Liquid injection head and liquid injection device

Abstract

This prevents the connecting plate of the liquid spray head from deforming and cracking due to external forces such as collisions with the medium. [Solution] The flow path member 100 comprises a plurality of nozzles 21, a plurality of individual flow paths 80, and a common flow path 90. The flow path member 100 comprises a pressure chamber substrate 10 on which a pressure chamber 12 is provided, and a communication plate 60 on which nozzle communication passages 67, which are part of the individual flow paths 80, are provided, and the communication plate 60 has a second surface 62 which is a surface in the -Z direction. The pressure chamber substrate 10 is laminated on the second surface 62, and in the Y-axis direction of the pressure chamber substrate 10, a case member 40 located in the -Z direction more than the second surface 62 is arranged on the second surface 62 via a gap GR. The communication plate 60 has a plurality of first recesses 71 that are recessed to a first bottom surface 73a, and a plurality of first recesses 71 that, when viewed in the +Z direction, partially overlap with a gap G, and the space defined by the first recesses 71 is part of the individual flow paths 80.

Description

[Technical Field]

[0001] The present invention relates to a liquid ejecting head that ejects liquid from nozzles and a liquid ejecting apparatus. [Background Art]

[0002] Patent Document 1 discloses a liquid ejecting head in which a flow path forming substrate 26 and a pressure chamber substrate 23 are laminated on one surface of a communication plate 22. The communication plate 22 is provided with a part of individual flow paths RK that individually communicate with nozzles N, and a part of common flow paths R1 and R2 that commonly communicate with the plurality of individual flow paths RK. The flow path forming substrate 26 and the pressure chamber substrate 23 are laminated in a direction opposite to the Z1 direction of the communication plate 22, and there is a gap between the flow path forming substrate 26 and the pressure chamber substrate 23. Therefore, among the flow paths provided in the communication plate 22, the flow paths BA1 and BA2 overlapping the gap when viewed in the Z1 direction are defined in recesses recessed from the Z1 direction surface of the communication plate 22 in a direction opposite to the Z1 direction. In other words, the communication plate 22 has a wall portion that closes the gap, and the common flow paths BA1 and BA2 provided in the communication plate 22 are defined by the wall portion. [Prior Art Document] [Patent Document]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2024-14040 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] It is desired to eject liquid at high speed without reducing the liquid ejection amount, and shortening the flow path length from the pressure chamber to the nozzle is effective for this purpose. In order to shorten the flow path length, it is necessary to reduce the thickness of the communication plate. However, when the communication plate is thinned, the wall portion also needs to be thinned, which reduces the rigidity of the wall portion. Therefore, when an external force such as collision with a medium is applied to the ejection surface of the head, there is a risk that the communication plate may deform and crack. [Means for Solving the Problem]

[0005] An aspect of the present invention that solves the above problems comprises a flow path member having a plurality of nozzles for spraying liquid in a first direction, a plurality of individual flow paths communicating individually with the plurality of nozzles, and a common flow path communicating in common with the plurality of individual flow paths, wherein the flow path member comprises a pressure chamber substrate which is part of the individual flow paths and is provided with a pressure chamber for which pressure is applied to the liquid in order to spray the liquid, and a communication plate which is part of the individual flow paths and is provided with a flow path that communicates the nozzles and the pressure chamber, and has a second surface which is a surface in a second direction opposite to the first direction, The liquid injection head is characterized in that the pressure chamber substrate is laminated on the second surface, and in the third direction which is perpendicular to the first and second directions of the pressure chamber substrate, flow channels located in the second direction relative to the second surface are arranged with gaps between them, and the communication plate has a plurality of first recesses that are recessed from the first surface which is the surface of the communication plate in the first direction to the bottom surface located between the first surface and the second surface, and a portion of the plurality of first recesses overlaps with the gap when viewed in the first direction, and the space defined by the first recesses is a part of the individual flow channels.

[0006] Another aspect of the present invention that solves the above problems is a liquid injection device characterized by comprising a liquid injection head according to the above aspect and a liquid storage unit that supplies liquid to the liquid injection head. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of a liquid injection device. [Figure 2] This is a disassembled perspective view of the liquid injection head unit. [Figure 3] This is a cross-sectional view of the main part of the liquid injection head unit, following line AA in Figure 2. [Figure 4] This is an exploded perspective view of the liquid injection head H. [Figure 5] This is a top view of the communication plate as seen in the +Z direction. [Figure 6] This is a bottom view of the connecting plate as seen in the -Z direction. [Figure 7] Figure 6 is a cross-sectional view of the liquid injection head passing through line BB. [Figure 8] Figure 6 is a cross-sectional view of the liquid injection head passing through the CC line. [Figure 9] Figure 6 is a cross-sectional view showing a modified example of a liquid injection head passing through line BB. [Modes for carrying out the invention]

[0008] The present invention will be described in detail below based on embodiments. However, the following description represents one aspect of the present invention and can be arbitrarily modified within the scope of the invention. In each figure, the same reference numerals indicate the same components, and their descriptions are omitted as appropriate. In each figure, X, Y, and Z represent three mutually orthogonal spatial axes. In this specification, the directions along these axes are referred to as the X direction, Y direction, and Z direction. In each figure, the direction in which the arrow points is described as the positive (+) direction, and the opposite direction of the arrow is described as the negative (-) direction. Furthermore, the Z direction indicates the vertical direction, with the +Z direction indicating vertically downward and the -Z direction indicating vertically upward. In addition, the directions of the three spatial axes that are not limited to positive and negative directions will be described as the X-axis direction, Y-axis direction, and Z-axis direction.

[0009] Figure 1 shows a schematic configuration of the liquid injection device 1 of the present invention. As shown in the figure, the liquid injection device 1 is an inkjet recording device that sprays and deposits ink, a type of liquid, as ink droplets onto a medium S such as printing paper, and prints images and the like by the arrangement of dots formed on the medium S. In addition to recording paper, any material such as resin film or cloth can be used as the medium S.

[0010] The liquid injection device 1 comprises a liquid injection head unit 2, a liquid storage unit 3, a control unit 4, a transport mechanism 5, and a moving mechanism 6. The liquid injection head unit 2 injects ink supplied from the liquid storage unit 3 onto the medium S from multiple nozzles. The detailed configuration of the liquid injection head unit 2 will be described later.

[0011] The liquid storage unit 3 stores the ink sprayed from the liquid injection head unit 2. Examples of the liquid storage unit 3 include a cartridge that can be attached to and detached from the liquid injection device 1, a bag-shaped ink pack made of flexible film, and an ink tank that can be refilled with ink. Although not specifically shown in the figures, the liquid storage unit 3 may individually store multiple types of ink with different colors, components, etc.

[0012] In this embodiment, the liquid storage unit 3 has a main tank 3a and a sub-tank 3b for each type of ink. The sub-tank 3b is connected to the liquid spray head unit 2. When an ink droplet is sprayed by the liquid spray head unit 2, an amount of ink equivalent to the amount consumed by that spray is replenished from the main tank 3a to the sub-tank 3b. Of course, the liquid storage unit 3 may consist only of the main tank 3a.

[0013] The liquid injection device 1 has a circulation mechanism 7 for circulating ink between the liquid injection head unit 2 and the sub-tank 3b. The circulation mechanism 7 comprises a supply pump 7a, a circulation pump 7b, the sub-tank 3b, a supply tube 7c, and a recovery tube 7d.

[0014] The supply pump 7a is a pump that supplies ink stored in the main tank 3a to the sub-tank 3b. The circulation pump 7b is a pump that supplies, i.e., pressurizes, the ink stored in the sub-tank 3b to the liquid injection head unit 2. The supply tube 7c has a flow path for the ink supplied from the sub-tank 3b to the liquid injection head unit 2. The recovery tube 7d has a flow path for ink that is not used for printing in the liquid injection head unit 2 and is recovered in the sub-tank 3b. The sub-tank 3b is a container for temporarily storing ink. The sub-tank 3b also temporarily stores ink that is not used for printing in the liquid injection head unit 2 and is recovered via the recovery tube 7d.

[0015] Such a circulation mechanism 7 supplies ink from the sub tank 3b to the liquid ejecting head unit 2 via the supply tube 7c by means of a circulation pump 7b, and collects ink not used in the liquid ejecting head unit 2 into the sub tank 3b via the recovery tube 7d. This circulates ink between the liquid ejecting head unit 2 and the sub tank 3b. Further, when the amount of ink stored in the sub tank 3b falls below a predetermined level, ink is supplied from the main tank 3a to the sub tank 3b by the supply pump 7a.

[0016] The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and a storage device such as a semiconductor memory. The control unit 4 also includes a power supply device that supplies electric power supplied from an external power source such as a commercial power source to each element of the liquid ejecting apparatus 1. The control unit 4 is electrically connected to the liquid ejecting head unit 2 via an external wiring not shown. The control unit 4 comprehensively controls each element of the liquid ejecting apparatus 1 by causing the control device to execute a program stored in the storage device.

[0017] The conveyance mechanism 5 conveys the medium S in the X-axis direction, and includes, for example, a conveyance roller 5a rotated by a conveyance motor driven under the control of the control unit 4.

[0018] The moving mechanism 6 is a mechanism for reciprocating the liquid ejecting head unit 2 in the Y-axis direction, and includes a holding body 6a that holds the liquid ejecting head unit 2, and a conveyor belt 6b that is an endless belt laid along the Y-axis direction. The control unit 4 rotates the conveyor belt 6b by controlling driving of a conveyance motor (not shown), and reciprocates the liquid ejecting head unit 2 in the Y-axis direction together with the holding body 6a fixed to the conveyor belt 6b.

[0019] Under the control of the control unit 4, the liquid ejecting head unit 2 performs an ejecting operation of ejecting, as ink droplets in the +Z direction, ink supplied from the liquid storage unit 3 from each of the plurality of nozzles 21 (see FIG. 4 and the like). The ejecting operation by the liquid ejecting head unit 2 is performed in parallel with the conveyance of the medium S by the conveyance mechanism 5 and the reciprocating movement of the liquid ejecting head unit 2 by the moving mechanism 6, thereby applying ink to the medium S and performing so-called printing.

[0020] FIG. 2 is an exploded perspective view of the liquid ejecting head unit 2. FIG. 3 is a cross-sectional view of a main part of the liquid ejecting head unit 2 along the line A-A in FIG. 2. Each direction of the liquid ejecting head unit 2 will be described based on the direction when the liquid ejecting head unit 2 is mounted on the liquid ejecting apparatus 1, that is, based on the X-axis direction, the Y-axis direction, and the Z-axis direction.

[0021] As illustrated, the liquid ejecting head unit 2 includes a plurality of liquid ejecting heads H, a flow channel structure 200 having a supply flow channel 400 and a recovery flow channel 410, a relay substrate 210, and a cover 220.

[0022] The flow channel structure 200 has the supply flow channel 400 that supplies ink supplied from a sub-tank 3b to the liquid ejecting heads H, and the recovery flow channel 410 that recovers ink not used by the liquid ejecting heads H to the sub-tank 3b.

[0023] The flow channel structure 200 includes a first flow channel structure portion 201, a second flow channel structure portion 202, and a seal member 203. The first flow channel structure portion 201, the seal member 203, and the second flow channel structure portion 202 are stacked in this order in the +Z direction.

[0024] The first flow channel structure 201 is a member provided with a first supply channel 401 and a first recovery channel 411. In this embodiment, it is composed of three first members 201a, a second member 201b, and a third member 201c stacked in the Z-axis direction. The first flow channel structure 201 has a supply tube connection portion 204a and a recovery tube connection portion 204b on the surface facing the -Z direction. When the supply tube connection portion 204a and the recovery tube connection portion 204b are not distinguished, they are referred to as the tube connection portion 204. In this embodiment, the tube connection portion 204 has a shape that protrudes cylindrically in the -Z direction from the -Z direction surface of the first flow channel structure 201. A supply tube 7c is connected to the supply tube connection portion 204a, and a recovery tube 7d is connected to the recovery tube connection portion 204b. A first supply channel 401 is provided inside the supply tube connection part 204a, and a first recovery channel 411 is provided inside the recovery tube connection part 204b.

[0025] The first supply channel 401 and the first recovery channel 411 are composed of channels extending in the Z-axis direction, channels extending along the lamination interface of the laminated members, etc. In addition, a liquid reservoir 405 is provided in the middle of the first supply channel 401, which has a wider inner diameter than other areas, and a filter 406 is provided in the liquid reservoir 405 to capture foreign matter such as dust and air bubbles contained in the ink. In this embodiment, the first channel structure 201 comprises two supply tube connection parts 204a, two recovery tube connection parts 204b, two independent first supply channels 401, and two independent first recovery channels 411. The first supply channel 401 may be branched into two or more channels downstream of the filter 406, for example.

[0026] The second flow channel structure 202 has a second supply channel 402 communicating with each of the first supply channels 401, and a second recovery channel 412 communicating with each of the first recovery channels 411. That is, the second flow channel structure 202 has two second supply channels 402 and two second recovery channels 412. The first supply channels 401 and the second supply channels 402 are liquid-tightly connected via a sealing member 203. Similarly, the first recovery channels 411 and the second recovery channels 412 are liquid-tightly connected via a sealing member 203. The sealing member 203 can be made of a material that is liquid-resistant to liquids such as ink used in the liquid injection head unit 2 and is elastically deformable, such as rubber or elastomer. The sealing member 203 is provided with a third supply channel 403 and a third recovery channel 413 that penetrate in the Z-axis direction. The first supply channel 401 and the second supply channel 402 communicate via the third supply channel 403, and the first recovery channel 411 and the second recovery channel 412 communicate via the third recovery channel 413. In other words, the channel structure 200 comprises two supply channels 400, each supply channel 400 comprising a first supply channel 401, a second supply channel 402, and a third supply channel 403. The channel structure 200 also comprises two recovery channels 410, each recovery channel 410 comprising a first recovery channel 411, a second recovery channel 412, and a third recovery channel 413.

[0027] The second flow channel structure 202 has a housing portion 230 having a concave shape that opens to a surface facing the +Z direction. A liquid injection head H is housed within the housing portion 230. In this embodiment, the liquid injection head unit 2 comprises a plurality of liquid injection heads H, for example, two. Of these two liquid injection heads H, the one facing the -Y direction is also called liquid injection head Ha, and the one facing the +Y direction is also called liquid injection head Hb. The two liquid injection heads H are held within a common housing portion 230. The number of liquid injection heads H held by the liquid injection head unit 2 is not particularly limited and may be one or more than two. Furthermore, the housing portion 230 may be provided independently for each liquid injection head H, or it may be provided for each group of liquid injection heads composed of two or more liquid injection heads H.

[0028] In this embodiment, two liquid spray heads H are arranged side by side in the Y-axis direction so that they are in the same position with respect to the X-axis direction. The -Z-facing surface of the liquid spray heads H and the bottom surface of the housing 230, i.e., the surface facing the +Z direction, are bonded together with an adhesive (not shown). The arrangement of the multiple liquid spray heads H is not particularly limited to this.

[0029] The bottom surface of the housing section 230 of the second flow path structure section 202 has openings for a second supply flow path 402 and a second recovery flow path 412. The inlet 44a of the liquid injection head H is in communication with the second supply flow path 402, and the outlet 44b of the liquid injection head H is in communication with the second recovery flow path 412. In this embodiment, one second supply flow path 402 is provided for one liquid injection head H. One second recovery flow path 412 is provided for one liquid injection head H.

[0030] The second flow path structure 202 has a first wiring insertion hole 205 that penetrates in the Z-axis direction. The first wiring insertion hole 205 is provided with one end opening to the -Z-direction facing surface of the second flow path structure 202 and the other end opening to the flow path connection surface 231. The wiring member 110 of the liquid injection head H, which will be described in detail later, is led out to the -Z-direction facing surface of the second flow path structure 202 via the first wiring insertion hole 205. In this embodiment, two first wiring insertion holes 205 are provided corresponding to each of the two liquid injection heads H.

[0031] In the Z-axis direction, a relay board 210 is provided between the sealing member 203 and the second flow channel structure 202, to which the wiring members 110 of multiple liquid injection heads H are commonly connected. The relay board 210 is made of a rigid, inflexible substrate, and wiring and electronic components (not shown) are mounted on it. In this embodiment, as an example of electronic components, a connector 211 to which the wiring members 110 of the liquid injection heads H are connected, and an external wiring connector 212 to which external wiring (not shown) provided outside the liquid injection head unit 2 is connected are shown. Print signals for controlling the liquid injection heads H are input from the external wiring to the relay board 210 via the external wiring connector 212, and supplied to each liquid injection head H via the connector 211 and wiring members 110 of the relay board 210. An external wiring opening 206 is provided in the side wall of the flow channel structure 200 facing the external wiring connector 212 for inserting the external wiring connected to the external wiring connector 212. The external wiring is connected to the external wiring connector 212 of the relay board 210, which is located inside the flow channel structure 200, via the external wiring opening 206.

[0032] The relay substrate 210 has a second wiring insertion hole 213 that penetrates in the Z-axis direction. The second wiring insertion hole 213 is positioned to communicate with the first wiring insertion hole 205, that is, to overlap with the first wiring insertion hole 205 when viewed in the Z-axis direction. The wiring member 110 of the liquid injection head H is led out to the -Z-facing side of the relay substrate 210 through the first wiring insertion hole 205 and the second wiring insertion hole 213.

[0033] The relay substrate 210 has a projection insertion hole 214 that penetrates in the Z-axis direction. On the surface of the second flow channel structure 202 facing the -Z direction, a cylindrical projection 207 is provided that protrudes toward the -Z direction, and has a second supply channel 402 or a second recovery channel 412 inside. The projection 207 is inserted through the projection insertion hole 214 into the -Z side of the relay substrate 210, and the second supply channel 402 or second recovery channel 412 provided in the projection 207 is connected to the third supply channel 403 or third recovery channel 413.

[0034] A cover 220 is fixed to the surface of the flow channel structure 200 facing the +Z direction. The cover 220 is made of a metal plate such as stainless steel and is sized to cover the housing portion 230 of the flow channel structure 200. The cover 220 is a common component fixed to the surface of the two liquid spray heads H facing the +Z direction. The cover 220 is independently provided with an exposed opening 221 for each liquid spray head H, exposing the nozzle 21 of the liquid spray head H toward the +Z direction. Ink is sprayed toward the +Z direction from the nozzle 21 exposed through the exposed opening 221.

[0035] Figure 4 is an exploded perspective view of a liquid injection head H according to one embodiment of the present invention. Figure 5 is a top view of the communication plate as seen in the +Z direction. Figure 6 is a bottom view of the communication plate as seen in the -Z direction. Figure 7 is a cross-sectional view of the liquid injection head passing through line BB in Figure 6. Figure 8 is an enlarged cross-sectional view of the main part of the liquid injection head passing through line CC in Figure 6. The directions of the liquid injection head H will be described based on the directions when mounted on the liquid injection head unit 2, i.e., the X-axis direction, Y-axis direction, and Z-axis direction.

[0036] The liquid injection head H of this embodiment comprises a flow path member 100, a first piezoelectric element 51 and a second piezoelectric element 52, the flow path member 100 having a pressure chamber substrate 10, a nozzle plate 20, a case member 40 and a communication plate 60.

[0037] The pressure chamber substrate 10 is made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates. The pressure chamber substrate 10 is provided with a plurality of pressure chambers 12 and detection chambers 13 that penetrate in the Z-axis direction. The plurality of pressure chambers 12 are arranged in a row along the X-axis direction to form a pressure chamber row. Two adjacent pressure chambers 12 in the X-axis direction are separated by a pressure chamber partition wall (not shown). The plurality of detection chambers 13 are arranged in a row along the X-axis direction to form a detection chamber row. Two adjacent detection chambers 13 in the X-axis direction are separated by a detection chamber partition wall (not shown). In this embodiment, the pressure chamber row is arranged on the +Y direction side, and the detection chamber row is arranged on the -Y direction side. The detection chambers 13 are arranged with the same width as the X-axis width of the pressure chambers 12 and with the same pitch as the X-axis pitch of the pressure chambers 12. The detection chambers 13 are provided with a length shorter than the Y-axis length of the pressure chambers 12.

[0038] On the surface of the pressure chamber substrate 10 facing the +Z direction, the communication plate 60 and the nozzle plate 20 are sequentially stacked. On the surface of the pressure chamber substrate 10 facing the -Z direction, the diaphragm 50, the first piezoelectric element 51, and the second piezoelectric element 52 are sequentially stacked.

[0039] The connecting plate 60 is a plate-shaped member having a first surface 61 on the +Z direction side and a second surface 62 on the -Z direction side, with the pressure chamber substrate 10 and case member 40 laminated on the second surface 62. The connecting plate 60 also has a first through hole 63, a second through hole 64, a third through hole 65, and a fourth through hole 66 that penetrate from the first surface 61 to the second surface 62. A single-crystal silicon substrate or the like can be used as the connecting plate 60.

[0040] The second surface 62 of the communication plate 60 refers to the surface on which the pressure chamber substrate 10 is stacked and the surface that is coplanar with the surface on which the pressure chamber substrate 10 is stacked. The first surface 61 of the communication plate 60 refers to the surface on which the nozzle plate 20 is stacked and the surface that is coplanar with the surface on which the nozzle plate 20 is stacked.

[0041] The first through-hole 63 and the third through-hole 65 have a shape that extends in the X-axis direction when viewed in the Z-axis direction. The first through-hole 63 is located on the +Y side of the second through-hole row 64a described later, and the third through-hole 65 is located on the -Y side of the fourth through-hole row 66a described later. The length of the first through-hole 63 in the X-axis direction is longer than the length of the second through-hole row 64a, and the length of the third through-hole 65 in the X-axis direction is longer than the length of the fourth through-hole row 66a. The first through-hole 63 is positioned to overlap with the second through-hole row 64a when viewed in the Y-axis direction, and the third through-hole 65 is positioned to overlap with the fourth through-hole row 66a when viewed in the Y-axis direction.

[0042] Multiple second through-holes 64 are arranged in a row along the X-axis direction, forming a second through-hole row 64a. Multiple fourth through-holes 66 are arranged in a row along the X-axis direction, forming a fourth through-hole row 66a. On the communication plate 60, the second through-hole row 64a and the fourth through-hole row 66a are arranged with a gap in the Y-axis direction between the first through-hole 63 and the third through-hole 65. Each second through-hole 64 in the second through-hole row 64a communicates with each pressure chamber 12. Each fourth through-hole 66 in the fourth through-hole row 66a communicates with each detection chamber 13.

[0043] Furthermore, the communication plate 60 is provided with nozzle communication passages 67 that penetrate from the first surface 61 to the second surface 62. Multiple nozzle communication passages 67 are formed to connect each pressure chamber 12 to each nozzle 21. The opening width of the nozzle communication passages 67 narrows from the second surface 62 towards the first surface 61. In addition, the communication plate 60 has a recessed connecting channel 68 that extends from the second surface 62 to the bottom surface located between the first surface 61 and the second surface 62. The connecting channel 68 extends in the Y-axis direction, and one end communicates with the nozzle communication passage 67. The other end of the connecting channel 68 communicates with the detection chamber 13 of the pressure chamber substrate 10 which is joined to the communication plate 60.

[0044] The connecting plate 60 has a first wall portion 73 and a second wall portion 74. The first wall portion 73 is the part of the communication plate 60 located between the first through hole 63 and the second through hole 64 in the Y-axis direction, and is located between the second surface 62 and the first bottom surface 73a which is on the same plane. The area between the first through hole 63 and the second through hole 64 also includes the area between the first through hole 63 and the adjacent second through hole 64. In other words, in a plan view in the +Z direction as shown in Figure 5, the first wall portion 73 is the part between the first through hole 63 and the virtual area encompassing the row of second through holes 64a. The first bottom surface 73a is the surface located between the first surface 61 and the second surface 62 in the Z-axis direction.

[0045] The second wall portion 74 is the part of the communication plate 60 located between the third through hole 65 and the fourth through hole 66, and is located between the second surface 62 and the second bottom surface 74a, which are on the same plane. The area between the second through hole 64 and the fourth through hole 66 also includes the area between the second through hole 64 and the area between adjacent second through holes 64. In other words, in a plan view in the +Z direction as shown in Figure 5, the second wall portion 74 is the part between the second through hole 64 and the imaginary area encompassing the row of fourth through holes 66a. The second bottom surface 74a is the surface located between the first surface 61 and the second surface 62. Note that the first bottom surface 73a and the second bottom surface 74a are described as being on the same plane, but are not limited to this and may be on different planes.

[0046] Multiple partition walls 75 are provided on the first wall portion 73, positioned in the +Z direction from the first wall portion 73 and extending in the Y direction, spaced apart in the X direction. The first bottom surface 73a of the first wall portion 73 and a pair of opposing partition walls 75 define a single first recess 71. With multiple partition walls 75 provided on the first wall portion 73, the communication plate 60 has multiple first recesses 71 that are recessed from the first surface 61 to the first bottom surface 73a, separated by multiple partition walls 75, arranged in the X direction. The same number of first recesses 71 are provided as the number of pressure chambers 12, and each first recess 71 connects the -Y direction end of the first through hole 63 to the +Y direction end of each second through hole 64. When viewed in the Z-axis direction, the first recess 71 has its +Y-direction end overlapping with the case member 40, its -Y-direction end overlapping with the pressure chamber substrate 10, and its central area overlapping with the gap GR described later.

[0047] Multiple partition walls 75 are provided on the second wall 74, positioned in the +Z direction from the second wall 74 and extending in the Y-axis direction, spaced apart in the X-axis direction. The second bottom surface 74a of the second wall 74 and a pair of opposing partition walls 75 define a single second recess 72. With multiple partition walls 75 provided on the second wall 74, the communication plate 60 has multiple second recesses 72 that are recessed from the first surface 61 to the second bottom surface 74a, separated by multiple partition walls 75, arranged in the X-axis direction. The same number of second recesses 72 are provided as the number of detection chambers 13, and each second recess 72 connects the +Y direction end of the third through hole 65 to the -Y direction end of each fourth through hole 66. When viewed in the Z-axis direction, the second recess 72 has its -Y-direction end overlapping with the case member 40, its +Y-direction end overlapping with the pressure chamber substrate 10, and its central area overlapping with the gap GL described later.

[0048] The shape of the partition wall 75 is not particularly limited, but in this embodiment, as shown in Figure 6, the partition wall 75 defining the first recess 71 has a smaller width in the X-axis direction as it approaches the first through-hole 63, and the partition wall 75 defining the second recess 72 has a smaller width in the X-axis direction as it approaches the third through-hole 65. Also, as shown in Figure 8, the width W1 of the first recess 71 in the X-axis direction is greater than the width W2 of the partition wall 75 in the X-axis direction. Furthermore, the minimum width of the second recess 72 in the X-axis direction is greater than the width W2 of the partition wall 75 in the X-axis direction. The width W2 of the partition wall 75 refers to the maximum width of the partition wall 75 in the X-axis direction. The width W1 of the first recess 71 in the X-axis direction refers to the minimum width of the first recess 71 in the X-axis direction. As in this embodiment, for partition walls 75 whose width in the X-axis direction is not constant, the maximum width of partition wall 75 in the X-axis direction is set to width W2, and for first recesses 71 whose width in the X-axis direction is not constant, the minimum width of first recesses 71 in the X-axis direction is set to width W1, and it is preferable that the width W1 of the first recesses 71 be larger than the width W2.

[0049] As shown in Figure 8, the width W3 in the Z-axis direction of the first wall portion 73 is the width in the +Z direction from the second surface 62 to the first bottom surface 73a. The width W3 is not particularly limited, but it is preferable that it satisfies one or more of the following conditions. The width W3 is smaller than the width W4 in the +Z direction of the pressure chamber substrate 10. • The width W3 is smaller than the width W5 in the +Z direction of the nozzle plate 20. The width W3 is less than or equal to the width W6 in the +Z direction of the first recess 71. The width W3 is 150 μm or less. Furthermore, the width W3 of the first wall portion 73 is preferably 1 / 2 or less of the width of the connecting plate 60 in the Z-axis direction, more preferably 1 / 3 or less, and even more preferably 1 / 4 or less. Furthermore, the width of the second wall portion 74 in the Z-axis direction is the width in the +Z direction from the second surface 62 to the second bottom surface 74a. The width of the second wall portion 74 in the Z-axis direction is not particularly limited, but it is preferable that it satisfies one or more of the following conditions. • Smaller than the width W4 in the +Z direction of the pressure chamber substrate 10. • The width of nozzle plate 20 in the +Z direction is smaller than W5. • The width of the second recess 72 in the +Z direction is less than or equal to the width of the second recess 72. • It is 150 μm or less. Furthermore, the width of the second wall portion 74 is preferably 1 / 2 or less of the width of the communication plate 60 in the Z-axis direction, more preferably 1 / 3 or less, and even more preferably 1 / 4 or less.

[0050] The first recess 71 and the second recess 72 are formed by a partition wall 75 extending in the Y-axis direction, but are not limited to this. The first recess 71 and the second recess 72 may extend in any direction and do not need to be straight; they may be curved. Also, although the first recess 71 is shown with a constant depth from the first surface 61 to the first bottom surface 73a, it is not limited to this configuration. For example, the first bottom surface 73a of the first recess 71 may be inclined with respect to the XY plane. The same applies to the second bottom surface 74a of the second recess 72.

[0051] The nozzle plate 20 is joined to the surface of the communication plate 60 facing the +Z direction. Nozzles 21 are formed on the nozzle plate 20, which communicate with each pressure chamber 12 via nozzle communication passages 67. In this embodiment, the multiple nozzles 21 are arranged in a row along the X-axis direction. One row of nozzles consisting of nozzles 21 arranged in parallel along the X-axis direction is provided. The material of the nozzle plate 20 is not particularly limited, and for example, a silicon substrate can be used.

[0052] The case member 40 is laminated on the second surface 62 of the communication plate 60 and is located in the -Z direction relative to the second surface 62. It is a component that forms part of the common flow path 90, which will be described later. In a plan view in the +Z direction, the case member 40 has almost the same shape as the communication plate 60. The case member 40 can be made of metal, resin, or the like. The case member 40 is provided with a first common liquid chamber 41 and a second common liquid chamber 42.

[0053] The first common liquid chamber 41 is a recess opening on the +Z side of the case member 40, and this opening communicates with a part of the first through hole 63. Of the first through hole 63, the portion connected to the first common liquid chamber 41 is the second portion 63b, and the portion closed off by the +Z side surface of the case member 40 is the first portion 63a. That is, the first through hole 63 has a second portion 63b that connects to the first common liquid chamber 41, and a first portion 63a that connects to the second portion 63b and is closed off by the +Z side surface of the case member 40. The second portion 63b is the portion that is not closed off by the +Z side surface of the case member 40. The second portion 63b is the portion that overlaps with the first common liquid chamber 41 in the Z-axis direction, and the first portion 63a is the portion that does not overlap with the first common liquid chamber 41 in the Z-axis direction.

[0054] The second common liquid chamber 42 is a recess opening on the +Z side of the case member 40, and this opening communicates with a part of the third through hole 65. Of the third through hole 65, the portion connected to the second common liquid chamber 42 is the fourth portion 65b, and the portion closed off by the +Z side of the case member 40 is the third portion 65a. That is, the third through hole 65 has a fourth portion 65b that connects to the second common liquid chamber 42, and a third portion 65a that connects to the fourth portion 65b and is closed off by the +Z side of the case member 40. The fourth portion 65b is the portion of the case member 40 that is not closed off by the +Z side. The fourth portion 65b is the portion that overlaps with the second common liquid chamber 42 in the Z-axis direction, and the third portion 65a is the portion that does not overlap with the second common liquid chamber 42 in the Z-axis direction.

[0055] The case member 40 is laminated on the second surface 62 of the communication plate 60 and has a case opening 43, which is a through hole larger than the pressure chamber substrate 10 in a plan view in the +Z direction. The pressure chamber substrate 10 is positioned inside the case opening 43. A gap G is provided between the pressure chamber substrate 10 and the inner circumferential surface of the case opening 43. The gap G is the gap in the Y-axis direction between the pressure chamber substrate 10 and the inner circumferential surface of the case opening 43 when viewed in the X-axis direction. In this embodiment, gaps G are provided on both sides of the pressure chamber substrate 10 in the Y-axis direction. The gap G on the +Y direction side is also called gap GR, and the gap G on the -Y direction side is also called gap GL. The gap GR is positioned in the +Y direction of the pressure chamber substrate 10, and the case member 40 is positioned in the +Y direction of gap GR. The gap GL is positioned in the -Y direction of the pressure chamber substrate 10, and the case member 40 is positioned in the -Y direction of gap GL.

[0056] The case member 40 is provided with an inlet 44a and an outlet 44b. The inlet 44a and outlet 44b are provided openings on the face of the case member 40 facing the -Z direction. The inlet 44a is a flow path connecting the first common liquid chamber 41 and the supply flow path 400. The outlet 44b is a flow path connecting the second common liquid chamber 42 and the recovery flow path 410.

[0057] A compliance substrate 45 is provided on the +Z direction side of the communication plate 60. The compliance substrate 45 has a flexible member 46 and a support 47. The flexible member 46 is made of a flexible thin film. The flexible member 46 is laminated on the first surface 61 of the communication plate 60 and defines a first recess 71, a second recess 72, a first through hole 63, a second through hole 64, a third through hole 65, and a fourth through hole 66. That is, the openings on the +Z direction side of the first recess 71, the second recess 72, the first through hole 63, the second through hole 64, the third through hole 65, and the fourth through hole 66 are sealed by the flexible member 46. The support 47 is made of a hard material such as metal and is a member that fixes the flexible member 46 to the communication plate 60. The support 47 has openings 48, which are through holes, provided in the parts facing the first through hole 63 and the third through hole 65. In other words, the opening 48 is positioned in the +Z direction of the first through hole 63 and the third through hole 65. The support 47 is positioned in the +Z direction of at least the first recess 71 and the second recess 72, sandwiching the flexible member 46. Although not specifically shown, the flexible member 46 is bonded to the communication plate 60, and the support 47 is bonded to the flexible member 46. Of course, the fixing of the flexible member 46 and the support 47 is not limited to bonding, and they may be fixed by other known means.

[0058] In this embodiment, the support 47 is positioned not only in the first recess 71 and the second recess 72, but also in the +Z direction of the partition wall 75, the second through hole 64, the fourth through hole 66, and the opening edge of the first through hole 63. The portion of the flexible member 46 exposed to the opening 48 is the compliance portion 49. That is, the support 47 defines a flexible compliance portion 49 inside the opening 48. A cover 220 is joined to the surface of the compliance substrate 45 facing the +Z direction. The space between the cover 220 and the flexible member 46 is open to the atmosphere (not shown), and the compliance portion 49 of the flexible member 46 is deformable in accordance with the pressure of the ink applied to the compliance portion 49.

[0059] The pressure chamber substrate 10 and case member 40 are laminated on the second surface 62 of the communication plate 60, and the nozzle plate 20 and compliance substrate 45 are laminated on the first surface 61 of the communication plate 60, thereby forming individual channels 80 and common channels 90.

[0060] The individual flow path 80 is a flow path that communicates individually with a plurality of nozzles 21, and in this embodiment, the individual flow path 80 has a supply individual flow path 81 and a recovery individual flow path 82. The supply individual flow path 81 is a flow path that supplies ink to the nozzles 21, and is a flow path formed for each nozzle 21. Specifically, the supply individual flow path 81 has a space defined by a first recess 71, a second through hole 64, a pressure chamber 12, and a nozzle communication passage 67. The recovery individual flow path 82 is a flow path that recovers ink that was not ejected from the nozzles 21, and is a flow path formed for each nozzle 21. Specifically, the recovery individual flow path 82 has a connecting flow path 68, a detection chamber 13, a fourth through hole 66, and a second recess 72.

[0061] The common flow path 90 is a flow path that communicates with multiple individual flow paths 80 in common, and in this embodiment, the common flow path 90 has a supply common flow path 91 and a recovery common flow path 92. The supply common flow path 91 is a flow path that communicates with multiple individual supply flow paths 81. Specifically, it has a first common liquid chamber 41 and a first through-hole 63. The recovery common flow path 92 is a flow path that communicates with multiple individual recovery flow paths 82. Specifically, it has a third through-hole 65 and a second common liquid chamber 42.

[0062] The common channel 90 is illustrated in an example where one channel is provided that is in common with multiple individual channels 80, but it is not limited to this configuration. For example, multiple common channels 90 may be provided, and multiple individual channels may be connected to each of the multiple common channels 90. The configuration illustrated in the example where each of the multiple individual channels 80 supplies ink to one nozzle 21 is not limited to this configuration. For example, each of the multiple individual channels 80 may be configured to supply ink to two or more nozzles 21. Each of the multiple individual channels 80 is provided with a pressure chamber 12 and a detection chamber 13, but the detection chamber 13 does not need to be provided in all individual channels 80; the detection chamber 13 may be provided in only some of the individual channels 80, or not all of the individual channels 80 may be provided with a detection chamber 13.

[0063] The diaphragm 50 is provided on the -Z direction surface of the pressure chamber substrate 10 and seals the openings on the -Z direction side of the pressure chamber 12 and the detection chamber 13. The diaphragm 50 is composed of, for example, an elastic film made of silicon oxide provided on the pressure chamber substrate 10 side (not specifically shown), and an insulating film made of zirconium oxide provided on the surface of the elastic film facing the -Z direction. In this embodiment, the diaphragm 50 is common to the first piezoelectric element 51 and the second piezoelectric element 52, but is not limited thereto. The laminated structure, including film thickness and material, may differ for each of the first piezoelectric element 51 and the second piezoelectric element 52. Furthermore, the diaphragm 50 and the pressure chamber substrate 10 may be formed as a single unit.

[0064] The first piezoelectric element 51 is used as a driving element that generates vibrations in the diaphragm 50 by applying a voltage between its electrodes, thereby causing a pressure change in the ink in the pressure chamber 12. The second piezoelectric element 52 is used as a detection element that detects the vibrations applied to the diaphragm 50. The first piezoelectric element 51 comprises a first electrode 53 sequentially stacked on the diaphragm 50 in the -Z direction, a piezoelectric layer 54 made of a piezoelectric material consisting of a composite oxide with a perovskite structure represented by, for example, the general formula ABO3, and a second electrode 55. The second piezoelectric element 52 has the same configuration as the first piezoelectric element 51. The first piezoelectric element 51 and the second piezoelectric element 52 refer to the portion including the first electrode 53, the piezoelectric layer 54, and the second electrode 55. The portion in the piezoelectric layer 54 where piezoelectric strain occurs when a voltage is applied between the first electrode 53 and the second electrode 55 is called the active portion 56. In contrast, the portion in the piezoelectric layer 54 where piezoelectric strain does not occur is called the inactive portion. In other words, the active portion 56 is the part of the piezoelectric layer 54 sandwiched between the first electrode 53 and the second electrode 55. In this embodiment, an active portion 56 is formed for each pressure chamber 12 and each detection chamber 13. That is, the first piezoelectric element 51 has multiple active portions 56 arranged in the X-axis direction so as to face multiple pressure chambers 12 arranged in the X-axis direction. Similarly, the second piezoelectric element 52 has multiple active portions 56 arranged in the X-axis direction so as to face multiple detection chambers 13 arranged in the X-axis direction. Generally, one electrode of the active portion 56 is configured as an individual electrode independent of each active portion 56, and the other electrode is configured as a common electrode common to multiple active portions 56. In this embodiment, the first electrode 53 constitutes an individual electrode, and the second electrode 55 constitutes a common electrode.

[0065] Individual lead electrodes 57, which are lead wires, are drawn out from the first electrodes 53 of the first piezoelectric element 51 and the second piezoelectric element 52. A common lead electrode (not shown), which is a lead wire, is drawn out from the second electrode 55. A wiring member 110 made of a flexible substrate is connected to the ends of these individual lead electrodes 57 and the common lead electrode opposite to the ends connected to the first piezoelectric element 51 and the second piezoelectric element 52. A drive circuit 111 is mounted on the wiring member 110, which has multiple switching elements that select whether or not to supply a drive signal (COM) to each active part 56 of the first piezoelectric element 51 to drive each active part 56. Also, detection signals corresponding to vibrations generated in the second piezoelectric element 52 are transmitted to the control unit 4 via the wiring member 110. Although such a wiring member 110 is a COF (Chip On Film), the wiring member 110 does not necessarily have to be provided with a drive circuit 111. In other words, the wiring member 110 may be an FFC (Flexible Flat Cable), an FPC (Flexible Printed Circuits), etc.

[0066] A protective substrate 30, having approximately the same size as the pressure chamber substrate 10, is bonded to the surface of the pressure chamber substrate 10 facing the -Z direction. The protective substrate 30 has a first housing section 31 and a second housing section 32, which are spaces for protecting the first piezoelectric element 51 and the second piezoelectric element 52. The first housing section 31 houses a plurality of first piezoelectric elements 51 arranged in the X-axis direction, and the second housing section 32 houses a plurality of second piezoelectric elements 52 arranged in the X-axis direction. The protective substrate 30 is provided with a through hole 33 that penetrates in the Z-axis direction between the first housing section 31 and the second housing section 32. The ends of the individual lead electrodes 57 and the common lead electrode drawn from the electrodes of the first piezoelectric element 51 and the second piezoelectric element 52 extend so as to be exposed in this through hole 33, and the individual lead electrodes 57 and the common lead electrode and the wiring member 110 are electrically connected in the through hole 33. Such a protective substrate 30 is made of, for example, a silicon substrate.

[0067] In this liquid spray head unit 2, ink is supplied to the supply channel 400 of the flow channel structure 200 connected to the sub-tank 3b. Foreign matter such as dust and air bubbles contained in the ink is removed by a filter 406 provided in the flow channel structure 200 and supplied to the common supply channel 91 via the inlet 44a of the liquid spray head H. Ink is supplied from the common supply channel 91 to each of the multiple individual supply channels 81. According to the recording signal from the drive circuit 111, a voltage is applied to the active part 56 of each first piezoelectric element 51 corresponding to the pressure chamber 12. As a result, the diaphragm 50 flexes and deforms together with the active part 56, increasing the ink pressure in each pressure chamber 12, and ink droplets are ejected from each nozzle 21. Ink that is not ejected from the nozzle 21 flows through the individual recovery channel 82 and merges in the common recovery channel 92, and is recovered from the common recovery channel 92 to the sub-tank 3b via the outlet 44b and the recovery channel 410.

[0068] The liquid spray head H described above comprises a flow path member 100 having a plurality of nozzles 21 that spray liquid such as ink in the +Z direction, a plurality of individual flow paths 80 that communicate individually with the plurality of nozzles 21, and a common flow path 90 that communicates in common with the plurality of individual flow paths 80. The flow path member 100 is a pressure chamber substrate 10 which is part of the individual flow paths 80 and is provided with a pressure chamber 12 into which pressure is applied to the ink in order to spray the ink, and a communication plate 60 which is part of the individual flow paths 80 and is provided with a nozzle communication passage 67 that connects the nozzles 21 and the pressure chamber 12, and is a surface in the -Z direction. The pressure chamber substrate 10 has a communication plate 60 having a second surface 62, and the pressure chamber substrate 10 is laminated on the second surface 62, and in the Y-axis direction which is perpendicular to the +Z and -Z directions of the pressure chamber substrate 10, a case member 40 located in the -Z direction relative to the second surface 62 is arranged on the second surface 62 via a gap GR, and the communication plate 60 has a plurality of first recesses 71 that are recessed from the first surface 61 of the communication plate 60 to the first bottom surface 73a located between the first surface 61 and the second surface 62, and a portion of the first recesses 71 overlap with the gap G when viewed in the +Z direction, and the space defined by the first recesses 71 is part of the individual flow path 80.

[0069] In other words, the liquid injection head H is characterized in that, among the flow paths provided in the communication plate 60, the flow path that overlaps with the gap GR between the pressure chamber substrate 10 and the case member 40 in the Z-axis direction is a space defined by the first recess 71 and is part of the individual flow path 80.

[0070] If the gap GR between the pressure chamber substrate 10 and the case member 40 and the flow path overlapping in the Z-axis direction are not defined by the first recess 71, but are instead made part of a common flow path 90 common to each nozzle 21, then the partition wall 75 shown in Figure 8 does not exist, and a part of a single common flow path common to each nozzle 21 is located in the connecting plate. In such a configuration, the rigidity of the connecting plate 60 is relatively low.

[0071] On the other hand, in this embodiment, the liquid injection head H can improve the rigidity of the communication plate 60 by providing the first recess 71 as part of the individual flow path 80 in the communication plate 60, thereby suppressing deformation and cracking of the communication plate 60 when an external force, such as a collision with the medium S, is applied to the +Z direction side of the liquid injection head H. When the communication plate 60 is formed from a single-crystal silicon substrate, it is relatively prone to cracking. However, even when using such a communication plate 60, the rigidity can be improved by the first recess 71 as described above.

[0072] Furthermore, as described in the section on conventional technology, it is desirable to eject ink at high speed without reducing the amount of ink ejected, and to achieve this, shortening the flow path length from the pressure chamber 12 to the nozzle 21 is effective. The reason for this is as follows: In order to eject ink at high speed, it is necessary to shorten the natural oscillation period Tc inside the pressure chamber, which is expressed by the following equation. Tc = 2π√{M(C1+C2)} The natural vibration period Tc is proportional to the inertance M due to the weight of the ink in the flow path, the compliance C1 of the flow path, and the compliance C2 of the diaphragm 50. C1 is proportional to the volume of the ink. While C2 can be reduced by making the diaphragm 50 stiffer, this reduces the amount of ink ejected because the diaphragm 50 becomes less deformable. Therefore, by shortening the flow path length from the +Z-direction side surface of the diaphragm 50 to the nozzle 21, and in the above embodiment, the flow path lengths of the pressure chamber 12 and the nozzle communication passage 67, the weight and volume of the ink can be reduced, thereby decreasing the inertance M and C1 due to the weight of the ink, and thus reducing the natural vibration period Tc. In order to shorten the flow path length from the +Z-direction side surface of the diaphragm 50 to the nozzle 21 as much as possible, it is necessary to reduce the width of the communication plate 60 in the Z-axis direction. In other words, it is necessary to make the communication plate 60 thinner. If the connecting plate 60 is made thinner, the width of the first wall portion 73 and the second wall portion 74 in the Z-axis direction must also be made smaller than in the conventional design, which may reduce the rigidity of the first wall portion 73 and the second wall portion 74.

[0073] For these reasons, even when a thin connecting plate 60 is used, the liquid injection head H of this embodiment can ensure rigidity compared to a configuration in which a part of the common flow path 90 is provided, by providing the first recess 71 as part of the individual flow path 80 in the connecting plate 60.

[0074] In this embodiment, ink is supplied to the nozzle 21 from the common supply channel 91, and any un-ejected ink is recovered via the common recovery channel 92, thereby circulating the ink. However, the present invention is not limited to this configuration. That is, the present invention can also be applied to a liquid spray head that does not have an individual recovery channel 82 or a common recovery channel 92, and does not recover any ink that is not ejected from the nozzle 21. Note that the +Z direction is an example of a "first direction", the -Z direction is an example of a "second direction", and the Y-axis direction is an example of a "third direction". The nozzle communication passage 67 is an example of a "channel that connects the nozzle and the pressure chamber". The case member 40 is an example of a "channel section". The first recess 71 is an example of a "first recess", but the second recess 72 may be an example of a "first recess".

[0075] In the liquid injection head H of this embodiment, the communication plate 60 has a first through hole 63 and a second through hole 64 that penetrate from the first surface 61 to the second surface 62, a first wall portion 73 which is located between the first through hole 63 and the second through hole 64 and is located between the second surface 62 and the first bottom surface 73a on the same plane, and a plurality of partition walls 75 which are located in the +Z direction from the first wall portion 73 and separate a plurality of adjacent first recesses 71. The first through hole 63 defines a part of the common flow path 90, the second through hole 64 defines a part of the individual flow path 80, and the first recesses 71 connect the first through hole 63 and the second through hole 64. The first wall portion 73 is an example of "a wall portion which is located between the first through hole and the second through hole and is located between the second surface and the bottom surface on the same plane."

[0076] In the liquid spray head H of this embodiment, the multiple first recesses 71 are arranged in the X-axis direction, and the width W1 of the first recesses 71 in the X-axis direction is greater than the width W2 of the partition wall 75 in the X-axis direction. By making the width W2 of the partition wall 75 smaller and increasing the width W1 of the first recesses 71, which are part of the individual flow path 80, the pressure loss of ink due to the narrowing of the width of the individual flow path 80 can be reduced. Even if the width W2 of the partition wall 75 is small, the effect of the reduction in rigidity of the first wall portion 73 is small because there are multiple partition walls 75. Note that the X-axis direction is an example of the "fourth direction". Also, the width W1 is not limited to being greater than the width W2, and the width W1 may be less than or equal to the width W2.

[0077] In the liquid spray head H of this embodiment, the width of the partition wall 75 in the X-axis direction is smaller the closer it is to the first through-hole 63. By forming the first recess 71 as part of the individual flow path 80 in the first wall portion 73 of the communication plate 60 facing the gap GR, the flow path cross-sectional area is smaller compared to a configuration in which part of the individual flow path 80 is not provided, making it difficult for ink to flow from the common supply flow path 91 to each first recess 71. However, the width of the partition wall 75 is made smaller the closer it is to the first through-hole 63. In other words, the width of the first recess 71 in the X-axis direction widens toward the common supply flow path 91, and the cross-sectional area of ​​the first recess 71 increases, making it easier for ink to flow from the common supply flow path 91 to each first recess 71. Similarly, the ability to discharge bubbles from the common supply flow path 91 to the individual supply flow paths 81 can be improved. In addition, the pressure loss of the ink can be reduced.

[0078] In the liquid injection head H of this embodiment, a flexible member 46 having flexibility is stacked in the +Z direction of the communication plate 60 and defines a plurality of first recesses 71, a first through hole 63, and a second through hole 64, and a support 47 is stacked in the +Z direction of the flexible member 46 and fixes the flexible member 46, the support 47 being positioned in the +Z direction of the first recess 71 with the flexible member 46 in between.

[0079] As described in the prior art section, as the connecting plate 60 is thinned, a portion of the individual flow channels 80 defined in the first recess 71 is also thinned, so there is a risk that the flexible member 47 will bend and deform toward the individual flow channels 80, potentially blocking them. However, in the liquid spray head H of this embodiment, a support 47 is positioned in the +Z direction of the first recess 71 with a flexible member 46 in between. This support 47 can suppress the deformation of a portion of the flexible member 46 that defines the first recess 71, thus preventing a portion of the individual flow channels 80 formed by the first recess 71 from being blocked by the flexible member 46. Furthermore, the positioning of the support 47 with the flexible member 46 in between in the +Z direction of the first recess 71 increases the rigidity of the individual flow channels. In addition, the opening 48 formed in the support 47 is located in the +Z direction of the first through hole 63. Therefore, the flexible member 46 can deform in the first through hole 63. This allows the ink pressure fluctuations to be absorbed in the first through hole 63.

[0080] In the liquid injection head H of this embodiment, the first through-hole 63 has a second portion 63b that connects to a first common liquid chamber 41 provided in the case member 40, and a first portion 63a that connects to the second portion 63b and is closed off by the +Z direction surface of the case member 40.

[0081] In this type of liquid injection head H, the first portion 63a of the first through-hole 63 is part of the common flow path 90 rather than part of the individual flow path 80. Therefore, compared to a configuration in which the first recess 71 extends in the Y-axis direction to the boundary between the first portion 63a and the second portion 63b, and the first recess 71 is also formed in the first portion 63a, the width of the first recess 71 in the Y-axis direction can be reduced. This reduces the pressure loss of ink in the first recess 71. Also, the width of the supply common flow path 91 in the Y-axis direction can be increased due to the presence of the first portion 63a. As a result, the flexible member 46 can be deformed not only in the second portion 63b but also in the first portion 63a, increasing the absorption of pressure fluctuations of ink in the first through-hole 63. Note that the first through-hole 63 has a first portion 63a and a second portion 63b, but is not limited to this configuration. The entire opening of the first through-hole 63 may communicate with the first common liquid chamber portion 41 of the case member 40, meaning that it may consist only of the second portion 63b.

[0082] In the liquid spray head H of this embodiment, the communication plate 60 has a plurality of second recesses 72 that are recessed from the first surface 61 to the second bottom surface 74a located between the first surface 61 and the second surface 62, and a portion of the second recesses 72 overlap with the gap GL when viewed in the +Z direction. The individual flow path 80 has a supply individual flow path 81 that supplies ink to the nozzle 21 and a recovery individual flow path 82 that recovers ink that was not sprayed from the nozzle 21. The common flow path 90 has a supply common flow path 91 that communicates with the plurality of supply individual flow paths 81 and a recovery common flow path 92 that communicates with the plurality of recovery individual flow paths 82. Either the space defined by the first recess 71 or the space defined by the second recess 72 is a part of the supply individual flow path 81, and the other is a part of the recovery individual flow path 82. The supply individual flow path 81 is an example of the "space defined by the first recess," and the recovery individual flow path 82 is an example of the "space defined by the second recess."

[0083] In the liquid injection head H of this embodiment, the width W3 in the +Z direction from the second surface 62 to the first bottom surface 73a, i.e., the width W3 of the first wall portion 73, is smaller than the width W4 in the +Z direction of the pressure chamber substrate 10. Also, in the liquid injection head H of this embodiment, the flow path member 100 has a nozzle plate 20 provided with a plurality of nozzles 21, and the width W3 in the +Z direction from the second surface 62 to the first bottom surface 73a is smaller than the width W5 in the +Z direction of the nozzle plate 20. Thus, the width W3 of the first wall portion 73 of the communication plate 60 is thinner than the pressure chamber substrate 10 and the nozzle plate 20, and is relatively prone to cracking. However, as described above, rigidity can be improved by forming a plurality of first recesses 71.

[0084] In the liquid spray head H of this embodiment, the width W3 in the +Z direction from the second surface 62 to the first bottom surface 73a is less than or equal to the width W6 in the +Z direction of the first recess 71. If the cross-sectional area of ​​a part of the individual flow path 80 defined in the first recess 71 is small, the pressure loss of the ink will increase. Therefore, by reducing the width W3 of the first wall portion 73 to less than or equal to the width W6 of the first recess 71, the width of the first recess 71 in the +Z direction will increase, and the pressure loss of the ink can be reduced.

[0085] In the liquid spray head H of this embodiment, the width W3 in the +Z direction from the second surface 62 to the first bottom surface 73a is 150 μm or less. Note that 150 μm is an example, and it is more preferable to have a width of 80 μm or more and 150 μm or less.

[0086] Although one embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to that described above.

[0087] In the above-described embodiment, the liquid injection head H consists of a case member 40 and a connecting plate 60, which are separate components. However, as shown in the modified example in Figure 9, they may be composed of a single integrated component. Here, "composed of a single integrated component" means that no adhesive layer made of resin is placed between the case member 40 and the connecting plate 60, while "separate components" means that an adhesive layer made of resin is placed between the case member 40 and the connecting plate 60. Examples of cases where no adhesive layer made of resin is placed between the case member 40 and the connecting plate 60 include cases where solid-phase diffusion bonding is used, or where the case member 40 and the connecting plate 60 are integrally formed using the same mold, so that no layer different from the case member 40 or the connecting plate 60 is placed between them. It also includes cases where a layer of silicon oxide is placed between the case member 40, which is made of single-crystal silicon, and the connecting plate 60, which is also made of single-crystal silicon. In this case, where the case member 40 and the communication plate 60 are composed of a single integrated member, the communication plate 60 refers to the portion of the member on which the pressure chamber substrate 10 is laminated on the second surface 62, specifically the portion located in the +Z direction relative to the second surface 62. The case member 40, on the other hand, refers to the portion located in the -Z direction relative to the second surface 62.

[0088] In the embodiments described above, a circulating liquid spray head unit 2 was illustrated, which supplies ink from the liquid storage unit 3 and recovers ink that was not sprayed from the liquid spray head unit 2. However, the present invention is not limited to this, and can also be applied to a liquid spray head unit 2 that does not recover ink.

[0089] In the embodiments described above, a thin-film piezoelectric actuator was used as the pressure generating means for creating a pressure change in the pressure chamber 12. However, the invention is not limited to this, and for example, a thick-film piezoelectric actuator formed by attaching a green sheet or a longitudinal vibration type piezoelectric actuator that expands and contracts in the axial direction by alternately stacking piezoelectric material and electrode-forming material can be used. Furthermore, as the pressure generating means, a so-called electrostatic actuator can be used, which generates static electricity between a diaphragm and an electrode, deforming the diaphragm with electrostatic force and ejecting droplets from the nozzle opening.

[0090] Furthermore, while the liquid jetting device 1 described above is exemplified in which the liquid jetting head unit 2 is mounted on a holder 6a and moves in the Y-axis direction, which is the main scanning direction, the present invention is not limited to this. For example, the present invention can also be applied to a so-called line-type recording device in which the liquid jetting head unit 2 is fixed and printing is performed simply by moving a medium S such as paper in the X-axis direction.

[0091] Furthermore, the present invention broadly applies to liquid injection heads in general, and can be applied to recording heads such as various inkjet recording heads used in image recording devices such as printers, colorant injection heads used in the manufacture of color filters for liquid crystal displays, electrode material injection heads used in electrode formation for organic EL displays and FEDs (field emission displays), and bio-organic material injection heads used in biochip manufacturing.

[0092] (Note) From the forms exemplified above, the following configuration can be understood, for example.

[0093] A liquid spray head according to Embodiment 1, a preferred embodiment, comprises a flow path member having a plurality of nozzles for spraying liquid in a first direction, a plurality of individual flow paths communicating individually with the plurality of nozzles, and a common flow path communicating commonly with the plurality of individual flow paths, wherein the flow path member comprises a pressure chamber substrate which is part of the individual flow paths and is provided with a pressure chamber for which pressure is applied to the liquid in order to spray the liquid, and a communication plate which is part of the individual flow paths and is provided with a flow path that communicates the nozzles and the pressure chamber, the surface of which is the second direction which is the opposite direction to the first direction The device comprises a connecting plate having two surfaces, wherein the pressure chamber substrate is laminated on the second surface, and in the third direction, which is perpendicular to the first and second directions of the pressure chamber substrate, flow channels located in the second direction relative to the second surface are arranged with gaps between them, and the connecting plate has a plurality of first recesses that extend from the first surface, which is the surface of the connecting plate in the first direction, to the bottom surface located between the first surface and the second surface, and a portion of the first recesses overlaps with the gap when viewed in the first direction, and the space defined by the first recesses is part of the individual flow channels. According to this, by providing the first recesses as part of the individual flow channels in the connecting plate, the rigidity of the connecting plate can be improved, and deformation and cracking of the connecting plate when an external force such as a collision with a medium is applied to the surface on the first direction side of the liquid injection head can be suppressed.

[0094] In Embodiment 2, which is a specific example of Embodiment 1, the communication plate has a first through-hole and a second through-hole that penetrate from the first surface to the second surface, a wall portion which is a portion located between the first through-hole and the second through-hole and is located between the second surface and the bottom surface on the same plane, and a plurality of partition walls which are located in the first direction from the wall portion and separate adjacent plurality of first recesses, the first through-hole defines a part of the common flow path, the second through-hole defines a part of the individual flow path, and the first recess connects the first through-hole and the second through-hole.

[0095] In embodiment 3, which is a specific example of embodiment 2, the plurality of first recesses are arranged in a fourth direction intersecting the first and third directions, and the width of the first recesses in the fourth direction is greater than the width of the partition wall in the fourth direction. This reduces the liquid pressure loss due to the narrowing of the width of the partition wall and increases the width of the first recesses, which are part of the individual flow channels. Even if the width of the partition wall is small, the effect of reduced rigidity of the wall is small because there are multiple partition walls.

[0096] In Embodiment 4, which is a specific example of Embodiment 2, the width of the partition wall in the fourth direction intersecting the first and third directions is smaller the closer it is to the first through-hole. As a result, by forming the first recess as part of the individual flow path in the wall portion facing the gap of the connecting plate, the flow path cross-sectional area is smaller compared to a configuration in which part of the individual flow path is not provided, making it difficult for liquid to flow from the common supply flow path into each first recess. However, the width of the partition wall is smaller the closer it is to the first through-hole. In other words, the width of the first recess in the fourth direction widens toward the common supply flow path, and the cross-sectional area of ​​the first recess increases, making it easier for liquid to flow into the first recess. Similarly, the ability to discharge bubbles from the common supply flow path to the individual supply flow paths can be improved. Furthermore, the pressure loss of the liquid can be reduced.

[0097] In embodiment 5, which is a specific example of embodiment 2, the communication plate is laminated in the first direction and comprises a flexible member having flexibility that defines the plurality of first recesses, the first through-hole, and the second through-hole, and a support that is laminated in the first direction of the flexible member and fixes the flexible member, wherein the support is arranged in the first direction of the first recess. With this, the support can suppress deformation of a portion of the flexible member that defines the first recess, so that a portion of the individual flow channels formed by the first recess is not blocked by the flexible member. In addition, the rigidity of the individual flow channels is increased by arranging the support with the flexible member in between in the first direction of the first recess. Furthermore, no support is arranged in the first direction of the first through-hole. Therefore, the flexible member can be deformed in the first through-hole. This allows pressure fluctuations of the liquid to be absorbed in the first through-hole.

[0098] In embodiment 6, which is a specific example of embodiment 2, the first through-hole has a second portion that connects to a flow path provided in the flow path section, and a first portion that connects to the second portion and is closed to the first direction surface of the flow path section. This makes it possible to reduce the pressure loss of the liquid in the first recess. Furthermore, the flexible member can be deformed not only in the second portion but also in the first portion, which increases the absorption of pressure fluctuations of the liquid in the first through-hole.

[0099] In Embodiment 7, which is a specific example of Embodiment 1, the communication plate and the flow path are made of a single integrated member.

[0100] In embodiment 8, which is a specific example of embodiment 1, the communication plate has a plurality of second recesses that are recessed from the first surface to the bottom surface located between the first surface and the second surface, and a portion of the second recesses overlaps with the gap when viewed in the first direction, the plurality of individual channels have a supply individual channel for supplying liquid to the nozzle and a recovery individual channel for recovering liquid that was not sprayed from the nozzle, the common channel has a supply common channel that communicates with the plurality of supply individual channels and a recovery common channel that communicates with the plurality of recovery individual channels, and either the space defined by the first recesses or the space defined by the second recesses is the supply individual channel and the other is the recovery individual channel.

[0101] In embodiment 9, which is a specific example of embodiment 1, the width in the first direction from the second surface to the bottom surface is smaller than the width of the pressure chamber substrate in the first direction.

[0102] In embodiment 10, which is a specific example of embodiment 1, the flow path member has a nozzle plate on which the plurality of nozzles are provided, and the width in the first direction from the second surface to the bottom surface is smaller than the width of the nozzle plate in the first direction.

[0103] In embodiment 11, which is a specific example of embodiment 1, the width in the first direction from the second surface to the bottom surface is less than or equal to the width of the first recess in the first direction. According to this, by reducing the width of the first wall to less than or equal to the width of the first recess, the width of the first recess in the first direction increases, and pressure loss can be reduced.

[0104] In embodiment 12, which is a specific example of embodiment 1, the width in the first direction from the second surface to the bottom surface is 150 μm or less.

[0105] A liquid injection device according to embodiment 13, which is a preferred embodiment, comprises a liquid injection head described in any one of embodiments 1 to 12 above, and a liquid reservoir that supplies liquid to the liquid injection head. This provides a liquid injection device that can improve the rigidity of the communication plate and suppress deformation and cracking of the communication plate when an external force such as a collision with a medium is applied to the first direction side surface of the liquid injection head. [Explanation of Symbols]

[0106] G, GL, GR…Gap, H, Ha, Hb…Liquid injection head, S…Media, 1…Liquid injection device, 2…Liquid injection head unit, 3…Liquid reservoir, 10…Pressure chamber substrate, 12…Pressure chamber, 13…Detection chamber, 20…Nozzle plate, 21…Nozzle, 40…Case member (flow channel section), 41…First common liquid chamber section, 42…Second common liquid chamber section, 45…Compliance substrate, 46…Flexible member, 47…Support, 50…Vibrating plate, 51…First piezoelectric element, 52…Second piezoelectric element, 56…Activated section, 60…Communicating plate, 61…First surface, 62…Second surface, 63…First through hole, 63a… Part 1, 63b… Part 2, 64… Second through hole, 64a… Row of second through holes, 65… Third through hole, 65a… Part 3, 65b… Part 4, 66… Fourth through hole, 66a… Row of fourth through holes, 67… Nozzle connecting passage, 68… Connecting passage, 71… First recess, 72… Second recess, 73… First wall, 73a… First bottom surface, 74… Second wall, 74a… Second bottom surface, 75… Partition wall, 80… Individual passage, 81… Supply individual passage, 82… Recovery individual passage, 90… Common passage, 91… Supply common passage, 92… Recovery common passage, 100… Passageway member, 400… Supply passage, 410… Recovery passage

Claims

1. The flow path member comprises a plurality of nozzles for spraying liquid in a first direction, a plurality of individual flow paths communicating individually with the plurality of nozzles, and a common flow path communicating in common with the plurality of individual flow paths. The aforementioned flow channel member is A pressure chamber substrate, which is part of the aforementioned individual flow path and is provided with a pressure chamber in which pressure is applied to the liquid in order to inject the liquid, A communicating plate which is part of the individual flow path and is provided with a flow path that connects the nozzle and the pressure chamber, and which has a second surface which is a surface in a second direction opposite to the first direction, The pressure chamber substrate is laminated on the second surface, In the third direction, which is perpendicular to the first direction of the pressure chamber substrate, a flow channel is arranged with a gap between it and the second surface, which is located in the second direction. The communication plate has a plurality of first recesses that extend from the first surface, which is the surface of the communication plate in the first direction, to the bottom surface located between the first surface and the second surface, and a portion of the first recesses overlaps with the gap when viewed in the first direction. The space defined by the first recess is part of the individual flow path. A liquid spray head characterized by the following features.

2. The aforementioned communication plate is, A first through-hole and a second through-hole that penetrate from the first surface to the second surface, A portion located between the first through hole and the second through hole, comprising a wall portion located between the second surface and the bottom surface on the same plane, It has a plurality of partition walls that are arranged in the first direction from the wall portion and separate the plurality of adjacent first recesses, The first through-hole defines a portion of the common flow path, and the second through-hole defines a portion of the individual flow paths. The first recess connects the first through hole and the second through hole. A liquid spray head according to feature 1.

3. The plurality of first recesses are arranged in a fourth direction intersecting the first and third directions, The width of the first recess in the fourth direction is greater than the width of the partition wall in the fourth direction. A liquid spray head according to feature 2.

4. The width of the partition wall in the fourth direction intersecting the first and third directions is smaller the closer it is to the first through-hole. A liquid spray head according to feature 2.

5. A flexible member having flexibility is stacked in the first direction of the communication plate and defines the plurality of first recesses, the first through-hole, and the second through-hole, The flexible member comprises a support that is stacked in the first direction of the flexible member and fixes the flexible member, The support is arranged in the first direction of the first recess, A liquid spray head according to feature 2.

6. The first through hole is, A second portion connected to a flow path provided in the aforementioned flow path section, It has a first portion which is connected to the second portion and is closed off to the first direction surface of the flow path portion, A liquid spray head according to feature 2.

7. The connecting plate and the flow path section are made of a single, integrated component. A liquid spray head according to feature 1.

8. The communication plate has a plurality of second recesses that are recessed from the first surface to the bottom surface located between the first surface and the second surface, and a portion of the second recesses overlaps with the gap when viewed in the first direction. Each of the aforementioned plurality of individual channels includes a supply channel for supplying liquid to the nozzle and a recovery channel for recovering liquid that was not ejected from the nozzle. The common flow path comprises a common supply flow path communicating with the plurality of individual supply flow paths, and a common recovery flow path communicating with the plurality of individual recovery flow paths. Either the space defined by the first recess or the space defined by the second recess is the supply channel, and the other is the recovery channel. A liquid spray head according to feature 1.

9. The width in the first direction from the second surface to the bottom surface is smaller than the width of the pressure chamber substrate in the first direction. A liquid spray head according to feature 1.

10. The flow path member has a nozzle plate on which the plurality of nozzles are provided, The width in the first direction from the second surface to the bottom surface is smaller than the width of the nozzle plate in the first direction. A liquid spray head according to feature 1.

11. The width in the first direction from the second surface to the bottom surface is less than or equal to the width of the first recess in the first direction. A liquid spray head according to feature 1.

12. The width in the first direction from the second surface to the bottom surface is 150 μm or less. A liquid spray head according to feature 1.

13. A liquid spray head according to any one of claims 1 to 12, A liquid storage unit that supplies liquid to the liquid injection head, A liquid injection device characterized by being equipped with the following features.

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