Liquid jet head and liquid jet apparatus

Abstract

To provide a technique for suppressing reduction in strength of a flow channel formation member.SOLUTION: A liquid jet head includes: nozzles for jetting a liquid; first to fourth pressure chambers; a communication flow passage which is connected to the nozzles and communicates the nozzles with the first to fourth pressure chambers; first to fourth flow channels for connecting the communication flow passage with the first to fourth pressure chambers; first to fourth driving elements for changing the pressures of the first to fourth pressure chambers; a first common liquid chamber for communicating the first pressure chamber with the second pressure chamber; and a second common liquid chamber for communicating the third pressure chamber with the fourth pressure chamber. The first flow channel and the second flow channel are aligned in a first direction, the third flow channel and the fourth flow channel are aligned in the first direction, and the first flow channel and the second flow channel, and the third flow channel and the fourth flow channel are arranged so as to be shifted in a second direction perpendicular to the first direction. The first flow channel is shifted with respect to each of the third flow channel and the fourth flow channel in the first direction, and the second flow channel is shifted with respect to each of the third flow channel and the fourth flow channel in the first direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a liquid ejection head and a liquid ejection apparatus. [Background technology]

[0002] Patent Document 1 discloses a liquid ejection head in which four pressure chambers are provided on both sides of a nozzle, and flow paths from each of the four pressure chambers to the nozzle join together near the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-155768 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, a considerable amount of space was provided in the flow path forming member to form four flow paths leading from each of the four pressure chambers to the nozzle, which could result in an excessive reduction in the strength and rigidity of the flow path forming member. [Means for solving the problem]

[0005] a second flow path connecting the communicating flow path to the second pressure chamber; a third flow path connecting the communicating flow path to the third pressure chamber; a fourth flow path connecting the communicating flow path to the fourth pressure chamber; a first drive element changing the pressure of the first pressure chamber; a second drive element changing the pressure of the second pressure chamber; a third drive element changing the pressure of the third pressure chamber; a fourth drive element changing the pressure of the fourth pressure chamber; a first common liquid chamber communicating with the first pressure chamber and the second pressure chamber; and a second common liquid chamber communicating with the third pressure chamber and the fourth pressure chamber. The first flow path and the second flow path are arranged side by side in a first direction, the third flow path and the fourth flow path are arranged side by side in the first direction, and the first flow path and the second flow path, and the third flow path and the fourth flow path are arranged offset in a second direction perpendicular to the first direction. The first flow path is offset from each of the third flow path and the fourth flow path in the first direction, and the second flow path is offset from each of the third flow path and the fourth flow path in the first direction. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram illustrating a configuration of a liquid ejecting apparatus according to an embodiment. [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view showing the cross section III-III of FIG. 2. [Figure 4] 4 is a diagram showing a part of the flow paths for three nozzles and the first and second common liquid chambers as viewed from the bottom of FIG. 3. FIG. [Figure 5] 4 is a diagram showing a part of a flow path for one nozzle as seen from the bottom of FIG. 3. FIG. [Figure 6] FIG. 6 is an enlarged view of the flow path in FIG. 5. [Figure 7] FIG. 7 is a cross-sectional view showing the VII-VII cross section of FIG. 6. [Figure 8] FIG. 4 is a further enlarged view showing the communication flow path and the communication hole. [Figure 9] FIG. 4 is a further enlarged view showing the communication flow path and the communication hole. [Figure 10] 10 is a cross-sectional view showing the cross section XX in FIG. 9. [Figure 11] FIG. 10 is a cross-sectional view showing the cross section XI-XI of FIG. 9. [Figure 12] FIG. 10 is a diagram showing a communication flow path in a second embodiment. [Figure 13] FIG. 10 is a diagram showing a communication flow path in a third embodiment. [Figure 14] FIG. 10 is a diagram showing a communication flow path in a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] A. First embodiment FIG. 1 is an explanatory diagram showing the configuration of a liquid ejection apparatus 400 according to an embodiment. The liquid ejection apparatus 400 is an inkjet printing apparatus that ejects ink, an example of a liquid, onto a medium PM. The composition of the ink is not particularly limited, and may be, for example, an aqueous ink in which a colorant such as a dye or pigment is dissolved in an aqueous solvent, a solvent-based ink in which a colorant is dissolved in an organic solvent, or an ultraviolet-curable ink. The liquid ejection apparatus 400 may also eject paint as a liquid instead of ink. The liquid ejection apparatus 400 may be equipped with a liquid storage unit 420 that stores ink. The liquid ejection apparatus 400 performs printing by ejecting the ink in the liquid storage unit 420 toward the medium PM. The liquid ejection apparatus 400 includes a liquid ejection head 100, a movement mechanism 430, a transport mechanism 440, a control unit 450, and a circulation mechanism 60.

[0008] The liquid jet head 100 includes a plurality of nozzles 200, and jets liquid ink supplied from a liquid storage unit 420 from the plurality of nozzles 200. Specific examples of the liquid storage unit 420 include a cartridge that is detachable from the liquid jet device 400, a bag-shaped ink pack made of flexible film, and a container such as an ink tank that can be refilled with ink. The ink jetted from the nozzles 200 lands on a medium PM, which is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0009] The movement mechanism 430 includes a loop-shaped belt 432 and a carriage 434 fixed to the belt 432. The carriage 434 holds the liquid jet head 100. The movement mechanism 430 rotates the loop-shaped belt 432 in both directions, thereby causing the liquid jet head 100 to reciprocate along the X direction.

[0010] The transport mechanism 440 transports the medium PM along the Y direction between movements of the liquid jet head 100 by the movement mechanism 430. The Y direction is a direction perpendicular to the X direction. In this embodiment, the X and Y directions are horizontal. The Z direction is a direction intersecting the X and Y directions. In this embodiment, the Z direction is a vertically downward direction. The liquid jet head 100 ejects ink along the Z direction while being transported along the X direction. The Z direction is also referred to as the "ejection direction Z." In the following description, the tip side of an arrow indicating the X direction in the figure is referred to as the +X side, and the base end side is referred to as the -X side. The tip side of an arrow indicating the Y direction in the figure is referred to as the +Y side and the base end side is referred to as the -Y side. The tip side of an arrow indicating the Z direction in the figure is referred to as the +Z side and the base end side is referred to as the -Z side.

[0011] The control unit 450 controls the ink ejection operation from the liquid ejection head 100. The control unit 450 controls the transport mechanism 440, the movement mechanism 430, and the liquid ejection head 100 to form an image on the medium PM.

[0012] FIG. 2 is a bottom view of the liquid jet head 100. The liquid jet head 100 has a plurality of nozzles 200. The plurality of nozzles 200 are formed to penetrate a nozzle plate 240 that is arranged parallel to the XY plane. The plurality of nozzles 200 are arranged linearly along the Y direction to form a nozzle row NL. The nozzle plate 240 is manufactured by processing a silicon single crystal substrate using, for example, semiconductor processing technology. As the silicon single crystal substrate, for example, a (100) silicon single crystal substrate is suitably used. The nozzle plate 240 may also be formed from a material such as stainless steel (SUS) or titanium.

[0013] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. FIG. 4 is a diagram showing the flow paths for three nozzles, the first common liquid chamber 110, and a portion of the second common liquid chamber 120, as viewed from the bottom of FIG. 3. FIG. 5 is a diagram showing the flow paths for one nozzle and a portion of the common liquid chambers 110 and 120, as viewed from the bottom of FIG. 3. FIG. 6 is an enlarged view of the flow paths in FIG. 5. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6. Note that FIG. 4 only shows three nozzle flow paths 130, the first common liquid chamber 110, and the second common liquid chamber 120. Note that for ease of illustration, in FIGS. 5 and 6, the communicating flow path 350 is drawn with a solid line, the pressure chamber 330 with a dotted line, the drive element 300 with a dashed line, and the common liquid chambers 110 and 120 with a dashed line. 7, the reference numerals of the various parts in the cross section at the positions of the pressure chambers 331 and 332 are followed by the reference numerals of the various parts in the cross section taken along VII-VII in FIG. 6 at the positions of the other pressure chambers 333 and 334, in parentheses.

[0014] As shown in FIG. 4, the interval Pt1 between adjacent nozzles 200, i.e., the distance between the centers of the nozzles 200 in the Y direction, is constant. Furthermore, the interval Pt2 between adjacent pressure chambers 330_L1 among the multiple pressure chambers 330_L1 that make up row L1, i.e., the distance between the centers of the pressure chambers 330_L1 in the Y direction, is constant. A similar relationship applies to row L2. Furthermore, the interval Pt2 in row L1 and the interval Pt2 in row L2 are the same, and the interval Pt2 is half the interval Pt1. Furthermore, the interval Pt2 between the pressure chambers 330 is the same as the interval between the communication holes 340 and also the same as the interval between the centers of the nozzles 200 in the Y direction.

[0015] 3, the liquid jet head 100 has a first common liquid chamber 110 to which ink is supplied, a second common liquid chamber 120 from which ink is discharged, and individual nozzle flow paths 130 that connect the first common liquid chamber 110 and the second common liquid chamber 120. The first common liquid chamber 110 and the second common liquid chamber 120 are provided in common to a plurality of nozzles 200, and the individual nozzle flow paths 130 are provided individually for each nozzle 200. Each of the common liquid chambers 110, 120 extends in the Y direction, which is the direction along the nozzle row NL. In other words, the longitudinal direction of the common liquid chambers 110, 120 is parallel to the direction in which the plurality of nozzles 200 are arranged.

[0016] The liquid jet head 100 has a row L1 of a plurality of pressure chambers 330 that communicate with the first common liquid chamber 110, and a row L2 of a plurality of pressure chambers 330 that communicate with the second common liquid chamber 120. Row L1 is formed by a plurality of pressure chambers 330 lined up in the Y direction, and row L2 is formed by a plurality of pressure chambers 330 lined up in the Y direction. Row L1 is arranged on the −X side of the nozzle row NL, and row L2 is arranged on the +X side of the nozzle row NL. Hereinafter, the plurality of pressure chambers 330 that make up row L1 will be referred to as pressure chambers 330_L1, and the plurality of pressure chambers 330 that make up row L2 will be referred to as pressure chambers 330_L2. For the driving elements 300, connection flow paths 320, and communication holes 340 described in detail below, the driving elements 300 corresponding to row L1 will be referred to as driving elements 300_L1, the driving elements 300 corresponding to row L2 will be referred to as driving elements 300_L2, the connection flow paths 320 corresponding to row L1 will be referred to as connection flow paths 320_L1, the connection flow paths 320 corresponding to row L2 will be referred to as connection flow paths 320_L2, the communication holes 340 corresponding to row L1 will be referred to as communication holes 340_L1, and the communication holes 340 corresponding to row L2 will be referred to as communication holes 340_L2.

[0017] In this embodiment, the nozzle-specific flow path 130 corresponding to one nozzle 200 includes two pressure chambers 330_L1 in row L1, two pressure chambers 330_L2 in row L2, two connecting flow paths 320_L1 corresponding to each of the two pressure chambers 330_L1, two connecting flow paths 320_L2 corresponding to each of the two pressure chambers 330_L2, two communicating holes 340_L1 corresponding to each of the two pressure chambers 330_L1, two communicating holes 340_L2 corresponding to each of the two pressure chambers 330_L2, and a communicating flow path 350. Here, the two pressure chambers 330_L1 in this row L1 will be referred to as pressure chambers 331 and 332, the two pressure chambers 330_L2 in this row L2 will be referred to as pressure chambers 333 and 334, the two connection flow paths 320_L1 will be referred to as connection flow paths 321 and 322, the two connection flow paths 320_L2 will be referred to as connection flow paths 323 and 324, the two communication holes 340_L1 will be referred to as communication holes 341 and 342, and the two communication holes 340_L2 will be referred to as communication holes 343 and 344. Furthermore, the four drive elements 300 corresponding to the pressure chambers 331 to 334, respectively, will be referred to as drive elements 301 to 304.

[0018] Each of the common liquid chambers 110, 120 can be considered to extend in the Y direction or the direction in which the adjacent pressure chambers 331, 332 are aligned, in other words, the extension direction of the row L1 of the pressure chambers 330. In this embodiment, the direction in which the adjacent pressure chambers 331, 332 are aligned is an example of the "first direction." Furthermore, the multiple nozzle-specific flow paths 130 are aligned in the Y direction along the nozzle row NL.

[0019] The lower portions of the common liquid chambers 110, 120 and the multiple nozzle-specific flow paths 130 are mainly formed by the communication plate 140. The communication plate 140 may be configured by stacking multiple plate-shaped members. A housing unit 160 and a pressure chamber substrate 250 are installed on the upper surface of the communication plate 140, i.e., the surface facing the -Z side of the communication plate 140. The pressure chamber substrate 250 is located inside the housing unit 160 in a plan view seen in the Z direction. A vibration plate 310 is located on the upper surface of the pressure chamber substrate 250, i.e., the surface facing the -Z side of the pressure chamber substrate 250. A multiple pressure chambers 330 are provided in the pressure chamber substrate 250. Each pressure chamber 330 is a space defined by the communication plate 140, the vibration plate 310, and the pressure chamber substrate 250. The pressure chamber substrate 250 is manufactured, for example, by processing a silicon single crystal substrate using semiconductor processing technology. As the silicon single crystal substrate, for example, a (110) substrate, that is, a silicon single crystal substrate whose main surface is a (110) plane, is preferably used.

[0020] The diaphragm 310 is a plate-like member that can elastically vibrate. The diaphragm 310 is a laminate including, for example, a first layer made of silicon dioxide (SiO2) and a second layer made of zirconium oxide (ZrO2). Here, another layer such as a metal oxide may be interposed between the first and second layers. Part or all of the diaphragm 310 may be integrally formed with the pressure chamber substrate 250 using the same material. For example, the diaphragm 310 and the pressure chamber substrate 250 can be integrally formed by selectively removing a portion of a plate-like member of a predetermined thickness in the thickness direction in an area corresponding to the pressure chamber 330 by etching or the like. The diaphragm 310 may also be formed from a layer of a single material.

[0021] A nozzle plate 240 is installed on the lower surface of the communicating plate 140, i.e., the surface of the communicating plate 140 facing the +Z side, and the lower ends of the first common liquid chamber 110 and the second common liquid chamber 120, i.e., the +Z side ends of the first common liquid chamber 110 and the second common liquid chamber 120, are sealed with a flexible sealing film 150 made of a resin film, a thin metal film, or the like.

[0022] A wiring board 59 is bonded to the surface of the vibration plate 310 facing the -Z side. The wiring board 59 is a mounting component on which a plurality of wires for electrically connecting the control unit 450 and the liquid jet head 100 are formed. The wiring board 59 is a flexible wiring board such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable). A drive circuit 70 for driving the drive elements 300 is mounted on the wiring board 59. The drive circuit 70 supplies drive signals to each drive element 300.

[0023] A plurality of drive elements 300 are provided on the upper surface of the vibration plate 310, i.e., the surface of the vibration plate 310 facing the -Z side, corresponding to each pressure chamber 330. These drive elements 300 are, for example, piezoelectric elements. The piezoelectric elements are, for example, composed of a piezoelectric layer and two electrodes arranged to sandwich the piezoelectric layer. For example, when the drive elements 301 to 304, which are piezoelectric elements, vibrate, the vibrations are transmitted to the pressure chambers 331 to 334, respectively, and pressure waves are generated in the pressure chambers 331 to 334. Ink is ejected from the nozzles 200 by the pressure generated by the drive elements 301 to 304. When ink is ejected from the nozzles 200, it is preferable that the four drive elements 301 to 304 corresponding to each nozzle 200 are driven simultaneously and in phase. Note that instead of piezoelectric elements, heat generating elements that heat the ink in the pressure chambers 330 may be used as the drive elements.

[0024] A circulation mechanism 60 is connected to the common liquid chambers 110, 120. The circulation mechanism 60 supplies ink to the first common liquid chamber 110 and recovers ink discharged from the second common liquid chamber 120 for re-supply to the first common liquid chamber 110. The circulation mechanism 60 has a first supply pump 61, a second supply pump 62, a storage container 63, a recovery flow path 64, and a supply flow path 65.

[0025] The first supply pump 61 is a pump that supplies ink stored in the liquid storage section 420 to the storage container 63. The storage container 63 is a sub-tank that temporarily stores ink supplied from the liquid storage section 420. The recovery flow path 64 is interposed between the second common liquid chamber 120 and the storage container 63, and is a flow path for recovering ink from the second common liquid chamber 120 to the storage container 63. The ink stored in the liquid storage section 420 is supplied to the storage container 63 from the first supply pump 61. Furthermore, ink that has been supplied from the first common liquid chamber 110 to the individual nozzle flow paths 130 but is not ejected from the nozzles 200 and is discharged from the individual nozzle flow paths 130 to the second common liquid chamber 120 is supplied to the storage container 63 via the recovery flow path 64. The second supply pump 62 is a pump that sends out ink stored in the storage container 63. The supply flow path 65 is interposed between the first common liquid chamber 110 and the storage container 63 , and is a flow path for supplying ink from the storage container 63 to the first common liquid chamber 110 .

[0026] An opening 161 at the upper end of the first common liquid chamber 110, i.e., at the end on the -Z side of the first common liquid chamber 110, is connected to a supply flow path 65 that is outside the liquid jet head 100. In other words, the opening 161 in this embodiment functions as an inlet for introducing liquid from the circulation mechanism 60. An opening 162 at the upper end of the second common liquid chamber 120, i.e., at the end on the -Z side of the second common liquid chamber 120, is connected to a recovery flow path 64 of the circulation mechanism 60 that is outside the liquid jet head 100. In other words, the opening 162 in this embodiment functions as an outlet for discharging liquid from the circulation mechanism 60.

[0027] The nozzle-specific flow path 130 has the following flow paths and spaces. In the following description, the term "connected" is used to mean directly connected. The term "communicating" is used in a broader sense to include not only direct connection but also indirect connection. <Connection channels 321 to 324> The first connection flow path 321 connects the first common liquid chamber 110 and the first pressure chamber 331 . The second connection flow path 322 connects the first common liquid chamber 110 and the second pressure chamber 332 . The third connection flow path 323 connects the second common liquid chamber 120 and the third pressure chamber 333 . The fourth connection flow path 324 connects the second common liquid chamber 120 and the fourth pressure chamber 334 . The connection flow paths 321-324 are all flow paths that extend in the Z direction and penetrate the communication plate 140. For convenience of illustration, the connection flow paths 321-324 are hatched in Figures 5 and 6. The intersection of the connection flow path 320 and the pressure chamber 330 can be considered to be part of the pressure chamber 330.

[0028] <Pressure Chambers 331-334> The first pressure chamber 331 to the fourth pressure chamber 334 are spaces that are subjected to pressure changes by the first drive element 301 to the fourth drive element 304, respectively. The first pressure chamber 331 and the second pressure chamber 332 are arranged side by side in a first direction Dr1, and the third pressure chamber 333 and the fourth pressure chamber 334 are also arranged side by side in the first direction Dr1. In this embodiment, the first direction Dr1 is parallel to the Y direction. The first pressure chamber 331 and the second pressure chamber 332, and the third pressure chamber 333 and the fourth pressure chamber 334 are arranged with a shift in a second direction Dr2 that is perpendicular to the first direction Dr1. In this embodiment, the second direction Dr2 is parallel to the X direction. Pressure waves generated in the first pressure chamber 331 to the fourth pressure chamber 334 reach the nozzle 200 and cause ink to be ejected from the nozzle 200. It is preferable that the pressure chambers 331 to 334 have the same shape. In this embodiment, the pressure chambers 331 to 334 are arranged in a staggered pattern. Each pressure chamber 330 extends in the second direction Dr2.

[0029] <Communication holes 341~344> The first to fourth communication holes 341 to 344 each extend in the Z direction and are flow paths connecting the communication flow path 350 to the first to fourth pressure chambers 331 to 334, respectively. That is, one end of each pressure chamber 330 is connected to the connection flow path 320 and the other end is connected to the communication hole 340. The first to fourth communication holes 341 to 344 are examples of the "first flow path" to "fourth flow path," respectively. Note that in FIGS. 5 and 6, the communication holes 341 to 344 are hatched for ease of illustration. The first to second communication holes 341 and 342 are arranged side by side in the first direction Dr1, and the third to fourth communication holes 343 and 344 are also arranged side by side in the first direction Dr1. 7, the first communication hole 341 and the second communication hole 342 are separated by a communication hole partition wall 145. The communication holes 341 to 344 are flow paths that extend in the same direction as the connection flow paths 321 to 324, and penetrate the communication plate 140. It is preferable that the communication holes 341 to 344 have the same shape. The portion where the communication hole 340 and the pressure chamber 330 intersect can be considered to be part of the pressure chamber 330.

[0030] <Communicating flow path 350> As shown in FIG. 3, the communication flow path 350 is a flow path that is connected to the nozzle 200 and that communicates the nozzle 200 with the first pressure chamber 331 to the fourth pressure chamber 334. The communication flow path 350 is a flow path that extends along the nozzle surface of the nozzle plate 240 on which the plurality of nozzles 200 are formed, and the nozzle 200 is provided midway along the communication flow path 350. Specifically, the communication flow path 350 extends along the X direction and is defined by the communication plate 140 and the surface of the nozzle plate 240 facing the -Z side. As shown in FIG. 6, the communication flow path 350 includes a first portion 351, a second portion 352, and a third portion 353. The first portion 351 of the communication flow path 350 is disposed at one end of the communication flow path 350 and is connected to the first communication hole 341 and the second communication hole 342. The second portion 352 of the communicating flow path 350 is disposed at the other end of the communicating flow path 350 and is connected to the third communication hole 343 and the fourth communication hole 344. The third portion 353 of the communicating flow path 350 is connected between the first portion 351 and the second portion 352. The third portion 353 has a narrower width in the first direction Dr1 than the first portion 351 and the second portion 352. In this embodiment, the width W353 of the third portion 353 in the first direction Dr1 is constant. The portions where the first to fourth communication holes 341 to 344 and the communicating flow path 350 intersect can be considered to be part of the communicating flow path 350.

[0031] The pressure waves generated in the first pressure chamber 331 and the second pressure chamber 332 join at a first joining position Pj1 located near the lower ends of the first communication hole 341 and the second communication hole 342, i.e., the +Z side ends of the first communication hole 341 and the second communication hole 342. The pressure waves generated in the third pressure chamber 333 and the fourth pressure chamber 334 join at a second joining position Pj2 located near the lower ends of the third communication hole 343 and the fourth communication hole 344, i.e., the +Z side ends of the third communication hole 343 and the fourth communication hole 344. These pressure waves act as a driving force to eject ink from the nozzle 200.

[0032] For example, a liquid having pseudoplasticity can be used as the ink. More specifically, the ink is a liquid having a shear rate of 1000 s at 25°C. -1 The viscosity is 0.01 Pa s or more and 0.2 Pa s or less when the shear rate is 0.01 s-1 Preferably, the viscosity at this time is 0.5 Pa·s or more and 50 Pa·s or less. In this embodiment, by using four pressure chambers 331-334, the cross-sectional area of ​​each flow path is reduced, and the flow rate is increased to reduce the viscosity of the ink, making it possible to use pseudoplastic liquid ink. However, because it is desirable to efficiently utilize the energy of the drive elements 301-304 from the pressure chambers 331-334 to the nozzle 200, it is undesirable to make the flow path resistance excessively high. Therefore, in this embodiment, as shown in FIG. 5, the individual flow paths leading from adjacent pressure chambers 330 to the nozzle 200 are merged early at merging positions Pj1 and Pj2, which are closer to the pressure chamber than the nozzle 200, to prevent the flow path resistance from becoming excessively high.

[0033] In this embodiment, four pressure chambers 331 to 334 are provided for one nozzle 200, but five or more pressure chambers may be provided. In either case, drive elements are provided so as to correspond to the individual pressure chambers.

[0034] The nozzle-specific flow path 130 in this embodiment can be considered to include four individual flow paths corresponding to the four drive elements 301 to 304. An "individual flow path" is a flow path that includes at least a pressure chamber 330, and one individual flow path corresponds to one drive element 300. In this embodiment, the first individual flow path can be considered to include the first connection flow path 321, the first pressure chamber 331, and the first communication hole 341. The second to fourth individual flow paths can be considered to include the first connection flow path 321, the first pressure chamber 331, and the first communication hole 341.

[0035] 8 and 9 are further enlarged views showing the communication flow path 350 and the communication holes 341 to 344. Hatching of the communication holes 341 to 344 has been omitted in FIGS. 8 and 9. FIGS. 8 and 9 are the same except for some differences in the reference numerals used in the drawings. FIG. 10 is a cross-sectional view showing a cross section XX in FIG. 9, in which a portion of the communication plate 140 is cut along the XZ plane. FIG. 11 is a cross-sectional view showing a cross section XI-XI in FIG. 9, in which a portion of the communication plate 140 is cut along the XZ plane. As will be described below with reference to FIGS. 8 to 11, the liquid jet head 100 of the first embodiment has various features related to the strength, rigidity, etc. of the communication plate 140 as a flow path forming member. <Feature E1> The first communication hole 341 and the second communication hole 342, and the third communication hole 343 and the fourth communication hole 344 are arranged so as to be offset in a second direction Dr2 that is perpendicular to the first direction Dr1. Furthermore, the first communication hole 341 is offset from each of the third communication hole 343 and the fourth communication hole 344 in the first direction Dr1, and the second communication hole 342 is offset from each of the third communication hole 343 and the fourth communication hole 344 in the first direction Dr1. In other words, the position of the first communication hole 341 in the second direction Dr2 is offset from the position of both the third communication hole 343 and the position of the fourth communication hole 344. Here, the term "offset" between the two communication holes 340 means that the centers of the two communication holes 340 are different from each other.

[0036] The above-mentioned feature E1 means that the four communication holes 341 to 344 are arranged in a staggered pattern. Generally, when a large number of spaces such as the communication holes 341 to 344 and the communication flow path 350 are provided in the communication plate 140, the strength and rigidity of the communication plate 140 decrease. In particular, in a cross section of the communication plate 140 cut along the XZ plane, the strength of the communication plate 140 is low at a position in the first direction Dr1 where both the communication hole 341 and the communication hole 344 are formed in the communication plate 140 as shown in FIG. 10 , in other words, where one communication hole 340_L1 and one communication hole 340_L2 are formed (hereinafter referred to as a weak position). On the other hand, in a cross section of the communicating plate 140 cut along the XZ plane, at a position in the first direction Dr1 where only one of the communicating holes 341 and 344 is formed in the communicating plate 140 as shown in Figure 11, in other words, where only one of the communicating holes 340_L1 and 340_L2 is formed (hereinafter referred to as the non-weak position), the strength of the communicating plate 140 is higher than that at the weak position.

[0037] Here, consider a conventional example in which the communicating holes 341-344 are not arranged in a staggered pattern. In this conventional example, the communicating holes 341 and 343 are located in the same position in the first direction Dr1, and the communicating holes 342 and 344 are located in the same position in the first direction Dr1. In other words, the positions of the communicating holes 340_L1 in the first direction Dr1 are the same as the positions of the communicating holes 340_L2 in the first direction Dr1. Therefore, when viewed in the second direction Dr2, the communicating holes 341 and 343 completely overlap, and the communicating holes 342 and 344 completely overlap. In other words, in the conventional example, the aforementioned weak positions are formed in the communicating plate 140 continuously across the width of the communicating holes 340 in the first direction Dr1, which tends to reduce the strength of the communicating plate 140 as a whole. As a result, in the conventional example, the bending strength of the communicating plate 140 is reduced, which may cause the communicating plate 140 to break during assembly. Furthermore, the reduction in the overall rigidity of the communicating plate 140 raises concerns about increased structural crosstalk. Furthermore, there is a risk of increased deformation due to the effects of linear expansion, etc.

[0038] 8 and 9, when the four communication holes 341-344 are arranged in a staggered pattern, the weakened position corresponding to the communication hole 341 is provided so that the overlapping range of the communication holes 341 and 343 as viewed in the second direction Dr2 is continuous in the first direction Dr1, and the overlapping range of the communication holes 341 and 344 as viewed in the second direction Dr2 is continuous in the first direction Dr1. Furthermore, the non-weakened position corresponding to the communication hole 341 is provided so that the overlapping range of the communication holes 341 and 344 as viewed in the second direction Dr2 is continuous in the first direction Dr1 between the communication holes 343 and 344. In other words, the two weakened positions corresponding to the communication hole 341 are separated by the non-weakened position corresponding to the communication hole 341. The same applies to the weakened positions and non-weakened positions corresponding to each of the communication holes 342-344. Therefore, the range over which the weakened positions are continuously provided in the first direction Dr1 is smaller than the width of the communication hole 340 in the first direction Dr1. As described above, by arranging the four communication holes 341 to 344 in a staggered pattern, the weak positions can be dispersed in the first direction Dr1, so the range in which the weak positions are continuously provided in the first direction Dr1 can be made smaller than in the conventional example, and excessive reduction in the strength and rigidity of the communication plate 140 can be prevented.

[0039] When the "communicating hole" in the above feature E1 is replaced with "pressure chamber," feature E1a, which is almost the same as feature E1, is obtained. <Feature E1a> The first pressure chamber 331 and the second pressure chamber 332 are arranged so as to be offset from the third pressure chamber 333 and the fourth pressure chamber 334 in a second direction Dr2 that is perpendicular to the first direction Dr1. The first pressure chamber 331 is also offset from the third pressure chamber 333 and the fourth pressure chamber 334 in the first direction Dr1, and the second pressure chamber 332 is also offset from the third pressure chamber 333 and the fourth pressure chamber 334 in the first direction Dr1. Similar to the above-described feature E1, this feature E1a also makes it possible to suppress a decrease in the strength and rigidity of the pressure chamber substrate 250.

[0040] <Feature E2> The first communication hole 341 is disposed between the third communication hole 343 and the fourth communication hole 344 in the first direction Dr1, and the fourth communication hole 344 is disposed between the first communication hole 341 and the second communication hole 342 in the first direction Dr1. In other words, in the first direction Dr1, the first communication hole 341 is included within a range spanning both the third communication hole 343 and the fourth communication hole 344, and the fourth communication hole 344 is included within a range spanning both the first communication hole 341 and the second communication hole 342. In this embodiment, as shown in FIG. 8 , the first communication hole 341 partially overlaps with the third communication hole 343 and the fourth communication hole 344 when viewed in the second direction Dr2, specifically toward the +X side, and the fourth communication hole 344 partially overlaps with the first communication hole 341 and the second communication hole 342 when viewed in the second direction Dr2, specifically toward the −X side. However, the first communication hole 341 does not have to overlap with the third communication hole 343 and the fourth communication hole 344 at all when viewed in the second direction Dr2, and the fourth communication hole 344 does not have to overlap with the first communication hole 341 and the second communication hole 342 at all. This feature E2 further prevents a decrease in the strength and rigidity of the communication plate 140. Furthermore, the communication flow path 350 connecting the communication holes 341 to 344 can be shortened.

[0041] Hereinafter, the communication holes 341 to 344 corresponding to one nozzle 200 may be referred to as a communication hole group. Feature E2 above is preferably applied not only to one communication hole group corresponding to one nozzle 200, but also to two communication hole groups corresponding to two adjacent nozzles 200. This point will be specifically described by focusing on the two communication hole groups corresponding to nozzles 200a and 200b, where nozzle 200a is located at the end on the +Y side of the three nozzles 200 shown in FIG. 4 and nozzle 200b is located adjacent to nozzle 200a and on the -Y side of nozzle 200a. As shown in Figure 4, it is preferable that the second communication hole 342 corresponding to nozzle 200a is arranged between the third communication hole 343 corresponding to nozzle 200b and the fourth communication hole 344 corresponding to nozzle 200a in the first direction Dr1, and that the third communication hole 343 corresponding to nozzle 200b is arranged between the first communication hole 341 corresponding to nozzle 200b and the second communication hole 342 corresponding to nozzle 200a in the first direction Dr1.

[0042] When the "communicating hole" in the above feature E2 is replaced with "pressure chamber," feature E2a, which is almost the same as feature E2, is obtained. <Feature E2a> The first pressure chamber 331 is disposed between the third pressure chamber 333 and the fourth pressure chamber 334 in the first direction Dr1, and the fourth pressure chamber 334 is disposed between the first pressure chamber 331 and the second pressure chamber 332 in the first direction Dr1. That is, in the first direction Dr1, the first pressure chamber 331 is included in a range spanning both the third pressure chamber 333 and the fourth pressure chamber 334, and the fourth pressure chamber 334 is included in a range spanning both the first pressure chamber 331 and the second pressure chamber 332. In this embodiment, the first pressure chamber 331 partially overlaps with the third pressure chamber 333 and the fourth pressure chamber 334 when viewed in the second direction Dr2, and the fourth pressure chamber 334 partially overlaps with the first pressure chamber 331 and the second pressure chamber 332 when viewed in the second direction Dr2. However, when viewed in the second direction Dr2, the first pressure chamber 331 does not have to overlap at all with the third pressure chamber 333 and the fourth pressure chamber 334, and the fourth pressure chamber 334 does not have to overlap at all with the first pressure chamber 331 and the second pressure chamber 332. Similar to the above-mentioned feature E2, this feature E2a can further suppress a decrease in the strength and rigidity of the pressure chamber substrate 250.

[0043] <Feature E3> 8 , the first center C1 of the first communication hole 341 is disposed at the center between the third center C3 of the third communication hole 343 and the fourth center C4 of the fourth communication hole 344 in the first direction Dr1, and the fourth center C4 of the fourth communication hole 344 is disposed at the center between the first center C1 of the first communication hole 341 and the second center C2 of the second communication hole 342 in the first direction Dr1. That is, the first communication hole 341 is located at the center between the third communication hole 343 and the fourth communication hole 344, and the fourth communication hole 344 is located at the center between the first communication hole 341 and the second communication hole 342 in the first direction Dr1. Feature E3 further prevents a decrease in the strength and rigidity of the communication plate 140. The above centers C1 to C4 relating to the feature E3 may be interpreted as the centers of the communicating holes 341 to 344 in a plan view in the Z direction, or as the centers of the communicating holes 341 to 344 in the first direction Dr1.

[0044] Feature E3 is preferably applied not only to one communication hole group corresponding to one nozzle 200, but also to two communication hole groups corresponding to two adjacent nozzles 200. Specifically, as shown in Fig. 4, the second center C2 of the second communication hole 342 corresponding to the nozzle 200a is preferably disposed at the center, in the first direction Dr1, between the third center C3 of the third communication hole 343 corresponding to the nozzle 200b and the fourth center C4 of the fourth communication hole 344 corresponding to the nozzle 200a, and the third center C3 of the third communication hole 343 corresponding to the nozzle 200b is preferably disposed at the center, in the first direction Dr1, between the first center C1 of the first communication hole 341 corresponding to the nozzle 200b and the second center C2 of the second communication hole 342 corresponding to the nozzle 200a.

[0045] When the "communicating hole" in the above feature E3 is replaced with "pressure chamber," a feature E3a that is almost the same as feature E3 is obtained. <Feature E3a> The first center of the first pressure chamber 331 is disposed at the center between the third center of the third pressure chamber 333 and the fourth center of the fourth pressure chamber 334 in the first direction Dr1, and the fourth center of the fourth pressure chamber 334 is disposed at the center between the first center of the first pressure chamber 331 and the second center of the second pressure chamber 332 in the first direction Dr1. In other words, the first pressure chamber 331 is located at the center between the third pressure chamber 333 and the fourth pressure chamber 334, and the fourth pressure chamber 334 is located at the center between the first pressure chamber 331 and the second pressure chamber 332. Similar to the above-described feature E3, this feature E3a can further suppress a decrease in the strength and rigidity of the pressure chamber substrate 250.

[0046] <Feature E4> The first communication hole 341 overlaps with both the third communication hole 343 and the fourth communication hole 344 when viewed in the second direction Dr2, specifically toward the +X side, and the fourth communication hole 344 overlaps with both the first communication hole 341 and the second communication hole 342 when viewed in the second direction Dr2, specifically toward the -X side. Here, "overlap" means partially overlapping. Feature E4 further prevents a decrease in the strength and rigidity of the communication plate 140.

[0047] In this embodiment, the first direction Dr1 is the +Y direction, but the first direction Dr1 may be the -Y direction. Also, the second direction Dr2 is the +X direction, but the second direction Dr2 may be the -X direction. Furthermore, the first direction Dr1 and the second direction Dr2 may be set in directions different from these.

[0048] Feature E4 is preferably applied not only to one communication hole group corresponding to one nozzle 200, but also to two communication hole groups corresponding to two adjacent nozzles 200. Specifically, as shown in Fig. 4, the second communication hole 342 corresponding to nozzle 200a preferably overlaps with both the third communication hole 343 corresponding to nozzle 200b and the fourth communication hole 344 corresponding to nozzle 200a when viewed in the second direction Dr2, and the third communication hole 343 corresponding to nozzle 200b preferably overlaps with both the first communication hole 341 corresponding to nozzle 200b and the second communication hole 342 corresponding to nozzle 200a when viewed in the second direction Dr2.

[0049] When the "communicating hole" in the above feature E4 is replaced with "pressure chamber", a feature E4a that is almost the same as feature E4 is obtained. <Feature E4a> When viewed in the second direction Dr2, the first pressure chamber 331 overlaps with both the third pressure chamber 333 and the fourth pressure chamber 334. According to this feature E4a, similar to the feature E4 described above, the decrease in strength and rigidity of the pressure chamber substrate 250 can be further suppressed.

[0050] <Feature E5> Each of the communication holes 341-344 extends in a direction intersecting the extension direction of the communication flow path 350. In this embodiment, the "extension direction of the communication flow path 350" is the X direction, and each of the communication holes 341-344 extends in the Z direction. Note that each of the communication holes 341-344 can also be considered to extend in a direction intersecting the extension direction of the pressure chambers 331-334, which in this embodiment is the second direction Dr2. Each of the communication holes 341-344 can also be considered to extend along a direction perpendicular to the surface of the nozzle plate 240. Furthermore, each of the communication holes 341-344 can also be considered to extend along the ejection direction Z.

[0051] <Feature E6> The extension direction of the third portion 353 of the communicating flow path 350 is parallel to the second direction Dr2. According to feature E6, the third portion 353 does not extend in a direction inclined with respect to the second direction Dr2, but extends in the second direction Dr2, which is the shortest direction of the third portion 353. This allows the flow path length of the communicating flow path 350 to be shortened. As a result, flow path resistance can be reduced, and discharge efficiency is improved. Note that the third portion 353 has a narrower width in the first direction Dr1 than the first portion 351 and the second portion 352. Furthermore, as shown in FIG. 6, in this embodiment, the width W353 of the third portion 353 in the first direction Dr1 is constant.

[0052] <Feature E7> 8, the third portion 353 of the communicating flow path 350 is defined by side wall surfaces WL5 and WL6 that face each other in the first direction Dr1. In a plan view in the Z direction, each of these side wall surfaces WL5 and WL6 is offset from a side of each of the communicating holes 341-344 that extends in the second direction Dr2 with respect to its position in the first direction Dr1. Here, "a side of each of the communicating holes 341-344 that extends in the second direction Dr2" refers to a side of the outer edge of the communicating holes 341-344 that is parallel to the second direction Dr2 when viewed in the Z direction, and there are two of these for each of the communicating holes 341-344. In this embodiment, the outer edge of the communicating hole 340 when viewed in the Z direction is a parallelogram, and the side of the communicating hole 340 that extends in the second direction Dr2 is the long side of the parallelogram. The shape of the communication hole 340 in plan view is not limited to a parallelogram, and may be a rectangle or polygon having sides extending in the second direction Dr2. The shape of the communication hole 340 in plan view does not have to have sides extending in the second direction Dr2, and may be, for example, a circle.

[0053] Specifically, as the "sides extending in the second direction Dr2 of each of the communication holes 341 to 344," the first communication hole 341 has a +Y side 341_1 and a -Y side 341_2, the second communication hole 342 has a +Y side 342_1 and a -Y side 342_2, the third communication hole 343 has a +Y side 343_1 and a -Y side 343_2, and the fourth communication hole 344 has a +Y side 344_1 and a -Y side 344_2. Note that although these sides are actually wall surfaces, they can be recognized as "sides" because they are composed of line segments in a plan view. 8, in order to clearly show the positions in the first direction Dr1 of sides 341_1, 341_2, 342_1, 342_2, 343_1, 343_2, 344_1, and 344_2 of the communication holes 341 to 344 that are parallel to the second direction Dr2, virtual straight lines VL1_1, VL1_2, VL2_1, VL2_2, VL3_1, VL3_2, VL4_1, and VL4_2 that extend in the second direction Dr2 along those sides are indicated by two-dot chain lines. Side wall surfaces WL5 and WL6 of the third portion 353 are parallel to the second direction Dr2 in a plan view.

[0054] As can be seen from this imaginary straight line, in a plan view seen in the Z direction, the side wall surfaces WL5, WL6 are positioned in the first direction Dr1 offset from the sides extending in the second direction Dr2 of the communicating holes 341 to 344. This feature E7 enables the strength and rigidity of the communicating plate 140 to be increased compared to when the side wall surfaces WL5, WL6 of the third portion 353 parallel to the second direction Dr2 are positioned at the same positions as the sides 341_1, 341_2, 343_1, 343_2, 343_1, 343_2, 344_1, 344_2 of the communicating holes 341 to 344 parallel to the second direction Dr2.

[0055] <Feature E8> The first portion 351 of the communicating flow path 350 has a first side wall surface WP1 and a second side wall surface WP2 that are positioned farthest apart as side wall surfaces that define the first portion 351 and face each other in the first direction Dr1. Similarly, the second portion 352 has a third side wall surface WL3 and a fourth side wall surface WL4 that are positioned farthest apart as side wall surfaces that define the second portion 352 and face each other in the first direction Dr1. Furthermore, the third portion 353 has side wall surfaces WL5 and WL6 that define the third portion 353 and face each other in the first direction Dr1. The side wall surfaces WL5 and WL6 of the third portion 353 are positioned between the first side wall surface WL1 and the second side wall surface WL2 and between the third side wall surface WL3 and the fourth side wall surface WL4. Feature E8 further suppresses a decrease in the strength and rigidity of the communicating plate 140. Furthermore, since ink flows evenly from the first portion 351 and the second portion 352 to the nozzle 200, the flow path resistance can be reduced.

[0056] <Feature E9> The distance from the first communication hole 341 to the nozzle 200 is shorter than the distance from the second communication hole 342 to the nozzle 200, and the distance from the fourth communication hole 344 to the nozzle 200 is shorter than the distance from the third communication hole 343 to the nozzle 200. Of the side wall surfaces that define the first portion 351 of the communication flow path 350 and that face each other in the first direction Dr1, one side wall surface that is closer to the first communication hole 341 than the second communication hole 342 has a first tapered surface TP1, and the other side wall surface that is closer to the second communication hole 342 than the first communication hole 341 has a second tapered surface TP2. In other words, the distance between one side wall surface having the first tapered surface TP1 and the first communicating hole 341 is shorter than the distance between one side wall surface having the first tapered surface TP1 and the second communicating hole 342, and the distance between the other side wall surface having the second tapered surface TP2 and the second communicating hole 342 is shorter than the distance between the other side wall surface having the second tapered surface TP2 and the first communicating hole 341.

[0057] Similarly, of the side wall surfaces that define the second portion 352 of the communicating flow path 350 and face each other in the first direction Dr1, one side wall surface that is closer to the third communication hole 343 than the fourth communication hole 344 has a third tapered surface TP3, and the other side wall surface that is closer to the fourth communication hole 344 than the third communication hole 343 has a fourth tapered surface TP4. In other words, the distance between one side wall surface that has the third tapered surface TP3 and the third communication hole 343 is shorter than the distance between one side wall surface that has the third tapered surface TP3 and the fourth communication hole 344, and the distance between the other side wall surface that has the fourth tapered surface TP4 and the fourth communication hole 344 is shorter than the distance between the other side wall surface that has the fourth tapered surface TP4 and the third communication hole 343.

[0058] At this time, the second tapered surface TP2 is farther from the nozzle 200 than the first tapered surface TP1, and the third tapered surface TP3 is farther from the nozzle 200 than the fourth tapered surface TP4. According to this feature E9, the spaces of the first communicating hole 341 and the second communicating hole 342 can be merged early, thereby reducing the amount of removal of the communicating plate 140 and further suppressing a decrease in the strength and rigidity of the communicating plate 140.

[0059] <Feature E10> In a plan view seen in the Z direction, the length of the first tapered surface TP1 is shorter than the length of the second tapered surface TP2. Furthermore, the length of the fourth tapered surface TP4 is shorter than the length of the third tapered surface TP3. This feature E10 makes it easy to achieve a configuration in which the four communication holes 341-344 are shifted from one another in the first direction Dr1.

[0060] <Feature E11> In a plan view seen in the Z direction, sides 341_1 and 341_2 of the first communication hole 341 extending in the second direction Dr2 are misaligned in terms of their positions in the first direction Dr1 from sides 343_1 and 343_2 of the third communication hole 343 extending in the second direction Dr2 and sides 344_1 and 344_2 of the fourth communication hole 344. Similarly, sides 342_1 and 342_2 of the second communication hole 342 extending in the second direction Dr2 are misaligned in terms of their positions in the first direction Dr1 from sides 343_1 and 343_2 of the third communication hole 343 extending in the second direction Dr2 and sides 344_1 and 344_2 of the fourth communication hole 344.

[0061] 8, this can be seen from the fact that the aforementioned imaginary lines VL1_1, VL1_2, VL2_1, VL2_2, VL3_1, VL3_2, VL4_1, and VL4_2 are all located at different positions relative to one another in the first direction Dr1. This feature E11 can further suppress a decrease in the strength and rigidity of the communicating plate 140. In particular, because the communicating plate 140 of this embodiment is formed from single crystal silicon, the sides of the communicating holes 340 in a plan view, particularly the long sides extending in the second direction Dr2, are likely to become the starting points for cracks in the communicating plate 140. Therefore, in order to prevent damage to the communicating plate 140, it is preferable that the sides 341_1, 341_2, 342_1, and 342_2, and the sides 343_1, 343_2, 344_1, and 344_2, which are arranged offset from one another in the second direction Dr2, are offset from one another in the first direction Dr1. Note that the term "extending sides" may be interpreted as "parallel sides" or "parallel wall surfaces."

[0062] Feature E11 is preferably applied not only to one communication-hole group corresponding to one nozzle 200, but also to two communication-hole groups corresponding to two adjacent nozzles 200. Specifically, as shown in Fig. 4, it is preferable that the sides extending in the second direction Dr2 of the first communication hole 341 and the second communication hole 342 corresponding to the nozzle 200a and the nozzle 200b, respectively, are shifted in the first direction Dr1 with respect to the sides extending in the second direction Dr2 of the third communication hole 343 and the fourth communication hole 344 corresponding to the nozzle 200a and the nozzle 200b, respectively.

[0063] When the "communicating hole" in the above feature E11 is replaced with "pressure chamber", a feature E11a that is almost the same as feature E11 is obtained. <Feature E11a> In a plan view, the side of the first pressure chamber 331 extending in the second direction Dr2 is misaligned in position in the first direction Dr1 from the side of the third pressure chamber 333 extending in the second direction Dr2 and the side of the fourth pressure chamber 334 extending in the second direction Dr2. Similar to the above-described feature E11, this feature E11a can further suppress a decrease in the strength and rigidity of the pressure chamber substrate 250.

[0064] <Feature E12> As shown in FIG. 8 , in a plan view seen in the Z direction, the nozzle 200 overlaps the intersection of a first line segment L1 connecting the first communication hole 341 and the fourth communication hole 344 and a second line segment L2 connecting the second communication hole 342 and the third communication hole 343. The first line segment L1 is a line segment connecting the center C1 of the first communication hole 341 and the center C4 of the fourth communication hole 344. The second line segment L2 is a line segment connecting the center C2 of the second communication hole 342 and the center C3 of the third communication hole 343. Feature E12 allows pressure waves from the four pressure chambers 331-334 to reach the nozzle 200 almost uniformly. The center of the communication hole 340 in feature E12 may be interpreted as the position that is the center of the communication hole 340 in the first direction Dr1 and the center of the communication hole 340 in the second direction Dr2, or may be interpreted as the geometric center of the communication hole 340.

[0065] <Feature E13> In a plan view, the entire first line segment L1 overlaps the communicating flow path 350, and a part of the second line segment L2 does not overlap the communicating flow path 350. According to this feature E13, the pressure waves can be made to reach the nozzle 200 more uniformly from the four pressure chambers 331-334.

[0066] <Feature E14> The angle θ1 of the first tapered surface TP1 relative to the second direction Dr2, the angle θ2 of the second tapered surface TP2 relative to the second direction Dr2, the angle θ3 of the third tapered surface TP3 relative to the second direction Dr2, and the angle θ4 of the fourth tapered surface TP4 relative to the second direction Dr2 are all equal. In this embodiment, the angles θ1, θ2, θ3, and θ4 are approximately 35°. When the communication plate 140 is fabricated from a single-crystal silicon substrate, the flow path within the communication plate 140 is formed using, for example, anisotropic wet etching. The wall surfaces of the space formed by anisotropic wet etching of the single-crystal silicon substrate are not only parallel to the first direction Dr1 and the second direction Dr2 in FIG. 8, but also have specific angles inclined from these directions Dr1 and Dr2. In this embodiment, the front and back surfaces of the single-crystal silicon substrate are set to the (110) plane, and anisotropic etching is performed so that the angles θ1, θ2, θ3, and θ4 are 35°±2°. In this way, a clean tapered surface can be formed by anisotropic wet etching. However, the communicating plate 140 may be formed using a material other than single crystal silicon.

[0067] <Feature E15> The first side wall surface WP1 and the second side wall surface WP2, which are side wall surfaces that define the first portion 351 and extend along the second direction Dr2, are preferably offset in the first direction Dr1 from the third side wall surface WP3 and the fourth side wall surface WP4, which are side wall surfaces that define the second portion 352 and extend along the second direction Dr2. This feature E15 can further suppress a decrease in the strength and rigidity of the communicating plate 140.

[0068] Feature E15 is preferably applied not only to one communication-hole group corresponding to one nozzle 200, but also to two communication-hole groups corresponding to two adjacent nozzles 200. Specifically, as shown in Fig. 4, each of a first side wall surface WP1 and a second side wall surface WP2, which are side wall surfaces that define a first portion 351 corresponding to nozzle 200a and extend along the second direction Dr2, is preferably offset in the first direction Dr1 from a third side wall surface WP3 and a fourth side wall surface WP4, which are side wall surfaces that define a second portion 352 corresponding to nozzle 200b and extend along the second direction Dr2.

[0069] In the first embodiment, the liquid jet head 100 has at least some of the above-described features E1 to E15, and therefore it is possible to suppress a decrease in the strength and rigidity of the communication plate 140. Note that some of the above-described features may be omitted.

[0070] The liquid jet head 100 according to the first embodiment further has the following features related to the attenuation of pressure waves. <Feature F1> As shown in FIG. 6, the first merging position Pj1 is closer to the nozzle 200-side ends of the pressure chambers 331 and 332 than the nozzle 200 in a plan view in the Z direction. That is, the distance from the first merging position Pj1 to each end of the pressure chambers 331 and 332 on the nozzle 200 side is shorter than the distance from the first merging position Pj1 to the nozzle 200. Here, the "first end of the pressure chamber 331 on the nozzle 200 side" refers to the end opposite the first common liquid chamber 110, in the X direction, of both ends of the pressure chamber 331. In other words, the end on the +X side. The "second end of the pressure chamber 332 on the nozzle 200 side" refers to the end opposite the first common liquid chamber 110, in the X direction, of both ends of the pressure chamber 332. Similarly, the second merging position Pj2 is closer to the ends of the pressure chambers 333 and 334 than the nozzle 200 in a plan view in the Z direction. The "third end of the pressure chamber 333 on the nozzle 200 side" refers to the end of the pressure chamber 333 opposite the second common liquid chamber 120, in other words, the end on the -X side, of both ends of the pressure chamber 333 in the X direction. The "fourth end of the pressure chamber 334 on the nozzle 200 side" refers to the end of the pressure chamber 334 opposite the second common liquid chamber 120, in other words, the end on the -X side.

[0071] According to this feature F1, the pressure wave from the first pressure chamber 331 and the pressure wave from the second pressure chamber 332 combine near the pressure chambers 331, 332 rather than near the nozzle 200, so it is possible to prevent the pressure waves traveling from the individual pressure chambers 330 toward the nozzle 200 from being excessively attenuated, compared to the conventional example in which the pressure wave from the first pressure chamber 331 and the pressure wave from the second pressure chamber 332 combine near the nozzle 200. The same is true for the third pressure chamber 333 and the fourth pressure chamber 334.

[0072] Furthermore, according to feature F1, the proportion of the portion of the flow path from each end of the pressure chambers 331, 332 to the nozzle 200 that is common to both the pressure chambers 331, 332 can be increased compared to the conventional example. Therefore, the flow path resistance from the pressure chambers 331, 332 to the nozzle 200 can be reduced compared to the conventional example. The same is true for the third pressure chamber 333 and the fourth pressure chamber 334. As a result, pressure loss can be reduced and ejection efficiency can be improved. The effect of improving ejection efficiency is particularly significant when using high-viscosity ink such as pseudoplastic ink. On the other hand, in a configuration in which pressure waves merge near the nozzle 200, as in the conventional example, the pressure waves are significantly attenuated, reducing ejection efficiency. Furthermore, there is a risk that it may be difficult to refill the nozzle 200 with ink or that air bubbles may be trapped in the nozzle.

[0073] The first junction position Pj1 can also be considered to be the junction position of the flow path from the first pressure chamber 331 to the nozzle 200 and the flow path from the second pressure chamber 332 to the nozzle 200. Similarly, the second junction position Pj2 can also be considered to be the junction position of the flow path from the third pressure chamber 333 to the nozzle 200 and the flow path from the fourth pressure chamber 334 to the nozzle 200. As described above, in reality, liquid is supplied from the outside to the first common liquid chamber 110, is guided from the first common liquid chamber 110 to the first pressure chamber 331 and the second pressure chamber 332, and then, in the communication flow path 350, a portion of the liquid is ejected from the nozzle 200, is guided via the third pressure chamber 333 and the fourth pressure chamber 334 to the second common liquid chamber 120, and is discharged from the second common liquid chamber 120 to the outside. Therefore, the "flow path from the third pressure chamber 333 to the nozzle 200" and the "flow path from the fourth pressure chamber 334 to the nozzle 200" are both assumed to have a flow in the opposite direction to the actual flow of liquid, but it can be understood that these flow paths can be assumed regardless of the direction of the liquid.

[0074] <Feature F2> As shown in Figure 6, in a plan view in the Z direction, the first junction position Pj1 is located between the first pressure chamber 331 and the second pressure chamber 332, and the second junction position Pj2 is located between the third pressure chamber 333 and the fourth pressure chamber 334.

[0075] <Feature F3> 6, a first junction position Pj1 is located at one end of the communication flow path 350, and a second junction position Pj2 is located at the other end. According to feature F3, the pressure waves from the pressure chambers 331 and 332 join near their generation sources, and the pressure waves from the pressure chambers 333 and 334 join near their generation sources, so that attenuation of the pressure waves can be more efficiently suppressed.

[0076] <Feature F4> 6 and 7, the first junction position Pj1 is located in a first portion 351 of the communication flow path 350, and the second junction position Pj2 is located in a second portion 352 of the communication flow path 350. According to this feature F4, as shown in FIG. 7, the communication hole partition walls 145 are present between adjacent communication holes 341, 342 and between adjacent communication holes 343, 344, so that crosstalk between the pressure chambers 331, 332 and between the pressure chambers 333, 334 can be reduced.

[0077] <Feature F5> 6, the dimension L353 of the third portion 353 of the communication flow path 350 measured along the second direction Dr2 is longer than the dimension L351 of the first portion 351. In addition, the dimension L353 of the third portion 353 is longer than the dimension L352 of the second portion 352.

[0078] <Feature F6> 6, the third portion 353 of the communication flow path 350 is connected to the nozzle 200. According to the feature F6, the pressure waves from the pressure chambers 331 to 334 join together near their sources, so that the attenuation of the pressure waves can be more efficiently suppressed.

[0079] <Feature F7> 6, the width W353 of the third portion 353 of the communicating flow path 350 measured along the first direction Dr1 is smaller than the width W351 of the first portion 351. The width W353 of the third portion 353 is also smaller than the width W352 of the second portion 352. According to this feature F7, when a pseudoplastic liquid is used, by reducing the width W353 of the third portion 353, it is possible to improve the flow rate near the nozzle 200 and reduce the viscosity of the ink near the nozzle 200.

[0080] <Feature F8> 3, each of the first communication hole 341 to the fourth communication hole 344 extends in a direction intersecting with the extension direction of the communication flow path 350. That is, the longitudinal direction of each of the first communication hole 341 to the fourth communication hole 344 is a direction intersecting with the longitudinal direction of the communication flow path 350. In this embodiment, the X direction is an example of the "extension direction of the communication flow path 350", and the Z direction is an example of the "direction intersecting with the extension direction of the communication flow path 350".

[0081] It is also possible to consider the first communication hole 341 to the fourth communication hole 344 as extending in a direction intersecting the direction in which adjacent pressure chambers 330 are aligned. As can be seen from Fig. 3, the first communication hole 341 to the fourth communication hole 344 can also be considered as extending along a direction perpendicular to the surface of the nozzle plate 240. Furthermore, it is also possible to consider the first communication hole 341 to the fourth communication hole 344 as extending along the ejection direction Z.

[0082] <Feature F9> 3, in a plan view seen in the Z direction, each of the communication holes 341-344 is closer to the nozzle 200 than the connecting flow paths 321-324. In other words, the distance from each of the communication holes 341-344 to the nozzle 200 is shorter than the distance from each of the communication holes 341-344 to the connecting flow paths 321-324. According to this feature F9, the communication flow path 350 can be shortened, and flow path resistance can be reduced.

[0083] As described above, according to the first embodiment, the liquid jet head 100 has at least some of the above-described features F1 to F9, and therefore it is possible to combine pressure waves on the pressure chambers 331 to 334 side, rather than on the nozzle 200 side, and it is possible to prevent excessive attenuation of pressure waves traveling from the individual pressure chambers 330 toward the nozzle 200. Note that some of the above-described features may be omitted.

[0084] B. Other Embodiments FIG. 12 is a diagram showing the shape of a communication flow path 350 in the second embodiment. The main difference from the first embodiment shown in FIG. 6 is the shape of a third portion 353 located at the center of the communication flow path 350; the other configurations are substantially the same as those in the first embodiment. That is, in the second embodiment, the third portion 353 is bent midway, unlike in the first embodiment. More specifically, both sides of the third portion 353 are parallel to the second direction Dr2, and the center of the third portion 353 is inclined with respect to the second direction Dr2. However, the second embodiment is similar to the first embodiment in that the entire communication flow path 350 extends in the second direction Dr2, i.e., the entire longitudinal direction of the communication flow path 350 is parallel to the second direction Dr2. Also similar to the first embodiment, the plurality of communication holes 341-344 and the plurality of pressure chambers are arranged in a staggered pattern. It is preferable that the third portion 353 be located inside the smallest circumscribed convex polygon CF that encompasses the first portion 351 and the second portion 352. This has the advantage that the communicating flow paths 350 of adjacent nozzles do not interfere with each other, eliminating the need to separate the nozzles.

[0085] FIG. 13 is a diagram showing the shape of a communicating flow path 350 in a third embodiment. The third embodiment differs from the first embodiment shown in FIG. 6 mainly in the shape of a third portion 353 located at the center of the communicating flow path 350; the other configurations are substantially the same as those of the first embodiment. That is, in the third embodiment, the third portion 353 is linear, as in the first embodiment, but extends in a direction inclined from the second direction Dr2. However, the third embodiment is similar to the first embodiment in that the entire communicating flow path 350 extends in the second direction Dr2. Furthermore, in the third embodiment, the third portion 353 is located inside the smallest circumscribed convex polygon CF that encompasses the first portion 351 and the second portion 352.

[0086] FIG. 14 is a diagram showing the shape of the communicating flow path 350 in the fourth embodiment. The main difference between this fourth embodiment and the first embodiment shown in FIG. 6 is the shape of the third portion 353 located at the center of the communicating flow path 350; the other configurations are substantially the same as those of the first embodiment. That is, in the fourth embodiment, the third portion 353 has a shape in which three portions parallel to the second direction Dr2 are sequentially connected at an angle. However, the fourth embodiment is similar to the first embodiment in that the entire communicating flow path 350 extends in the second direction Dr2. Furthermore, in the fourth embodiment, the third portion 353 is located inside the smallest circumscribed convex polygon CF that encompasses the first portion 351 and the second portion 352. The second to fourth embodiments described above also achieve substantially the same effects as the first embodiment.

[0087] As described above, the liquid jet head 100 of the present disclosure can suppress a decrease in the strength and rigidity of the communicating plate by having at least some of the above-described features E1 to E14. Furthermore, by having at least some of the above-described features F1 to F9, it is possible to prevent excessive attenuation of the pressure waves traveling from the individual pressure chambers to the nozzles.

[0088] Variation 1 In each of the above-described embodiments, a serial-type liquid ejection device 400 is exemplified, in which the carriage 434 holding the liquid ejection head 100 is reciprocated, but the present disclosure can also be applied to a line-type liquid ejection device in which a plurality of nozzles 200 are distributed across the entire width of the medium PM. In other words, the carriage holding the liquid ejection head 100 is not limited to a serial-type carriage, and may be a structure that supports the liquid ejection head 100 in a line-type manner. In this case, for example, a plurality of liquid ejection heads 100 are arranged side by side in the width direction of the medium PM, and the plurality of liquid ejection heads 100 are collectively held by a single carriage.

[0089] Variation 2 In each of the above-described embodiments, the liquid ejecting device 400 is exemplified as being equipped with the circulation mechanism 60, but the liquid ejecting device 400 does not necessarily have to be equipped with the circulation mechanism 60. That is, both of the openings 161, 162 of the housing 160 may be inlets for introducing liquid from the liquid storage section 420, and both the first common liquid chamber 110 and the second common liquid chamber 120 may be used as flow paths for supplying the liquid supplied from the liquid storage section 420 to the nozzles 200.

[0090] Variation 3 In the above-described embodiments, four pressure chambers 330 are provided corresponding to one nozzle, but four or more pressure chambers 330 may be provided corresponding to one nozzle. For example, in a case where six pressure chambers 330 are provided corresponding to one nozzle, the same effects as those of the above-described embodiments can be obtained if the first merging position Pj1 of pressure waves from three of the six pressure chambers 330 is closer to the ends of those three pressure chambers 330 than the nozzle 200, and the second merging position Pj2 of pressure waves from the other three pressure chambers 330 is closer to the ends of those other three pressure chambers 330 than the nozzle 200.

[0091] Variation 4 In the above-described embodiments, one connection flow path 320 is connected to each of the pressure chambers 331 to 334, but a common connection flow path 320 may be provided for the pressure chambers 331 and 332 connected to the same first common liquid chamber 110. In other words, a configuration may be adopted in which one connection flow path 320 is provided corresponding to a plurality of pressure chambers 330. The same applies to the pressure chambers 333 and 334 connected to the same second common liquid chamber 120. When considering four individual flow paths corresponding to the individual pressure chambers 331 to 334 in Modification 4, for example, the first individual flow path does not include the connection flow path 320. The second to fourth individual flow paths can also be understood in a similar manner.

[0092] Variation 5 In each of the above-described embodiments, the connection flow path 320 is a flow path extending in the Z direction, but the connection flow path 320 may be a flow path extending in a direction intersecting the Z direction, or may be a flow path including both a portion extending in the Z direction and a portion extending in a direction intersecting the Z direction.

[0093] Variation 6 The liquid ejection apparatus exemplified in the above-described embodiment can be employed in various devices such as facsimile machines and copiers, as well as devices dedicated to printing. However, the uses of the liquid ejection apparatus are not limited to printing. For example, a liquid ejection apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming color filters for display devices such as liquid crystal display panels. Furthermore, a liquid ejection apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes on a wiring board. Furthermore, a liquid ejection apparatus that ejects a solution of an organic substance related to a living body is used as a manufacturing apparatus for manufacturing biochips, for example.

[0094] Other forms: The present disclosure is not limited to the above-described embodiments and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following aspects. The technical features in the above embodiments corresponding to the technical features in each aspect described below can be appropriately replaced or combined 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 a technical feature is not described as essential in this specification, it can be appropriately deleted.

[0095] (1) A liquid jet head according to a first aspect of the present disclosure includes a nozzle for ejecting liquid, first to fourth pressure chambers, a communication flow path connected to the nozzle and communicating the nozzle with the first to fourth pressure chambers, a first flow path connecting the communication flow path with the first pressure chamber, a second flow path connecting the communication flow path with the second pressure chamber, a third flow path connecting the communication flow path with the third pressure chamber, a fourth flow path connecting the communication flow path with the fourth pressure chamber, a first drive element that changes the pressure of the first pressure chamber, a second drive element that changes the pressure of the second pressure chamber, a third drive element that changes the pressure of the third pressure chamber, a fourth drive element that changes the pressure of the fourth pressure chamber, a first common liquid chamber that communicates with the first pressure chamber and the second pressure chamber, and a second common liquid chamber that communicates with the third pressure chamber and the fourth pressure chamber. The first flow path and the second flow path are arranged side by side in a first direction, the third flow path and the fourth flow path are arranged side by side in the first direction, and the first flow path and the second flow path, and the third flow path and the fourth flow path are arranged offset in a second direction perpendicular to the first direction. The first flow path is offset from each of the third flow path and the fourth flow path in the first direction, and the second flow path is offset from each of the third flow path and the fourth flow path in the first direction. With this liquid ejection head, the reduction in strength and rigidity of the flow path forming member can be suppressed compared to when the first flow path and the third flow path are located at the same position in the first direction and the second flow path and the fourth flow path are located at the same position in the first direction.

[0096] (2) In the above liquid jet head, the first flow path may be arranged between the third flow path and the fourth flow path in the first direction, and the fourth flow path may be arranged between the first flow path and the second flow path in the first direction.

[0097] (3) In the above liquid jet head, the first center of the first flow path may be positioned at the center between the third center of the third flow path and the fourth center of the fourth flow path in the first direction, and the fourth center may be positioned at the center between the first center and the second center of the second flow path in the first direction.

[0098] (4) In the above liquid jet head, the first flow path may overlap both the third flow path and the fourth flow path when viewed in the second direction, and the fourth flow path may overlap both the first flow path and the second flow path when viewed in the second direction.

[0099] (5) In the liquid jet head described above, each of the first to fourth flow paths may extend in a direction intersecting the extension direction of the communication flow path.

[0100] (6) In the above liquid jet head, the communicating flow path may include a first portion connected to the first flow path and the second flow path, a second portion connected to the third flow path and the fourth flow path, and a third portion connected to the first portion and the second portion and connected to the nozzle, and the extension direction of the third portion may be parallel to the second direction.

[0101] (7) In the liquid jet head, each of the side wall surfaces that define the third portion and face each other in the first direction may be offset in a plan view from the sides of each of the first to fourth flow paths that extend in the second direction with respect to the first direction.

[0102] (8) In the above liquid ejection head, the first portion may be defined by a first side wall surface and a second side wall surface that are positioned furthest apart from each other among the side wall surfaces that define the first portion and face each other in the first direction, and the second portion may be defined by a third side wall surface and a fourth side wall surface that are positioned furthest apart from each other among the side wall surfaces that define the second portion and face each other in the first direction, and the side wall surfaces that define the third portion and face each other in the first direction may be positioned between the first side wall surface and the second side wall surface and between the third side wall surface and the fourth side wall surface.

[0103] (9) In the above liquid ejection head, the distance from the first flow path to the nozzle may be shorter than the distance from the second flow path to the nozzle, and of the side wall surfaces that define the first portion and face each other in the first direction, one that is closer to the first flow path than the second flow path has a first tapered surface, and the other that is closer to the second flow path than the first flow path has a second tapered surface, and the second tapered surface may be farther from the nozzle than the first tapered surface.

[0104] (10) In the liquid jet head described above, the length of the first tapered surface may be shorter than the length of the second tapered surface in a plan view.

[0105] (11) In the above liquid jet head, in a plan view, a side of the first flow path extending in the second direction may be offset from a side of the third flow path extending in the second direction and a side of the fourth flow path extending in the second direction with respect to the first direction.

[0106] (12) In the liquid jet head described above, in a plan view, the nozzle may overlap an intersection of a first line segment connecting the first flow path and the fourth flow path and a second line segment connecting the second flow path and the third flow path.

[0107] (13) In the liquid jet head described above, in a plan view, the entire first line segment may overlap the communication flow path, and in a plan view, a portion of the second line segment may not overlap the communication flow path.

[0108] (14) In the above liquid jet head, the first common liquid chamber may be a flow path for supplying liquid to the first pressure chamber and the second pressure chamber, and the second common liquid chamber may be a flow path for recovering liquid from the third pressure chamber and the fourth pressure chamber.

[0109] (15) In the liquid jet head, the liquid may be ink having pseudoplasticity.

[0110] (16) In the liquid jet head, the pseudoplastic ink has a shear rate of 1000 s at 25°C. -1 The viscosity is 0.01 Pa s or more and 0.2 Pa s or less when the shear rate is 0.01 s -1 The viscosity at this time may be 0.5 Pa·s or more and 50 Pa·s or less.

[0111] (17) A second aspect of the present disclosure is a liquid ejection apparatus including the liquid ejection head described above and a liquid storage unit that stores liquid to be supplied to the liquid ejection head.

[0112] The present disclosure may be realized in various forms other than the liquid jet head and the liquid jet device, such as a method for manufacturing the liquid jet head and the liquid jet device, a method for controlling the liquid jet head and the liquid jet device, a computer program for realizing the control method, or a non-transitory recording medium on which the computer program is recorded. [Explanation of symbols]

[0113] 60...circulation mechanism, 100...liquid jet head, 110...first common liquid chamber, 120...second common liquid chamber, 130...flow path for each nozzle, 140...communicating plate, 145...communicating hole partition wall, 150...sealing film, 160...casing portion, 200, 200a...nozzle, 240...nozzle plate, 250...pressure chamber substrate, 301-304...drive element, 310...vibration plate, 321-324...connecting flow path, 331-334...pressure chamber, 341-344...communicating hole, 350...communicating flow path, 351-353...first part to third part of communicating flow path, 361-364...connecting portion, 400...liquid jet device, 420...liquid storage portion, 430...moving mechanism, 432...belt, 434...carriage, 440...transport mechanism, 450...control unit

Claims

1. A nozzle for spraying a liquid; first to fourth pressure chambers; a communication flow path connected to the nozzle and communicating the nozzle with the first to fourth pressure chambers; a first flow path connecting the communication flow path and the first pressure chamber; a second flow path connecting the communication flow path and the second pressure chamber; a third flow path connecting the communication flow path and the third pressure chamber; a fourth flow path connecting the communication flow path and the fourth pressure chamber; a first driving element that changes the pressure in the first pressure chamber; a second driving element that changes the pressure in the second pressure chamber; a third driving element that changes the pressure in the third pressure chamber; a fourth driving element that changes the pressure in the fourth pressure chamber; a first common liquid chamber communicating with the first pressure chamber and the second pressure chamber; a second common liquid chamber communicating with the third pressure chamber and the fourth pressure chamber; Equipped with The first flow path and the second flow path are arranged side by side in a first direction, The third flow path and the fourth flow path are arranged side by side in the first direction, the first flow path and the second flow path, and the third flow path and the fourth flow path are arranged to be shifted in a second direction perpendicular to the first direction, the first flow path is offset from each of the third flow path and the fourth flow path in the first direction; the second flow path is offset from each of the third flow path and the fourth flow path in the first direction; A liquid jet head characterized by:

2. the first flow path is disposed between the third flow path and the fourth flow path in the first direction, The fourth flow path is disposed between the first flow path and the second flow path in the first direction. The liquid jet head according to claim 1 .

3. a first center of the first flow path is disposed at a center between a third center of the third flow path and a fourth center of the fourth flow path in the first direction; the fourth center is disposed at a center between the first center and the second center of the second flow path in the first direction; The liquid jet head according to claim 2 .

4. the first flow path overlaps both the third flow path and the fourth flow path when viewed in the second direction; the fourth flow path overlaps both the first flow path and the second flow path when viewed in the second direction; The liquid jet head according to claim 2 or 3.

5. Each of the first to fourth flow paths extends in a direction intersecting the extension direction of the communication flow path. The liquid jet head according to claim 1 .

6. The communication flow path is a first portion connected to the first flow path and the second flow path; a second portion connected to the third flow path and the fourth flow path; a third portion connected to the first portion and the second portion and connected to the nozzle; The extension direction of the third portion is parallel to the second direction. The liquid jet head according to claim 1 .

7. each of the side wall surfaces that define the third portion and that face each other in the first direction is offset in the first direction from a side of each of the first to fourth flow paths that extends in the second direction, in a plan view; The liquid jet head according to claim 6 .

8. Among side wall surfaces that define the first portion and face each other in the first direction, the side wall surface includes a first side wall surface and a second side wall surface that are disposed farthest apart, Among the side wall surfaces that define the second portion and face each other in the first direction, a third side wall surface and a fourth side wall surface are disposed farthest apart, side wall surfaces that define the third portion and that face each other in the first direction are disposed between the first side wall surface and the second side wall surface and between the third side wall surface and the fourth side wall surface; The liquid jet head according to claim 6 or 7.

9. a distance from the first flow path to the nozzle is shorter than a distance from the second flow path to the nozzle; one of the side wall surfaces that define the first portion and face each other in the first direction and that is closer to the first flow path than the second flow path has a first tapered surface, and the other of the side wall surfaces that is closer to the second flow path than the first flow path has a second tapered surface; the second tapered surface is farther from the nozzle than the first tapered surface; The liquid jet head according to claim 6 .

10. In a plan view, the length of the first tapered surface is shorter than the length of the second tapered surface. The liquid jet head according to claim 9 .

11. In a plan view, a side of the first flow path extending in the second direction is shifted with respect to a side of the third flow path extending in the second direction and a side of the fourth flow path extending in the second direction, with respect to the first direction. The liquid jet head according to claim 1 .

12. In a plan view, the nozzle overlaps an intersection of a first line segment connecting the first flow path and the fourth flow path and a second line segment connecting the second flow path and the third flow path. The liquid jet head according to claim 1 .

13. In a plan view, all of the first line segments overlap with the communication flow path, In a plan view, a portion of the second line segment does not overlap the communication flow path. The liquid jet head according to claim 12.

14. the first common liquid chamber is a flow path for supplying liquid to the first pressure chamber and the second pressure chamber, the second common liquid chamber is a flow path for recovering liquid from the third pressure chamber and the fourth pressure chamber. The liquid jet head according to claim 1 .

15. the liquid is a pseudoplastic ink; The liquid jet head according to claim 1 .

16. The pseudoplastic ink was heated at 25° C. at a shear rate of 1000 s －１ The viscosity is 0.01 Pa s or more and 0.2 Pa s or less when the shear rate is 0.01 s －１ The viscosity is 0.5 Pa s or more and 50 Pa s or less. The liquid jet head according to claim 15.

17. A liquid jet head according to any one of claims 1 to 16, a liquid storage section that stores the liquid to be supplied to the liquid jet head; A liquid ejection device comprising:

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