Liquid injection head and liquid injection device

Abstract

The present invention provides a liquid injection head and a liquid injection device that suppress damage to the substrates stacked to constitute the liquid injection head. [Solution] The device comprises a head chip 8, a holder 200 for holding the head chip 8, and a relay member 250. The head chip 8 includes a first flow path member 15, a pressure chamber substrate 10, a drive element 300, a flexible substrate 110 electrically connected to the drive element 300, a protective substrate 30, and a second flow path member 40 having an opening 43 into which the flexible substrate 110 is inserted, and is laminated on the first flow path member 15 at a different position from the pressure chamber substrate 10. The relay member 250 is inserted into the opening 43 of the second flow path member 40 and does not define a flow path through which liquid flows, and includes a contact portion 256 that contacts the upper surface 30a of the protective substrate 30 and a supported portion 255 that is supported by the holder 200.

Description

Technical Field

[0001] The present invention relates to a liquid injection head for injecting a liquid from a nozzle and a liquid injection device, and particularly to an inkjet recording head for discharging ink as the liquid and an inkjet recording device.

Background Art

[0002] A liquid injection head includes a head chip for injecting a liquid, a fixing plate to which a plurality of head chips are fixed, and a holder for holding the plurality of head chips between the fixing plate (see, for example, Patent Document 1). The head chip includes a nozzle plate in which nozzles for injecting droplets are formed, a communication plate for supplying the liquid to the nozzles, a pressure chamber substrate provided with pressure chambers communicating with the nozzles, a drive element provided on the pressure chamber substrate via a diaphragm, a protection substrate disposed above the pressure chamber substrate, and a case provided above the communication plate.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional liquid injection head, a space is provided between the upper surface of the protection substrate and the lower surface of the case so as not to adhere to each other. However, when the medium contacts the nozzle plate or the fixing plate of the liquid injection head due to poor conveyance of the medium or the like, and an external force is applied to the liquid injection head in a direction opposite to the liquid injection direction, the fixing plate is deformed with the portion fixed to the holder of the fixing plate as a fulcrum, or the nozzle plate is pushed upward to fill the space, so that the protection substrate is displaced with respect to the case, and there is a problem that the substrates constituting the liquid injection head are destroyed.

Means for Solving the Problems

[0005] An aspect of the present invention that solves the above problems comprises a first head tip having a nozzle for spraying liquid in a first direction, a holder arranged in a second direction opposite to the first direction and holding the first head tip, and a relay member, wherein the first head tip comprises a first flow path member having a flow path communicating with the nozzle, a pressure chamber substrate having a pressure chamber communicating with the nozzle and laminated in the second direction relative to the first flow path member, a driving element for causing a pressure change in the liquid in the pressure chamber, a flexible substrate electrically connected to the driving element, and the The liquid spray head is characterized by comprising: a protective substrate stacked in a second direction and housing the drive element; a second flow channel member having a flow channel communicating with the flow channel of the first flow channel member and an opening into which the flexible substrate is inserted, and being stacked in a second direction relative to the first flow channel member at a position different from that of the pressure chamber substrate; the intermediate member being inserted into the opening of the second flow channel member and not defining a flow channel through which liquid flows, and including a contact portion that contacts the upper surface of the protective substrate facing the second direction and a supported portion that is supported by the holder.

[0006] Another aspect of the present invention is a liquid injection device characterized by comprising a liquid injection head as described in the above aspect and a liquid storage unit for storing the liquid supplied to the liquid injection head. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows the schematic configuration of the liquid injection device according to Embodiment 1. [Figure 2] This is an exploded perspective view of the liquid injection head according to Embodiment 1. [Figure 3] This is a cross-sectional view of the liquid injection head according to Embodiment 1. [Figure 4] This is a perspective view of the relay member according to Embodiment 1. [Figure 5] This is an enlarged cross-sectional view of the main part of the liquid injection head according to Embodiment 1. [Figure 6]This is an exploded perspective view of the head chip according to Embodiment 1. [Figure 7] This is a plan view of the head chip according to Embodiment 1. [Figure 8] This is a cross-sectional view of the head tip and fixing plate according to Embodiment 1. [Figure 9] This is a perspective view of a relay member according to a modified example of Embodiment 1. [Figure 10] This is a cross-sectional view of the liquid injection head according to Embodiment 2. [Figure 11] This is a perspective view showing the main parts of the holder and relay member according to Embodiment 2 cut out. [Figure 12] This is a perspective view of the relay member according to Embodiment 3. [Figure 13] This is a cross-sectional view of the liquid injection head according to Embodiment 3. [Figure 14] This is a cross-sectional view illustrating a method for manufacturing a liquid injection head according to Embodiment 3. [Figure 15] This is a perspective view of a relay member according to a modified example of Embodiment 3. [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 directions of the three spatial axes that are not limited to positive and negative directions are described as the X-axis direction, Y-axis direction, and Z-axis direction.

[0009] (Embodiment 1) Figure 1 shows a schematic configuration of the liquid injection device 1 of the present invention.

[0010] As shown in the figure, the liquid injection device 1 is an inkjet recording device that injects and lands ink, which is a kind of liquid, as ink droplets onto a medium S such as printing paper, and performs printing such as an image by the arrangement of dots formed on the medium S. As the medium S, in addition to recording paper, any material such as a resin film or cloth can be used.

[0011] The liquid injection device 1 includes a liquid injection head 2, a liquid storage unit 3, a control unit 4 which is a control unit, a conveyance mechanism 5 that feeds out the medium S, and a moving mechanism 6.

[0012] The liquid injection head 2 injects the ink supplied from the liquid storage unit 3 onto the medium S from a plurality of nozzles 21 (see FIG. 3). The detailed configuration of the liquid injection head 2 will be described later.

[0013] The liquid storage unit 3 stores the ink ejected from the liquid injection head 2. Examples of the liquid storage unit 3 include a cartridge that is detachable from the liquid injection device 1, a bag-shaped ink pack formed of a flexible film, and an ink tank that can be refilled with ink. Although not particularly shown in the figure, for example, a plurality of types of inks having different colors, components, etc. are individually stored in the liquid storage unit 3.

[0014] In the present 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 injection head 2 and replenishes the ink consumed by ejecting ink droplets from the liquid injection head 2 from the main tank 3a to the sub-tank 3b. Of course, the liquid storage unit 3 may be composed of only the main tank 3a.

[0015] The liquid injection device 1 has a circulation mechanism 7 for circulating ink between the liquid injection head 2 and the sub-tank 3b.

[0016] The circulation mechanism 7 is configured to include a supply pump 7a, a circulation pump 7b, a sub-tank 3b, a recovery tube 7c, and a supply tube 7d.

[0017] 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 spray head 2.

[0018] The recovery tube 7c is a component that forms a channel for ink that is not used for printing by the liquid spray head 2 and is recovered into the sub-tank 3b. The supply tube 7d is a component that forms a channel for ink supplied from the sub-tank 3b to the liquid spray head 2.

[0019] Sub-tank 3b is a container that temporarily stores ink supplied from liquid storage unit 3. Sub-tank 3b also temporarily stores ink that is not used for printing by the liquid spray head 2 and is recovered via recovery tube 7c.

[0020] In this circulation mechanism 7, the circulation pump 7b supplies ink from the sub-tank 3b to the liquid spray head 2 via the supply tube 7d, and the ink not used by the liquid spray head 2 is recovered into the sub-tank 3b via the recovery tube 7c. This circulates ink between the liquid spray head 2 and the sub-tank 3b. Furthermore, when the amount of ink stored in the sub-tank 3b falls below a certain level, the supply pump 7a supplies ink from the main tank 3a to the sub-tank 3b.

[0021] The control unit 4 includes, for example, a control device such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array), and a storage device such as semiconductor memory. The control unit 4 comprehensively controls each element of the liquid injection device 1, namely the liquid injection head 2, the transport mechanism 5, the moving mechanism 6, etc., by having the control device execute a program stored in the storage device.

[0022] The conveying mechanism 5 conveys the medium S in the X-axis direction and has conveying rollers 5a. That is, the conveying mechanism 5 conveys the medium S in the X-axis direction by the rotation of the conveying rollers 5a. Note that the conveying mechanism 5 that conveys the medium S is not limited to one equipped with conveying rollers 5a, but may also convey the medium S by a belt or drum, for example.

[0023] The moving mechanism 6 comprises a transport body 6a and a transport belt 6b. The transport body 6a is a roughly box-shaped structure, a so-called carriage, that houses the liquid injection head 2 and is fixed to the transport belt 6b. The transport belt 6b is an endless belt installed along the Y-axis direction. The transport belt 6b is rotated by the drive of a transport motor (not shown). The control unit 4 controls the drive of the transport motor to rotate the transport belt 6b, causing the liquid injection head 2 to reciprocate along the Y-axis direction along a guide rail (not shown) together with the transport body 6a. The sub-tank 3b of the liquid storage unit 3 can also be mounted on the transport body 6a together with the liquid injection head 2.

[0024] The liquid spray head 2, under the control of the control unit 4, performs a spraying operation in which it ejects ink supplied from the liquid reservoir 3 as ink droplets in the +Z direction from each of the multiple nozzles 21 (see Figures 7 and 8). This ink droplet spraying operation by the liquid spray head 2 is performed in parallel with the transport of the medium S by the transport mechanism 5 and the reciprocating movement of the liquid spray head 2 by the moving mechanism 6, thereby forming an image with ink on the surface of the medium S, a so-called printing operation.

[0025] Figure 2 is an exploded perspective view of the liquid injection head 2. Figure 3 is a cross-sectional view of the liquid injection head 2, taken along the Y-axis and Z-axis directions. Figure 4 is a perspective view of the intermediate member 250. Figure 5 is an enlarged view of the main part of Figure 3. The directions of the liquid injection head 2 will be described based on the directions when mounted on the liquid injection device 1, i.e., the X-axis, Y-axis, and Z-axis directions. Of course, the position of the liquid injection head 2 within the liquid injection device 1 is not limited to those shown below.

[0026] As shown in the figure, the liquid injection head 2 comprises a head tip 8, a holder 200, a connecting flow path member 210, a sealing member 220, a relay substrate 230, a fixing plate 240, and a relay member 250.

[0027] The head chip 8 of this embodiment will now be described. Figure 6 is an exploded perspective view of the head chip 8. Figure 7 is a plan view of the pressure chamber substrate 10 of the head chip 8 as seen in the +Z direction. Figure 8 is a cross-sectional view corresponding to line AA' in Figure 7. The directions of the head chip 8 will be described based on the directions when mounted on the liquid injection head 2, i.e., the X-axis direction, Y-axis direction, and Z-axis direction.

[0028] As shown in Figures 6 to 8, the head chip 8 of this embodiment includes a pressure chamber substrate 10. The pressure chamber substrate 10 is made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates.

[0029] Multiple pressure chambers 12 are arranged in a line along the X-axis on the pressure chamber substrate 10. The multiple pressure chambers 12 are arranged on a straight line along the X-axis so that they are in the same position with respect to the Y-axis. Two pressure chambers 12 adjacent to each other in the X-axis direction are separated by a partition wall. In this embodiment, two rows of pressure chambers 12 arranged in a line along the X-axis direction are provided in the Y-axis direction.

[0030] On the surface of the pressure chamber substrate 10 facing the +Z direction, the communication plate 15 and the nozzle plate 20 are sequentially stacked.

[0031] The communication plate 15 consists of a plate-shaped member joined to the surface of the pressure chamber substrate 10 facing the +Z direction. The communication plate 15 is provided with a nozzle communication passage 16 that connects the pressure chamber 12 and the nozzle 21.

[0032] Furthermore, the communication plate 15 is provided with a first manifold section 17 and a second manifold section 18, which constitute a part of the manifold 100 that forms a common liquid chamber through which multiple pressure chambers 12 communicate. The first manifold section 17 is provided penetrating the communication plate 15 in the Z-axis direction. The second manifold section 18 is provided opening onto a surface facing the +Z direction, without penetrating the communication plate 15 in the Z-axis direction.

[0033] Furthermore, the communication plate 15 is provided with an independent supply passage 19 for each of the pressure chambers 12, which communicates with one end of the pressure chamber 12 in the Y-axis direction. The supply passage 19 connects the second manifold section 18 and the pressure chamber 12, supplying ink from the manifold 100 to the pressure chamber 12.

[0034] Such connecting plates 15 can be silicon substrates, glass substrates, SOI substrates, various ceramic substrates, or metal substrates such as stainless steel substrates. Preferably, the connecting plate 15 is made of a material with a thermal expansion coefficient approximately the same as that of the pressure chamber substrate 10. By using materials with approximately the same thermal expansion coefficient for both the pressure chamber substrate 10 and the connecting plate 15, it is possible to reduce warping caused by heat due to differences in thermal expansion coefficients.

[0035] The nozzle plate 20 is bonded to the side of the communication plate 15 opposite to the pressure chamber substrate 10, that is, the side facing the +Z direction.

[0036] The nozzle plate 20 has nozzles 21 that communicate with each pressure chamber 12 via nozzle communication passages 16. In this embodiment, the multiple nozzles 21 are arranged in a line along the X-axis. In this embodiment, two rows of nozzles 21 arranged in parallel along the X-axis are provided separated in the Y-axis direction. The two rows of nozzles arranged in parallel along the Y-axis direction may be arranged in a so-called staggered pattern, with the nozzles 21 constituting each row offset from each other by half a pitch in the X-axis direction. As such a nozzle plate 20, silicon substrates, glass substrates, SOI substrates, various ceramic substrates, metal substrates such as stainless steel substrates, and organic materials such as polyimide resin can be used. It is preferable that the nozzle plate 20 be made of a material with approximately the same thermal expansion coefficient as the communication plate 15. By using materials with approximately the same thermal expansion coefficient for the nozzle plate 20 and the communication plate 15, it is possible to reduce warping caused by heat due to differences in thermal expansion coefficients. The surface of the nozzle plate 20 facing the +Z direction from which the nozzles 21 open is referred to as the nozzle surface 20a.

[0037] The diaphragm 50 and the piezoelectric actuator 300 are sequentially stacked on the surface of the pressure chamber substrate 10 facing the -Z direction.

[0038] In this embodiment, the diaphragm 50 has an elastic film 51 made of silicon oxide provided on the pressure chamber substrate 10 side, and an insulating film 52 made of zirconium oxide provided on the surface of the elastic film 51 facing the -Z direction. The diaphragm 50 may consist only of the elastic film 51, or only of the insulating film 52, or it may have other films in addition to the elastic film 51 and the insulating film 52. Furthermore, a recess as a pressure chamber 12 may be formed by etching the surface of the pressure chamber substrate 10 in the +Z direction in the -Z direction. In this case, the bottom surface of the recess becomes the elastic film 51, so the pressure chamber substrate 10 and the elastic film 51 which is part of the diaphragm 50 are formed as a single unit. Alternatively, the entire diaphragm 50 and the pressure chamber substrate 10 may be formed as a single unit.

[0039] The piezoelectric actuator 300 comprises a first electrode 60, a piezoelectric layer 70, and a second electrode 80 sequentially stacked on a diaphragm 50 in the -Z direction. Such a piezoelectric actuator 300 is also called a piezoelectric element, and refers to the portion including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. Furthermore, the portion in the piezoelectric layer 70 where piezoelectric strain occurs when a voltage is applied between the first electrode 60 and the second electrode 80 is called the active portion 310. In contrast, the portion in the piezoelectric layer 70 where no piezoelectric strain occurs is called the inactive portion. That is, the active portion 310 refers to the portion of the piezoelectric layer 70 sandwiched between the first electrode 60 and the second electrode 80. In this embodiment, an active portion 310 is formed for each pressure chamber 12. In other words, multiple active portions 310 are arranged in parallel in the X-axis direction of the piezoelectric actuator 300. These multiple active portions 310 act as driving elements that cause pressure changes in the ink within the pressure chamber 12. Generally, one electrode of the active section 310 is configured as an individual electrode independent of each active section 310, while the other electrode is configured as a common electrode common to multiple active sections 310. In this embodiment, the first electrode 60 constitutes an individual electrode, and the second electrode 80 constitutes a common electrode. Of course, the first electrode 60 may constitute a common electrode, and the second electrode 80 may constitute an individual electrode.

[0040] Such a piezoelectric layer 70 is constructed using a piezoelectric material consisting of a composite oxide with a perovskite structure represented by the general formula ABO3.

[0041] Furthermore, lead electrodes 90, which are lead wires, are drawn out from the first electrode 60. A flexible substrate 110, which is a flexible substrate, is connected to the end of the lead electrode 90 opposite to the end connected to the piezoelectric actuator 300. A drive circuit 111 having multiple switching elements that select whether or not to drive each of the active parts 310 is mounted on the flexible substrate 110. In other words, the flexible substrate 110 is made of COF. In this embodiment, the side of the flexible substrate 110 on which the drive circuit 111 is not mounted is called the first side 110a, and the side on which the drive circuit 111 is mounted is called the second side 110b. Note that the drive circuit 111 is not required to be provided on the flexible substrate 110. In other words, the flexible substrate 110 may be FFC, FPC, etc.

[0042] In this piezoelectric actuator 300, which includes a first electrode 60, a piezoelectric layer 70, and a second electrode 80, each layer is formed by film deposition and lithography. Therefore, the piezoelectric actuator 300 of this embodiment is a piezoelectric thin film including a piezoelectric layer 70, which is a "thin-film piezoelectric material." Here, a piezoelectric thin film including a thin-film piezoelectric material refers to a film with a thickness of less than 10 μm in the Z-axis direction, which is the stacking direction including the first electrode 60, the piezoelectric layer 70, and the second electrode 80. It is preferable that the piezoelectric thin film be 3 μm or less in thickness in order to arrange multiple nozzles 21 at high density.

[0043] A protective substrate 30, having approximately the same size as the pressure chamber substrate 10, is laminated on the surface of the pressure chamber substrate 10 facing the -Z direction via a diaphragm 50. "The protective substrate is laminated to the pressure chamber substrate" means both that the protective substrate 30 is indirectly laminated to the pressure chamber substrate 10 via the diaphragm 50, and that part or all of the diaphragm 50 is directly laminated to the member integrally formed with the pressure chamber substrate 10. The protective substrate 30 has a holding portion 31, which is a space for protecting the piezoelectric actuator 300. The holding portions 31 are independently provided for each row of piezoelectric actuators 300 arranged in the X-axis direction, and two are formed side-by-side in the Y-axis direction. Furthermore, the protective substrate 30 has a through hole 32 that penetrates in the Z-axis direction between the two holding portions 31 arranged in the Y-axis direction. The ends of the lead electrodes 90, which are drawn out from the electrodes of the piezoelectric actuator 300, are extended so as to be exposed within the through-hole 32, and the lead electrodes 90 and the flexible substrate 110 are electrically connected within the through-hole 32.

[0044] Such a protective substrate 30 may be made of, for example, a silicon substrate, a glass substrate, an SOI substrate, or various ceramic substrates, similar to the pressure chamber substrate 10. It is preferable that the protective substrate 30 be made of a material with approximately the same thermal expansion coefficient as the pressure chamber substrate 10. By using materials with approximately the same thermal expansion coefficient for both the pressure chamber substrate 10 and the protective substrate 30, it is possible to reduce warping caused by heat due to differences in thermal expansion coefficients.

[0045] Furthermore, the case member 40 is joined to the surface of the communication plate 15 facing the -Z direction via an adhesive (not shown). The case member 40 has substantially the same shape as the communication plate 15 in plan view and is joined to a different position on the communication plate 15 than the pressure chamber substrate 10. In other words, the joining region where the case member 40 and the communication plate 15 are joined to each other when viewed in the +Z direction is a position that does not overlap with the pressure chamber substrate 10.

[0046] Such a case member 40 has a recess 41 on the protective substrate 30 side that is deep enough to accommodate the pressure chamber substrate 10 and the protective substrate 30. This recess 41 has a larger opening area than the surface of the protective substrate 30 that is joined to the pressure chamber substrate 10. With the pressure chamber substrate 10 and the protective substrate 30 housed in the recess 41, the opening surface of the recess 41 on the nozzle plate 20 side is sealed by the communication plate 15. Within the recess 41, the lower surface 40a of the case member 40 facing the +Z direction and the upper surface 30a of the protective substrate 30 facing the -Z direction are not bonded together but are spaced apart in the Z-axis direction. Here, "space" refers to a gap of 1 μm or more. Furthermore, the gap between the lower surface 40a and the upper surface 30a is preferably 50 μm or more, taking into account the manufacturing tolerances of the case member 40 and the protective substrate 30. By setting the gap to 50 μm or more, even if manufacturing errors occur in the case member 40 or the protective substrate 30, contact between the lower surface 40a and the upper surface 30a can be suppressed. In this embodiment, the lower surface 40a is the bottom surface located in the -Z direction of the recess 41. In this way, by arranging the lower surface 40a of the case member 40 and the upper surface 30a of the protective substrate 30 with a gap between them without bonding them, the influence of deformation of the case member 40 on the protective substrate 30 can be suppressed. For example, if the upper surface 30a of the protective substrate 30 and the lower surface 40a of the case member 40 are bonded together, the influence of deformation of the case member 40 due to the difference in the coefficient of thermal expansion between the protective substrate 30 and the case member 40 will be transmitted to the protective substrate 30, and there is a risk that the piezoelectric actuator 300 on the diaphragm 50 bonded to the protective substrate 30 may be destroyed. For example, the pressure chamber substrate 10, the communication plate 15, the protective substrate 30, and the nozzle plate 20 are made of materials that have a smaller coefficient of thermal expansion and are more prone to cracking than the case member 40. In this embodiment, by not bonding the upper surface 30a of the protective substrate 30 to the lower surface 40a of the case member 40, the deformation of the case member 40 caused by the difference in the coefficients of thermal expansion between the protective substrate 30 and the case member 40 is not transmitted to the protective substrate 30, thereby suppressing damage to the piezoelectric actuator 300.

[0047] Furthermore, the case member 40 is provided with a third manifold section 42 that communicates with the first manifold section 17 of the communication plate 15. The manifold 100 of this embodiment is composed of the first manifold section 17 and the second manifold section 18 provided on the communication plate 15 and the third manifold section 42 provided on the case member 40. Two manifolds 100 are provided for each row of pressure chambers 12, i.e., two in total. Each manifold 100 is provided continuously along the X-axis direction in which the pressure chambers 12 are arranged side by side, and the supply passages 19 that connect each pressure chamber 12 and the manifold 100 are arranged side by side along the X-axis direction. The case member 40 also has an inlet 44a that communicates with the manifolds 100 and supplies ink to each manifold 100. The case member 40 also has an opening 43 through which the flexible substrate 110 is inserted, communicating with the through hole 32 of the protective substrate 30. The flexible substrate 110 is guided to the side of the liquid spray head 2 facing the -Z direction through the through hole 32 and the opening 43. The width of the opening 43 in the Y direction is wider than the width of the through hole 32 in the protective substrate 30 in the Y direction. Therefore, the side of the protective substrate 30 facing the -Z direction on the central side in the Y direction is exposed into the opening 43 without being covered by the case member 40.

[0048] Furthermore, the case member 40 has a housing portion 45 having a concave shape that opens to the surface facing the -Z direction. As shown in Figure 6, the housing portion 45 is provided with openings on one side in the Y-axis direction and both sides in the X-axis direction. The flange portion 252 (see Figure 2) of the relay member 250, which will be described in more detail later, is inserted into this housing portion 45. For this reason, when viewed in the +Z direction, the housing portion 45 has substantially the same shape as the flange portion 252, and the depth of the housing portion 45 in the Z-axis direction is greater than the thickness of the flange portion 252 in the Z-axis direction. For this reason, the surface of the flange portion 252 facing the +Z direction is spaced apart from the upper surface of the housing portion 45 of the case member 40 facing the -Z direction. Here, "space" refers to a gap of 1 μm or more. This ensures that the contact portion 256 of the relay member 250 and the upper surface 30a of the protective substrate 30 make reliable contact. Incidentally, the inlet 44a is located in the part where the housing portion 45 is not provided. Metal materials, resin materials, and the like can be used for such case components 40.

[0049] Furthermore, a compliance substrate 120 is provided on the +Z direction side of the communication plate 15 where the first manifold portion 17 and the second manifold portion 18 are open. This compliance substrate 120 seals the openings on the nozzle surface 20a side of the first manifold portion 17 and the second manifold portion 18. In this embodiment, such a compliance substrate 120 comprises a sealing film 121 made of a flexible thin film and a fixed substrate 122 made of a hard material such as metal. Since the region of the fixed substrate 122 facing the manifold 100 is an opening 123 that is completely removed in the thickness direction, one side of the manifold 100 becomes a compliance portion 124 which is a flexible portion sealed only by the flexible sealing film 121.

[0050] A fixing plate 240, which will be described in more detail later, is bonded to the surface of the compliance substrate 120 facing the +Z direction. In other words, the fixing plate 240 is bonded to the fixing substrate 122 so as to cover the opening 123. The space between the fixing plate 240 and the sealing film 121 is opened to the atmosphere, allowing the compliance portion 124 of the sealing film 121 to deform in accordance with the pressure of the ink in the manifold 100.

[0051] Furthermore, a filler 22 is filled between the nozzle plate 20 and the compliance substrate 120 and the exposed opening 241 of the fixing plate 240. The filler 22 can be an adhesive, potting agent, molding agent, etc. By filling the gap between the nozzle plate 20 and the fixing plate 240 with the filler 22, it is possible to suppress the accumulation of ink in this gap when the nozzle surface 20a is wiped with a blade. In addition, the filler 22 prevents the wiping blade from contacting and wearing down the corners of the nozzle plate 20, thereby preventing a reduction in blade life.

[0052] As shown in Figures 2 to 5, the holder 200, the connecting channel member 210, and the sealing member 220 have a channel 400 which includes a supply channel that supplies ink supplied from the liquid reservoir 3 to the head tip 8, and a discharge channel that returns ink that was not ejected from the nozzle 21 of the head tip 8 back to the liquid reservoir 3. Figure 3 shows only the supply channel as part of the channel 400, and the following is a description of the channel 400 which is the supply channel.

[0053] The holder 200, the sealing member 220, and the connecting channel member 210 are stacked in this order in the -Z direction. The holder 200 has a first channel 401, and the connecting channel member 210 has a second channel 402. The first channel 401 and the second channel 402 are connected in a liquid-tight manner by the sealing member 220.

[0054] In this embodiment, the connecting channel member 210 is constructed by stacking three members 211, 212, and 213 in this order in the +Z direction. The connecting channel member 210 has a supply-side channel connection portion 214a that is connected to a liquid storage portion 3 in which liquid ink is stored. In this embodiment, the supply-side channel connection portion 214a is a cylindrical projection in the -Z direction from the -Z direction surface of the connecting channel member 210. A supply tube 7d is connected to this supply-side channel connection portion 214a. Inside this supply-side channel connection portion 214a, a second channel 402 is provided through which ink from the liquid storage portion 3 is supplied.

[0055] The second channel 402 consists of channels extending in the Z-axis direction and channels extending along the lamination interface of the laminated members. In addition, a filter chamber 402a is provided in the middle of the second channel 402, which has a wider inner diameter than other regions, and a filter 402b is provided inside the filter chamber 402a to capture foreign matter such as dust and air bubbles contained in the ink.

[0056] In this embodiment, one connecting channel member 210 comprises four supply-side channel connection sections 214a and four independent second channels 402. The second channels 402 may be branched into two or more channels downstream of the filter 402b, for example.

[0057] Furthermore, as shown in Figure 2, the connecting flow path member 210 has four discharge-side flow path connection sections 214b. A recovery tube 7c (see Figure 1) is connected to each discharge-side flow path connection section 214b, and ink that is not ejected from the nozzle 21 of the liquid spray head 2 is returned to the sub-tank 3b via the recovery tube 7c. In addition, a discharge flow path is provided inside the discharge-side flow path connection section 214b (not shown). In other words, the holder 200 is provided with four discharge flow paths (not shown). Incidentally, it is not necessary to provide a filter in the middle of the discharge flow path. Hereafter, when the supply-side flow path connection section 214a and the discharge-side flow path connection section 214b are not distinguished, they will be referred to as flow path connection section 214.

[0058] The holder 200 has a first flow path 401 that communicates with each of the second flow paths 402 of the connecting flow path member 210. In other words, the holder 200 has four first flow paths 401. The first flow paths 401 and the second flow paths 402 are liquid-tightly connected via a sealing member 220. The sealing member 220 can be made of a material that is liquid-resistant to liquids such as ink used in the liquid spray head 2 and is elastically deformable, such as rubber or elastomer. Such a sealing member 220 is provided with a communication flow path 403 that penetrates in the Z-axis direction, and the first flow paths 401 and the second flow paths 402 communicate via the communication flow path 403. In other words, the flow path 400, which is the supply flow path of the holder 200, comprises the first flow paths 401, the second flow paths 402, and the communication flow path 403.

[0059] Furthermore, the head tip 8 is held on the surface of the holder 200 facing the +Z direction. Specifically, the holder 200 has a head tip housing portion 201 having a concave shape that opens on the surface facing the +Z direction, and the head tip 8 is held within the head tip housing portion 201. The liquid spray head 2 of this embodiment holds a plurality of head tips 8, in this embodiment, for example, two. Also, in this embodiment, a head tip housing portion 201 is provided independently for each head tip 8. In other words, the holder 200 has two head tip housing portions 201. Of course, the head tip housing portion 201 may be provided in common across multiple head tips 8. Also, the number of head tips 8 held by the liquid spray head 2 is not particularly limited, and may be one or more. Also, in this embodiment, the two head tips 8 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. Of course, the arrangement of the multiple head tips 8 is not particularly limited, and for example, they may be arranged in a staggered pattern along the X-axis direction. Such a holder 200 is made of metal or resin.

[0060] Furthermore, the bottom surface of the head chip housing 201 facing the +Z direction and the surface of the head chip 8 facing the -Z direction are spaced apart. Here, "space" refers to a gap of 1 μm or more. The first flow path 401 communicates with each inlet 44a of the head chip 8. In this embodiment, the first flow path 401 and each inlet 44a are liquid-tightly connected by an adhesive 130 provided in the space between the holder 200 and the head chip 8. That is, the adhesive 130 is provided so as to surround the entire circumference of the opening of the inlet 44a formed on the surface of the head chip 8 facing the -Z direction when viewed in the +Z direction, and so as to surround the entire circumference of the opening of the first flow path 401 formed on the surface of the holder 200 facing the +Z direction when viewed in the -Z direction. As such an adhesive 130, an adhesive with high resistance to the liquid used in the liquid spray head 2, i.e., an adhesive with high liquid resistance, such as an epoxy adhesive, is used. Furthermore, the adhesive 130 may be a silicone-based adhesive that has a viscosity sufficient to fill the gaps before curing, exhibits relatively little curing shrinkage, and is relatively soft after curing. If the viscosity of the adhesive 130 before curing is too low, it is undesirable because the adhesive 130 will easily flow out from the gaps. Also, if an adhesive 130 with relatively large curing shrinkage is used, there is a risk that the curing shrinkage of the adhesive 130 will cause misalignment in the Z-axis direction between the multiple head tips 8. However, by using an adhesive that is relatively soft after curing as the adhesive 130, the misalignment between the head tips 8 due to the curing shrinkage of the adhesive 130 can be suppressed. Note that an unillustrated discharge channel of the holder 200 is connected to the outlet 44b of the head tip 8. The outlet 44b and the discharge channel have a similar configuration.

[0061] Furthermore, the holder 200 is provided with wiring retention holes 202 for inserting the flexible substrate 110 of each head chip 8. In this embodiment, a total of two wiring retention holes 202 are provided, one for each head chip 8. The flexible substrate 110 of the head chip 8, which will be described in detail later, is led out through the wiring retention holes 202 to the side of the holder 200 facing the -Z direction.

[0062] Furthermore, in the Z-axis direction, a relay board 230 is provided between the sealing member 220 and the connecting flow channel member 210, to which the flexible substrates 110 of multiple head chips 8 are commonly connected. The relay board 230 is made of a rigid substrate that is not flexible, and has wiring and electronic components (not shown) mounted on it. In this embodiment, a connector 231 to which external wiring is connected is shown as an electronic component. Print signals for controlling the head chips 8 are input from the external wiring to the relay board 230 via the connector 231, and supplied from the relay board 230 to each head chip 8. An external wiring opening 203 is provided on the side wall of the holder 200 facing the connector 231 for inserting the external wiring connected to the connector 231. The external wiring is connected to the connector 231 of the relay board 230, which is provided inside the holder 200, via the external wiring opening 203.

[0063] The relay board 230 is provided with wiring insertion holes 232 for leading the flexible substrate 110 of the head chip 8 to the side facing the -Z direction. There is one wiring insertion hole 232 for each head chip 8, for a total of two holes.

[0064] Furthermore, the relay substrate 230 is provided with a projection insertion hole 233 that penetrates in the Z-axis direction. On the surface of the holder 200 facing the -Z direction, a projection 204 is provided that has a first flow channel 401 inside and protrudes toward the -Z direction. The projection 204 is inserted through the projection insertion hole 233 into the -Z side of the relay substrate 230 and connected to the communication flow channel 403.

[0065] Furthermore, a fixing plate 240 is fixed to the surface of the holder 200 facing the +Z direction, where the head chip housing portion 201 opens. In this embodiment, the fixing plate 240 is sized to cover two head chips 8. The fixing plate 240 is provided with an exposure opening 241 independently for each head chip 8, which exposes the nozzle 21 of the head chip 8 toward the +Z direction. Ink is ejected from the nozzle 21 exposed through the exposure opening 241 toward the +Z direction. Of course, the exposure opening 241 may be provided in common for multiple head chips 8.

[0066] As shown in Figures 3 to 5, the relay member 250 is inserted into the opening 43 of the case member 40 of the head chip 8 and is a member that does not define the flow path for ink. The relay member 250 comprises a base portion 251 and a flange portion 252.

[0067] The base portion 251 is a cylindrical member having a rectangular shape when viewed in the +Z direction and an opening 253 that penetrates through in the Z-axis direction. In other words, the opening 253 is provided inside the base portion 251, which is continuous in an annular shape when viewed in the +Z direction. The flexible substrate 110 is inserted into this opening 253.

[0068] The flange portion 252 is provided at the -Z end of the base portion 251, extending from the base portion 251 along the XY plane defined by the X and Y axes. The flange portion 252 has notches 254 at each end in the X-axis direction, positioned to overlap the inlet 44a and outlet 44b when viewed in the +Z direction.

[0069] In this configuration, the flange portion 252 of the intermediate member 250 is fixed to the lower surface 200a of the holder 200, which faces in the +Z direction, with the -Z-facing surface of the flange portion 252. In this embodiment, the lower surface 200a of the holder 200, which faces in the +Z direction, is the bottom surface of the head chip housing portion 201. In other words, the outer peripheral end of the flange portion 252 becomes the supported portion 255, which is supported by the holder 200. The -Z-facing surface 255a of this supported portion 255 is fixed to the lower surface 200a of the holder 200. In this embodiment, the flange portion 252 and the holder 200 are bonded together via an adhesive 260. As the adhesive 260, it is preferable, but not limited to, a high-temperature curing epoxy resin. Of course, the method of fixing the supported portion 255 of the flange portion 252 to the holder 200 is not limited to adhesive bonding. For example, the supported portion 255 of the flange portion 252 and the holder 200 may be joined by brazing, soldering, welding, or other methods.

[0070] Furthermore, the +Z-direction end of the base portion 251 of the relay member 250 is a contact portion 256 that contacts the upper surface 30a of the protective substrate 30 facing the -Z direction. In other words, the surface 256a of the contact portion 256 of the base portion 251 facing the +Z direction contacts the upper surface 30a. Note that the surface 256a of the relay member 250 contacts the upper surface 30a of the protective substrate 30, but is not bonded to it. Note that when two surfaces are in contact, it means that at least a part of the two surfaces is in contact. In other words, this includes configurations in which the two surfaces are in point contact at one or more locations, as well as configurations in which the two surfaces are in surface contact.

[0071] Such a relay member 250 can be formed from metal or resin. Forming the relay member 250 from metal can increase its rigidity. Forming the relay member 250 from resin can suppress electrical conductivity between the drive circuit 111 and the relay member 250, thereby suppressing electrical malfunctions caused by electrical conductivity between the drive circuit 111 and the relay member 250. The relay member 250 may also consist of a mixture of resin and metal parts. For example, if the opening 253 side of the base portion 251 is formed from resin, and the other parts of the base portion 251 and the flange portion 252 are formed from metal, the rigidity of the relay member 250 can be increased, and electrical conductivity between the drive circuit 111 and the relay member 250 can be suppressed. Alternatively, the base portion 251 may be formed from metal, and an insulating film may be provided on the inner circumferential surface of the opening 253.

[0072] In this type of relay member 250, the supported portion 255 is supported by the holder 200, and the contact portion 256 contacts the upper surface 30a of the protective substrate 30, thereby restricting the movement of the protective substrate 30 in the -Z direction.

[0073] Here, as described above, if the deformation of the case member 40 caused by the difference in the coefficient of thermal expansion between the protective substrate 30 and the case member 40 is transmitted to the protective substrate 30, there is a risk that the piezoelectric actuator 300 on the diaphragm 50 bonded to the protective substrate 30 may be destroyed. For this reason, if the protective substrate 30 and the case member 40 are arranged with a gap between them and are not bonded to each other, as in this embodiment, when the medium S comes into contact with the nozzle surface 20a of the liquid spray head 2 or the fixed plate 240 due to a transport failure of the medium S, so-called paper jam, an external force is applied to the liquid spray head 2 in the -Z direction, which is opposite to the ink spraying direction. At this time, as shown in Figure 5, the communication plate 15 deforms in the direction shown by the dotted line, narrowing the gap between the protective substrate 30 and the case member 40, with the inner end in the Y-axis direction of the joint surface between the fixed plate 240 and the holder 200 (the position indicated by the arrow in Figure 5) as the fulcrum, and there is a risk that the communication plate 15 may crack. Furthermore, since the holder 200 and the case member 40 are bonded together with a relatively soft adhesive 130, the connecting plate 15 may deform in the direction indicated by the dotted line, causing the adhesive 130 to collapse and potentially leading to the connecting plate 15 cracking. Also, if the rigidity of the fixing plate 240 is relatively high, or if a reinforcing plate or the like is placed between the fixing plate 240 and the holder 200, the connecting plate 15 will deform in the direction indicated by the dotted line, with the joint surface between the fixing plate 240 or the reinforcing plate and the compliance substrate 120, i.e., the inner end of the fixing substrate 122 in the Y-axis direction, as the pivot point. Incidentally, the reinforcing plate constitutes a part of the holder 200.

[0074] In this embodiment, by providing a relay member 250 that is supported by the holder 200 and in contact with the upper surface 30a of the protective substrate 30, even if an external force is applied to the liquid spray head 2 in the -Z direction, the movement of the protective substrate 30 in the -Z direction can be restricted by the holder 200 via the relay member 250. Therefore, by restricting the movement of the protective substrate 30 in the -Z direction by the holder 200 via the relay member 250, deformation of the communication plate 15 into a convex shape in the -Z direction can be suppressed, and the cracking of the communication plate 15 can be suppressed. In particular, in this embodiment, the supported portion 255 of the relay member 250 is fixed to the lower surface 200a of the holder 200 that faces the +Z direction. Therefore, since the movement of the relay member 250 in the -Z direction can be restricted by the lower surface 200a of the holder 200 that faces the +Z direction, it is easier to suppress the movement of the protective substrate 30 due to deformation of the communication plate 15. Furthermore, by providing a flange portion 252 on the relay member 250 and fixing the -Z-facing surface of the flange portion 252 to the holder 200, the pressure-receiving area of ​​the holder 200 from the relay member 250 can be made relatively larger compared to the case where the flange portion 252 is not provided. This also suppresses deformation of the holder 200 itself and suppresses cracking due to deformation of the communication plate 15. In addition, by providing the opening 253 inside the base portion 251 which is continuous in an annular shape when viewed in the +Z direction, the rigidity of the base portion 251 is improved, suppressing deformation of the base portion 251 due to external forces and further suppressing deformation of the communication plate 15. Moreover, the holder 200 in this embodiment is a relatively rigid member that can hold multiple head chips 8, in this embodiment two. For this reason, instead of bringing the protective substrate 30 into contact with the case member 40 as in this embodiment, bringing the protective substrate 30 into contact with the relatively rigid holder 200 via the relay member 250 can further suppress deformation of the communication plate 15.

[0075] Incidentally, even if the lower surface 40a of the recess 41 of the case member 40 is not provided and the case member 40 is not adhered to the upper surface 30a of the protective substrate 30, a gap will be formed between the communication plate 15 and the case member 40 due to manufacturing errors in the case member 40, or a load in the +Z direction will be applied to the protective substrate 30 by adhering the communication plate 15 and the case member 40 without any gaps. In this embodiment, by providing a gap between the lower surface 40a of the recess 41 of the case member 40 and the upper surface 30a of the protective substrate 30, even if manufacturing errors in the case member 40 occur, the case member 40 and the communication plate 15 can be adhered without any gaps, and the load in the +Z direction applied to the protective substrate 30 by the case member 40 can be suppressed.

[0076] Furthermore, by not bonding the relay member 250 to the protective substrate 30, the protective substrate 30 is not affected by the deformation of the holder 200 and relay member 250 due to the difference in coefficients of thermal expansion between the holder 200 and the relay member 250 and the protective substrate 30, thereby suppressing damage to the piezoelectric actuator 300.

[0077] Furthermore, in this embodiment, the intermediate member 250 is in contact with the surface 256a of the contact portion 256 of the base portion 251 facing the +Z direction and the upper surface 30a of the protective substrate 30 facing the -Z direction, when viewed in the +X direction, at a point inside the center position between the inner circumferential surface of the through hole 32 of the protective substrate 30 and the outer circumferential surface of the protective substrate 30. The center side of the protective substrate 30 in the Y axis direction is the part where the deformation of the communication plate 15 is greatest due to the external force applied to the liquid injection head 2. Therefore, by having the intermediate member 250 contact the protective substrate 30 on the side where the deformation of the communication plate 15 is greatest, the intermediate member 250 can effectively suppress the deformation of the communication plate 15 in the -Z direction.

[0078] Furthermore, in this embodiment, the case member 40 has a housing portion 45 with a concave shape that opens to the surface facing the -Z direction, and the flange portion 252 of the relay member 250 is housed within the housing portion 45. Therefore, it is possible to suppress the enlargement of the liquid injection head 2 in the Z-axis direction and to miniaturize the liquid injection head 2 in the Z-axis direction.

[0079] In this embodiment, the +Z direction is an example of the "first direction," and the -Z direction is an example of the "second direction." The communication plate 15 is an example of the "first flow path member," and any or all of the nozzle communication passage 16, first manifold section 17, second manifold section 18, and supply communication passage 19 of the communication plate 15 are examples of "flow paths communicating with the nozzle 21." The case member 40 is an example of the "second flow path member," and the third manifold section 42 is an example of a "flow path communicating with the flow path of the first flow path member." One of the two head tips 8 is an example of the "first head tip," and the other is an example of the "second head tip."

[0080] (modified version) Figure 9 is a perspective view showing a modified example of the relay member 250 according to Embodiment 1 of the present invention.

[0081] As shown in Figure 9, the relay member 250 has a rib 257 projecting in the -Z direction on the -Z-facing surface of the flange portion 252. The rib 257 extends in the X-axis direction on the +Y-direction side of the opening 253 of the flange portion 252. The rib 257 is also provided to project in the -Z direction beyond the -Z-facing surface 255a of the supported portion 255. Such a rib 257 is inserted into the wiring holding hole 202 of the holder 200.

[0082] By providing ribs 257 on the intermediate member 250 in this way, the rigidity of the intermediate member 250, particularly its rigidity against deformation in the -Z direction in the X-axis direction, can be improved, further suppressing the deformation of the connecting plate 15. Of course, the ribs 257 may be provided on both sides of the opening 253 in the Y-axis direction, and two ribs 257 provided on both sides of the opening 253 in the Y-axis direction may be connected so as to be continuous on both sides of the opening 253 in the X-axis direction. In other words, the ribs 257 may be provided in a continuous ring shape around the opening 253 when viewed in the +Z direction. This further improves the rigidity of the intermediate member 250.

[0083] (Embodiment 2) Figure 10 is a cross-sectional view of the liquid injection head 2 according to Embodiment 2 of the present invention. Figure 11 is a perspective view with the main parts of the holder 200 and relay member 250 according to Embodiment 2 cut out. Note that the same reference numerals are used for components similar to those in the above-described embodiments, and redundant descriptions are omitted.

[0084] As shown in the figure, the intermediate member 250 has the same shape as the embodiment 1 described above. That is, the intermediate member 250 comprises a base portion 251 and a flange portion 252.

[0085] Furthermore, the +Z-facing surface of the flange portion 252 of the intermediate member 250 is fixed to the -Z-facing upper surface 200b of the holder 200. In other words, in this embodiment, the outer peripheral end of the flange portion 252 becomes the supported portion 255 that is supported by the holder 200. The +Z-facing surface 255b of this supported portion 255 is fixed to the upper surface 200b of the holder 200. In this embodiment, the +Z-facing surface 255b of the supported portion 255 of the flange portion 252 and the upper surface 200b of the holder 200 are bonded together via adhesive 260. Note that the bonding between the supported portion 255 of the flange portion 252 and the holder 200 is not limited to bonding with adhesive 260, but may also be done by soldering, brazing, welding, welding, screws, etc. However, if a gap occurs between the surface 255b of the supported portion 255 facing the +Z direction and the upper surface 200b of the holder 200 due to manufacturing tolerances of the holder 200 or the intermediate member 250, fastening with screws is undesirable because the intermediate member 250 will move in the +Z direction by the amount of this gap, and the intermediate member 250 will place a load on the protective substrate 30. By bonding the holder 200 and the supported portion 255 with adhesive 260, even if a gap occurs between the holder 200 and the supported portion 255, the gap can be filled with adhesive 260, and the two can be fixed to each other without placing a load on the protective substrate 30.

[0086] Furthermore, a recess 205 is formed in the portion of the holder 200 where the supported portion 255 is fixed, which is recessed in the +Z direction compared to other areas. The recess 205 is shaped to match the outer shape of the flange portion 252 when viewed in the +Z direction, and by inserting the supported portion 255 of the flange portion 252 into the recess 205, the intermediate member 250 can be positioned with high precision in the XY plane relative to the holder 200. In other words, by bringing the side surface of the recess 205 into contact with the outer circumferential surface of the flange portion 252, the intermediate member 250 is positioned in the XY plane relative to the holder 200. Of course, the positioning of the intermediate member 250 relative to the holder 200 is not limited to this, and a positioning pin protruding toward the other may be provided on one of the intermediate member 250 and the holder 200, and a positioning hole into which the positioning pin is inserted may be provided on the other, and both may be positioned by inserting the positioning pin into the positioning hole. It is preferable to provide two such positioning pins and positioning holes. This allows the intermediate member 250 to be positioned with high precision in the XY plane relative to the holder 200.

[0087] Furthermore, in this embodiment, notches 254 are provided at the four corners of the flange portion 252 when viewed in the +Z direction. The notches 254 are positioned to overlap with the projection 204 when viewed in the +Z direction. This prevents interference between the projection 204 and the flange portion 252.

[0088] In this liquid injection head 2, similar to Embodiment 1 described above, the movement of the protective substrate 30 in the -Z direction is restricted by the holder 200 via the relay member 250. Therefore, even if an external force is applied to the liquid injection head 2 from the liquid injection surface side in the -Z direction, deformation of the communication plate 15 is reduced, and cracking of the communication plate 15 can be suppressed.

[0089] Furthermore, in the liquid spray head 2 of this embodiment, the relay member 250 can be inserted into the wiring holding hole 202 from the upper surface 200b side facing the -Z direction of the holder 200 and fixed, making it easy to fix the relay member 250 to the holder 200. Also, the head chip 8 and fixing plate 240 can be fixed to the holder 200 before fixing the relay member 250 to the holder 200. In other words, before fixing the relay member 250 to the holder 200, the holder 200 and the fixing plate 240 to which the multiple head chips 8 are fixed can be bonded and cured, allowing the multiple head chips 8 to be positioned relative to the holder 200. Therefore, the fixing process between the relay member 250 and the holder 200 can be suppressed from affecting the positioning of the head chip 8 and the holder 200. Furthermore, by fixing the supported portion 255 of the flange portion 252 to the upper surface 200b of the holder 200 facing the -Z direction, the distance between the case member 40 and the holder 200, that is, the distance between the surface of the case member 40 facing the -Z direction and the bottom surface of the head chip housing portion 201 can be reduced. As a result, the height of the case member 40 can be increased accordingly, thus preventing further miniaturization of the manifold 100.

[0090] Furthermore, in this embodiment, a recess 205 is provided on the upper surface 200b of the holder 200 facing the -Z direction, and the supported portion 255 of the flange portion 252 is fixed within the recess 205, thereby enabling miniaturization of the liquid injection head 2 in the Z-axis direction. In this embodiment, the recess 205 is used to position the intermediate member 250 in the XY plane, but this is not limited to this. For example, the recess 205 may be provided with an opening larger than the outer shape of the flange portion 252. In other words, the recess 205 may not have a positioning function for the intermediate member 250. Also, in this embodiment, the depth of the recess 205 in the Z-axis direction is smaller than the thickness of the flange portion 252 in the Z-axis direction, but this is not limited to this, and further miniaturization of the liquid injection head 2 in the Z-axis direction can be achieved by making the depth of the recess 205 in the Z-axis direction larger than the thickness of the flange portion 252 in the Z-axis direction.

[0091] In this embodiment, the +Z direction is an example of the "first direction," and the -Z direction is an example of the "second direction." The communication plate 15 is an example of the "first flow path member," and any or all of the nozzle communication passage 16, first manifold section 17, second manifold section 18, and supply communication passage 19 of the communication plate 15 are examples of "flow paths communicating with the nozzle 21." The case member 40 is an example of the "second flow path member," and the third manifold section 42 is an example of a "flow path communicating with the flow path of the first flow path member." One of the two head tips 8 is an example of the "first head tip," and the other is an example of the "second head tip."

[0092] (Embodiment 3) Figure 12 is a perspective view of the relay member 250 according to Embodiment 3 of the present invention. Figure 13 is a cross-sectional view of the liquid injection head 2 according to Embodiment 3. Figure 14 is a cross-sectional view showing the assembly process of the liquid injection head 2 according to Embodiment 3.

[0093] As shown in the figure, the relay member 250 has a first member 250A that faces the first surface 110a of the flexible substrate 110 and a second member 250B that faces the second surface 110b of the flexible substrate 110.

[0094] The first member 250A and the second member 250B are two separate members that are not continuous with each other.

[0095] The first member 250A and the second member 250B are made of the same shape, and the second member 250B is rotated 180 degrees relative to the first member 250A with an axis along the Z-axis as the axis of rotation.

[0096] These first member 250A and second member 250B each comprise a plate-shaped base portion 251 aligned with the XZ plane and a plate-shaped flange portion 252 extending along the Y axis from the -Z end of the base portion 251. In other words, each of the first member 250A and second member 250B has a shape in which a plate-shaped member is bent at a 90-degree angle.

[0097] The end of the base portion 251 in the +Z direction forms a contact portion 256 that contacts the upper surface 30a of the protective substrate 30, and the surface 256a of the contact portion 256 facing the +Z direction contacts the upper surface 30a without being bonded to it.

[0098] Furthermore, the end of the flange portion 252 opposite to the base portion 251 is a supported portion 255 fixed to the holder 200, and the surface 255b of the supported portion 255 facing the +Z direction is fixed to the upper surface 200b of the holder 200. In this embodiment as well, the surface 255b of the supported portion 255 facing the +Z direction and the upper surface 200b of the holder 200 are bonded together via adhesive 260, similar to Embodiment 2 described above. Note that the bond between the supported portion 255 of the flange portion 252 and the holder 200 is not limited to bonding with adhesive 260, but may also be fastened by soldering, brazing, welding, welding, screws, etc. Also in this embodiment as well, similar to Embodiment 2 described above, a recess 205 is provided on the upper surface 200b of the holder 200, and the supported portion 255 is positioned within the recess 205.

[0099] Even when using such a relay member 250, the same effects as in Embodiment 2 described above can be achieved. Furthermore, by configuring the relay member 250 as a separate first member 250A and second member 250B, the flexible substrate 110 is positioned between the first member 250A and the second member 250B in the Y-axis direction. Therefore, when inserting the first member 250A and the second member 250B into the opening 43 of the case member 40 or into the wiring holding hole 202 of the holder 200, they can be inserted individually, making insertion easier and improving ease of assembly. Incidentally, when the first member 250A and the second member 250B are inserted into the wiring holding hole 202 of the holder 200, the base portion 251 may be in a position tilted in the Y-axis direction relative to the Z-axis direction. Therefore, as shown in Figure 14, the first jig 270 can be inserted between the first member 250A and the second member 250B to position the first member 250A and the second member 250B so that the base portion 251 is closed along the Z axis. After correcting the position of the first member 250A and the second member 250B with the first jig 270, the flange portion 252 can be pressed in the +Z direction with the second jig 271 to bond the flange portion 252 and the holder 200 with adhesive 260. This allows each contact portion of the relay member 250 to make surface contact with the upper surface 30a of the protective substrate 30, increasing the pressure receiving area and suppressing deformation of the communication plate 15.

[0100] Furthermore, it is preferable that the first member 250A is made of metal and the second member 250B is made of resin. This is because the drive circuit 111 is mounted on the second surface 110b of the flexible substrate 110, and by making the second member 250B out of resin, electrical conductivity between the second member 250B and the drive circuit 111 can be suppressed, thereby suppressing electrical malfunctions caused by electrical conductivity between the drive circuit 111 and the second member 250B. In addition, by making the first member 250A out of metal, the rigidity of the first member 250A can be improved, further suppressing deformation of the communication plate 15.

[0101] In this embodiment, the +Z direction is an example of the "first direction," and the -Z direction is an example of the "second direction." The communication plate 15 is an example of the "first flow path member," and any or all of the nozzle communication passage 16, first manifold section 17, second manifold section 18, and supply communication passage 19 of the communication plate 15 are examples of "flow paths communicating with the nozzle 21." The case member 40 is an example of the "second flow path member," and the third manifold section 42 is an example of a "flow path communicating with the flow path of the first flow path member." One of the two head tips 8 is an example of the "first head tip," and the other is an example of the "second head tip."

[0102] (modified version) Figure 15 is a perspective view showing a modified example of the second member 250B of the relay member 250 of Embodiment 3.

[0103] As shown in Figure 15, the second member 250B comprises a base portion 251 and a flange portion 252. The base portion 251 has a first reinforcing portion 258a extending in the X-axis direction at its +Z-axis end. The base portion 251 and the flange portion 252 also have plate-shaped second reinforcing portions 258b aligned with the YZ plane at both ends in the X-axis direction. The +Z-axis end of the second reinforcing portion 258b forms a contact portion 256. The first reinforcing portion 258a and the second reinforcing portion 258b are connected by a triangular plate-shaped third reinforcing portion 258c. By providing the second member 250B with the first reinforcing portion 258a, the second reinforcing portion 258b, and the third reinforcing portion 258c, the rigidity of the second member 250B is improved, deformation of the second member 250B is suppressed, and deformation of the connecting plate 15 by the second member 250B can be suppressed. Furthermore, the first member 250A can have the same shape as the second member 250B. Also, in the modified embodiment of Embodiment 3, a first reinforcing part 258a, a second reinforcing part 258b, and a third reinforcing part 258c are provided, but any one or two of these first reinforcing part 258a, second reinforcing part 258b, and third reinforcing part 258c may be provided.

[0104] (Other embodiments) Although various embodiments of the present invention have been described above, the basic configuration of the present invention is not limited to those described above.

[0105] For example, in the embodiments described above, the case member 40 and the communication plate 15 are directly joined, but the invention is not limited to this, and the case member 40 and the communication plate 15 may be joined via a filter that captures dust and air bubbles contained in the ink. Of course, the filter may be provided in the middle of the third manifold section 42. In other words, the case member 40 and the filter may be just one example of a "case".

[0106] Furthermore, in embodiments 2 and 3, ribs 257 similar to those in the modified example of embodiment 1 may also be provided. By providing ribs 257 to the intermediate member 250 of embodiments 2 and 3, the rigidity of the intermediate member 250 can be improved.

[0107] Furthermore, although a thin-film piezoelectric actuator 300 was described as the driving element for generating a pressure change in the pressure chamber 12 in the embodiments described above, the invention is not limited to this, and the driving element can be, 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. In addition, the driving element can be a so-called electrostatic actuator in which a heating element is placed in the pressure chamber 12 and droplets are ejected from the nozzle 21 by bubbles generated by the heat generated by the heating element, or an electrostatic actuator that generates static electricity between a diaphragm and an electrode, deforming the diaphragm with electrostatic force and ejecting droplets from the nozzle 21.

[0108] Furthermore, although a thin-film piezoelectric actuator 300 was described as the driving element for generating a pressure change in the pressure chamber 12 in the embodiments described above, the invention is not limited to this, and the driving element can be, 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. In addition, the driving element can be a so-called electrostatic actuator in which a heating element is placed in the pressure chamber 12 and droplets are ejected from the nozzle 21 by bubbles generated by the heat generated by the heating element, or an electrostatic actuator that generates static electricity between a diaphragm and an electrode, deforming the diaphragm with electrostatic force and ejecting droplets from the nozzle 21.

[0109] (Note) From the forms exemplified above, the following configuration can be understood, for example.

[0110] A liquid spray head according to Embodiment 1, which is a preferred embodiment, comprises a first head tip having a nozzle for spraying liquid in a first direction, a holder arranged in a second direction opposite to the first direction and holding the first head tip, and a relay member, wherein the first head tip comprises a first flow path member having a flow path communicating with the nozzle, a pressure chamber substrate having a pressure chamber communicating with the nozzle and laminated in the second direction relative to the first flow path member, a drive element for causing a pressure change in the liquid in the pressure chamber, and a flexible substrate electrically connected to the drive element, and The device comprises a protective substrate stacked in the second direction on the pressure chamber substrate and housing the drive element, and a second flow channel member stacked in the second direction on the first flow channel member at a different position from the pressure chamber substrate, having a flow channel communicating with the flow channel of the first flow channel member and an opening into which the flexible substrate is inserted. The intermediate member is inserted into the opening of the second flow channel member and does not define a flow channel through which liquid flows, and includes a contact portion that contacts the upper surface of the protective substrate facing the second direction and a supported portion that is supported by the holder. With this configuration, when an external force is applied in the second direction from the nozzle surface side of the liquid spray head, such as when the printing medium collides with the nozzle surface, the movement of the protective substrate in the second direction can be restricted by the holder via the intermediate member. Therefore, deformation of the first flow channel member due to external force can be suppressed, and the cracking of the first flow channel member can be suppressed.

[0111] In Embodiment 2, which is a specific example of Embodiment 1, the contact portion of the relay member is in contact with the upper surface of the protective substrate, but is not adhered to it, and the supported portion of the relay member is positioned at a distance from the holder and fixed to the holder by adhesive placed at that distance. This prevents the relay member from being adhered to the protective substrate, thereby preventing the deformation of the holder and relay member due to the difference in coefficients of thermal expansion between the holder and the protective substrate from being transmitted to the protective substrate, and thus suppressing damage to the piezoelectric actuator 300.

[0112] In Embodiment 3, which is a specific example of Embodiment 1, the relay member includes a base portion extending from the contact portion in a second direction beyond the second flow path member, and a flange portion extending from the base portion in a direction perpendicular to the second direction, and the supported portion is provided on the flange portion. With this, the pressure-receiving area can be increased by providing the flange portion, thereby suppressing deformation of the holder.

[0113] In Embodiment 4, which is a specific example of Embodiment 1, the supported portion is supported on the lower surface of the holder facing the first direction. This makes it easier to suppress deformation of the first flow path member by having the intermediate member receive pressure on the lower surface of the holder.

[0114] In embodiment 5, which is a specific example of embodiment 4, a recess is formed on the upper surface of the second flow channel member facing the second direction for accommodating the supported portion. This allows the liquid injection head to be miniaturized in the second direction by providing a recess in the second flow channel member and accommodating the supported portion within the recess.

[0115] In embodiment 6, which is a specific example of embodiment 4, the relay member includes a rib that protrudes in the second direction from the supported portion. This improves the rigidity of the relay member, suppresses deformation of the relay member, and further suppresses deformation of the first flow channel member.

[0116] In Embodiment 7, which is a specific example of Embodiment 1, the supported portion is supported on the upper surface of the holder facing the second direction. With this configuration, after the positioning of the head chip relative to the holder is completed, the intermediate member can be inserted from the surface of the holder facing the second direction and fixed to the holder. Therefore, the influence of fixing the intermediate member to the holder on the positioning of the head chip relative to the holder can be suppressed. In addition, since the gap between the second flow channel member and the holder can be reduced, the narrowing of the flow channel provided in the second flow channel member can be suppressed.

[0117] In embodiment 8, which is a specific example of embodiment 7, a recess is formed on the upper surface of the holder for accommodating the supported portion. This allows the liquid spray head to be miniaturized in the second direction by providing a recess in the holder and accommodating the supported portion within the recess.

[0118] In embodiment 9, which is a specific example of embodiment 1, the relay member has an annular opening for inserting the flexible substrate when viewed in the first direction. This improves the rigidity of the relay member, suppresses deformation of the relay member, and further suppresses deformation of the first flow channel member.

[0119] In embodiment 10, which is a specific example of embodiment 1, the flexible substrate has a first surface and a second surface opposite to the first surface, and the relay member includes a first member facing the first surface and a second member separate from the first member and facing the second surface. This makes it easier to secure space for inserting the flexible substrate between the first member and the second member, thereby improving ease of assembly.

[0120] In embodiment 11, which is a specific example of embodiment 10, a drive circuit for driving the drive element is provided on the second surface of the flexible substrate, the first member is made of metal, and the second member is made of resin. With this, by making the second member of resin, conductivity between the drive circuit and the second member can be suppressed, thereby suppressing electrical malfunctions caused by conductivity. Furthermore, by making the first member of metal, the rigidity of the first member can be improved, and deformation of the first flow channel member can be suppressed.

[0121] In embodiment 12, which is a specific example of embodiment 1, the holder comprises a second head tip having a nozzle for spraying liquid, and a fixing plate to which the first head tip and the second head tip are fixed, and which has a plurality of exposed openings for exposing the nozzle of the first head tip and the nozzle of the second head tip to the outside, wherein the holder holds the first head tip and the second head tip between itself and the fixing plate.

[0122] A liquid injection device according to embodiment 13, which is a preferred embodiment, comprises a liquid injection head as described in any of embodiments 1 to 12, and a liquid storage unit for storing the liquid supplied to the liquid injection head. This makes it possible to realize a liquid injection device that suppresses damage to the liquid injection head. [Explanation of Symbols]

[0123] S...medium, 1...liquid injection device, 2...liquid injection head, 3...liquid reservoir, 4...control unit, 5...transport mechanism, 6...moving mechanism, 7...circulation mechanism, 8...head tip, 10...pressure chamber substrate, 12...pressure chamber, 15...communication plate, 16...nozzle communication passage, 19...supply communication passage, 20...nozzle plate, 21...nozzle, 22...filler, 30...protective substrate, 30a...top surface, 31...holding part, 32...through hole, 40...case member, 40a...bottom surface, 41...recess, 43...opening 44a...Inlet, 44b...Outlet, 45...Housing section, 50...Diaphragm, 51...Elastic film, 52...Insulating film, 60...First electrode, 70...Piezoelectric layer, 80...Second electrode, 90...Lead electrode, 100...Manifold, 110...Flexible substrate, 110a...First surface, 110b...Second surface, 111...Drive circuit, 120...Compliance substrate, 121...Sealing film, 122...Fixed substrate, 123...Opening, 124...Compliance section, 130...Adhesive, 200...H Holder, 200a...bottom surface, 200b...top surface, 201...head chip housing section, 202...wiring holding hole, 203...opening for external wiring, 204...projection, 205...recess, 210...connecting flow path member, 211...member, 214...flow path connection section, 214a...supply side flow path connection section, 214b...discharge side flow path connection section, 220...sealing member, 230...intermediate substrate, 232...wiring insertion hole, 233...projection insertion hole, 240...fixing plate, 241...exposed opening, 250...intermediate member, 250A...First member, 250B...Second member, 251...Base part, 252...Flange part, 253...Opening, 254...Notch part, 255...Supported part, 256...Contact part, 257...Rib, 258a...First reinforcement part, 258b...Second reinforcement part, 258c...Third reinforcement part, 260...Adhesive, 270...First jig, 271...Second jig, 300...Piezoelectric actuator, 310...Activated part, 400...Flow path, 401...First flow path, 402...Second flow path, 403...Communicating flow path.

Claims

1. A first head tip having a nozzle for spraying liquid in a first direction, A holder for holding the first head tip is positioned in a second direction opposite to the first direction, Intermediate members and Equipped with, The first head tip is A first flow channel member having a flow channel that communicates with the nozzle, A pressure chamber substrate having a pressure chamber communicating with the nozzle, and stacked in the second direction relative to the first flow path member, A driving element that causes a pressure change in the liquid inside the pressure chamber, A flexible substrate electrically connected to the aforementioned drive element, A protective substrate is stacked in the second direction relative to the pressure chamber substrate and houses the drive element, The first flow channel member has a flow channel that communicates with the flow channel of the first flow channel member, and an opening into which the flexible substrate is inserted, and the second flow channel member is stacked in the second direction relative to the first flow channel member at a position different from the pressure chamber substrate, The relay member is inserted into the opening of the second flow path member and does not define a flow path through which liquid flows, and includes a contact portion that contacts the upper surface of the protective substrate facing the second direction, and a supported portion that is supported by the holder. A liquid spray head characterized by the following features.

2. The contact portion of the relay member is not adhered to the upper surface of the protective substrate, but is in contact with it. The supported portion of the relay member is positioned at a distance from the holder and is fixed to the holder by an adhesive placed at that distance. A liquid spray head according to claim 1.

3. The relay member includes a base portion extending from the contact portion in a direction more toward the second direction than the second flow channel member, and a flange portion extending from the base portion in a direction perpendicular to the second direction. The supported portion is provided on the flange portion, A liquid spray head according to feature 1.

4. The supported portion is supported on the lower surface of the holder facing the first direction. A liquid spray head according to feature 1.

5. A recess for accommodating the supported portion is formed on the upper surface of the second flow channel member facing the second direction. A liquid spray head according to feature 4.

6. The relay member includes a rib that protrudes in the second direction from the supported portion, A liquid spray head according to feature 4.

7. The supported portion is supported on the upper surface of the holder facing the second direction. A liquid spray head according to feature 1.

8. A recess for accommodating the supported portion is formed on the upper surface of the holder. A liquid spray head according to feature 7.

9. The relay member has an annular opening for inserting the flexible substrate when viewed in the first direction, A liquid spray head according to feature 1.

10. The flexible substrate has a first surface and a second surface opposite to the first surface. The relay member includes a first member facing the first surface and a second member that is separate from the first member and facing the second surface. A liquid spray head according to feature 1.

11. A drive circuit for driving the drive element is provided on the second surface of the flexible substrate. The first member is made of metal, The second member is made of resin, A liquid spray head according to the features of 10.

12. A second head tip having a nozzle for spraying liquid, A fixing plate to which the first head tip and the second head tip are fixed, having a plurality of exposure openings for exposing the nozzle of the first head tip and the nozzle of the second head tip to the outside, Equipped with, The holder holds the first head chip and the second head chip between itself and the fixing plate. 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 for storing the liquid to be supplied to the liquid injection head, A liquid injection device characterized by being equipped with the following features.

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