Liquid jet head and liquid jet device

Abstract

To provide a technology capable of suppressing occurrence of variation in pressure loss between flow paths in a liquid jet head.SOLUTION: A liquid jet head comprises a plurality of head chips and a distribution flow path member. A second chip row is arranged to deviate in a second direction with respect to a first chip row. A first clearance is formed between adjacent first head chips of a plurality of first head chips, and a second clearance is formed between adjacent second head chips of a plurality of second head chips. The second head chips which are at least some of the plurality of second head chips are arranged to fill one or a plurality of first clearances when viewed in a second direction. Distribution flow paths have a main branched flow path, first sub branched flow paths, arranged among the main branched flow path and the plurality of head chips with respect to a laminating direction and communicated with the first main branched part, which have first sub branched parts A and first sub branched parts B which are branched at a first sub branching position, where the first sub branching position overlaps with the first clearances, when viewed in the laminating direction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to techniques for liquid ejection heads and liquid ejection apparatuses. [Background technology]

[0002] A conventional technology is known for a liquid jet head having one common supply flow path arranged between a first head row and a second head row, branched distribution flow paths that supply liquid from the common supply flow path to each head, and a supply port that supplies liquid to the common supply flow path (Patent Document 1). The supply port is connected to a central portion of the common supply flow path in the direction in which the heads are arranged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-214130 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology, when a common supply flow path connected to a supply port and a plurality of distribution flow paths branching from the common supply flow path are formed on the same plane, there is variation in the length of each flow path from the supply port to each head, which tends to cause variation in pressure loss between each flow path. [Means for solving the problem]

[0005] According to a first aspect of the present disclosure, there is provided a liquid ejection head, the liquid ejection head including a plurality of head chips including a plurality of first head chips arranged in a first direction to form a first chip row and a plurality of second head chips arranged in the first direction to form a second chip row, and a distribution flow path member configured by stacking a plurality of flow path substrates in a stacking direction and having a distribution flow path that distributes and supplies liquid to the plurality of head chips, the second chip row being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, a first gap being formed between adjacent first head chips among the plurality of first head chips, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, and the plurality of first head chips being shifted from the first chip row in a second direction perpendicular to the first direction and the stacking direction, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to the first direction and the stacking direction, and the plurality of first head chips being shifted from the first chip row in a second direction perpendicular to the first direction and the stacking direction, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to the first direction and the stacking direction, and the plurality of first head chips being shifted from the first chip row in a second direction perpendicular to the first chip row and the stacking direction, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to the first chip row ... A second gap is formed between adjacent second head chips among the chips, and at least some of the second head chips among the multiple second head chips are arranged to fill one or more of the first gaps when viewed in the second direction, and the distribution flow path has a main branch flow path having a first main branch portion and a second main branch portion branching at a main branch position, and a first sub-branch flow path which is arranged between the main branch flow path and the multiple head chips in the stacking direction and communicates with the first main branch portion, and has a first sub-branch portion A and a first sub-branch portion B branching at a first sub-branch position, and the first sub-branch position overlaps with the first gap when viewed in the stacking direction.

[0006] According to a second aspect of the present disclosure, there is provided a liquid ejecting apparatus comprising: the liquid ejecting head of the above aspect; and a liquid storage portion that stores liquid to be supplied to the liquid ejecting head. [Brief description of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating a configuration of a liquid ejecting apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view illustrating a liquid jet head. [Diagram 3] FIG. 2 is a cross-sectional view of an arbitrary head chip. [Figure 4] 1 is a plan view of the relay board as viewed from the front side located on the filter unit side. FIG. [Diagram 5] FIG. 1 is a diagram for explaining a distribution flow path. [Figure 6] FIG. 2 is a diagram illustrating a distribution flow path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. Embodiment: FIG. 1 is a diagram showing a schematic configuration of a liquid ejection device 1 of this embodiment. FIG. 1 shows an X-axis, a Y-axis, and a Z-axis that are orthogonal to each other. The Z-axis is a coordinate axis parallel to the vertical direction. The arrows representing the X-axis, the Y-axis, and the Z-axis in FIG. 1 and the arrows representing the X-axis, the Y-axis, and the Z-axis in other figures point in the same direction. When specifying a direction, positive and negative signs are used in combination to indicate the direction, with the positive direction indicated by the arrow being "+" and the negative direction opposite to the direction indicated by the arrow being "-". The -Z axis direction is the opening direction in which a nozzle Nz described later opens, and is the direction in which liquid is ejected from the nozzle Nz.

[0009] The liquid ejection device 1 includes a liquid ejection head 3, a control device 4, a transport mechanism 5, and a liquid storage unit 6. In this embodiment, the liquid ejection device 1 is a printer, which ejects ink, a type of liquid, from nozzles Nz of the liquid ejection head 3 onto the surface of a medium 2, such as a recording paper or a synthetic resin film, to record an image or the like. The control device 4 comprehensively controls each unit constituting the liquid ejection device 1. The transport mechanism 5 transports the medium 2 from the paper feed side to the paper discharge side in response to a control command from the control device 4. The liquid storage unit 6 communicates with the liquid ejection head 3 via a flow path such as a tube, and stores liquid to be supplied to the liquid ejection head 3. The liquid storage unit 6 can be of various configurations, such as a cartridge or a tank that can be refilled with liquid. The liquid in the liquid storage unit 6 is sent to the liquid ejection head 3 by driving a pump (not shown). In other embodiments, the liquid may be circulated between the liquid storage unit 6 and the liquid ejection head 3.

[0010] The liquid jet head 3 includes a plurality of head chips 70 that eject liquid. The plurality of head chips 70 include a plurality of first head chips 70a that are arranged at intervals in the direction along the X-axis direction to form a first chip row Ln1, and a plurality of second head chips 70b that are arranged at intervals in the direction along the X-axis direction to form a second chip row Ln2. The direction along the X-axis direction is the longitudinal direction of the liquid jet head 3. In this embodiment, four first head chips 70a are provided, and three second head chips 70b are provided. That is, the number of the first head chips 70a is greater than the number of the second head chips 70b and is an even number. The second chip row Ln2 is shifted in the direction along the Y-axis direction with respect to the first chip row Ln1. The stacking direction is the direction in which a plurality of flow path substrates, which will be described later, included in the liquid jet head 3 are stacked.

[0011] In this embodiment, the "first direction" is a direction along the X-axis direction, which is the longitudinal direction of the liquid jet head 3. The "second direction" is a direction perpendicular to the direction along the X-axis direction and the stacking direction along the Z-axis direction, which is a direction along the Y-axis direction in this embodiment.

[0012] A first gap Ga is formed between adjacent first head chips 70a among the multiple first head chips 70a. In this embodiment, the interval between adjacent first head chips 70a is constant, so the size of each first gap Ga is the same. A second gap Gb is formed between adjacent second head chips 70b among the multiple second head chips 70b. In this embodiment, the interval between adjacent second head chips 70b is constant, so the size of each second gap Gb is the same. At least a part of the second head chips 70b among the multiple second head chips 70b are arranged to fill one or more first gaps Ga when viewed in the direction along the Y axis direction. In this embodiment, each second head chip 70b is arranged to fill the corresponding first gap Ga when viewed in the direction along the Y axis direction. In other words, when viewed in the direction along the Y axis, the +X direction end of the second head chip 70b overlaps with the -X direction end of one of the pair of first head chips 70a arranged to sandwich the first gap Ga therebetween, and the -X direction end of the second head chip 70b overlaps with the +X direction end of the other first head chip 70a of the pair of first head chips 70a. In this way, the multiple first head chips 70a and the multiple second head chips 70b are arranged in a staggered pattern. Note that the number of the first head chips 70a and the second head chips 70b is not limited to this embodiment. For example, the number of the first head chips 70a and the number of the second head chips 70b may be the same, or the number of the second head chips 70b may be greater than the number of the first head chips 70a.

[0013] Each of the head chips 70 has a plurality of nozzles Nz formed at regular intervals in the X-axis direction. In each of the head chips 70, the nozzles Nz include a first nozzle row 70L1 extending in the X-axis direction and a second nozzle row 70L2 extending in the X-axis direction. The first nozzle row 70L1 and the second nozzle row 70L2 are offset in the Y-axis direction.

[0014] 2 is a schematic cross-sectional view illustrating the liquid jet head 3. The liquid jet head 3 includes a filter unit 25, a distribution flow path member 260, a head chip 70, a relay substrate 80, and a fixing plate 90.

[0015] The filter unit 25 has therein a filter 12 through which liquid passes to be supplied to a main branch flow path 580 (described later) of the distribution flow path member 260. The filter 12 captures foreign matter such as dust and air bubbles in the liquid. The filter 12 may be, for example, a sheet-like filter having a plurality of micropores formed by finely weaving fibers of metal, resin, or the like, or a plate-like member of metal, resin, or the like having a plurality of micropores formed therethrough.

[0016] The filter unit 25 constitutes an upper wall of the liquid jet head 3. The filter unit 25 further includes a cover 20 and a filter forming member 30. The cover 20 and the filter forming member 30 are laminated.

[0017] The cover 20 has a concave shape that opens on the -Z axis direction side, which is the opening direction of the nozzle Nz. The cover 20 has a cover upper wall 22 that constitutes the head upper wall, and a cover side wall 24 that extends from the peripheral portion of the cover upper wall 22 to the -Z axis direction side. The cover upper wall 22 is formed with a connection member 26 that protrudes to the +Z axis direction side, and a first filter chamber 27 that is partitioned by the cover upper wall 22. The connection member 26 is cylindrical. A flow path such as a tube through which the liquid in the liquid storage section 6 flows is connected to the connection member 26. The first filter chamber 27 is in communication with the internal flow path of the connection member 26.

[0018] The filter forming member 30 has a second filter chamber 37 and a supply pipe 36. The second filter chamber 37 is partitioned by the filter forming member 30, and is located on the opposite side to the first filter chamber 27 across the filter 12. The supply pipe 36 is a member that protrudes from the second filter chamber 37 in the -Z direction. The internal flow path of the supply pipe 36 communicates with the second filter chamber 37. The liquid supplied to the connection member 26 passes through the first filter chamber 27, the filter 12, the second filter chamber 37, and the supply pipe 36 in that order, and flows into an introduction pipe of a distribution flow path member 260, which will be described later.

[0019] The distribution flow path member 260 is configured by stacking a plurality of flow path substrates 40, 50, 60 in a stacking direction. The stacking direction is a direction along the opening direction of the nozzle Nz, which is the Z-axis direction. The distribution flow path member 260 is disposed between the relay substrate 80 and the plurality of head chips 70 when viewed in the stacking direction. The distribution flow path member 260 has a distribution flow path 265 that distributes and supplies liquid to the plurality of head chips 70 included in the liquid ejecting device 1. The plurality of flow path substrates 40, 50, 60 are, in order from the side where the filter unit 25 is located, the first flow path substrate 40, the second flow path substrate 50, and the third flow path substrate 60 as a holder.

[0020] The first flow path substrate 40 has a plate-shaped substrate body 42 and a flow path pipe 41 protruding from the substrate body 42 toward the supply pipe 36. The flow path pipe 41 is connected to the supply pipe 36 via a seal member 39. The flow path pipe 41 defines an inlet 41h for introducing liquid into a main branch flow path 580, which will be described later. A part of the distribution flow path 265 is formed on the surface of the substrate body 42 facing the second flow path substrate 50.

[0021] The second flow path substrate 50 is a plate-shaped member. On the surface of the second flow path substrate 50 facing the first flow path substrate 40 and the surface facing the third flow path substrate 60, a part of the distribution flow path 265 is formed.

[0022] The third flow path substrate 60 has a plate-shaped substrate main body 61, a chip accommodating chamber 63 that accommodates the head chip 70, and a flange portion 64 extending outward from the substrate main body 61. A part of the distribution flow path 265 is formed on the surface of the substrate main body 61 that faces the second flow path substrate 50. The chip accommodating chamber 63 is defined by a plate member extending from the substrate main body 61 to the -Z axis direction side. The flange portion 64 is fixed to the cover side wall 24.

[0023] The relay substrate 80 is disposed on the substrate body 42 of the first flow path substrate 40. The relay substrate 80 is a plate-shaped member. The relay substrate 80 is electrically connected to each of the multiple head chips 70. The relay substrate 80 is a substrate that relays various signals supplied from the control device 4. The various signals include control signals for controlling the liquid jet head 3 and drive signals for driving the liquid jet head 3.

[0024] The head chip 70 ejects liquid supplied from the distribution flow path 265 of the distribution flow path member 260. Each of the head chips 70 has a flexible substrate 78 electrically connected to the relay substrate 80 so as to penetrate the distribution flow path member 260 and the relay substrate 80. For the flexible substrate 78, for example, a flexible wiring substrate such as FPC, COF, or FFC is preferably adopted. Here, FPC is an abbreviation for Flexible Printed Circuit. COF is an abbreviation for Chip on Film. FFC is an abbreviation for Flexible Flat Cable. The flexible substrate 78 has a drive circuit 781. The drive circuit 781 is an electric circuit that switches whether or not to supply a drive signal Com to a piezoelectric element of the head chip 70 described later under a control signal. The head chip 70 will be described in detail later.

[0025] The fixed plate 90 is a flat plate-shaped member. The fixed plate 90 is made of metal. In the fixed plate 29, openings are formed at positions facing the nozzle rows 70L1 and 70L2 of each head chip 70. The fixed plate 90 is fixed to the head chip 70 with an adhesive.

[0026] As described above, the distribution flow path member 260 is disposed between the relay substrate 80 and the plurality of head chips 70 in the Z-axis direction which is the stacking direction.

[0027] FIG. 3 is a cross-sectional view of an arbitrary head chip 70. However, in FIG. 3, a fixing plate 90 is shown in addition to the head chip 70. The head chip 70 has a communication plate 71, a pressure chamber substrate 72 laminated on the surface of the communication plate 71 in the -Z axis direction, a vibration plate 73 laminated on the pressure chamber substrate 72 in the -Z axis direction, and a nozzle plate 74 and a compliance portion 75 arranged on the surface of the communication plate 71 in the +Z direction. The nozzles Nz are formed in the nozzle plate 74. Note that in one head chip 70, structures corresponding to the nozzle rows 70L1 and 70L2 of the nozzles Nz are formed in a substantially line-symmetrical manner, so the structure of the head chip 70 will be described below by focusing on one row of the nozzles Nz for convenience.

[0028] The communicating plate 71 is a flat member that constitutes a liquid flow path. In the communicating plate 71 of this embodiment, an opening 712, a supply flow path 714, and a communicating flow path 716 are formed. The supply flow path 714 and the communicating flow path 716 are formed for each nozzle Nz, and the opening 712 is continuous across the multiple nozzles Nz. The pressure chamber substrate 72 is a flat member in which multiple openings 722 corresponding to different nozzles Nz are formed. The communicating plate 71 and the pressure chamber substrate 72 are formed of, for example, a single crystal silicon substrate.

[0029] The compliance section 75 is a mechanism for suppressing pressure fluctuations in the flow paths of the head chip 70. The compliance section 75 has a sealing plate 752 and a support 754. The sealing plate 752 is a film-like resin member having flexibility. The support 754 fixes the sealing plate 752 to the communicating plate 71 so that the opening 712 of the communicating plate 71 and each of the supply flow paths 714 are closed. The support 754 is formed of a metal such as stainless steel.

[0030] The vibration plate 73 is a flat plate-like member that can vibrate elastically. The vibration plate 73 is composed of a laminate of an elastic film made of an elastic material such as silicon oxide and an insulating film made of an insulating material such as zirconium oxide. The lower end of the flexible substrate 78 is electrically connected to the vibration plate 73. The vibration plate 73 and the communication plate 71 face each other at a distance from each other inside each opening 722 formed in the pressure chamber substrate 72. The space between the communication plate 71 and the vibration plate 73 inside each opening 722 functions as a pressure chamber C that applies pressure to the liquid. In this embodiment, the rows of the pressure chambers C arranged along the Y-axis direction are arranged in two rows along the X-axis direction.

[0031] A driving element 732 is formed for each pressure chamber C on the surface of the vibration plate 73 opposite to the pressure chamber C. The driving element 732 is an elongated piezoelectric element extending along the X-axis in a plan view. The piezoelectric element includes, for example, a pair of electrodes and a piezoelectric body sandwiched between the pair of electrodes. The driving element 732 may be an electrothermal conversion element that generates thermal energy.

[0032] A support 77 is fixed to the communication plate 71 and the protective plate 76. The support 77 is integrally formed, for example, by molding a resin material. The support 77 in this embodiment is a member in which a space 772 that forms a storage chamber R together with the opening 712 of the communication plate 71, and a supply port 774 that communicates with the storage chamber R are formed. The storage chamber R stores liquid introduced from the supply port 774. The ink stored in the storage chamber R is distributed and filled into each pressure chamber C by the multiple supply flow paths 714, and is ejected from each pressure chamber C in the -Z axis direction through the communication flow path 716 and the nozzle Nz. Note that, although the two supply ports 774 are illustrated as being formed at the same position in the X axis direction in FIG. 3, they are actually formed at positions shifted from each other.

[0033] 4 is a plan view of the relay board 80 as viewed from the surface 80fa side located on the filter unit 25 side. The relay board 80 includes a through hole 85 into which the flow path tube 41 is inserted, a plurality of electric terminal portions 83, a plurality of connectors 87, and a plurality of insertion holes 88. The through hole 85 is formed in approximately the center of the relay board 80 in the X-axis direction which is the longitudinal direction of the relay board 80. Note that the relay board 80 may have a notch formed in the peripheral portion of the relay board 80 instead of the through hole 85. The flow path tube 41 is inserted into this notch.

[0034] The electrical terminal portions 83 are provided corresponding to the head chips 70. In this embodiment, the number of the electrical terminal portions 83 is seven. The upper end portion of the corresponding flexible substrate 78 is connected to each of the electrical terminal portions 83. This electrically connects the driving element 732 and the electrical terminal portion 83 via the flexible substrate 78.

[0035] Electrical wiring electrically connected to the control device 4 is connected to the multiple connectors 87. In this embodiment, the number of the multiple connectors 87 is three. The multiple connectors 87 are formed outside the multiple electrical terminal portions 83 in the Y-axis direction.

[0036] The multiple insertion holes 88 are formed corresponding to the electrical terminal portions 83. Each insertion hole 88 is rectangular, and is formed adjacent to a corresponding electrical terminal portion 83. An upper end portion of a corresponding flexible board 78 is inserted into each insertion hole 88. Note that wiring (not shown) that electrically connects the connector 87 and the electrical terminal portion 83 is formed in the relay board 80.

[0037] FIG. 5 is a first diagram for explaining the distribution flow path 265. FIG. 6 is a second diagram for explaining the distribution flow path 265. FIG. 5 shows a main branch flow path 580 defined by the first flow path substrate 40 and the second flow path substrate 50, and a sub-branch flow path 680 defined by the second flow path substrate 50 and the third flow path substrate 60, among the distribution flow paths 265. FIG. 6 shows the connection relationship between the sub-branch flow path 680 and the head chip 70 by arrows in a schematic manner. In addition, in FIG. 6, the suffixes "A" to "G" are added to distinguish each of the multiple head chips 70.

[0038] As shown in the lower diagram of FIG. 5, the main branch flow path 580 is constituted by a groove formed in at least one of the surface of the first flow path substrate 40 facing the second flow path substrate 50 and the surface of the second flow path substrate 50 facing the first flow path substrate 40, or a through hole formed in the second flow path substrate 50. FIG. 5 shows the main branch flow path 580 formed by a groove or a through hole formed in the second flow path substrate 50. As shown in the upper diagram of FIG. 5, the sub-branch flow path 680 is constituted by a groove formed in at least one of the surface of the second flow path substrate 50 facing the third flow path substrate 60 and the surface of the third flow path substrate 60 facing the second flow path substrate 50, or a through hole formed in the third flow path substrate 60. FIG. 5 shows the sub-branch flow path 680 formed by a groove or a through hole formed in the third flow path substrate 60.

[0039] The first flow path substrate 40 has a through hole 48 shown in FIG. 2 through which the corresponding flexible substrate 78 is inserted. A plurality of through holes 48 are formed, and seven are formed in this embodiment. The through holes 48 are rectangular. As shown in FIG. 5, the second flow path substrate 50 has a through hole 58 through which the corresponding flexible substrate 78 is inserted. A plurality of through holes 58 are formed, and seven are formed in this embodiment. Similarly, the third flow path substrate 60 has a through hole 68 through which the corresponding flexible substrate 78 is inserted. A plurality of through holes 68 are formed, and seven are formed in this embodiment. When viewed in the stacking direction, the corresponding through holes 48, 58, 68 are arranged at positions overlapping with the corresponding insertion holes 88 shown in FIG. 4.

[0040] The distribution flow path 265 has a main branch flow path 580 defined by the first flow path substrate 40 and the second flow path substrate 50, and a sub-branch flow path 680 defined by the second flow path substrate 50 and the third flow path substrate 60. The main branch flow path 580 has four main branch portions 51, 52, 53, and 54 that branch off at a main branch position Mp. The main branch position Mp is the position of a portion of the distribution flow path 265 to which the inlet 41h of the flow path pipe 41 is connected. In other words, the main branch position Mp overlaps with the inlet 41h when viewed in the stacking direction.

[0041] Moreover, the main branch position Mp overlaps with the first gap Ga when viewed in the stacking direction. In other embodiments, the main branch position Mp may overlap with the second gap Gb when viewed in the stacking direction. When the main branch position Mp overlaps with the first gap Ga or the second gap Gb when viewed in the stacking direction, the variation in pressure loss in each flow path from the main branch position Mp through the distribution flow path 265 to each head chip 70 can be reduced compared to when the main branch position Mp overlaps with the head chip 70. This allows liquid to be supplied to each head chip 70 more uniformly.

[0042] Furthermore, the main branch position Mp overlaps with the first gap Gac that is located at the center of the first gaps Ga in the X-axis direction, among the plurality of first gaps Ga. This makes it possible to further reduce the variation in pressure loss in each flow path from the main branch position Mp through the distribution flow path 265 to each head chip 70.

[0043] The main branch portion 51 is a flow path extending in one direction along the X-axis direction from the main branch position Mp. The main branch portion 51 does not have a substantially U-shaped bend. In this embodiment, the main branch portion 51 is substantially linear. Note that in other embodiments, the main branch portion 51 is not limited to being linear as long as it does not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more.

[0044] The main branch portion 52 is a flow path that extends from the main branch position Mp in a direction different from the direction along the X-axis direction. The main branch portion 52 is a bent flow path. The main branch portion 52 has a substantially U-shaped bend portion 521 where the flow direction of the liquid changes by 110° or more. In this embodiment, the bend portion 521 changes the flow direction of the liquid by 180°, changing the flow direction to the opposite direction.

[0045] The main branch portion 53 is a flow path that extends from the main branch position Mp in the other direction along the X-axis direction, which is the opposite direction to the direction in which the main branch portion 51 extends. The main branch portion 53 does not have a substantially U-shaped bend. In this embodiment, the main branch portion 53 is substantially linear. Note that in other embodiments, the main branch portion 53 is not limited to being linear, as long as it does not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more.

[0046] The main branch portion 54 is a flow path that extends from the main branch position Mp in a direction different from the direction along the X-axis direction. The main branch portion 54 is a bent flow path. The main branch portion 54 has a substantially U-shaped bend portion 541 where the flow direction of the liquid changes by 110° or more. In this embodiment, the bend portion 541 changes the flow direction of the liquid by 180°, changing the flow direction to the opposite direction.

[0047] If a line that passes through the main branch position Mp and is parallel to the Y-axis is taken as a reference line Ls, the main branch portion 51 and the main branch portion 53 are line-symmetrical about the reference line Ls. Also, the main branch portion 52 and the main branch portion 54 are line-symmetrical about the reference line Ls.

[0048] The distribution flow path 265 further has connection flow paths 513, 523, 533, and 543 formed in the second flow path substrate 50. The connection flow paths 513, 523, 533, and 543 are through holes that penetrate the second flow path substrate 50 in the stacking direction. That is, the connection flow paths 513, 523, 533, and 543 are flow paths extending in the stacking direction. In the flow direction, which is the flow direction of the liquid from the flow path pipe 41 to the head chip 70, the connection flow path 513 is connected to the downstream end of the main branching portion 51. In the flow direction, the connection flow path 523 is connected to the downstream end of the main branching portion 52. In the flow direction, the connection flow path 533 is connected to the downstream end of the main branching portion 53. In the flow direction, the connection flow path 543 is connected to the downstream end of the main branching portion 54. The connection relationship of each of the connection flow paths 513, 523, 533, and 543 will be described later.

[0049] 5, the distribution channel 265 further includes sub-branch channels 680A, 680B, 680C, and 680D defined by the second channel substrate 50 and the third channel substrate 60. The sub-branch channels 680A, 680B, 680C, and 680D constituting the sub-branch channel 680 are disposed between the main branch channel 580 and the plurality of head chips 70 in the stacking direction. Specifically, the sub-branch channels 680A, 680B, 680C, and 680D are disposed at the same position in the stacking direction.

[0050] The sub-branch flow path 680A is a flow path that communicates with the main branch portion 51. Specifically, the connection flow path 513 connects the main branch portion 51 and the sub-branch flow path 680A, so that the sub-branch flow path 680A communicates with the main branch portion 51. The sub-branch flow path 680A has sub-branch portions 614A, 614B, 614C, and 614D that branch at the sub-branch position 613. The sub-branch position 613 overlaps with the first gap Ga when viewed in the stacking direction. This can reduce the variation in pressure loss of each flow path that branches from the sub-branch position 613 and flows through the sub-branch portions 614A, 614B, 614C, and 614D to each head chip 70, compared to when the sub-branch position 613 overlaps with the head chip 70 when viewed in the stacking direction. Therefore, liquid is supplied to each head chip 70 more uniformly. The sub-branch position 613 also overlaps with the connection flow path 513 when viewed in the stacking direction. That is, the sub-branch position 613 is located directly below the connecting flow path 513. This allows the liquid to be branched immediately after passing through the connecting flow path 513, thereby reducing unnecessary flow path portions. This further reduces the variation in pressure loss in each flow path.

[0051] The sub-branching portions 614A, 614C, and 614D do not have a substantially U-shaped bend. In this embodiment, the sub-branching portions 614A, 614C, and 614D are shaped by combining a plurality of linear flow paths. In other embodiments, the sub-branching portions 614A, 614C, and 614D are not limited to the shape shown in FIG. 5 as long as they do not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more. The sub-branching portion 614B has a substantially U-shaped bend 611 where the liquid flow direction changes by 110° or more. In this embodiment, the bend 611 changes the liquid flow direction by 180°, changing the flow direction to the opposite direction.

[0052] A connection flow path 615A is connected to one end 613e of the sub-branch portion 614A. The connection flow path 615A is a through hole penetrating the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. As shown in FIG. 6, the connection flow path 615A is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1, 70L2 of the head chip 70A. The liquid that has passed through the connection flow path 615A is supplied to the head chip 70A.

[0053] 6, a connection flow path 615B is connected to one end 614e of the sub-branch portion 614B. The connection flow path 615B is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 615B is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1 and 70L2 of the head chip 70E. The liquid that has passed through the connection flow path 615B is supplied to the head chip 70E.

[0054] A connection flow path 615C is connected to one end of the sub-branch portion 614C. The connection flow path 615C is a through hole penetrating the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 615C is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1, 70L2 of the head chip 70A. The liquid that has passed through the connection flow path 615C is supplied to the head chip 70A.

[0055] A connection flow path 615D is connected to one end of the sub-branch portion 614D. The connection flow path 615D is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 615D is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1 and 70L2 of the head chip 70B. The liquid that has passed through the connection flow path 615D is supplied to the head chip 70B.

[0056] 5, the sub-branch flow channel 680B is a flow channel that communicates with the main branch portion 52. Specifically, the sub-branch flow channel 680B communicates with the main branch portion 52 by connecting the main branch portion 52 and the sub-branch flow channel 680B via the connection flow channel 523. The sub-branch flow channel 680B has sub-branch portions 624A, 624B, and 624C that branch at the sub-branch position 623. The number N1 of the sub-branch portions 614A, 614B, 614C, and 614D that branch at the sub-branch position 613 in the sub-branch flow channel 680A is different from the number N2 of the sub-branch portions 624A, 624B, and 624C that branch at the sub-branch position 623 in the sub-branch flow channel 680B. This allows the number of branched flow channels to be flexibly determined when the number N1 and the number N2 cannot be made the same number. In order to reduce variation in the length of each flow path from inlet 41h to each head chip 70, if number N1 and number N2 cannot be the same, it is preferable that the difference between number N1 and number N2 is 1.

[0057] The sub-branching position 623 overlaps with the second gap Gb when viewed in the stacking direction. This can reduce the variation in pressure loss of each flow path that branches from the sub-branching position 623 and flows through the sub-branching portions 624A, 624B, and 624C to reach each head chip 70, compared to when the sub-branching position 623 overlaps with the head chip 70 when viewed in the stacking direction. In addition, the sub-branching position 623 overlaps with the connecting flow path 523 when viewed in the stacking direction. That is, the sub-branching position 623 is located directly below the connecting flow path 523. This can branch the liquid immediately after passing through the connecting flow path 523, thereby reducing unnecessary flow path portions. Therefore, the variation in pressure loss of each flow path can be further reduced.

[0058] The sub-branching portions 624A and 624C do not have a substantially U-shaped bend. In this embodiment, the sub-branching portions 624A and 624C are shaped by combining a plurality of linear flow paths. In other embodiments, the sub-branching portions 624A and 624C are not limited to the shape shown in FIG. 5 as long as they do not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more. The sub-branching portion 624B has a substantially U-shaped bend 621 where the liquid flow direction changes by 110° or more. In this embodiment, the bend 621 changes the liquid flow direction by 180°, changing the flow direction to the opposite direction.

[0059] 6, a connection flow path 625A is connected to one end of the sub-branch portion 624A. The connection flow path 625A is a through hole penetrating the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 625A is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1 and 70L2 of the head chip 70E. The liquid that has passed through the connection flow path 625A is supplied to the head chip 70E.

[0060] A connection flow path 625B is connected to one end of the sub-branch portion 624B. The connection flow path 625B is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 625B is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1, 70L2 of the head chip 70B. The liquid that has passed through the connection flow path 625B is supplied to the head chip 70B.

[0061] A connection flow path 625C is connected to one end of the sub-branch portion 624C. The connection flow path 625C is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 625C is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1, 70L2 of the head chip 70F. The liquid that has passed through the connection flow path 625C is supplied to the head chip 70F.

[0062] As shown in FIG. 5, the sub-branch flow path 680C is a flow path that communicates with the main branch portion 53. Specifically, the connection flow path 533 connects the main branch portion 53 and the sub-branch flow path 680C, so that the sub-branch flow path 680C communicates with the main branch portion 53. The sub-branch flow path 680C has sub-branch portions 634A, 634B, and 634C that branch off at the sub-branch position 633. The sub-branch position 633 overlaps with the first gap Ga when viewed in the stacking direction. This can reduce the variation in pressure loss of each flow path that branches off from the sub-branch position 633, flows through the sub-branch portions 634A, 634B, and 634C, and reaches each head chip 70, compared to when the sub-branch position 633 overlaps with the head chip 70 when viewed in the stacking direction. Therefore, liquid is supplied to each head chip 70 more uniformly. The sub-branch position 633 also overlaps with the connection flow path 533 when viewed in the stacking direction. That is, the sub-branch position 633 is located directly below the connecting flow path 533. This allows the liquid to be branched immediately after passing through the connecting flow path 533, thereby reducing unnecessary flow path portions. This makes it possible to further reduce variations in pressure loss in each flow path.

[0063] The sub-branching portions 634A, 634B, and 634C do not have a substantially U-shaped bend. In this embodiment, the sub-branching portions 634A, 634B, and 634C are shaped by combining a plurality of linear flow paths. In other embodiments, the sub-branching portions 634A, 634B, and 634C are not limited to the shape shown in FIG. 5 as long as they do not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more.

[0064] A connection flow path 635A is connected to one end of the sub-branch portion 634A. The connection flow path 635A is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. As shown in Fig. 6, the connection flow path 635A is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1 and 70L2 of the head chip 70D. The liquid that has passed through the connection flow path 635A is supplied to the head chip 70D.

[0065] A connection flow path 635B is connected to one end of the sub-branch portion 634B. The connection flow path 635B is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 635B is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1, 70L2 of the head chip 70C. The liquid that has passed through the connection flow path 635B is supplied to the head chip 70C.

[0066] A connection flow path 635C is connected to one end of the sub-branch portion 634C. The connection flow path 635C is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 635C is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1 and 70L2 of the head chip 70D. The liquid that has passed through the connection flow path 635C is supplied to the head chip 70D.

[0067] As shown in FIG. 5, the sub-branch flow path 680D is a flow path that communicates with the main branch portion 54. Specifically, the connection flow path 543 connects the main branch portion 54 and the sub-branch flow path 680D, so that the sub-branch flow path 680D communicates with the main branch portion 54. The sub-branch flow path 680D has sub-branch portions 644A, 644B, 644C, and 644D that branch at the sub-branch position 643. The sub-branch position 643 overlaps with the second gap Gb when viewed in the stacking direction. This can reduce the variation in pressure loss of each flow path that branches from the sub-branch position 643, flows through the sub-branch portions 644A, 644B, 644C, and 644D, and reaches each head chip 70, compared to when the sub-branch position 643 overlaps with the head chip 70 when viewed in the stacking direction. In addition, the sub-branch position 643 overlaps with the connection flow path 543 when viewed in the stacking direction. That is, the sub-branch position 643 is located directly below the connecting flow path 543. This allows the liquid to branch immediately after passing through the connecting flow path 543, thereby reducing unnecessary flow path portions. This further reduces the variation in pressure loss in each flow path.

[0068] The sub-branching portions 644A, 644C, and 644D do not have a substantially U-shaped bend. In this embodiment, the sub-branching portions 644A, 644C, and 644D are shaped by combining a plurality of linear flow paths. In other embodiments, the sub-branching portions 644A, 644C, and 644D are not limited to the shape shown in FIG. 5 as long as they do not have a substantially U-shaped bend where the liquid flow direction changes by 110° or more. The sub-branching portion 644B has a substantially U-shaped bend 641 where the liquid flow direction changes by 110° or more. In this embodiment, the bend 641 changes the liquid flow direction by 180°, changing the flow direction to the opposite direction.

[0069] 6, a connection flow path 645A is connected to one end of the sub-branch portion 644A. The connection flow path 645A is a through hole penetrating the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 645A is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1 and 70L2 of the head chip 70F. The liquid that has passed through the connection flow path 645A is supplied to the head chip 70F.

[0070] A connection flow path 645B is connected to one end of the sub-branch portion 644B. ​​The connection flow path 645B is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 645B is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1, 70L2 of the head chip 70C. The liquid that has passed through the connection flow path 645B is supplied to the head chip 70C.

[0071] A connection flow path 645C is connected to one end of the sub-branch portion 644C. The connection flow path 645C is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 645C is connected to a supply port 774 that communicates with the nozzles Nz in one of the two nozzle rows 70L1, 70L2 of the head chip 70G. The liquid that has passed through the connection flow path 645C is supplied to the head chip 70G.

[0072] A connection flow path 645D is connected to one end of the sub-branch portion 644D. The connection flow path 645D is a through hole that penetrates the third flow path substrate 60 in the stacking direction, and extends in the stacking direction. The connection flow path 645D is connected to a supply port 774 that communicates with the nozzles Nz of the other of the two nozzle rows 70L1, 70L2 of the head chip 70G. The liquid that has passed through the connection flow path 645D is supplied to the head chip 70G.

[0073] 5, in the stacking direction, a distance L2 from the main branch position Mp to an end 52e of the main branch portion 52 on the opposite side to the main branch position Mp is shorter than a distance L1 from the main branch position Mp to an end 51e of the main branch portion 51 on the opposite side to the main branch position Mp. In addition, in the stacking direction, a distance L4 from the sub branch position 613 to an end 614e of the sub branch portion 614B on the opposite side to the sub branch position 613 is shorter than a distance L3 from the sub branch position 613 to an end 613e of the sub branch portion 614A on the opposite side to the sub branch position 613. Distances L1 to L4 are the shortest distances connecting two points.

[0074] According to the above embodiment, as shown in FIG. 5, the main branch flow channel 580 and the sub-branch flow channel 680 are formed at different positions in the stacking direction. That is, the main branch flow channel 580 is formed at a position between the first flow channel substrate 40 and the second flow channel substrate 50, and the sub-branch flow channel 680 is formed between the second flow channel substrate 50 and the third flow channel substrate 60. Since the flow channels are branched at the main branch flow channel 580 and the sub-branch flow channel 680 formed at different positions in the stacking direction, the size of the distribution flow channel member can be suppressed in a direction perpendicular to the stacking direction, compared to a case where a plurality of flow channels branched only at the same position in the stacking direction are formed. In addition, since the flow channels are branched at the main branch flow channel 580 and the sub-branch flow channel 680 formed at different positions in the stacking direction, the layout of the flow channels at the same position in the stacking direction can be suppressed from becoming complicated. In addition, even if a large number of branches are required, the number of distribution flow channels 265 can be reduced by performing two branchings, that is, branching the flow channel at the main branch flow channel 580 and branching the flow channel at the sub-branch flow channel 680. This makes it possible to reduce the effort required for connecting a flow path such as a tube directly to the flow path pipe 41 of the distribution flow path member 260.

[0075] 5, the above embodiment has the main branch flow path 580 and the sub-branch flow path 680 at different positions in the stacking direction, and the flow paths branch off at each of the main branch flow path 580 and the sub-branch flow path 680, so that the branching positions Mp, 613, 623, 633, 643 of the flow paths can be dispersed. This can reduce the variation in the length of each flow path leading to each head chip 70 in the distribution flow path 265, so that the variation in pressure loss of each flow path can be further reduced. This can reduce the possibility of variation in the amount of liquid supplied to each head chip 70.

[0076] 5, the number of distribution channels 265 can be reduced by branching the channel twice at the main branch channel 580 and the sub branch channel 680. Specifically, in this embodiment, liquid can be supplied to each of the seven head chips 70 by one distribution channel 265. This allows the number of main branch channels 580 to be reduced, and therefore the number of filter units 25 to be reduced. This allows the manufacturing costs of the liquid jet head 3 to be reduced.

[0077] Furthermore, according to the above embodiment, the number of distribution flow paths 265 can be reduced by branching the flow paths twice at the main branch flow path 580 and the sub-branch flow path 680. This allows the number of flow path pipes 41 to be reduced according to the number of distribution flow paths 265, and therefore the number of through holes 85 or notches formed in the relay substrate 80 can be reduced, thereby ensuring space for wiring formed in the relay substrate 80. This allows the relay substrate 80 to be made smaller in size.

[0078] According to the embodiment, as shown in FIG. 5, the main branch flow channel 580 has four main branch portions 51, 52, 53, and 54, and has sub-branch flow channels 680A, 680B, 680C, and 680D that communicate with the main branch portions 51, 52, 53, and 54. This allows more branched flow channels to be formed by the main branch flow channel 580 and the sub-branch flow channel 680 formed at different positions in the stacking direction. According to the embodiment, as shown in FIG. 5, the sub-branch flow channels 680A, 680B, 680C, and 680D have three or more branched sub-branch portions 614A to 614D, 624A to 624C, 634A to 634C, and 644A to 644D. This allows more branched flow channels to be formed.

[0079] According to the above embodiment, the distance L2 is shorter than the distance L1, while the main branch portion 52 has a bent portion 521. This can prevent the difference between the flow path length of the main branch portion 52 and the flow path length of the main branch portion 51 from increasing, and therefore the difference between the pressure loss of the main branch portion 51 and the pressure loss of the main branch portion 52 can be prevented from increasing. In particular, the main branch portion 51 does not have a substantially U-shaped bent portion, and therefore the difference between the flow path length of the main branch portion 52 and the flow path length of the main branch portion 51 can be prevented from increasing, and therefore the difference between the pressure loss of the main branch portion 51 and the pressure loss of the main branch portion 52 can be prevented from increasing. Note that the positional relationship and flow path shape between the main branch portion 53 and the main branch portion 54 are similar to those between the main branch portion 51 and the main branch portion 52, and therefore the main branch portion 53 and the main branch portion 54 also have the same effect on pressure loss.

[0080] Further, according to the above embodiment, in the sub-branch flow path 680A, the distance L4 is shorter than the distance L3, while the sub-branch portion 614B has a substantially U-shaped bend 611. This can prevent the difference between the flow path length of the sub-branch portion 614A and the flow path length of the sub-branch portion 614B from increasing, and therefore the difference between the pressure loss of the sub-branch portion 614A and the pressure loss of the sub-branch portion 614B can be prevented from increasing. In particular, since the sub-branch portion 614A does not have a substantially U-shaped bend, it can further prevent the difference between the flow path length of the sub-branch portion 614A and the flow path length of the sub-branch portion 614B from increasing, and therefore the difference between the pressure loss of the sub-branch portion 614A and the pressure loss of the sub-branch portion 614B can be further prevented from increasing. In the sub-branch flow channel 680A, the relationship between the flow channel length of the sub-branch portion 614B and the flow channel length of the other sub-branch portions 614C, 614D that do not have a bent portion is similar to the relationship between the flow channel length of the sub-branch portion 614B and the flow channel length of the sub-branch portion 614A. In addition, in the sub-branch flow channels 680B, 680D, the relationship between the flow channel length of the sub-branch portions 624B, 644B that have the bent portions 621, 641 and the flow channel length of the sub-branch portions 624A, 624C, 644A, 644C, 644D that do not have a bent portion is similar to the relationship between the flow channel length of the sub-branch portion 614B and the flow channel length of the sub-branch portion 614A.

[0081] 5, the sub-branch positions 613, 633 overlap the first gap Ga, and the sub-branch positions 623, 643 overlap the second gap Gb when viewed in the stacking direction. This makes it possible to prevent the sub-branch positions 613, 623, 633, 643 from interfering with the flexible substrate 78 extending in the stacking direction in the distribution flow path member 260. This also makes it possible to effectively utilize the gaps Ga, Gb between the head chips 70 to form flow paths branched at the sub-branch flow paths 680A-680D, making it possible to prevent the distribution flow path member 260 from becoming large in the horizontal direction perpendicular to the stacking direction.

[0082] According to the above embodiment, the main branch position Mp overlaps with the first gap Ga when viewed in the stacking direction, and therefore it is possible to prevent the main branch position Mp from interfering with the flexible substrate 78 extending along the stacking direction in the distribution flow path member 260. According to this embodiment, the gap Ga between the head chips 70 can be effectively utilized to form flow paths branching at the main branch flow path 580, and therefore it is possible to prevent the distribution flow path member 260 from becoming large in the horizontal direction perpendicular to the stacking direction.

[0083] According to the embodiment, the main branch position Mp overlaps with the inlet 41h when viewed in the stacking direction, and the sub-branch positions 613, 623, 633, and 644 overlap with the corresponding connecting flow paths 513, 523, 533, and 543, thereby reducing unnecessary flow path portions. Therefore, the pressure loss of each flow path leading to the head chip 70 can be reduced.

[0084] The main branch portion 51 is an example of a "first main branch portion". The main branch portion 52 is an example of a "second main branch portion". The main branch portion 53 is an example of a "third main branch portion". The main branch portion 54 is an example of a "fourth main branch portion". The connection flow path 513 is an example of a "first connection flow path". The connection flow path 523 is an example of a "second connection flow path". The connection flow path 533 is an example of a "third connection flow path". The connection flow path 543 is an example of a "fourth connection flow path". The sub-branch flow path 680A is an example of a "first sub-branch flow path". The sub-branch flow path 680B is an example of a "second sub-branch flow path". The sub-branch flow path 680C is an example of a "third sub-branch flow path". The sub-branch flow path 680D is an example of a "fourth sub-branch flow path". The sub-branch position 613 is an example of a "first sub-branch position". The sub-branch position 623 is an example of a "second sub-branch position". The sub-branch position 633 is an example of a "third sub-branch position". The sub-branch position 643 is an example of a "third sub-branch position". The sub-branch portion 614A is an example of a "first sub-branch portion A". The sub-branch portion 614B is an example of a "first sub-branch portion B". The sub-branch portion 614C is an example of a "first sub-branch portion C". The sub-branch portion 614D is an example of a "first sub-branch portion D". The sub-branch portion 624A is an example of a "second sub-branch portion A". The sub-branch portion 624B is an example of a "second sub-branch portion B". The sub-branch portion 624C is an example of a "second sub-branch portion C". The sub-branch portion 634A is an example of a "third sub-branch portion A". The sub-branch portion 634B is an example of a "third sub-branch portion B".

[0085] B. Other embodiments: 2, the flow path pipe 41 is provided on the first flow path substrate 40 of the distribution flow path member 260, but the present invention is not limited to this. The flow path pipe 41 may be provided by further protruding the supply pipe 36 toward the distribution flow path member 260 in the filter unit 25.

[0086] C. Other forms: The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various forms without departing from the spirit of the present disclosure. For example, the present disclosure can be realized in the following aspects. The technical features in the above-mentioned embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined in order to solve some or all of the problems of the present disclosure, or to achieve some or all of the effects of the present disclosure. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0087] (1) According to a first aspect of the present disclosure, there is provided a liquid ejection head, the liquid ejection head including a plurality of head chips including a plurality of first head chips arranged in a first direction to form a first chip row and a plurality of second head chips arranged in the first direction to form a second chip row, and a distribution flow path member formed by stacking a plurality of flow path substrates in a stacking direction and having a distribution flow path that distributes and supplies liquid to the plurality of head chips, the second chip row being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, a first gap being formed between adjacent first head chips among the plurality of first head chips, and the plurality of second head chips being shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, A second gap is formed between adjacent second head chips among the chips, and at least some of the second head chips among the multiple second head chips are arranged to fill one or more of the first gaps when viewed in the second direction, and the distribution flow path has a main branch flow path having a first main branch portion and a second main branch portion branching at a main branch position, and a first sub-branch flow path which is arranged between the main branch flow path and the multiple head chips in the stacking direction and communicates with the first main branch portion, and has a first sub-branch portion A and a first sub-branch portion B branching at a first sub-branch position, and the first sub-branch position overlaps with the first gap when viewed in the stacking direction.

[0088] (2) In the above embodiment, the distribution flow path includes a second sub-branch flow path that is disposed at the same position as the first sub-branch flow path in the stacking direction and communicates with the second main branch portion, the second sub-branch flow path having a second sub-branch portion A and a second sub-branch portion B that branch off at a second sub-branch position, The second sub-branch position may overlap the second gap as viewed in the stacking direction. According to this embodiment, it is possible to further reduce variations in pressure loss in each flow path leading to each head chip in the distribution flow path.

[0089] (3) In the above embodiment, a relay substrate electrically connected to the head chips may be provided, the distribution flow path member may be disposed between the relay substrate and the head chips in the stacking direction, and each of the head chips may have a flexible substrate electrically connected to the relay substrate so as to penetrate the distribution flow path member. According to this embodiment, the first sub-branching position overlaps with the first gap when viewed in the stacking direction, so that interference between the first sub-branching position and the flexible substrate can be suppressed.

[0090] (4) In the above embodiment, the first sub-branch flow path may further include a first sub-branch portion C that branches at the first sub-branch position. According to this embodiment, the number of flow paths branched in the first sub-branch flow path can be increased. Also, according to this embodiment, the first sub-branch position overlaps with the first gap when viewed in the stacking direction, so that the gap between the head chips can be effectively utilized to form the flow paths branched in the first sub-branch flow path, and therefore, it is possible to prevent the distribution flow path member from becoming large in the horizontal direction perpendicular to the stacking direction.

[0091] (5) In the above embodiment, the main branch position may overlap with the first gap or the second gap as viewed in the stacking direction. According to this embodiment, it is possible to reduce variation in pressure loss in each flow path leading to each head chip, compared to a case in which the main branch position is located at a position overlapping with a head chip as viewed in the stacking direction.

[0092] (6) In the above embodiment, the number of the first head chips may be greater than the number of the second head chips and may be an even number, and the main branch position may overlap with a first gap that is centrally arranged in the first direction among the plurality of first gaps as viewed in the stacking direction. According to this embodiment, it is possible to further reduce the variation in pressure loss of each flow path leading to each head chip in the distribution flow path.

[0093] (7) In the above-mentioned embodiment, a relay substrate electrically connected to the head chips may be provided, the distribution flow path member may be disposed between the relay substrate and the head chips in the stacking direction, and each of the head chips may have a flexible substrate electrically connected to the relay substrate so as to penetrate the distribution flow path member. According to this embodiment, the main branch position overlaps with the first gap or the second gap as viewed in the stacking direction, so that interference between the main branch position and the flexible substrate can be suppressed.

[0094] (8) In the above embodiment, the main branch flow path may further have a third main branch portion branching at the main branch position. According to this embodiment, the number of flow paths branching in the main branch flow path can be increased. Also, according to this embodiment, the main branch position overlaps with the first gap or the second gap when viewed in the stacking direction, so that the gap between the head chips can be effectively used to form the flow paths branching in the main branch flow path, and therefore, the distribution flow path member can be prevented from becoming large in the horizontal direction perpendicular to the stacking direction.

[0095] (9) In the above embodiment, the distribution flow path may have an inlet for introducing liquid into the main branch flow path, and a first connection flow path that connects the first main branch portion and the first sub-branch flow path and extends in the stacking direction, and the main branch position may overlap the inlet as viewed in the stacking direction, and the first sub-branch position may overlap the first connection flow path as viewed in the stacking direction. According to this embodiment, the main branch position overlaps the inlet as viewed in the stacking direction, and the first sub-branch position overlaps the first connection flow path as viewed in the stacking direction, thereby reducing unnecessary flow path portions and reducing pressure loss in each flow path leading to the head chip.

[0096] (10) According to a second aspect of the present disclosure, a liquid ejection device is provided. This liquid ejection device includes the liquid ejection head of the above aspect, and a liquid storage section that stores liquid to be supplied to the liquid ejection head. According to this aspect, the main branch flow path and the sub-branch flow path are located at different positions in the stacking direction, and the flow paths are branched at each of the main branch flow path and the sub-branch flow path, so that the branching positions of the flow paths can be dispersed. This can further reduce the variation in pressure loss of each flow path leading to each head chip in the distribution flow path. Furthermore, according to this embodiment, the variation in pressure loss of each flow path can be reduced compared to the case where the sub-branch position is located at a position overlapping with the head chip when viewed in the stacking direction.

[0097] The present disclosure may be realized in various forms other than those described above, for example, in the form of a manufacturing method for a liquid ejection head or a liquid ejection device. [Explanation of symbols]

[0098] 1...liquid ejection device, 2...medium, 3...liquid ejection head, 4...control device, 5...transport mechanism, 6...liquid storage section, 12...filter, 20...cover, 22...cover upper wall, 24...cover side wall, 25...filter unit, 26...connecting member, 27...first filter chamber, 30...filter forming member, 36...supply pipe, 37...second filter chamber, 39...sealing member, 40...first flow path substrate, 41...flow path tube, 41h...inlet, 42...substrate body, 48...through hole, 50...second flow path substrate, 51, 52, 53, 54...main branch portion, 51e, 52e ...end portion, 58...through hole, 60...third flow path substrate, 61...substrate body, 63...chip storage chamber, 64...flange portion, 68...through hole, 70, 70A to 70G...head chips, 70L1...first nozzle row, 70L2...second nozzle row, 70a...first head chip, 70b...second head chip, 71...communication plate, 72...pressure chamber substrate, 73...diaphragm, 74...nozzle plate, 75...compliance portion, 76...protection plate, 77...support, 78...flexible substrate, 80...relay substrate, 83...electrical terminal portion, 85...through hole, 87...connector, 88...insertion hole, 90...fixing plate, 260...distribution flow path member, 265...distribution flow path, 513...connection flow path, 521, 523, 533, 543...bending portion, 541, 611...bending portion, 580...main branch flow path, 613...sub-branching position, 613e...end portion, 614A-614D...sub-branching portion, 614e...end portion, 615A-615D...connection flow path, 621...bending portion, 623...sub-branching position, 624A-624C...sub-branching portion, 625A-625C...connection flow path, 633...sub-branching position, 634A-634C...sub-branching portion, 635A-635C...connection Flow path, 641...bend portion, 643...sub-branch position, 644A to 644D...sub-branch portion, 645A to 645D...connection flow path, 680, 680A to 680D...sub-branch flow path, 712...opening, 714...supply flow path, 716...communication flow path, 722...opening, 752...sealing plate, 754...support, 772...space, 774...supply port, 781...drive circuit, C...pressure chamber, Ga, Gac...first gap, Gb...second gap, L1 to L4...distance, Ln1...first chip row, Ln2...second chip row, Ls...reference line, Mp...main branch position, Nz...nozzle, R...storage chamber

Claims

1. A plurality of head chips including a plurality of first head chips arranged in a first direction to form a first chip row, and a plurality of second head chips arranged in the first direction to form a second chip row; A distribution flow path member is configured by stacking a plurality of flow path substrates in a stacking direction, and has a distribution flow path that distributes and supplies liquid to the plurality of head chips; Equipped with the second chip row is arranged to be shifted from the first chip row in a second direction perpendicular to both the first direction and the stacking direction, a first gap is formed between adjacent first head chips among the plurality of first head chips, A second gap is formed between adjacent ones of the second head chips, At least a part of the second head chips among the plurality of second head chips is disposed so as to fill one or a plurality of the first gaps as viewed in the second direction, The distribution flow path is a main branch flow path having a first main branch portion and a second main branch portion branched at a main branch position; a first sub-branch flow path that is disposed between the main branch flow path and the plurality of head chips in the stacking direction and communicates with the first main branch portion, the first sub-branch flow path having a first sub-branch portion A and a first sub-branch portion B that branch at a first sub-branch position; The first sub-branch position overlaps with the first gap when viewed in the stacking direction. A liquid jet head comprising:

2. the distribution flow path has a second sub-branch flow path that is disposed at the same position as the first sub-branch flow path in the stacking direction and is in communication with the second main branch portion, the second sub-branch flow path having a second sub-branch portion A and a second sub-branch portion B that branch off at a second sub-branch position; The second sub-branch position overlaps with the second gap when viewed in the stacking direction. The liquid jet head according to claim 1 .

3. a relay substrate electrically connected to the plurality of head chips, the distribution flow path member is disposed between the relay substrate and the plurality of head chips in the stacking direction, Each of the plurality of head chips has a flexible substrate electrically connected to the relay substrate so as to penetrate the distribution flow path member. The liquid jet head according to claim 1 .

4. The first sub-branch flow path further includes a first sub-branch portion C branching at the first sub-branch position. The liquid jet head according to claim 1 .

5. The main branch position overlaps with the first gap or the second gap when viewed in the stacking direction. The liquid jet head according to claim 1 .

6. the number of the first head chips is greater than the number of the second head chips and is an even number; The main branch position overlaps with a first gap that is disposed at a center in the first direction among the plurality of first gaps as viewed in the stacking direction. The liquid jet head according to claim 5 .

7. a relay substrate electrically connected to the plurality of head chips, the distribution flow path member is disposed between the relay substrate and the plurality of head chips in the stacking direction, Each of the plurality of head chips has a flexible substrate electrically connected to the relay substrate so as to penetrate the distribution flow path member. The liquid jet head according to claim 5 .

8. The main branch flow path further includes a third main branch portion branching at the main branch position. The liquid jet head according to claim 5 .

9. The distribution flow path is an inlet for introducing a liquid into the main branch flow path; a first connecting flow path that connects the first main branch portion and the first sub-branch flow path and extends in the stacking direction; The main branch position overlaps with the inlet when viewed in the stacking direction, The first sub-branch position overlaps with the first connection flow path when viewed in the stacking direction. The liquid jet head according to claim 1 .

10. A liquid jet head according to claim 1 , a liquid storage section configured to store a liquid to be supplied to the liquid jet head; A liquid ejection apparatus comprising:

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