JP2019014197A - Liquid jet head and liquid jet device - Google Patents

Abstract

To provide a liquid jet head and a liquid jet device which can improve discharge stability.SOLUTION: A liquid jet head includes: a first head chip and a second head chip which are stacked in a Y direction; a first channel member which is arranged in a -Y direction to the first head chip and has a first ink channel communicating with the first head chip; and a second channel member 51B which is arranged in a +Y direction to the second chip and has a second ink channel 155 communicating with the second head chip, where the first channel member is formed with a first bubble discharge channel communicating inside and outside of the first ink channel and the second channel member 51B is formed with a second bubble discharge channel 160 communicating inside and outside of the second ink channel 155.SELECTED DRAWING: Figure 13

Description

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

  2. Description of the Related Art Conventionally, there is an ink jet printer equipped with an ink jet head as an apparatus for recording an image or a character on a recording medium by ejecting ink droplets onto a recording medium such as recording paper. The ink jet head is configured, for example, by mounting a plurality of jet modules corresponding to each color on a carriage.

  The jet module described above includes a head chip that ejects ink, a manifold in which an ink flow path that supplies ink to the head chip is formed, and the like. For example, Patent Document 1 below discloses a configuration in which a plurality of head chips are mounted on one jet module in order to enable high-resolution printing, high-speed printing, and the like.

JP 2010-208226 A

  By the way, when air is entrained in the course of the ink flowing through the ink flow path, it may stay in the ink as bubbles. When the bubbles reach the head chip, ink filling in each head chip becomes insufficient, and ink ejection from the nozzle holes becomes unstable.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting head and a liquid ejecting apparatus capable of improving ejection stability.

  In order to solve the above problems, a liquid ejecting head according to one embodiment of the present invention is stacked in a first direction, and the first head chip and the second head chip that eject liquid, and in the first direction, A first flow path member disposed on the opposite side of the first head chip from the second head chip and having a first liquid flow path communicating with the first head chip; and in the first direction, A second flow path member disposed on the opposite side of the second head chip from the first head chip and having a second liquid flow path communicating with the second head chip, and The first channel member is formed with a first bubble discharge channel that communicates the inside and outside of the first liquid channel, and the second channel member is a first channel that communicates the inside and outside of the second liquid channel. A two-bubble discharge channel is formed.

  According to this configuration, the bubbles staying in the first liquid channel and the second liquid channel can be discharged through the first bubble discharge channel and the second bubble discharge channel, respectively. Therefore, it is possible to suppress the bubble from entering each head chip and improve the liquid filling property in each head chip. Thereby, injection stability can be improved.

In the liquid ejecting head according to the above aspect, the first head chip includes a first pressure fluctuation chamber that applies a pressure fluctuation to the liquid, and the second head chip provides a second pressure fluctuation that applies a pressure fluctuation to the liquid. The first head chip and the second head chip are each provided with an injection hole plate in which injection holes communicating with the first pressure fluctuation chamber and the second pressure fluctuation chamber are formed, A first discharge hole that communicates with the first bubble discharge channel and a second discharge hole that communicates with the second bubble discharge channel are opened on an injection surface of the injection hole plate where the injection hole opens. You may do it.
According to this aspect, since the ejection hole and each discharge hole are open on the same surface (ejection surface), for example, when the ejection surface is sealed with a cap when filling with liquid or when the printing operation is stopped, etc. In this case, the injection holes and the respective discharge holes can be covered together by one cap. Therefore, it is possible to improve the maintainability.

In the liquid ejecting head according to the above aspect, the first flow path member has an inflow port that connects a liquid supply source and the first liquid flow path, and the first flow path member and the second flow path. A communication channel for communicating the first liquid channel and the second liquid channel is disposed between the members, and the inner diameter of the second discharge hole is smaller than the inner diameter of the first discharge hole. It may be.
A part of the liquid in the first liquid channel is supplied to the second liquid channel through the communication channel. In this case, since the second liquid channel is located on the downstream side with respect to the first liquid channel, the pressure tends to be higher than the pressure in the first liquid channel.
Therefore, according to this aspect, the surface tension acting on the inner surface of the second discharge hole is made to act on the inner surface of the first discharge hole by making the inner diameter of the second discharge hole smaller than the inner diameter of the first discharge hole. It can be higher than the tension. Thereby, it becomes easy to stabilize a meniscus in the 2nd discharge hole, and it can control that a liquid leaks unexpectedly through the 2nd discharge hole.
Further, since the meniscus is stabilized in the second discharge hole, the meniscus is broken by, for example, a negative pressure generated in the second head chip when the liquid jet head is used (during liquid jet or the like), and the second discharge hole Thus, it is possible to prevent the outside air (air) from entering the second head chip. Therefore, it is possible to suppress the air that has entered from the second discharge hole from becoming bubbles and stay in the head chip, thereby improving the jetting stability.

In the liquid jet head according to the above aspect, the second head chip has a jet region in which a second pressure chamber that applies a pressure fluctuation to the liquid is arranged in a second direction intersecting the first direction, The communication channels are arranged in pairs in portions located on both sides of the injection region in the second direction, and the second bubble discharge channels are between the pair of communication channels in the second direction. The central portion may communicate with the second liquid channel.
According to this aspect, the distance from each communication channel to the second bubble discharge channel is set to be equal to each other. Therefore, in the process in which the liquid flows through the second liquid channel from each communication channel to the central portion in the second direction, the bubbles remaining in the second liquid channel are discharged from both sides in the second direction. It can be pushed evenly toward the road. Thereby, it can suppress more reliably that a bubble approachs into the 2nd head chip.

In the liquid jet head according to the above aspect, a filter for filtering the liquid may be disposed in the second bubble discharge channel.
According to this aspect, the flow path resistance in the second bubble discharge channel is increased by the filter, so that the second bubble discharge channel in the second bubble discharge channel caused by the liquid flow from the upstream, the liquid injection from the injection hole, or the like. It is possible to prevent the meniscus in the second discharge hole from being broken by the pressure fluctuation. Thereby, it becomes easy to stabilize a meniscus in the 2nd discharge hole, and it can control that a liquid leaks unexpectedly through the 2nd discharge hole.

A liquid ejecting apparatus according to one aspect of the invention includes the liquid ejecting head according to the above aspect.
According to this aspect, it is possible to provide a liquid ejecting apparatus having excellent ejection performance.

  According to one embodiment of the present invention, ejection stability can be improved.

1 is a schematic configuration diagram of an inkjet printer according to an embodiment. It is a perspective view of the ink jet head concerning an embodiment. 1 is a partially exploded perspective view of an inkjet head according to an embodiment. In the inkjet head which concerns on embodiment, it is an exploded perspective view of a base member and a 1st jet module. It is a disassembled perspective view of the 1st jet module concerning an embodiment. It is a disassembled perspective view of the discharge part which concerns on embodiment. It is sectional drawing which follows the VII-VII line of FIG. In the 1st channel member concerning an embodiment, it is an exploded perspective view developed in the + Y direction from the 1st channel plate. It is the front view which looked at the 1st channel board concerning an embodiment from the + Y direction. It is sectional drawing of the 1st jet module equivalent to the XX line of FIG. It is an XI section enlarged view of FIG. In the 1st channel member concerning an embodiment, it is an exploded perspective view developed in the -Y direction from the 1st channel plate. It is the front view which looked at the 2nd channel board concerning an embodiment from the + Y direction. It is a fragmentary sectional view which follows the XIV-XIV line | wire of FIG.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In the following embodiments, an ink jet printer (hereinafter simply referred to as a printer) that performs recording on a recording medium using ink (liquid) will be described as an example. In the drawings used for the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.

[Printer]
FIG. 1 is a schematic configuration diagram of the printer 1.
As shown in FIG. 1, the printer 1 of this embodiment includes a pair of transport mechanisms 2 and 3, an ink supply mechanism 4, inkjet heads 5 </ b> A and 5 </ b> B, and a scanning mechanism 6. In the following description, an X, Y, Z orthogonal coordinate system is used as necessary. In this case, the X direction (second direction) coincides with the transport direction (sub-scanning direction) of the recording medium P (for example, paper). The Y direction (first direction) coincides with the scanning direction (main scanning direction) of the scanning mechanism 6. The Z direction indicates a height direction (gravity direction) orthogonal to the X direction and the Y direction. In the following description, among the X direction, the Y direction, and the Z direction, the arrow direction in the figure is a plus (+) direction, and the direction opposite to the arrow is a minus (−) direction. In the present embodiment, the + Z direction corresponds to the upper side of the gravity direction, and the −Z direction corresponds to the lower side of the gravity direction.

  The transport mechanisms 2 and 3 transport the recording medium P in the + X direction. Specifically, the transport mechanism 2 includes a grit roller 11 extending in the Y direction, a pinch roller 12 extending in parallel to the grit roller 11, and a drive mechanism such as a motor that rotates the grit roller 11 (not configured). (Shown). Similarly, the transport mechanism 3 includes a grit roller 13 that extends in the Y direction, a pinch roller 14 that extends in parallel to the grit roller 13, a drive mechanism (not shown) that rotates the grit roller 13, and It has.

The ink supply mechanism 4 includes an ink tank 15 that stores ink, and an ink pipe 16 that connects 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 ink of yellow, magenta, cyan, and black.
The ink pipe 16 is a flexible hose having flexibility, for example. The ink pipe 16 connects between each ink tank 15 and each inkjet head 5A, 5B.

  The scanning mechanism 6 reciprocates the inkjet heads 5A and 5B in the Y direction. Specifically, the scanning mechanism 6 includes a pair of guide rails 21 and 22 extending in the Y direction, a carriage 23 supported movably on the pair of guide rails 21 and 22, and moving the carriage 23 in the Y direction. And a drive mechanism 24 to be operated.

  The drive mechanism 24 is disposed between the guide rails 21 and 22 in the X direction. The drive mechanism 24 is a pair of pulleys 25 and 26 disposed at intervals in the Y direction, an endless belt 27 wound between the pair of pulleys 25 and 26, and a drive that rotationally drives one pulley 25. And a motor 28.

  The carriage 23 is connected to an endless belt 27. A plurality of inkjet heads 5A and 5B are mounted on the carriage 23 in a state of being arranged in the Y direction. Each inkjet head 5A, 5B is configured to be able to eject ink of two colors per inkjet head 5A, 5B. Therefore, the printer 1 according to the present embodiment is configured such that each of the inkjet heads 5A and 5B ejects two different colors of ink, thereby ejecting four colors of ink of yellow, magenta, cyan, and black. .

<Inkjet head>
FIG. 2 is a perspective view of the inkjet head 5A. FIG. 3 is a partially exploded perspective view of the inkjet head 5A. The inkjet heads 5A and 5B have the same configuration 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 FIGS. 2 and 3, the inkjet head 5 </ b> A of this embodiment includes a base member 38 including jet modules 30 </ b> A and 30 </ b> B (see FIG. 3), a damper 31, a nozzle plate 32 (see FIG. 2), a nozzle guard 33, and the like. It is mounted and configured.

(Base member)
FIG. 4 is an exploded perspective view of the base member 38 and the first jet module 30A in the inkjet head 5A.
As shown in FIG. 4, 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 base main body portion 41 that holds the jet modules 30A and 30B, and a carriage fixing portion 42 for fixing the base member 38 to the carriage 23 (see FIG. 1). In the present embodiment, the base member 38 is integrally formed of a metal material.

  In the base main body 41, module housing portions (first module housing portion 44A and second module housing portion 44B) are formed. Each of the module housing portions 44A and 44B is formed side by side in the Y direction so as to correspond to the jet modules 30A and 30B. Each of the module housing portions 44A and 44B penetrates the base main body portion 41 in the Z direction. Corresponding jet modules 30A and 30B can be inserted into the module housing portions 44A and 44B, respectively. That is, the jet modules 30 </ b> A and 30 </ b> B are held by the base body 41 while standing in the + Z direction from the base member 38 by inserting the end portions in the −Z direction into the module housing portions 44 </ b> A and 44 </ b> B.

In the base main body portion 41, a partition 46 that partitions the module housing portions 44A and 44B is formed at a portion located between the module housing portions 44A and 44B.
The pair of short side portions 45a and 45b facing each other in the X direction in the base main body portion 41 is formed with a protruding wall 47 that protrudes inward in the X direction. The protruding wall 47 is formed for each module housing portion 44A, 44B, with the protruding walls 47 facing each other in the X direction as a set.

  A first urging member 48 is provided on the first short side 45a. The first urging member 48 is provided corresponding to each module housing portion 44A, 44B. Each first urging member 48 is formed in a leaf spring shape interposed between the first short side portion 45a and each jet module 30A, 30B. Each first urging member 48 urges each jet module 30A, 30B toward the second short side portion 45b (−X direction).

  The carriage fixing portion 42 projects from the + Z direction end portion of the base main body portion 41 to the XY plane. The carriage fixing portion 42 is formed with an attachment hole for attaching the base member 38 to the carriage 23 (see FIG. 1).

(Jet module)
As shown in FIG. 3, the jet modules 30A and 30B are formed in a plate shape whose thickness direction is the Y direction. The jet modules 30A and 30B are configured to be able to discharge ink supplied from the ink tank 15 (see FIG. 1) toward the recording medium P. The jet modules 30A and 30B are mounted on the base member 38 with an interval in the Y direction.

  In the ink jet head 5A of the present embodiment, each of the jet modules 30A and 30B ejects ink one color at a time. The number of jet modules 30A and 30B mounted on the base member 38 and the color and type of ink ejected from the jet modules 30A and 30B can be changed as appropriate. In each of the jet modules 30A and 30B, jet modules having the same configuration are mounted on the base member 38 in the Y direction opposite to each other. Therefore, in the following configuration, the first jet module 30A will be described as an example.

FIG. 5 is an exploded perspective view of the first jet module 30A.
As shown in FIG. 5, the first jet module 30A mainly includes a discharge unit 50 and a first flow path member 51A and a second flow path member 51B that face each other in the Y direction with the discharge part 50 interposed therebetween. I have.

(Discharge part)
FIG. 6 is an exploded perspective view of the discharge unit 50.
As illustrated in FIG. 6, the ejection unit 50 includes a first head chip 52A and a second head chip 52B stacked in the + Y direction with respect to the first head chip 52A. Each of the head chips 52A and 52B is of a so-called edge chute type that ejects ink from an end portion in the extending direction (Z direction) of an ejection channel 57 described later.

  The first head chip 52A is configured by overlapping a first actuator plate 55 and a first cover plate 56 in the Y direction.

  The first actuator plate 55 is a piezoelectric substrate formed of PZT (lead zirconate titanate) or the like. The polarization direction of the first actuator plate 55 is set in one direction along the thickness direction (Y direction). The first actuator plate 55 may be formed by stacking two piezoelectric substrates having different polarization directions in the Y direction (so-called chevron type).

  The first actuator plate 55 is provided with a plurality of channels 57 and 58 that are open in a plane facing the −Y direction (hereinafter referred to as “surface”) in parallel with an interval in the X direction. Each channel 57, 58 is formed linearly along the Z direction. Each channel 57, 58 is open on the −Z direction end face of the first actuator plate 55. Each channel 57, 58 may be inclined and extended with respect to the Z direction.

7 is a cross-sectional view taken along line VII-VII in FIG.
As shown in FIGS. 6 and 7, the plurality of channels 57 and 58 described above are the ejection channel 57 filled with ink and the non-ejection channel 58 not filled with ink. The ejection channels 57 and the non-ejection channels 58 are arranged alternately in the X direction. Each of the channels 57 and 58 is partitioned in the X direction by a drive wall 61 made of the first actuator plate 55. A drive electrode 59 is formed on the inner surfaces of the channels 57 and 58. The drive electrode 59 is connected to a drive terminal (not shown) formed on the surface of the first actuator plate 55 at the + Z direction end of the first actuator plate 55.

  The first cover plate 56 is formed in a rectangular shape in plan view as viewed from the Y direction. The first cover plate 56 is joined to the surface of the first actuator plate 55 with the + Z direction end of the first actuator plate 55 protruding (see FIG. 10).

The first cover plate 56 has a common ink chamber 62 that opens on a surface facing the −Y direction (hereinafter referred to as “front surface”) and a plurality of openings that open on the surface facing the + Y direction (hereinafter referred to as “back surface”). And a slit 63.
The common ink chamber 62 is formed at a position corresponding to the + Z direction end of the ejection channel 57 in the Z direction. The common ink chamber 62 is recessed from the surface of the first cover plate 56 in the + Y direction and extends in the X direction. Ink flows into the common ink chamber 62 through the first flow path member 51A described above.
The slit 63 is formed in the common ink chamber 62 at a position facing the ejection channel 57 in the Y direction. The slit 63 communicates the inside of the common ink chamber 62 and the inside of each discharge channel 57 separately. Therefore, the non-ejection channel 58 does not communicate with the common ink chamber 62.

  A pair of first air bubble removal holes 65 </ b> A are formed in a portion of the first cover plate 56 located outside the common ink chamber 62 in the X direction. Each first air bubble removal hole 65 </ b> A extends in the −Z direction between the first cover plate 56 and the first actuator plate 55 after passing through the first cover plate 56 in the Y direction. That is, in the first air bubble removal hole 65A, the first opening portion opens at the surface of the first cover plate 56, and the second opening portion opens at the −Z direction end surface of the first head chip 52A.

  The second head chip 52B is configured by overlapping a second actuator plate 71 and a second cover plate 72 in the Y direction. In the following description, the same configurations as those of the first head chip 52A in the second head chip 52B are denoted by the same reference numerals as those of the first head chip 52A, and description thereof is omitted.

  The second actuator plate 71 is joined to a surface of the first actuator plate 55 facing the + Y direction (hereinafter referred to as “back surface”). The ejection channels 57 and the non-ejection channels 58 of the second head chip 52B are arranged with a half pitch shift with respect to the arrangement pitch of the ejection channels 57 and the non-ejection channels 58 of the first head chip 52A. That is, the ejection channels 57 and the non-ejection channels 58 of the head chips 52A and 52B are arranged in a staggered manner.

  The second cover plate 72 is joined to a surface (hereinafter referred to as “surface”) facing the + Y direction in the second actuator plate 71. A second air bubble removal hole 65 </ b> B is formed in a portion of the second cover plate 72 located at least in the + X direction from the common ink chamber 62. The second bubble removal hole 65B extends in the −Z direction between the second cover plate 72 and the second actuator plate 71 after penetrating the second cover plate 72 in the Y direction.

  In the discharge unit 50, a region where the channels 57 and 58 are arranged is a discharge region Q1, and a pair of regions (regions outside the outermost channels 57 and 58) located on both sides in the X direction with respect to the discharge region Q1. The non-ejection region Q2. In the non-ejection region Q2, a communication hole 73 (only one communication hole 73 is shown in FIGS. 6 and 7) penetrating the ejection unit 50 (the head chips 52A and 52B) in the Y direction is formed. The communication hole 73 penetrates the head chips 52A and 52B (actuator plates 55 and 71 and cover plates 56 and 72) in the Y direction, and communicates the common ink chambers 62 of the head chips 52A and 52B. Note that the number, position, shape, and the like of the communication holes 73 can be changed as appropriate.

(First flow path member)
FIG. 8 is an exploded perspective view of the first flow path member 51A developed from the first flow path plate 77 in the + Y direction.
As shown in FIG. 8, the first flow path member 51 </ b> A has a first manifold 75 and an inflow port 76. The first manifold 75 and the inflow port 76 may be integrally formed.
The first manifold 75 is formed in a plate shape having the Y direction as a whole in the thickness direction. As shown in FIG. 3, the first manifold 75 is held by the base member 38 in an upright state in the + Z direction by inserting an end portion in the −Z direction into the first module housing portion 44 </ b> A described above.

  As shown in FIG. 8, the first manifold 75 has a first flow path plate 77, a front cover 78 disposed in the + Y direction with respect to the first flow path plate 77, and the first flow path plate 77. And a rear cover 79 disposed in the -Y direction.

  The first flow path plate 77 is made of a material having excellent thermal conductivity. In the present embodiment, a metal material (for example, aluminum or the like) is preferably used as the material of the first flow path plate 77. The first flow path plate 77 is formed with a first ink flow path 81 through which ink flows toward the first head chip 52A.

FIG. 9 is a front view of the first flow path plate 77 as viewed from the + Y direction.
As shown in FIGS. 8 and 9, the first ink flow path 81 is formed by connecting an upstream flow path 83, a filtration flow path 84, a downstream flow path 85, and a supply flow path 86 (see FIG. 11).
The upstream flow path 83 opens in the + Y direction in the first flow path plate 77. Specifically, the upstream flow path 83 includes a narrow flow path 91 and a connection flow path 92 that connects the narrow flow path 91 and the filtration flow path 84.

  The narrow flow passage 91 has a portion located in the + X direction and the + Z direction in the first flow passage plate 77 as an upstream end, and a portion located in the center portion in the Z direction and the X direction in the first flow passage plate 77 in the downstream. As an end, it extends while bending from the upstream end toward the downstream end. Specifically, the narrow channel 91 extends from the upstream end in the −Z direction, then extends in the −X direction toward the −Z direction, and further extends in the −Z direction. In the present embodiment, the channel width (width in the direction orthogonal to the flow direction and the Y direction) and the channel depth (depth in the Y direction) of the narrow channel 91 are uniform throughout. Is set to However, the shape, the channel width, and the channel depth of the narrow channel 91 can be changed as appropriate.

  As shown in FIG. 9, the connection flow path 92 is formed in a triangular shape in which the flow path width gradually increases in the −Z direction when viewed from the + Y direction. The connection channel 92 communicates with the downstream end of the narrow channel 91 at the end in the + Z direction. In the present embodiment, the channel width at the upstream end (+ Z direction end) of the connection channel 92 is equal to the channel width at the downstream end of the narrow channel 91.

FIG. 10 is a cross-sectional view of the first jet module 30A corresponding to the XX line of FIG.
As shown in FIG. 10, the connection channel 92 has a channel depth that gradually decreases in the −Z direction in a cross-sectional view as viewed from the + X direction. That is, the connection flow path 92 of the present embodiment has a flow path width that increases from the upstream side to the downstream side, and a flow path depth that decreases from the upstream side to the downstream side. In the present embodiment, the channel depth at the upstream end of the connection channel 92 is equal to the channel depth at the downstream end of the narrow channel 91.

It is preferable that the flow path cross-sectional area (cross-sectional area in the XY plane) at the downstream end (−Z direction end) in the connection flow path 92 is smaller than the flow path cross-sectional area at the upstream end. However, the channel width, the channel depth, and the channel cross-sectional area of the connection channel 92 can be changed as appropriate.
In the present embodiment, the configuration in which the channel width and the channel depth are continuously (linearly) changed has been described. However, the present invention is not limited to this configuration. That is, the connection channel 92 may be formed in a stepped shape or a curved shape, for example, as long as the channel width and the channel depth gradually change toward the downstream side. Further, a configuration in which a plurality of straight lines having different inclinations are connected may be employed.

FIG. 11 is an enlarged view of the XI portion of FIG.
As shown in FIGS. 9 and 11, the filtration flow path 84 communicates with the downstream end of the connection flow path 92 in the Z direction, and causes the ink flowing from the connection flow path 92 to flow in the −Y direction. Specifically, the filtration flow path 84 includes a filter inlet flow path 95 located in the + Y direction and a filter outlet flow path 96 connected to the filter inlet flow path 95 in the −Y direction.
The filter inlet channel 95 communicates with the connection channel 92 at the end in the + Z direction (the upper end in the direction of gravity). The width in the X direction of the filter inlet channel 95 is equal to the width in the X direction at the downstream end of the connection channel 92.

  The filter outlet channel 96 has an area (channel cross-sectional area) in a front view as viewed from the Y direction that is slightly smaller than the filter inlet channel 95. That is, a step surface 97 facing the + Y direction is formed at the boundary between the filter inlet channel 95 and the filter outlet channel 96. The step surface 97 is formed in a frame shape extending along the outer peripheral edge of the filter inlet channel 95.

  The filter inlet channel 95 is provided with a main filter 99 that partitions the filtration channel 84 into a filter inlet channel 95 and a filter outlet channel 96 in the Y direction. The main filter 99 is a mesh sheet having a plan view outer shape viewed from the Y direction and having a size equivalent to that of the filter inlet channel 95. The main filter 99 has an outer peripheral portion joined to the step surface 97 described above from the + Y direction. Ink passes through the main filter 99 in the process of flowing from the filter inlet channel 95 to the filter outlet channel 96. Thereby, the main filter 99 captures foreign matters and bubbles contained in the ink.

  As shown in FIG. 11, a storage wall portion 100 that partitions between the filter outlet channel 96 and the downstream channel 85 in the Y direction is formed on the inner surface of the filter outlet channel 96. The storage wall portion 100 is erected in the + Z direction from the inner side surface of the −Z direction located in the −Z direction (below the gravitational direction) among the inner surfaces of the filter outlet flow channel 96, and X in the filter outlet flow channel 96. It is formed over the entire direction.

  A communication channel 102 that penetrates the storage wall 100 in the Y direction is formed at the + Z direction end of the storage wall 100. The communication channel 102 is formed continuously over the entire X direction in the storage wall 100 (filter outlet channel 96). In the present embodiment, among the inner surfaces of the communication channel 102, the + Z direction inner surface located in the + Z direction is flush with the + Z direction inner surface located in the + Z direction among the inner surfaces of the filter outlet channel 96. Yes. That is, the communication channel 102 is open at the uppermost end portion of the filter outlet channel 96. However, the + Z direction inner side surfaces of the communication channel 102 and the filter outlet channel 96 are not limited to being flush with each other.

  The channel cross-sectional area (area in the XZ plane) at the upstream end of the communication channel 102 is smaller than the minimum channel cross-sectional area (cross-sectional area in the XY plane) of the filter inlet channel 95 described above. Is preferred. However, the channel cross-sectional area of the communication channel 102 may be equal to or greater than the minimum channel cross-sectional area of the filter inlet channel 95. In the present embodiment, the case where the minimum channel cross-sectional area of the filter inlet channel 95 is set at the upstream end of the filter inlet channel 95 (the boundary portion with the connection channel 92) has been described. Not limited to. That is, the minimum channel cross-sectional area of the filter inlet channel 95 can be set at an arbitrary position of the filter inlet channel 95.

FIG. 12 is an exploded perspective view of the first flow path member 51 </ b> A developed from the first flow path plate 77 in the −Y direction.
As shown in FIGS. 10 and 12, the downstream flow path 85 opens in the −Y direction in the first flow path plate 77. Specifically, the downstream flow path 85 includes a straight portion 110 and an enlarged portion 111 connected to the downstream side of the straight portion 110.

  The straight portion 110 faces the filter outlet channel 96 in the Y direction with the storage wall portion 100 interposed therebetween. The straight portion 110 has a channel width in the X direction that is the same as that of the filter outlet channel 96, and a channel depth in the Y direction is uniformly formed over the entire Z direction. The straight portion 110 communicates with the filter outlet channel 96 through the communication channel 102 at the end in the + Z direction. In addition, the flow path width and the flow path depth of the straight part 110 can be changed as appropriate.

  The enlarged portion 111 extends in the −Z direction from the −Z direction end of the straight portion 110. The enlarged portion 111 has a channel width in the X direction that is equal to that of the straight portion 110. In the enlarged portion 111, the flow path depth in the Y direction gradually becomes deeper toward the -Z direction. That is, the flow path cross-sectional area (cross-sectional area in the direction orthogonal to the Z direction) of the enlarged portion 111 gradually increases toward the downstream side (−Z direction).

  The supply flow path 86 penetrates the first flow path plate 77 in the Y direction at the −Z direction end of the first flow path plate 77. The channel width in the X direction in the supply channel 86 is wider than that of the enlarged portion 111. In the present embodiment, the channel width of the supply channel 86 is set to be equal to that of the common ink chamber 62.

  The upstream end (−Y direction end) of the supply flow path 86 communicates with the downstream end (−Z direction end) of the enlarged portion 111. On the other hand, the downstream end of the supply flow channel 86 opens in the + Y direction in the first flow channel plate 77.

  As shown in FIG. 9, the first flow path plate 77 is formed with a first bubble discharge flow path 120 that communicates with the first ink flow path 81. The first bubble discharge channel 120 is formed as a pair on both sides in the X direction with respect to the filtration channel 84. That is, each first bubble discharge channel 120 is formed in line symmetry with respect to an axis of symmetry that passes through the center in the X direction of the first channel member 51A and extends in the Z direction. Therefore, in the following description, the first bubble discharge channel 120 located in the + X direction with respect to the first ink channel 81 will be described. In addition, the 1st bubble discharge flow path 120 is not restricted to a pair.

As shown in FIGS. 9 and 12, the first bubble discharge channel 120 includes a guide part 121, a first penetration part 122, a discharge part 123, and a second penetration part 124.
The guide part 121 opens in the + Y direction in the first flow path plate 77. The guide part 121 is continuous in the + X direction with respect to the connection flow path 92 and the filter inlet flow path 95 described above. Specifically, the guide part 121 is formed in a tapered shape in which the width in the Z direction is gradually reduced toward the + X direction. Specifically, the inner surface of the + Z direction located in the + Z direction among the inner surfaces of the guide part 121 extends linearly along the X direction. However, the inner surface of the + Z direction may extend while inclining toward the + Z direction or the −Z direction toward the + X direction.

  Of the inner surface of the guide portion 121, the inner surface in the −Z direction located in the −Z direction is formed as an inclined surface extending in the + Z direction toward the + X direction. In addition, the depth in the Y direction in the guiding part 121 is uniform over the entire guiding part 121. However, the depth of the guide part 121 may gradually become shallower toward the + X direction, for example.

  The first penetrating portion 122 communicates with the guiding portion 121 at the top portion of the guiding portion 121 (intersection portion between the + Z direction inner side surface and the −Z direction inner side surface). The first penetration part 122 penetrates the first flow path plate 77 in the Y direction. In the present embodiment, the first penetrating portion 122 is disposed in the + Z direction and in the + X direction with respect to the filtration channel 84. In addition, it is preferable that the 1st penetration part 122 satisfy | fills either one arrange | positioned in the + Z direction rather than the filtration flow path 84, or arrange | positioned in the + X direction rather than the filtration flow path 84. FIG. However, the position of the first penetration part 122 in the Z direction and the X direction can be changed as appropriate.

  As shown in FIG. 12, the discharge part 123 opens in the −Y direction in the first flow path plate 77. The discharge part 123 extends in the Z direction. The + Z direction end of the discharge portion 123 communicates with the first through portion 122 described above.

  The second penetrating part 124 communicates with the −Z direction end of the discharging part 123. The second penetration part 124 penetrates the first flow path plate 77 in the Y direction. A sub filter 126 is disposed at a boundary portion between the second through portion 124 and the discharge portion 123.

  The rear cover 79 has an outer shape equivalent to that of the first flow path plate 77 in a front view as viewed from the Y direction, and is formed in a rectangular plate shape whose thickness in the Y direction is thinner than that of the first flow path plate 77. . The rear cover 79 is fixed to the surface of the first flow path plate 77 facing the −Y direction. That is, the rear cover 79 closes the first ink flow path 81 (downstream flow path 85 and supply flow path 86) and the first bubble discharge flow path 120 (through portions 122, 124 and discharge section 123) from the −Y direction. Yes. In the present embodiment, the rear cover 79 is formed of a metal material (for example, stainless steel) having excellent thermal conductivity.

  A heater 130 is disposed on the surface of the rear cover 79 facing the −Y direction. The heater 130 heats the inside of the first ink flow path 81 through the rear cover 79, thereby holding (holding) the ink flowing through the first ink flow path 81 within a predetermined temperature range.

  As shown in FIG. 8, the front cover 78 is a rectangular plate having the same shape and size as the rear cover 79. That is, the front cover 78 is thinner in the Y direction than the first flow path plate 77. The front cover 78 is fixed to the surface of the first flow path plate 77 facing the + Y direction. That is, the front cover 78 closes the first ink flow path 81 (upstream flow path 83 and filtration flow path 84) and the first bubble discharge flow path 120 (guide part 121 and penetration part 122) from the + Y direction.

A communication port 132 that opens the supply flow path 86 is formed in the front cover 78 at a position overlapping the supply flow path 86 when viewed from the Y direction. The communication port 132 has the same shape as the supply flow path 86 in a front view as viewed from the Y direction, and penetrates the front cover 78 in the Y direction.
In the front cover 78, an inlet 133 that opens the upstream flow path 83 is formed at a position overlapping the upstream end (+ Z direction end) of the upstream flow path 83 when viewed from the Y direction. The inflow port 133 passes through the front cover 78 in the Y direction.

  A discharge port 134 for opening the second through portion 124 is formed in the front cover 78 at a position overlapping the second through portion 124 when viewed from the Y direction. The discharge port 134 penetrates the front cover 78 in the Y direction.

  In the present embodiment, the case where the groove-shaped first ink flow path 81 is formed only on the first flow path plate 77 has been described. However, the present invention is not limited to this configuration, and the first flow path plate 77, the front cover 78, and the rear cover are provided. It is only necessary that an ink flow path is formed in at least one of 79. In this case, for example, a groove portion may be formed in each of the first flow path plate 77, the front cover 78, and the rear cover 79, and these groove portions may be overlapped to form an ink flow path.

  The inflow port 76 is formed in a cylindrical shape extending in the Z direction. The inflow port 76 is fixed to the + Z direction end of the front cover 78. The inside of the inflow port 76 communicates with the first ink flow path 81 through the inflow port 133 described above.

(First insulation sheet)
As shown in FIG. 8, a first insulating sheet 135 is provided on the surface of the front cover 78 facing the + Y direction. The first insulating sheet 135 is formed in a U shape that opens in the −Z direction when viewed from the front in the Y direction. The first insulating sheet 135 surrounds the communication port 132 in the front cover 78. Specifically, the first insulating sheet 135 includes a pair of outer pedestal portions 136 located on both sides in the X direction with respect to the communication port 132, and a bridge portion 137 that connects the + Z direction end portions of the outer pedestal portion 136, have. In the present embodiment, the first insulating sheet 135 is preferably made of polyimide, for example. However, the material of the first insulating sheet 135 may be appropriately changed as long as it is formed of a relatively soft material (for example, a resin material or a rubber material) that has insulation properties and ink resistance (elution resistance). Is possible.

In the outer pedestal 136, an exposure port 140 that exposes the discharge port 134 is formed at a position overlapping the discharge port 134 described above when viewed from the Y direction. The exposure port 140 penetrates the outer pedestal 136 in the Y direction.
A positioning hole 142 that penetrates the outer pedestal 136 in the Y direction is formed in a portion of the outer pedestal 136 that is positioned in the + Z direction with respect to the exposure port 140. The positioning hole 142 accommodates an engagement pin 143 that protrudes from the first flow path member 51A in the + Y direction. Note that the positioning hole 142 may be formed in the bridge portion 137.

  The bridge portion 137 is located in the + Z direction with respect to the communication port 132. That is, in the front cover 78, a portion located in the −Z direction with respect to the communication port 132 is a blank region 141 where the first insulating sheet 135 is not located. In addition, the 1st insulating sheet 135 should just have only the outer base part 136 in the non-discharge area | region Q2.

  As shown in FIG. 10, the first head chip 52A described above is fixed to the front cover 78 and the first insulating sheet 135 with the surface of the first cover plate 56 facing the -Y direction. Specifically, a portion of the surface of the first cover plate 56 that faces the first insulating sheet 135 is fixed to the first insulating sheet 135 with an adhesive S1. On the other hand, a portion of the surface of the first cover plate 56 that faces the blank region 141 is directly fixed to the front cover 78 via the adhesive S1.

  In a state where the first head chip 52A is fixed to the first flow path member 51A, the drive wall 61 (the discharge region Q1 shown in FIG. 6) faces the blank region 141 in the Y direction. That is, in the present embodiment, only the adhesive S1 is interposed between the drive wall 61 and the front cover 78 (the first insulating sheet 135 is not interposed). In this case, the adhesive S1 surrounds the common ink chamber 62 and the communication port 132, and seals between the first head chip 52A and the first flow path member 51A. The adhesive S1 used in the present embodiment is made of an insulating material that is relatively soft (softer than the first insulating sheet 135) (for example, silicone).

  In a state where the first head chip 52A is fixed to the first flow path member 51A, the common ink chamber 62 of the first cover plate 56 communicates with the supply flow path 86 through the communication port 132. On the other hand, as shown in FIG. 8, the first air bubble removal hole 65 </ b> A (see FIG. 7) of the first head chip 52 </ b> A passes through the exposure port 140 and the discharge port 134, and the first bubble discharge channel 120 (second through portion 124). Communicate with.

(Second channel member)
As shown in FIG. 5, the second flow path member 51 </ b> B has a second manifold 150 and a second urging member 151.
The second manifold 150 as a whole is formed in a plate shape in which the Y direction is the thickness direction and the length in the Z direction is shorter than that of the first manifold 75. As shown in FIG. 3, the second manifold 150 is held by the base member 38 in a standing state in the + Z direction by inserting the end portion in the −Z direction into the first module housing portion 44 </ b> A described above.

As shown in FIG. 5, the second manifold 150 has a second flow path plate 152 and a flow path cover 153.
Similarly to the first flow path plate 77, the second flow path plate 152 is formed of a metal material (for example, aluminum) or the like. The second flow path plate 152 is formed with a second ink flow path 155 through which ink flows toward the second head chip 52B.

FIG. 13 is a front view of the second flow path plate 152 as viewed from the + Y direction.
As shown in FIG. 13, the second ink flow path 155 penetrates the second flow path plate 152 in the Y direction and extends in a strip shape in the X direction. The second ink flow path 155 is formed in the same shape as the common ink chamber 62 in the front view when viewed from the Y direction. Therefore, the communication hole 73 of the ejection unit 50 faces the second ink flow path 155 in the Y direction at both ends in the X direction of the second ink flow path 155. In the present embodiment, the total volume of the common ink chamber 62 of the second ink channel 155 and the second head chip 52B is equal to the total volume of the common ink chamber 62 of the supply channel 86 and the first head chip 52A described above. It is preferable that they are set equally.

  Reference numeral 157 in FIG. 13 is a cleaning flow path communicating with the second ink flow path 155. The cleaning liquid that has been sucked up from a nozzle hole 240 (to be described later) and passed through the discharge section 50, the second ink flow path 155, and the like flows into the cleaning flow path 157 during maintenance or the like. The cleaning liquid that has flowed into the cleaning channel 157 is sucked through the cleaning port 158.

The second channel plate 152 is formed with a second bubble discharge channel 160 that communicates with the second ink channel 155. The second bubble discharge channel 160 has a discharge part 161 and a through part 162.
The discharge part 161 opens in the + Y direction in the second flow path plate 152. The discharge part 161 extends in the X direction a portion of the second flow path plate 152 that is positioned in the + Z direction with respect to the second ink flow path 155. The upstream end of the discharge portion 161 is open at the central portion in the X direction on the inner surface of the second ink flow path 155 in the + Z direction (upward in the gravity direction) located in the + Z direction. That is, the distance in the X direction between the pair of communication holes 73 and the upstream end of the discharge portion 161 is set to be equal. The distance in the X direction between the pair of communication holes 73 and the upstream end of the discharge portion 161 can be changed as appropriate. Further, the number and positions of the communication holes 73 can be changed as appropriate.

  The downstream end of the discharge portion 161 communicates with the through portion 162 at a portion located in the + X direction with respect to the second ink flow path 155. In the present embodiment, the configuration in which the second bubble discharge channel 160 is arranged in the + Z direction with respect to the second ink channel 155 has been described. However, the present invention is not limited to this configuration.

  The penetrating portion 162 penetrates the second flow path plate 152 in the Y direction. A sub filter 165 is disposed in the through portion 162.

  In the second flow path plate 152, a sensor accommodating portion 167 is formed in a portion of the second bubble discharge flow path 160 located in the + Z direction. The sensor accommodating portion 167 opens in the + Y direction in the second flow path plate 152 and extends in the X direction.

  As shown in FIG. 5, the flow path cover 153 has an outer shape equivalent to that of the second flow path plate 152 when viewed from the Y direction, and has a thickness in the Y direction that is greater than that of the second flow path plate 152. It is formed in a thin rectangular plate shape. The flow path cover 153 closes the second ink flow path 155, the second bubble discharge flow path 160, and the sensor housing portion 167 from the + Y direction. The flow path cover 153 is formed of a metal material (for example, stainless steel) having excellent thermal conductivity.

  The second urging member 151 is provided as a pair at both ends of the second flow path plate 152 in the X direction. Each second urging member 151 has a leaf spring shape with a free end disposed in the + Y direction with respect to the second flow path plate 152. As shown in FIG. 3, the second urging member 151 includes a long side portion 45c opposed to the base body portion 41 in the Y direction in a state where the second flow path member 51B is inserted into the first module housing portion 44A. Among 45d, it is interposed between the first long side portion 45c and the second manifold 150. That is, the second urging member 151 urges the jet module 30A toward the −Y direction.

(Second insulation sheet)
As shown in FIG. 5, a second insulating sheet 170 is provided on the surface of the second flow path plate 152 facing the −Y direction. The second insulating sheet 170 has an outer pedestal portion 171 and a bridge portion 172 in the same manner as the first insulating sheet 135 described above.

  In each outer pedestal portion 171, in the outer pedestal portion 171 positioned in the + X direction, an exposure port 175 that exposes the through portion 162 is formed at a position overlapping the through portion 162 when viewed from the Y direction. The exposure port 175 penetrates the outer base portion 171 in the Y direction.

The bridge portion 172 is located in the + Z direction with respect to the second ink flow path 155. That is, in the second flow path plate 152, the portion located in the −Z direction with respect to the second ink flow path 155 is a blank area 178 (see FIG. 10) where the second insulating sheet 170 is not located. .
In the bridge portion 172, positioning holes 173 penetrating the bridge portion 172 in the Y direction are formed at both ends in the X direction. The positioning hole 173 accommodates an engagement pin (not shown) protruding in the −Y direction from the second flow path member 51B. Note that the positioning hole 173 may be formed in the outer pedestal 171.

  As shown in FIG. 10, the above-described second head chip 52B is fixed to the second flow path plate 152 and the second insulating sheet 170 with the surface of the second cover plate 72 facing the + Y direction. Specifically, a portion of the surface of the second cover plate 72 that faces the second insulating sheet 170 is fixed to the second insulating sheet 170 via an adhesive S2. On the other hand, a portion of the surface of the second cover plate 72 facing the blank region 178 is directly fixed to the second flow path plate 152 via the adhesive S2. In a state where the second head chip 52B is fixed to the second flow path member 51B, the drive wall 61 (the discharge region Q1 shown in FIG. 6) faces the blank region 178 in the Y direction. In this case, the adhesive S2 surrounds the common ink chamber 62 and the second ink flow path 155, and seals between the second head chip 52B and the second flow path member 51B. Note that the same materials are used for the adhesives S1 and S2.

  In the present embodiment, the configuration in which the insulating sheets 135 and 170 are separately provided between the head chips 52A and 52B and the flow path members 51A and 51B has been described, but at least the first head chip 52A and the first flow path member. It suffices if the first insulating sheet 135 is interposed between 51A and 51A.

  In a state where the second head chip 52B is fixed to the second flow path member 51B, the common ink chamber 62 of the second cover plate 72 communicates with the second ink flow path 155. The second bubble vent hole 65B of the second head chip 52B communicates with the second bubble discharge channel 160 (through portion 162) through the exposure port 175.

  Thus, in the jet module 30A of the present embodiment, the first flow path member 51A and the second flow path member 51B face each other in the Y direction, and two head chips 52A and 52B are provided between the flow path members 51A and 51B. A discharge portion 50 having a gap is sandwiched.

(FPC unit)
As shown in FIG. 5, the FPC unit 180 is supported on the front cover 78 of the first manifold 75. The FPC unit 180 includes a drive board 181 and a wiring board 182. The drive board 181 and the wiring board 182 are each a flexible printed board, and are configured by forming a wiring pattern on a base film.

  The drive substrate 181 includes a mounting part 185, a chip connection part 186, a sensor connection part 187, and a lead-out part 188. Note that the drive substrate 181 may use a rigid substrate or the like for the mounting portion 185.

  The mounting portion 185 is supported by the front cover 78. For example, a plurality of drivers 190A and 190B are mounted on the mounting unit 185. The drivers 190A and 190B are a first driver 190A that drives the first head chip 52A and a second driver 190B that drives the second head chip 52B. The drivers 190A and 190B are arranged in a straight line in the X direction. In the present embodiment, a configuration in which the first driver 190A and the second driver 190B are collectively mounted on one drive substrate 181 will be described. However, the present invention is not limited to this configuration, and the drive substrate corresponding to each driver. May be provided.

  As shown in FIG. 10, the chip connection portion 186 extends from the mounting portion 185 in the −Z direction. The −Z direction end of the chip connecting portion 186 is fixed to the + Z direction end of the first actuator plate 55 by pressure bonding or the like. Thus, the first driver 190A and the drive electrode 59 of the first head chip 52A are electrically connected via the chip connection unit 186.

  As shown in FIGS. 5 and 13, the sensor connection portion 187 extends from the mounting portion 185 in the + X direction. A temperature sensor 191 (for example, a thermistor or the like) is mounted on the distal end portion of the sensor connection portion 187. The sensor connection portion 187 is accommodated in the sensor accommodation portion 167 described above. That is, the temperature sensor 191 detects the ink temperature of the ejection unit 50 via the second flow path plate 152.

  The lead portion 188 extends from the mounting portion 185 in the + Z direction. The drawer 188 is connected to the interface 192 (see FIG. 3). The interface 192 is for supplying power supplied from the outside of the inkjet head 5A to the FPC unit 180 or transmitting / receiving control signals, for example.

  As shown in FIGS. 5 and 10, the wiring board 182 connects the mounting portion 185 and the second head chip 52 </ b> B. Specifically, in the wiring substrate 182, the + Z direction end is connected to the mounting portion 185, and the −Z direction end is fixed to the + Z direction end of the second actuator plate 71 by pressure bonding or the like. Accordingly, the second driver 190B and the drive electrode 59 of the second head chip 52B are electrically connected via the wiring board 182.

  As shown in FIGS. 3 and 5, a heat radiating plate 195 is disposed in the first flow path member 51 </ b> A at a position overlapping the above-described drivers 190 </ b> A and 190 </ b> B when viewed from the Y direction. The heat sink 195 is formed so as to straddle the drive substrate 181 in the X direction. The heat sink 195 covers the drivers 190A and 190B with the heat transfer sheet 196 interposed therebetween. Both end portions in the X direction of the heat radiating plate 195 are fixed to the first flow path member 51 </ b> A outside the drive substrate 181. In addition, the heat sink 195 and the heat transfer sheet 196 are formed of a material having excellent thermal conductivity. In the present embodiment, the heat radiating plate 195 is made of, for example, aluminum, and the heat transfer sheet 196 is made of, for example, a silicone resin.

  As shown in FIGS. 3 and 4, the first jet module 30 </ b> A described above includes the first module with the first flow path member 51 </ b> A facing the −Y direction and the second flow path member 51 </ b> B facing the + Y direction. It is inserted into the accommodating portion 44A. At this time, in the first jet module 30A, the first urging member 48 is interposed between the second flow path member 51B and the first short side part 45a, and the second flow path member 51B and the first long side part 45c. Is held by the base member 38 with the second biasing member 151 interposed therebetween. Therefore, the first jet module 30 </ b> A is urged in the −X direction (direction toward the second short side 45 b) by the first urging member 48, and in the −Y direction (to the partition portion 46) by the second urging member 151. The base member 38 is held in a state of being urged in the direction of heading. At this time, the end surface in the −Z direction of the discharge unit 50 is arranged flush with the end surface in the −Z direction of the base member 38 (base main body portion 41), or in the −Z direction with respect to the end surface in the −Z direction of the base member 38. Preferably they are arranged.

  The second jet module 30B is inserted into the second module housing portion 44B with the first flow path member 51A facing the + Y direction and the second flow path member 51B facing the -Y direction. That is, the first flow path member 51A of the second jet module 30B is opposed to the first flow path member 51A of the first jet module 30A in the Y direction. The jet modules 30A and 30B are fixed to the corresponding module housing portions 44A and 44B with an adhesive.

(Stay unit)
As shown in FIG. 2, the base member 38 is provided with a stay unit 200 that supports components mounted on the base member 38. The stay unit 200 stands up in the + Z direction from the base member 38 and collectively surrounds the jet modules 30A and 30B.

  A module holding mechanism 210 is interposed between the stays 200 in the X direction stays (first stay 201 and second stay 202) located on both sides in the X direction and the jet modules 30A and 30B. Since each module holding mechanism 210 has the same configuration, in the following description, the module holding mechanism 210 interposed between the first stay 201 and the first jet module 30A will be described as an example.

  The first stay 201 is located in the + X direction with respect to the jet modules 30A and 30B. The first stay 201 stands up in the + Z direction from the base member 38 with the −Z direction end portion inserted into the module housing portions 44A and 44B. The first stay 201 is assembled to the base member 38 after the jet modules 30A and 30B are assembled to the base member 38.

14 is a partial cross-sectional view taken along line XIV-XIV in FIG.
As shown in FIGS. 3 and 14, the module holding mechanism 210 includes a positioning pin 212 provided in the first flow path member 51 </ b> A, a first housing portion 214 formed in the first stay 201, and a positioning pin 212. And a support piece 216 connecting the first stay 201.

  The positioning pin 212 protrudes from the first flow path plate 77 in the + X direction. The positioning pins 212 are preferably arranged at positions separated from the base member 38 in the Z direction. In the present embodiment, the positioning pin 212 is disposed in a portion located in the + Z direction with respect to the central portion in the Z direction in the first flow path plate 77.

  The first accommodating portion 214 is formed so as to penetrate a portion overlapping the positioning pin 212 in the X direction in the first stay 201 as viewed from the side in the X direction. The first accommodating portion 214 is formed in a circular shape in a side view as viewed from the X direction, and has an uniform inner diameter. The inner diameter of the first housing portion 214 is larger than the outer diameter of the positioning pin 212. The positioning pin 212 described above passes through the first housing portion 214 and protrudes in the + X direction with respect to the first stay 201.

  The support piece 216 is a plate material whose longitudinal direction is the Z direction. The support piece 216 is fixed to the first stay 201 so as to close the first housing portion 214 from the + X direction. Specifically, in the support piece 216, a second accommodation portion 220 that penetrates the support piece 216 in the X direction is formed at a position overlapping the first accommodation portion 214 in a side view as viewed from the X direction. The second accommodating portion 220 is formed in a circular shape as viewed from the side as viewed from the X direction, and has an uniform inner diameter. The inner diameter of the second housing part 220 is smaller than the inner diameter of the first housing part 214 and larger than the outer diameter of the positioning pin 212. The positioning pin 212 described above is inserted into the second housing part 220. And the movement in the direction orthogonal to the X direction of the 1st jet module 30A with respect to the 1st stay 201 is controlled because the outer peripheral surface of the positioning pin 212 contacts the inner peripheral surface of the 2nd accommodating part 220. FIG.

Note that the positioning pin 212 may be fitted in the second housing portion 220. The first storage portion 214 and the second storage portion 220 are not limited to a circular shape when viewed from the side, and may be rectangular or triangular. Further, the first housing part 214 and the second housing part 220 may have different shapes. Even in such a case, the opening area of the second housing part 220 is set smaller than the opening area of the first housing part 214.
As long as the positioning pin 212 can be inserted, the second accommodating portion 220 may not penetrate the support piece 216.
The 1st accommodating part 214 and the 2nd accommodating part 220 may be the structures from which an internal diameter changes gradually.

  The support piece 216 is fixed to the first stay 201 with screws 222 on both sides in the Z direction with respect to the second accommodating portion 220. Specifically, escape holes 223 are formed on both sides of the support piece 216 in the Z direction with respect to the second accommodating portion 220. The inner diameter of the escape hole 223 is larger than the outer diameter of the shaft portion of the screw 222. The screw 222 is fastened to the first stay 201 through the escape hole 223. The support piece 216 is fixed to the first stay 201 by sandwiching the support piece 216 in the X direction between the head of the screw 222 and the first stay 201. The tip of the screw 222 is close to the first flow path plate 77 in the X direction.

  As described above, the first jet module 30A of the present embodiment is held by the base member 38 by inserting the −Z direction end portion into the first module housing portion 44A, and the + Z direction end portion by the module holding mechanism 210. Is retained.

(damper)
As shown in FIG. 2, the damper 31 is provided in the + Z direction with respect to the jet modules 30 </ b> A and 30 </ b> B, corresponding to each jet module 30 </ b> A and 30 </ b> B (corresponding to the ink color). Each damper 31 is provided side by side in the Y direction. Each damper 31 has the same configuration except for the color of the supplied ink. Therefore, in the following description, one damper 31 (the damper 31 of the first jet module 30A) will be described, and the description of the other damper 31 will be omitted.

  The damper 31 is fixed to the above-described stay unit 200 in the + Z direction with respect to the first jet module 30A. The damper 31 has an inlet port 230, a pressure buffer 231, and an outlet port 232. The damper 31 may be provided separately from the inkjet head 5A.

The inlet port 230 is formed in a cylindrical shape protruding from the pressure buffering portion 231 in the + Z direction. The ink pipe 16 (see FIG. 1) described above is connected to the inlet port 230. The ink in the ink tank 15 flows into the inlet port 230 through the ink pipe 16.
The pressure buffer 231 is formed in a box shape. The pressure buffer 231 is configured by accommodating a movable film or the like therein. The pressure buffer 231 is disposed between the ink tank 15 (FIG. 1) and the first jet module 30 </ b> A, and absorbs pressure fluctuations of ink supplied to the damper 31 through the inlet port 230.

  The outlet port 232 protrudes in the −Z direction from a position diagonal to the inlet port 230 in the pressure buffer portion 231. Ink discharged from the pressure buffer 231 flows into the outlet port 232. The outlet port 232 is connected to the inflow port 76 of the first jet module 30A.

  The interface 192 described above is disposed in a portion located between the dampers 31 facing each other in the Y direction. The interface 192 is supported by the stay unit 200.

(Nozzle plate)
The nozzle plate 32 described above is formed of a resin material such as polyimide. The nozzle plate 32 is fixed to an end surface in the −Z direction of the base main body 41 and an end surface in the −Z direction of the discharge unit 50 (a portion exposed from the module housing portions 44A and 44B) via an adhesive or the like. The nozzle plate 32 covers the ejection units 50 of the jet modules 30A and 30B together from the −Z direction.

  As shown in FIGS. 6 and 7, the nozzle plate 32 is formed with nozzle holes 240 that penetrate the nozzle plate 32 in the Z direction. The nozzle holes 240 are formed separately at positions facing the ejection channels 57 of the head chips 52A and 52B in the Z direction.

  In the nozzle plate 32, discharge holes 241A and 241B penetrating the nozzle plate 32 in the Z direction are formed at positions facing the bubble vent holes 65A and 65B in the Z direction. That is, in the present embodiment, the nozzle hole 240 and the discharge holes 241A and 241B are opened on the discharge surface (the surface facing the −Z direction) of the nozzle plate 32, respectively. The discharge holes 241A and 241B of the present embodiment are a first discharge hole 241A that communicates with the first bubble removal hole 65A and a second discharge hole 241B that communicates with the second bubble removal hole 65B. The inner diameter (opening area) of the second discharge hole 241B is smaller than the inner diameter of the first discharge hole 241A. However, the inner diameters of the discharge holes 241A and 241B can be changed as appropriate. Moreover, each discharge hole 241A, 241B is not restricted to the case where it is a round hole.

  The ink in the nozzle holes 240 and the discharge holes 241A and 241B forms an appropriate (concave) meniscus due to the surface tension acting on the inner surfaces of the nozzle holes 240 and the discharge holes 241A and 241B. That is, in the printer 1 of this embodiment, the pressure in the discharge channel 57 is maintained at a desired negative pressure due to the water head difference between the liquid level of the ink tank 15 and the liquid level of the meniscus. As a result, the meniscus described above is retained, and ink is prevented from leaking unexpectedly.

  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 be a laminated structure of a resin material and a metal material. In the present embodiment, the configuration in which one nozzle plate 32 covers the jet modules 30A and 30B together has been described. However, the present invention is not limited to this configuration, and each jet module 30A and 30B is individually provided by a plurality of nozzle plates 32. It may be configured to cover.

(Nozzle guard)
As shown in FIG. 2, the nozzle guard 33 is formed by pressing a plate material such as stainless steel. The nozzle guard 33 covers the base body 41 from the −Z direction with the nozzle plate 32 sandwiched therebetween.

  An exposure hole 245 for exposing the nozzle plate 32 to the outside is formed in the nozzle guard 33 at a position facing the ejection unit 50 of each jet module 30A, 30B in the Z direction. The exposure hole 245 penetrates the nozzle guard 33 in the Z direction and is formed in a slit shape extending in the X direction. The exposure holes 245 are formed in two rows at intervals in the Y direction corresponding to the jet modules 30A and 30B. The nozzle hole 240 and the discharge holes 241A and 241B described above communicate with the outside of the inkjet head 5A through the exposure hole 245. The nozzle guard 33 has a cap that seals the nozzle hole 240 and the discharge holes 241A and 241B as described above, in close contact with the nozzle guard 33 from the −Z direction when ink is filled or when the printing operation is stopped. It may be configured to be mounted.

[How the printer works]
Next, a method for recording information on the recording medium P using the printer 1 described above will be described.
As shown in FIG. 1, when the printer 1 is operated, the grit rollers 11 and 13 of the transport mechanisms 2 and 3 rotate, so that the recording medium P is interposed between the grit rollers 11 and 13 and the pinch rollers 12 and 14. It is conveyed in the + X direction. At the same time, the drive motor 28 rotates the pulley 26 to run the endless belt 27. As a result, 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 inkjet heads 5A and 5B, a drive voltage is applied to the drive electrodes 59 (see FIG. 7) of the head chips 52A and 52B. As a result, a thickness-slip deformation is caused in the drive wall 61, and a pressure wave is generated in the ink filled in the ejection channel 57. Due to this pressure wave, the internal pressure of the ejection channel 57 increases, and ink is ejected through the nozzle hole 240. Various types of information are recorded on the recording medium P by the ink landing on the recording medium P.

Here, the flow of ink in the first jet module 30A of the inkjet head 5A will be described.
In the present embodiment, the ink supplied from the ink tank 15 to the inkjet head 5A flows through the damper 31 and then flows into the first manifold 75 of the jet module 30A through the inflow port 76, as shown in FIG.

  As indicated by the solid line arrow in FIG. 10, the ink that has flowed into the first manifold 75 passes through the upstream flow path 83 and then flows into the filter inlet flow path 95 of the filtration flow path 84 from the + Z direction. As indicated by the solid line arrow in FIG. 11, the ink that has flowed into the filter inlet channel 95 passes through the main filter 99 in the process from the filter inlet channel 95 toward the filter outlet channel 96. As a result, foreign matter and bubbles contained in the ink are captured by the main filter 99. The ink reaching the filter outlet channel 96 is blocked from flowing in the −Y direction (downstream channel 85) by the storage wall 100. As a result, the filter outlet channel 96 is filled with ink.

  When the ink filled in the filter outlet channel 96 reaches the communication channel 102, the ink flows into the downstream channel 85 through the communication channel 102. The ink flows in the −Z direction through the downstream flow path 85 and then flows in the supply flow path 86 in the + Y direction. The ink flowing in the supply flow path 86 flows into the common ink chamber 62 of the first head chip 52A through the communication port 132. Among the ink that has flowed into the common ink chamber 62 of the first head chip 52A, a part of the ink passes through the slit 63 and flows into the discharge channel 57 in the first head chip 52A, and is then discharged through the nozzle hole 240. The

  On the other hand, some of the ink that has flowed into the common ink chamber 62 of the first head chip 52 </ b> A flows into the communication hole 73 at both ends in the X direction of the common ink chamber 62. Thereafter, the ink flows into the common ink chamber 62 of the second head chip 52 </ b> B through the communication hole 73. The ink that has flowed into the common ink chamber 62 of the second head chip 52 </ b> B flows inward in the X direction while filling the second ink flow path 155. Thereafter, the ink that has flowed into the second head chip 52B passes through the slit 63 and flows into the discharge channel 57, and is then discharged through the nozzle hole 240.

  By the way, as indicated by the broken-line arrows in FIG. 9, the bubbles remaining in the filter inlet channel 95 (upstream with respect to the main filter 99) in the first ink channel 81 are the first bubble discharge channel 120. Through the first jet module 30A. Specifically, bubbles trapped by the main filter 99 and bubbles staying in the filter inlet channel 95 are pushed out to both sides in the X direction while the ink flows through the filter inlet channel 95 on both sides in the X direction. It is. Thereafter, after the bubble enters the guiding portion 121, the bubble moves inside the guiding portion 121 in the X direction and in the + Z direction. Then, the bubbles move in the −Y direction through the first penetration part 122. Thereafter, the bubbles move in the −Z direction through the discharge portion 123 and then enter the second through portion 124 through the sub filter 126 (see FIG. 12). Air bubbles that have entered the second through portion 124 enter the first air bubble removal hole 65A of the first head chip 52A as shown in FIG. 6, and are then discharged to the outside through the first discharge hole 241A of the nozzle plate 32.

  On the other hand, when air bubbles remain in the common ink chamber 62 of the second head chip 52B or in the second flow path member 51B (second ink flow path 155), the air bubbles are first passed through the second bubble discharge flow path 160. It is discharged outside the jet module 30A. Specifically, the bubbles staying in the second ink flow path 155 and the like reach the penetration part 162 through the discharge part 161. The air bubbles that have reached the penetrating portion 162 pass through the sub-filter 165 and then enter the second air vent hole 65B of the second head chip 52B shown in FIG. Thereafter, the bubbles are discharged to the outside through the second discharge holes 241B of the nozzle plate 32.

Thus, in the present embodiment, the first flow path member 51A is formed with the first bubble discharge flow path 120 that connects the inside and the outside of the first ink flow path 81, and the second flow path member 51A has the first flow path 51A. A second bubble discharge channel 160 that allows communication between the inside and outside of the two-ink channel 155 is formed.
According to this configuration, bubbles staying in the first ink flow path 81 and the second ink flow path 155 can be discharged through the first bubble discharge flow path 120 and the second bubble discharge flow path 160, respectively. Therefore, it is possible to suppress bubbles from entering the head chips 52A and 52B, and to improve the ink filling properties of the head chips 52A and 52B. Thereby, discharge stability can be improved.

In the present embodiment, the nozzle hole 240 and the discharge holes 241A and 241B are configured to open on the same surface (discharge surface) of the nozzle plate 32.
According to this configuration, for example, when the nozzle hole 240 and the discharge holes 241A and 241B are sealed with a cap at the time of ink filling or when the printing operation is stopped, the nozzle hole 240 and the discharge holes 241A and 241B are combined into one cap. It becomes possible to cover together. Therefore, it is possible to improve the maintainability.

Incidentally, as described above, a part of the ink in the first ink flow path 81 is supplied to the second ink flow path 155 through the communication hole 73. In this case, since the second ink flow path 155 is located on the downstream side with respect to the first ink flow path 81, the second ink flow path 155 is likely to have a higher pressure than the pressure in the first ink flow path 81.
Therefore, according to the present embodiment, by making the inner diameter of the second discharge hole 241B smaller than the inner diameter of the first discharge hole 241A, the surface tension acting on the inner surface of the second discharge hole 241B can be increased. It can be higher than the surface tension acting on the inner surface. Thereby, it becomes easy to stabilize the meniscus in the 2nd discharge hole 241B, and it can suppress that ink leaks through the 2nd discharge hole 241B unexpectedly.
Further, since the meniscus is stabilized in the second discharge hole 241B, the meniscus is destroyed by, for example, the negative pressure generated in the second head chip 52B when the ink jet heads 5A and 5B are used (when ink is ejected). It is possible to suppress the outside air (air) from entering the second head chip 52B through the second discharge hole 241B. Therefore, it is possible to suppress the air that has entered from the second discharge hole 241B from becoming bubbles and stay in the second head chip 52B, thereby improving the discharge stability.

In this embodiment, the distance between the pair of communication holes 73 and the upstream end of the discharge portion 161 in the X direction is set to be equal.
According to this configuration, in the process in which the ink flows through the second ink flow path 155 from the respective communication holes 73 to the central portion in the X direction, the bubbles staying in the second ink flow path 155 are generated from both sides in the X direction. It is possible to push evenly toward the two-bubble discharge channel 160. Thereby, it can suppress more reliably that a bubble approachs into the 2nd head chip 52B.

In the present embodiment, the sub-filters 126 and 165 are arranged in the first bubble discharge channel 120 and the second bubble discharge channel 160, respectively.
According to this configuration, the flow resistance in the bubble discharge flow paths 120 and 160 is increased by the sub-filters 126 and 165, so that the first flow caused by the ink flow from the upstream, the ink discharge from the nozzle holes 240, and the like. It is possible to prevent the meniscus in the second discharge hole 241B from being broken by the pressure fluctuation in the two-bubble discharge channel 160. Thereby, it becomes easy to stabilize the meniscus in the discharge holes 241A and 241B, and it is possible to prevent ink from leaking unexpectedly through the discharge holes 241A and 241B. In the present embodiment, the configuration of adjusting the surface tension by changing the inner diameters of the discharge holes 241A and 241B has been described. However, the present invention is not limited to this configuration, and the flow resistances of the sub-filters 126 and 165 are different. The surface tension may be adjusted.

  In the present embodiment, since the inkjet heads 5A and 5B described above are provided, the printer 1 having excellent ejection performance can be provided.

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 spirit of the present invention.
For example, in the above-described embodiment, the ink jet printer 1 is described as an example of the liquid ejecting apparatus, but the present invention is not limited to the printer. For example, a fax machine or an on-demand printer may be used.

  In the above-described embodiment, the configuration in which the two jet modules 30A and 30B are mounted on the base member 38 has been described, but the configuration is not limited thereto. The number of jet modules mounted on the base member 38 may be one or a plurality of three or more.

In the embodiment described above, the edge chute head chip has been described, but the present invention is not limited to this. For example, the present invention may be applied to a so-called side shoot type head chip that ejects ink from the central portion of the ejection channel in the extending direction.
Further, the present invention may be applied to a so-called roof chute type head chip in which the direction of pressure applied to the ink and the direction of ink ejection are the same.

In the above-described embodiment, the configuration in which the communication hole 73 is formed in each of the head chips 52A and 52B has been described. However, the configuration is not limited to this configuration. In addition to the head chips 52A and 52B, a communication channel for communicating the head chips 52A and 52B may be provided.
In the above-described embodiment, the configuration in which the ink flow paths 81 and 155 communicate with each other through the communication hole 73 has been described. However, the present invention is not limited to this configuration, and each flow path member 51A and 51B is provided with an inflow port. A configuration may be employed in which ink is supplied independently to the path members 51A and 51B.

In the above-described embodiment, the configuration in which the Z direction coincides with the gravity direction has been described. However, the configuration is not limited to this configuration, and the Z direction may coincide with the horizontal direction.
In the above-described embodiment, the configuration in which the discharge holes 241A and 241B are formed in the nozzle plate 32 has been described. However, the configuration is not limited to this configuration. For example, a discharge hole may be formed in each flow path member 51A, 51B, head chip 52A, 52B, or the like.

  In the above-described embodiment, the configuration in which the two head chips 52A and 52B are mounted on one jet module has been described. However, the configuration is not limited thereto. That is, the configuration may be such that one head chip is mounted on one jet module.

  In addition, in the range which does not deviate from the meaning of this invention, it is possible to replace suitably the component in the embodiment mentioned above by a known component, and you may combine each modification mentioned above suitably.

1 ... Inkjet printer (liquid ejecting device)
5A, 5B ... Inkjet head (liquid jet head)
15 ... Ink tank (supply source)
32 ... Nozzle plate (spray hole plate)
51A ... first flow path member 51B ... second flow path member 52A ... first head chip 52B ... second head chip 57 ... discharge channel (first pressure fluctuation chamber, second pressure fluctuation chamber)
62 ... Common ink chamber (liquid chamber)
71 ... 2nd actuator plate 72 ... 2nd cover plate 73 ... Communication hole (communication flow path)
76: Inflow port 81: First ink flow path (first liquid flow path)
120 ... first bubble discharge channel 126.165 ... sub-filter 155 ... second ink channel (second liquid channel)
160 ... second bubble discharge channel 241A ... first discharge hole 241B ... second discharge hole Q1 ... discharge region (injection region)

Claims (6)

A first head chip and a second head chip that are stacked in the first direction and that eject liquid; and
A first channel member disposed on the opposite side of the first head chip from the second head chip in the first direction and having a first liquid channel communicating with the first head chip; ,
A second channel member disposed on the opposite side of the second head chip from the first head chip in the first direction and having a second liquid channel communicating with the second head chip; Have
The first channel member is formed with a first bubble discharge channel that communicates the inside and outside of the first liquid channel,
The liquid jet head according to claim 2, wherein a second bubble discharge channel is formed in the second channel member to communicate the inside and outside of the second liquid channel. The first head chip has a first pressure fluctuation chamber that applies a pressure fluctuation to the liquid,
The second head chip has a second pressure fluctuation chamber for imparting pressure fluctuation to the liquid,
The first head chip and the second head chip are each provided with an injection hole plate in which injection holes communicating with the first pressure fluctuation chamber and the second pressure fluctuation chamber are formed.
A first discharge hole that communicates with the first bubble discharge channel and a second discharge hole that communicates with the second bubble discharge channel are opened on an injection surface of the injection hole plate where the injection hole opens. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is provided. The first flow path member has an inflow port that connects a liquid supply source and the first liquid flow path,
Between the first flow path member and the second flow path member, a communication flow path for communicating the first liquid flow path and the second liquid flow path is disposed,
The liquid ejecting head according to claim 2, wherein an inner diameter of the second discharge hole is smaller than an inner diameter of the first discharge hole. The second head chip has a jet region in which second pressure chambers that apply pressure fluctuations to the liquid are arranged side by side in a second direction intersecting the first direction,
The communication flow path is disposed in a pair at portions located on both sides of the injection region in the second direction,
4. The liquid jet head according to claim 3, wherein the second bubble discharge channel communicates with the second liquid channel at a central portion between the pair of communication channels in the second direction. 5. .   5. The liquid jet head according to claim 3, wherein a filter for filtering the liquid is disposed in the second bubble discharge channel.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

Images