other among the nozzle rows 130A to 130D.

[ method of operating Printer ]

Next, a method of recording information on the recording medium P by the printer 1 will be described.

As shown in fig. 1, when the printer 1 is operated, the

raster rollers

11 and 13 of the

transport mechanisms

2 and 3 rotate, and the recording medium P is transported in the + X direction between the

raster rollers

11 and 13 and the

pinch rollers

12 and 14. Further, at the same time, the pulley 26 is rotated by the drive motor 28 to move the endless belt 27. Thereby, the carriage 23 reciprocates in the Y direction while being guided by the guide rails 21 and 22.

During this time, in each of the ink jet heads 5A and 5B, a driving voltage is applied to the driving electrodes of the head chip 51. This causes the thickness of the driving wall 61 to be slidably deformed, thereby generating a pressure wave in the ink filled in the discharge passage 57. The pressure wave increases the internal pressure of the discharge channel 57, and ink is discharged through the nozzle holes 131A to 131D. Then, various kinds of information are recorded on the recording medium P by the ink hitting on the recording medium P.

Here, in the present embodiment, for example, in the first head module 30A, the head chip 51 and the drive substrate 53 are supported by the manifold 52 having the ink flow path 71.

According to this configuration, the member supporting the head chip 51 and the drive substrate 53, and the ink flow path 71 are integrated with the manifold 52 disposed on one side in the Y direction with respect to the head chip 51. Thus, the first module 30A can be miniaturized in the Y direction (main scanning direction) as compared with a configuration in which a member for supporting the head chip and the drive substrate is disposed on one side in the Y direction with respect to the head chip and a member having an ink flow path is disposed on the other side in the Y direction with respect to the head chip as in the related art. This enables the inkjet head 5A to be downsized in the Y direction.

Heat generated in the head chip 51 and the drive substrate 53 is dissipated to the outside via the manifold 52. This ensures heat dissipation performance of the head chip 51 and the drive substrate 53.

Further, since the head chip 51 and the drive substrate 53 are supported by the manifold 52 having the ink flow path 71, the ink flowing through the ink flow path 71 can be heated (kept warm) by the heat of discharge generated in the head chip 51 and the drive substrate 53 and transmitted to the manifold 52. This enables the ink to be supplied to the head chip 51 at a desired temperature (viscosity), and excellent printing characteristics can be obtained.

In addition, in the present embodiment, since the head modules 30A to 30D can be downsized in the Y direction, the manifold 52 can be provided for each head chip 51. Therefore, the heat radiation performance of each head chip 51 can be ensured compared to a configuration in which a plurality of head chips 51 are mounted on one head module 30A to 30D in order to achieve high-density recording.

In the present embodiment, since the buffer 31 is disposed in the + Z direction with respect to the manifold 52, the ink jet head 5A can be downsized in the Y direction compared to a configuration in which the buffer 31 and the manifold 52 are arranged in the Y direction.

In the present embodiment, since the ink flow path 71 extends in a meandering manner, the heat discharged from the head chip 51 and the drive substrate 53 can be efficiently transferred to the ink in the ink flow path 71. This enables the ink to be supplied to the head chip 51 at a desired temperature (viscosity), and excellent printing characteristics can be obtained.

In the present embodiment, the heater 85 is disposed on a surface facing in the + Y direction (a surface opposite to the surface supporting the drive substrate 53) of the manifold 52.

According to this configuration, the ink flowing through the ink flow path 71 can be heated by the heater 85 in addition to the heat release of the head chip 51 and the drive substrate 53, and thus the ink can be reliably supplied to the head chip 51 at a desired temperature.

In the present embodiment, since the insulation sheet 86 is interposed between the head chip 51 and the manifold 52, the stray capacitance between the head chip 51 and the manifold 52 can be reduced. This can suppress electrical noise generated when the head chip 51 is driven, and ensure operational reliability of the ink jet head 5A.

Further, by using a material having ink resistance such as polyimide for the insulating sheet 86, the insulating sheet 86 can be prevented from being eluted with ink, and discharge failure can be prevented.

Further, by using a soft material such as polyimide for the insulating sheet 86, it is possible to alleviate the stress applied to the head chip 51 and the manifold 52 due to the difference in the thermal expansion coefficient between the head chip 51 and the manifold 52. This can prevent, for example, the head chip 51 from being damaged or the head chip 51 from being peeled off from the manifold 52.

In the present embodiment, the nozzle plate 32 is disposed on the-Z direction end face of the base member 38, and the nozzle plate 32 has the nozzle arrays 130A to 130D corresponding to the respective head modules 30A to 30D.

With this configuration, the positional accuracy of the nozzle holes 131A to 131D can be improved as compared with a configuration in which the nozzle plate 32 is attached to each of the head modules 30A to 30D.

In the present embodiment, since the spacer 120 is interposed between the nozzle plate 32 and the base member 38, stress acting on the nozzle plate 32 and the base member 38 due to a difference in thermal expansion coefficient between the nozzle plate 32 and the base member 38 can be relaxed.

In addition, in the present embodiment, since the spacer 120 is bonded to the base member 38 with the soft adhesive, it is possible to reliably alleviate the stress applied to the spacer 120 and the base member 38 due to the difference in the thermal expansion coefficient between the spacer 120 and the base member 38.

This can prevent the nozzle plate 32 from being peeled off from the head chip 51.

In the present embodiment, the nozzle guard 33 and the first bonding region 150 of the spacer 120 are arranged so as to surround the nozzle plate 32.

According to this configuration, when ink adhering to the-Z-direction end surfaces of the nozzle plate 32 and the nozzle guard 33 attempts to enter the inkjet head 5A through the gap between the nozzle plate 32 and the nozzle guard 33, the ink can be blocked by the first adhesion region 150. This can suppress the entry of ink into the inkjet head 5A.

In the present embodiment, the nozzle guard 33 and the second bonding region 151 of the spacer 120 are disposed between the

nozzle rows

130B and 130C that discharge different color inks among the nozzle rows 130A to 130D.

With this configuration, ink of different colors attached to the-Z direction end surface of the nozzle plate 32 and the like is blocked by the second adhesion region 151. This can prevent ink of different colors (ink discharged from the

nozzle rows

130B and 130C) from mixing at the-Z-direction end surface of the nozzle plate 32 and leaking to the outside of the inkjet head 5A.

In the present embodiment, the nozzle plate 32 has a structure in which the slit 135 is formed between the

nozzle rows

130B and 130C.

According to this configuration, after the nozzle plate 32 is attached to the head chip 51 and the spacer 120, when the nozzle plate 32 expands and contracts with a temperature change at the time of curing the adhesive, the slits 135 expand and contract, thereby absorbing deformation of the nozzle plate 32. This can ensure the positional accuracy of the nozzle plate 32 with respect to the head chip 51, and can suppress peeling of the nozzle plate 32 and the like.

In the present embodiment, the spacer 120 and the nozzle guard 33 are bonded to each other through the slit 135 (the second bonding region 151), and the nozzle guard 33 can be bonded to each other even when the water repellent treatment is performed on the-Z-direction end face of the nozzle plate 32. Further, since the spacers 120 and the nozzle guard 33 are connected by the adhesive, it is possible to reliably suppress the mixing of the inks of different colors on the-Z direction end surface of the nozzle plate 32.

In the present embodiment, the first acting member and the second acting member 70 that act on the base member 38 and the head modules 30A to 30D in one side of the X direction and the Y direction are interposed between the base member 38 and the head modules 30A to 30D.

With this configuration, the head modules 30A to 30D are held by the base member 38 in a state pushed toward one side in the X direction and the Y direction. Therefore, the head modules 30A to 30D can be positioned with high accuracy with respect to the base member 38. This can improve the ease of assembly when the head modules 30A to 30D are fixed to the base member 38 via the support posts or the like.

In the present embodiment, since the temperature sensor 94 is disposed on the back surface of the actuator plate 55, the ink temperature in the discharge channel 57 can be accurately detected as compared with the case where the temperature sensor 94 is disposed at a position spaced apart from the actuator plate 55.

In particular, in the present embodiment, the heat transfer plate 65 is provided between the temperature sensor 94 and the actuator plate 55 so as to cover the entire range of each of the

passages

57, 58. Therefore, the average ink temperature of all the discharge channels 57 can be detected.

Further, since the printer 1 of the present embodiment includes the ink jet head 5A, the printer 1 can be provided which is reduced in size in the Y direction and has excellent reliability.

(modification example)

Next, a modification of the above embodiment will be described. Fig. 9 is a cross-sectional view of an ink jet head 205 according to a modification.

In the inkjet head 205 shown in fig. 9, as in the above-described embodiment, the nozzle plate 32 and each head chip 51 are bonded by the hard adhesive B1, and the spacer 120 and the base member 38 are bonded by the soft adhesive B2. The nozzle guard 33 is bonded to the spacer 120 and the nozzle plate 32 by the soft adhesive B3 in the first bonding region 150. The nozzle guard 33 is bonded to the nozzle plate 32 through the slits 135 by the soft adhesive B4 in the second bonding region 151. However, the combination of the adhesives can be changed as appropriate.

In the above-described embodiment, the case where the spacer 120 is made of a resin material has been described, but the present invention is not limited to this configuration, and a metal material (for example, a thin plate of stainless steel or the like) may be used for the spacer 120 as in the inkjet head 205 shown in fig. 9.

According to this configuration, since the rigidity of the spacer 120 can be ensured, for example, when the spacer 120 and the base member 38 are bonded or when the spacer 120 and the nozzle guard 33 are bonded, the flexural deformation of the spacer 120 can be suppressed. This can improve the assembling property.

In the above embodiment, the configuration in which the slits 135 are formed in two rows has been described, but the slits 135 may be formed in one row as in the present modification.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the inkjet printer 1 is described as an example of the liquid ejecting apparatus, but the present invention is not limited to the printer. For example, it may also be a facsimile machine, an on-demand printer, etc.

In the above embodiment, the configuration in which the four head modules 30A to 30D are mounted on the base member 38 has been described, but the present invention is not limited to this configuration. The number of head modules mounted on the base member 38 may be one or plural.

Although the above embodiment has been described with respect to the configuration in which two head modules eject ink of one color, the configuration is not limited to this, and ink of one color may be ejected by a plurality of three or more head modules, or ink of one color may be ejected by one head module.

Although the head chip for irradiation is described in the above embodiments, the present invention is not limited to this. For example, the present invention can be applied to a head chip of a so-called side shooter type (side shooter type) which ejects ink from a central portion in an extending direction of an ejection channel.

The present invention can be applied to a head chip of a so-called top-shooter type (roof type) in which the direction of pressure applied to ink and the direction of ejection of ink droplets are aligned.

Although the above embodiment has described the case where the partition portion is formed by an adhesive (for example, soft adhesive B4), the present invention is not limited to this configuration, and the partition portion may be provided separately from the nozzle plate 32, the nozzle plate 33, and the like.

In the above embodiment, the configuration in which the partitioning portions are arranged continuously in the X direction has been described, but the present invention is not limited to this configuration, and may be arranged intermittently in the X direction. In addition, the partition portion is not limited to a straight line.

In the above embodiment, the configuration in which the head chips 51 that discharge different color inks are partitioned by the partition portion has been described, but the configuration is not limited to this, and the head chips 51 that discharge the same color ink may be partitioned by the partition portion.

The adhesive used for bonding the nozzle plate 32, the nozzle guard 33, the spacer 120, and the like is not limited to a heat-curable type and may be a pressure-sensitive type, as long as it has corrosion resistance against ink.

In the above embodiment, the configuration in which the head chip 51 and the drive substrate 53 are supported by the same surface of the manifold has been described, but the present invention is not limited to this configuration. For example, the head chip 51 and the drive substrate 53 may be supported by different surfaces (for example, two surfaces facing the Y direction) of the manifold 52.

In the above embodiment, the configuration in which the nozzle plate 32 is fixed to the base member 38 via the spacer 120 has been described, but the present invention is not limited to this configuration, and the nozzle plate 32 may be directly fixed to the base member 38.

In addition, the components in the above embodiments may be replaced with known components as appropriate without departing from the scope of the present invention, and the above modifications may be combined as appropriate.

(1) A liquid ejecting head, wherein a buffer is disposed on a side opposite to the ejection orifice plate in a normal direction of the ejection surface with respect to the first manifold and the second manifold, the buffer being connected to the liquid flow path and absorbing pressure fluctuation of the liquid supplied to the liquid flow path.

(2) A liquid ejection head, characterized in that the liquid flow path extends meandering.

(3) A liquid ejecting head, wherein a heater is disposed on a surface of the manifold opposite to the supporting surface in the first direction.

(4) A liquid ejection head, characterized in that a first insulation sheet is interposed between the first manifold and the first head chip, and a second insulation sheet is interposed between the second manifold and the second head chip.

(5) The liquid ejecting head is characterized in that the base unit includes a base member that supports the first head chip and the second head chip, and a spacer that is interposed between the base member and the ejection orifice plate.

(6) The spacer is bonded to the base member with a soft adhesive, and the nozzle orifice plate is bonded to the spacer with a hard adhesive made of a material harder than the soft adhesive.

(7) A liquid ejecting head, wherein the ejection orifice plate is formed smaller than an outer shape of the spacer in a plan view seen from the normal direction, the ejection orifice guard is bonded to the spacer in a region on an outer side than the ejection orifice plate in the plan view seen from the normal direction, and a bonded portion of the ejection orifice guard and the spacer surrounds a periphery of the ejection orifice plate.

Description of the symbols

1 ink jet printer (liquid jet device)

5A, 5B ink jet head (liquid jet head)

32 nozzle plate (jet orifice plate)

33 nozzle guard (jet hole guard)

38 base member (base unit)

51 head chip (first head chip, second head chip)

Manifold 52 (first manifold, second manifold)

53 drive substrate (first drive substrate, second drive substrate)

57 discharge channel

71 ink flow path (liquid flow path)

120 spacer (base unit)

131B second nozzle hole (first nozzle hole)

131C third nozzle hole (second nozzle hole)

135 slit

141 exposure hole

151 second adhesive region (partition)

B4 Soft adhesive (separator)

Claims

1. A liquid ejecting head is provided with:

a first head chip and a second head chip, which are respectively formed with channels filled with liquid and are arranged in parallel along a first direction;

an injection orifice plate which is fixed to the first head chip and the second head chip together, and which is formed with a first injection hole communicating with the passage of the first head chip and a second injection hole communicating with the passage of the second head chip;

a partition portion that is located on an ejection surface of the ejection orifice plate facing a side opposite to the first head chip and the second head chip and partitions the first ejection hole and the second ejection hole;

a base unit that supports the first head chip and the second head chip, and to which the ejection orifice plate is adhesively fixed; and

an injection hole guard that is formed with exposure holes exposing the first injection holes and the second injection holes and covers the injection orifice plate from the opposite side of the base unit with the injection orifice plate interposed therebetween,

the injection orifice plate is bonded and fixed to the first head chip and the second head chip,

a slit penetrating the injection orifice plate in a normal direction of the injection surface is formed in a portion of the injection orifice plate between the first injection hole and the second injection hole,

the partition is an adhesive that fixes the base unit and the injection hole guard through the slit.

2. The liquid ejection head according to claim 1, wherein a water-repellent treatment is applied to the ejection face of the ejection orifice plate.

3. The liquid ejecting head according to claim 1 or 2, comprising:

a first manifold that is disposed adjacent to the first head chip in the first direction, supports the first head chip with a support surface facing the first direction, and has a liquid flow path communicating with the channel;

a first driving substrate supported by the supporting surface of the first manifold and electrically connected to the first head chip;

a second manifold which is disposed adjacent to the second head chip in the first direction, supports the second head chip by a support surface facing the first direction, and has a liquid flow path communicating with the channel; and

a second driving substrate supported by the supporting surface of the second manifold and electrically connected to the second head chip.

4. A liquid ejecting apparatus including the liquid ejecting head according to any one of claims 1 to 3.