Liquid ejecting head and image forming apparatus

Abstract

The invention provides a liquid ejection head and an image forming apparatus capable of suppressing outflow of an adhesive to a vibrating plate. The liquid ejection head includes: a pressure chamber substrate in which a pressure chamber in which liquid to be ejected is stored is formed; a flow path forming substrate forming a flow path through which the liquid flows; a pressure unit that applies pressure to the liquid in the pressure chamber; and a vibration plate that is joined to the pressure part and vibrates in conjunction with the displacement of the pressure part, the pressure chamber substrate being joined to the flow path forming substrate by means of an adhesive, the pressure chamber substrate having an inclined part, and the inclined part being provided with an inclined surface. The inclined portion has one or more inclined surfaces inclined in a direction normal to a surface of the diaphragm so that a width of the pressure chamber becomes narrower toward the diaphragm.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and an image forming apparatus. Background Art

[0002] Image forming devices have long been proposed that include a liquid ejection head for ejecting liquids such as ink onto media such as printing paper. In recent years, image forming devices have garnered attention not only for printing applications but also as devices capable of applying liquefiable materials to any location. Among the liquid ejection heads used in image forming devices, one known type utilizes a piezoelectric element to vibrate a vibration plate forming the wall of a pressure chamber, thereby ejecting liquid from a nozzle within the pressure chamber.

[0003] The liquid ejection head described in Patent Document 1 includes an actuator substrate and a retaining substrate bonded to the actuator substrate via an adhesive. The actuator substrate includes a flow channel forming portion, a vibrating plate, a piezoelectric element, and a bonding portion. The flow channel forming substrate includes a liquid chamber. The vibrating plate forms one wall surface of the liquid chamber. The piezoelectric element is disposed on the surface of the vibrating plate opposite the liquid chamber. The bonding portion is a portion bonded to the retaining substrate via an adhesive.

[0004] When adhesive is used to connect the joint and the retaining substrate, there is a risk that softened excess adhesive may flow out of the joint and onto the vibrating plate. Furthermore, if the adhesive solidifies on the vibrating plate, the solidified adhesive can hinder the plate's displacement, causing ink ejection deviation. In this document, a protruding structure is provided near the joint to block the adhesive.

[0005] However, in the prior art, the steps formed by the protruding structures are parallel to the vertical direction. Therefore, the adhesive tends to flow vertically downward. Therefore, further efforts are needed to suppress the adhesive from flowing out to the vibration plate.

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-172328 Summary of the Invention

[0007] The liquid ejection head involved in a preferred embodiment of the present invention comprises: a pressure chamber substrate, which forms a pressure chamber for storing the ejected liquid; a flow channel forming substrate, which forms a flow channel for the liquid to flow; a pressure portion, which applies pressure to the liquid in the pressure chamber; a vibration plate, which is joined to the pressure portion and vibrates in a manner linked to the displacement of the pressure portion, the pressure chamber substrate is joined to the flow channel forming substrate by an adhesive, and the pressure chamber substrate has an inclined portion, which has one or more inclined surfaces that are inclined in the normal direction of the surface of the vibration plate in a manner that narrows the width of the pressure chamber as it approaches the vibration plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram illustrating the configuration of the image forming apparatus according to the first embodiment.

[0009] Figure 2 for Figure 1 An exploded perspective view of the liquid ejection head is shown.

[0010] Figure 3 for Figure 1 A cross-sectional view of a portion of a liquid ejection head is shown.

[0011] Figure 4 To magnify Figure 3 FIG. 1 is a diagram of a portion of a liquid ejection head.

[0012] Figure 5 To magnify Figure 3 FIG. 1 is a diagram of a portion of a liquid ejection head.

[0013] Figure 6 To express Figure 5 A perspective view of a portion of a pressure chamber substrate.

[0014] Figure 7 A diagram for explaining the bonding of a pressure chamber substrate and a flow path forming substrate.

[0015] Figure 8 A diagram for explaining the bonding of a pressure chamber substrate and a flow path forming substrate.

[0016] Figure 9 It is a diagram for explaining the outflow of the adhesive in the comparative example.

[0017] Figure 10 This is a diagram for explaining the outflow of the adhesive in this embodiment.

[0018] Figure 11 for Figure 5 An enlarged view of the inclined portion.

[0019] Figure 12For use in Figure 11 FIG. 1 is a diagram illustrating outflow of the adhesive in the inclined portion.

[0020] Figure 13 It is a diagram showing an inclined portion according to the second embodiment.

[0021] Figure 14 It is a diagram for explaining the outflow of the adhesive in the second embodiment.

[0022] Figure 15 This is a diagram for explaining another example of the outflow of the adhesive in the second embodiment.

[0023] Figure 16 A diagram showing an inclined portion of a modified example.

[0024] Figure 17 A diagram showing an inclined portion according to another modified example.

[0025] Figure 18 A diagram for explaining the bonding of a pressure chamber substrate and a flow path forming substrate. DETAILED DESCRIPTION

[0026] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the accompanying drawings, the dimensions or scales of each part are appropriately different from the actual ones, and there are also parts that are schematically shown for easy understanding. In addition, as far as the scope of the present invention is concerned, it is not limited to these embodiments as long as there is no record of the subject matter that specifically limits the present invention in the following description. In addition, the so-called "element β on element γ" is not limited to a structure in which element γ is in direct contact with element β, but also includes a structure in which element γ is not in direct contact with element β. The so-called "element γ is the same as element β" means that element γ and element β are substantially the same, including manufacturing errors, etc.

[0027] 1. First Implementation

[0028] 1-1. Overall Structure of Image Forming Apparatus 100

[0029] Figure 1 1 is a schematic diagram illustrating the structure of the image forming apparatus 100 according to the first embodiment. For ease of explanation, the following description uses, as appropriate, mutually orthogonal X-axis, Y-axis, and Z-axis. Furthermore, one direction along the X-axis is labeled as the X1 direction, and the direction opposite to the X1 direction is labeled as the X2 direction. Similarly, one direction along the Y-axis is labeled as the Y1 direction, and the direction opposite to the Y1 direction is labeled as the Y2 direction. One direction along the Z-axis is labeled as the Z1 direction, and the direction opposite to the Z1 direction is labeled as the Z2 direction.

[0030] Figure 1 The image forming apparatus 100 is an inkjet printing apparatus that ejects ink, which is an example of liquid, onto a medium 90. Although the medium 90 is typically printing paper, a printing object made of any material such as a resin film or cloth can also be used as the medium 90. Figure 1 As illustrated in FIG, the image forming apparatus 100 is provided with a liquid container 9 for storing ink. For example, a cartridge that can be attached to and detached from the image forming apparatus 100, an ink bag in the form of a bag made of a flexible film, or an ink tank capable of refilling ink can be used as the liquid container 9.

[0031] The image forming apparatus 100 includes a control unit 20, a medium transport mechanism 22, a moving mechanism 24, and a liquid ejection head 3. The control unit 20 includes, for example, one or more processing circuits such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and one or more storage circuits such as a semiconductor memory, and centrally controls the various components of the image forming apparatus 100.

[0032] The medium transport mechanism 22 transports the medium 90 in the direction along the Y-axis under the control of the control unit 20. Furthermore, the moving mechanism 24 reciprocates the liquid ejecting head 3 along the X-axis under the control of the control unit 20. The moving mechanism 24 includes a substantially box-shaped transport body 242 that houses the liquid ejecting head 3, and a transport belt 244 that secures the transport body 242. Alternatively, a configuration in which multiple liquid ejecting heads 3 are mounted on the transport body 242, or a configuration in which the liquid container 9 is mounted on the transport body 242 together with the liquid ejecting head 3, may be employed.

[0033] The liquid ejection head 3 ejects ink supplied from the liquid container 9 onto the medium 90 from a plurality of nozzles under the control of the control unit 20. Each liquid ejection head 3 ejects ink onto the medium 90 in parallel with the transport of the medium 90 by the medium transport mechanism 22 and the repeated reciprocating movement of the transport body 242, thereby forming an image on the surface of the medium 90.

[0034] The image forming apparatus 100 includes the liquid ejecting head 3 having the characteristics described below, thereby suppressing a decrease in printing quality.

[0035] 1-2. Overall Structure of the Liquid Ejection Head 3

[0036] Figure 2 for, Figure 1 An exploded perspective view of the liquid ejection head 3 is shown. Figure 3 for, Figure 1 A sectional view of a portion of the liquid ejection head shown in FIG. Figure 2 Cross-sectional view of line aa in . Figure 3 The cross section shown in FIG is a cross section parallel to the XZ plane. The Z axis is an axis along the direction of ink ejection from the liquid ejection head 3. The "first direction" intersecting the Z2 direction is, for example, a direction along the X axis, and is either the X1 direction or the X2 direction.

[0037] As Figure 2 As shown in the example, the liquid ejection head 3 includes a plurality of nozzles N arranged along the Y axis. The plurality of nozzles N in the first embodiment are divided into a first column La and a second column Lb, which are spaced apart from each other and arranged side by side along the X axis. The first column La and the second column Lb are respectively a collection of a plurality of nozzles N arranged in a straight line along the Y axis. The liquid ejection head 3 is a structure in which the elements associated with each nozzle N in the first column La and the elements associated with each nozzle N in the second column Lb are arranged in a roughly plane-symmetrical manner. In the following description, the elements corresponding to the first column La are mainly described, and the description of the elements corresponding to the second column Lb is appropriately omitted.

[0038] As Figure 2 as well as Figure 3 As shown, the liquid ejection head 3 includes a flow channel forming substrate 31, a pressure chamber substrate 32, a vibration plate 33, a nozzle plate 37, a vibration absorber 38, multiple pressure sections 34, a sealing member 35, a housing 36, and a wiring substrate 40. The flow channel forming substrate 31, the pressure chamber substrate 32, the vibration plate 33, the nozzle plate 37, the vibration absorber 38, the sealing member 35, and the housing 36 are each elongated plate-shaped members extending along the Y axis. Furthermore, the nozzle plate 37, the flow channel forming substrate 31, the pressure chamber substrate 32, the vibration plate 33, and the sealing member 35 are arranged in this order in the Z2 direction.

[0039] The nozzle plate 37 is a plate-shaped member formed with a plurality of nozzles N. Each of the plurality of nozzles N is a circular through-hole that ejects ink. The nozzle plate 37 is bonded to the surface of the flow path forming substrate 31 in the Z1 direction using, for example, an adhesive.

[0040] The flow channel forming substrate 31 forms a flow channel for ink to flow. Specifically, a space Ra, a relay liquid chamber Rb, a plurality of supply flow channels 312, and a plurality of connecting flow channels 314 are formed in the flow channel forming substrate 31. The space Ra is an opening formed in the shape of an elongated strip along the Y axis. The supply flow channel 312 and the connecting flow channel 314 are through-holes formed for each nozzle N, respectively. Each connecting flow channel 314 overlaps with a corresponding nozzle N when viewed from above in the Z1 direction. The relay liquid chamber Rb is a space formed in the shape of an elongated strip along the Y axis across the plurality of nozzles N, and the space Ra and the plurality of supply flow channels 312 are connected to each other. The pressure chamber substrate 32 is bonded to the surface of the flow channel forming substrate 31 in the Z2 direction by an adhesive.

[0041] A plurality of pressure chambers C1 are formed in the pressure chamber substrate 32. Ink ejected from the nozzle N is stored in the pressure chamber C1. The pressure chamber C1 is located between the nozzle plate 37 and the vibration plate 33 and is a space formed by the inner wall surface 32a of the pressure chamber substrate 32. The pressure chamber C1 is formed for each nozzle N. The pressure chamber C1 is a long strip of space and extends along the X1 direction. The plurality of pressure chambers C1 are arranged along the Y axis. Each pressure chamber C1 is connected to the connecting flow channel 314 and the supply flow channel 312. Therefore, the pressure chamber C1 is connected to the nozzle N via the connecting flow channel 314, and is connected to the space Ra via the supply flow channel 312 and the relay liquid chamber Rb.

[0042] The nozzle plate 37, the flow channel forming substrate 31, and the pressure chamber substrate 32 are manufactured, for example, by processing a single crystal silicon (Si) substrate using semiconductor manufacturing techniques such as photolithography and etching. However, any known materials or manufacturing methods can be used to manufacture the nozzle plate 37, the flow channel forming substrate 31, and the pressure chamber substrate 32.

[0043] The vibration plate 33 is connected to the surface of the pressure chamber substrate 32 opposite the flow channel substrate 31. The vibration plate 33 is positioned above the pressure chamber C1 and is elastically deformable. The vibration plate 33 is a plate-like component formed into a long rectangular shape along the Y axis when viewed from above. The vibration plate 33 and the pressure chamber can be either integral or separate components joined together using an adhesive or the like.

[0044] A pressure portion 34 is formed on the surface of the vibration plate 33 opposite the pressure chamber C1. Each pressure portion 34 is provided for each pressure chamber C1. When viewed from above, the pressure portion 34 is an elongated strip extending along the X-axis. The pressure portion 34 is a piezoelectric element that applies pressure to the ink in the pressure chamber C1. The pressure portion 34 is also a driving element that is driven by an applied driving signal.

[0045] The sealing body 35 is bonded to the vibration plate 33 using, for example, an adhesive. The sealing body 35 protects the multiple pressure portions 34 and reinforces the mechanical strength of the pressure chamber substrate 32 and the vibration plate 33. The sealing body 35 has a recess formed on the surface facing the vibration plate 33. The multiple pressure portions 34 are housed within this recess. The sealing body 35 also has a space 353 through which the wiring substrate 40 is inserted.

[0046] The housing 36 is bonded to the flow channel forming substrate 31 using, for example, an adhesive. The housing 36 is a casing for storing ink supplied to the multiple pressure chambers C1. The housing 36 is formed, for example, by injection molding of a resin material. A space Rc, a supply port 361, and a space 362 are formed in the housing 36. The supply port 361 is a conduit for supplying ink from the liquid container 9 and communicates with the space Rc. The space Rc communicates with the space Ra of the flow channel forming substrate 31. The space formed by the spaces Rc and Ra functions as a liquid storage chamber R for storing ink supplied to the multiple pressure chambers C1. Ink supplied from the liquid container 9 and passing through the supply port 361 is stored in the liquid storage chamber R. The ink stored in the liquid storage chamber R branches from the relay liquid chamber Rb to each supply channel 312 and is supplied in parallel to the multiple pressure chambers C1. Furthermore, the space 362 overlaps with the space 353 of the sealing body 35 when viewed from above. The wiring substrate 40 is inserted into the space 353 and the space 362 .

[0047] The wiring substrate 40 is connected to the vibration plate 33. The wiring substrate 40 is a mounting component formed with a plurality of wirings for electrically connecting the control unit 20 and the liquid ejection head 3. A flexible wiring substrate 40, such as an FPC (Flexible Printed Circuit) or FFC (Flexible Flat Cable), is preferably used. The driving signals and reference voltage for driving the pressure sections 34 are supplied to each pressure section 34 from the wiring substrate 40.

[0048] A vibration absorber 38 is bonded to the Z1 direction surface of the flow path forming substrate 31 with, for example, an adhesive. The vibration absorber 38 is a flexible film constituting the wall surface of the space Ra and absorbs pressure fluctuations of the ink in the liquid storage chamber R.

[0049] 1-3. Specific Structure of a Part of the Liquid Ejection Head 3

[0050] Figure 4 as well as Figure 5 They are magnified Figure 3 FIG. 1 is a diagram of a portion of the liquid ejection head 3. Figure 4 The cross section shown in FIG is a cross section parallel to the YZ plane. Figure 5 The cross section shown in FIG is a cross section parallel to the XZ plane.

[0051] like Figure 4 as well as Figure 5 As shown, the pressure portion 34 is schematically a structure in which a first electrode 341, a piezoelectric body 343, and a second electrode 342 are stacked in this order from the vibration plate 33. The first electrode 341 and the second electrode 342 have different potentials.

[0052] The first electrode 341 is formed on the surface of the vibration plate 33. The first electrode 341 is an independent electrode formed separately for each pressure portion 34. A driving signal with a varying voltage is applied to the first electrode 341. The first electrode 341 is in the shape of a strip extending along the X-axis. Multiple first electrodes 341 are arranged along the Y-axis with intervals between them. The first electrode 341 is formed of a conductive material such as platinum (Pt) or iridium (Ir).

[0053] The piezoelectric body 343 is provided on the first electrode 341. The piezoelectric body 343 is, for example, a strip-shaped dielectric film that extends across the plurality of pressure sections 34 and is continuous along the Y-axis. The piezoelectric body 343 is, for example, a strip-shaped film that extends along the Y-axis and is separated for each pressure section 34 by forming a plurality of cuts. The piezoelectric body 343 is formed of a known piezoelectric material, such as lead zirconate titanate (Pb(Zr,Ti)O3).

[0054] The second electrode 342 is provided on the piezoelectric body 343. The second electrode 342 is a common, strip-shaped electrode that extends continuously along the Y-axis, spanning multiple pressure sections 34. A predetermined reference voltage is applied to the second electrode 342. The second electrode 342 is formed of a low-resistance conductive material such as platinum or iridium.

[0055] A voltage corresponding to the difference between the reference voltage applied to the second electrode 342 and the drive signal corresponding to the ejection amount supplied to the first electrode 341 is applied to the piezoelectric element 343. The voltage applied between the first electrode 341 and the second electrode 342 causes the piezoelectric element 343 to deform. This deformation causes the pressure section 34 to flex, or vibrate, the vibration plate 33. The vibration of the vibration plate 33 changes the pressure in the pressure chamber C1, causing the ink within the pressure chamber C1 to be ejected from the nozzle N.

[0056] The vibration plate 33 vibrates by being driven by the pressure portion 34. In the illustrated example, the vibration plate 33 is composed of a stack including a first layer 331 and a second layer 332. The first layer 331 is in contact with the pressure chamber substrate 32. The first layer 331 is formed of an elastic material such as silicon dioxide (SiO2). The second layer 332 is formed of an insulating material such as zirconium dioxide (ZrO2). The first layer 331 is formed, for example, by thermally oxidizing a portion of the pressure chamber substrate 32. The second layer 332 is formed, for example, by a known film forming technique such as sputtering. In addition, the vibration plate 33 may be composed of one layer or three or more layers.

[0057] A recessed portion 330 is provided on the pressure chamber substrate 32 side of the vibration plate 33. The recessed portion 330 is formed by removing a portion of the vibration plate 33. In the illustrated example, the recessed portion 330 is provided on the first layer 331. While the recessed portion 330 does not penetrate the first layer 331, it may also penetrate the first layer 331. In this case, the bottom surface of the recessed portion 330 is formed by the second layer 332. Alternatively, the recessed portion 330 may be formed by removing a portion of the second layer 332.

[0058] The recessed portion 330 has a recessed portion 335 in the portion that joins the pressure chamber base plate 32. The recessed portion 335 corresponds to the outer periphery of the recessed portion 330 and is provided so as to span the entire circumference of the recessed portion 330 when viewed from above. As will be described later, the recessed portion 335 includes a portion that overlaps with the inclined portion 320 of the pressure chamber base plate 32 when viewed from above. Therefore, the recessed portion 335 includes a portion that is concave along the X1 direction and a portion that is concave along the X2 direction.

[0059] Figure 6 For, means Figure 5 A perspective view of a portion of the pressure chamber substrate 32. Figure 5 as well as Figure 6 As shown, the pressure chamber substrate 32 has two inclined portions 320 . The inclined portions 320 are provided at both ends of the pressure chamber C1 in the direction along the X axis. Furthermore, the inclined portions 320 are provided at the portion of the pressure chamber substrate 32 that is bonded to the vibration plate 33 .

[0060] Each inclined portion 320 includes an inclined surface 325. The inclined surface 325 is a flat surface and is inclined relative to the normal line A1 of the surface 33a of the vibration plate 33. The inclined surface 325 is inclined so that the width of the pressure chamber C1 becomes narrower toward the vibration plate 33 in the Z2 direction.

[0061] Figure 7 as well as Figure 8 3 is a diagram for explaining the bonding between the pressure chamber substrate 32 and the flow path forming substrate 31. Figure 7 As shown, adhesive 5 is first applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33. Adhesive 5 is a thermosetting resin. Therefore, before curing, adhesive 5 is fluid. Therefore, when adhesive 5 is applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33, there is a possibility that adhesive 5 will flow vertically downward from this opposite surface, in the Z2 direction. Note that the Z2 direction corresponds to vertically downward when adhesive 5 is applied.

[0062] like Figure 8 As shown, after the adhesive 5 is applied to the pressure chamber substrate 32, the flow path forming substrate 31 is placed on the pressure chamber substrate 32. Alternatively, the pressure chamber substrate 32 may be placed on the flow path forming substrate 31. Thereafter, the adhesive 5 is cured. As a result, the pressure chamber substrate 32 and the flow path forming substrate 31 are bonded together via the adhesive 5.

[0063] Figure 9 , which is a diagram for explaining the outflow of the adhesive 5 in the comparative example. Figure 9 In the comparative example, consider the case where the pressure chamber substrate 32 does not have the inclined surface 325, and the inner wall surface 32a of the pressure chamber substrate 32, which forms the pressure chamber C1, is aligned with the vertical axis, that is, the inner wall surface is aligned with the Z2 direction. In this case, the remaining adhesive 5 applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33 is likely to flow in the Z2 direction along the inner wall surface 32a of the pressure chamber substrate 32. Therefore, as indicated by arrow Ax, the adhesive 5 is likely to flow in the Z2 direction.

[0064] When the adhesive 5 flows on the inner wall surface 32a and reaches the vibration plate 33, the displacement of the vibration plate 33 is hindered by the adhesive 5, which may cause deviations in vibration characteristics. As a result, the discharge characteristics may vary, which may reduce the printing quality.

[0065] Figure 10 , is a diagram for explaining the outflow of the adhesive 5 in this embodiment. Figure 10In the present embodiment, the pressure chamber substrate 32 has an inclined portion 320 having an inclined surface 325. From another perspective, the inner wall surface 32a of the pressure chamber substrate 32 has the inclined surface 325. The inclined surface 325 is inclined relative to the Z2 direction in such a manner that the width of the pressure chamber C1 becomes narrower as it approaches the vibration plate 33 in the Z2 direction. Therefore, the remaining portion of the adhesive 5 applied to the surface of the pressure chamber substrate 32 opposite to the vibration plate 33 flows on the inclined surface 325. Therefore, the adhesive 5 flows as shown by the arrow mark A0. By having the inclined surface 325, the outflow of the adhesive 5 to the vibration plate 33 can be suppressed compared to the case where the inclined surface 325 is not provided. Therefore, compared with the existing structure, the outflow of the adhesive 5 to the vibration plate 33 can be suppressed by a simple structure.

[0066] Because the presence of the inclined surface 325 suppresses the outflow of the adhesive 5 onto the vibration plate 33, it is possible to suppress variations in the vibration characteristics of the vibration plate 33 caused by the presence of the adhesive 5. Consequently, variations in the discharge characteristics can be suppressed, thereby preventing degradation in printing quality.

[0067] Figure 11 for, Figure 5 An enlarged view of the inclined portion 320. Figure 11 As shown, the inclined surface 325 is inclined relative to the normal direction of the surface 33a of the vibration plate 33, that is, the Z2 direction. In other words, the inclined surface 325 is inclined relative to the normal A1 of the surface 33a of the vibration plate 33. Although the inclination angle of the inclined surface 325 relative to the normal A1 is not particularly limited, it is preferably greater than 0 degrees and less than 45 degrees. By making the inclination angle less than 45 degrees, the gravity of the adhesive 5 applied in the direction of the adhesive 5 flowing out is reduced to less than half. Therefore, by being within the range involved, the flow of the adhesive 5 to the vibration plate 33 can be more effectively suppressed compared to the case outside the range.

[0068] In this embodiment, the pressure chamber substrate 32 includes two inclined portions 320 for each pressure chamber C1. The inclined surfaces 325 of the two inclined portions 320 may have the same or different inclination angles θ.

[0069] Furthermore, the inclined portion 320 is provided on the portion of the pressure chamber substrate 32 that is bonded to the vibration plate 33. Furthermore, the inclined surface 325 is provided from the surface of the pressure chamber substrate 32 opposite the vibration plate 33 to the portion bonded to the vibration plate 33. Therefore, compared to a case where the inclined surface 325 is provided only midway along the Z2 direction of the pressure chamber substrate 32, it is possible to suppress the adhesive 5 from flowing out toward the vibration plate 33.

[0070] Figure 12 For Figure 11 FIG3 is a diagram illustrating the outflow of the adhesive 5 in the inclined portion 320. As described above, the vibration plate 33 has a recessed portion 330, and the inclined portion 320 overlaps with the recessed portion 335 of the recessed portion 330 when the vibration plate 33 is viewed from above. In other words, when the vibration plate 33 is viewed in the Z2 direction, the inclined portion 320 and the recessed portion 335 overlap in the X direction and the Y direction. Figure 12 As shown, by providing the recess 335 , the adhesive 5 is easily retained at the tip 320 x of the inclined portion 320 due to surface tension. Therefore, it is possible to suppress the adhesive 5 from flowing onto the vibration plate 33 .

[0071] The recessed portion 335 preferably overlaps with the inclined portion 320 within a range of 50 nm to 2000 nm, and more preferably overlaps with the inclined portion 320 within a range of 50 nm to 1000 nm, when the vibration plate 33 is viewed from above. Figure 11 The overlap range is represented by H1 in the figure. When the overlap range is less than 50 nm, the adhesive 5 may not stay at the top portion 320x and may instead flow into the recess 335, compared to when it is greater than 50 nm. Furthermore, an overlap range of 2000 nm or less facilitates forming the recess 335 even when the vibration plate 33 and the pressure chamber substrate 32 are integral. From this perspective, an overlap range of 1000 nm or less is more preferred. The overlap range is not limited to the above range.

[0072] In addition, if Figure 5 As shown, the inclined portion 320 overlaps with the pressure portion 34 when the vibration plate 33 is viewed from above. In particular, the inclined portion 320 overlaps with the piezoelectric body 343 when viewed from above. Since the top portion 320x of the inclined portion 320 has low rigidity, it may be broken due to deformation of the vibration plate 33. Therefore, by making the inclined portion 320 overlap with the pressure portion 34 when viewed from above, the possibility of the top portion 320x of the inclined portion 320 breaking can be suppressed. In addition, the inclined portion 320 can also be provided at a position that overlaps with the portion of the piezoelectric body 343 sandwiched between the first electrode 341 and the second electrode 342 when viewed from above. The possibility of the top portion 320x breaking can be further suppressed. In addition, the inclined portion 320 does not have to overlap with the pressure portion 34.

[0073] In addition, although in this embodiment, Figure 4As shown, the pressure chamber substrate 32 does not have the inclined portion 320 in the short-side direction of the pressure chamber C1, but it may also have the inclined portion 320. Therefore, the inclined surface 325 of the inclined portion 320 may be provided so as to extend along the entire circumference of the inner wall surface of the pressure chamber substrate 32 that forms the pressure chamber C1. Providing the inclined surface 325 along the entire circumference can particularly effectively suppress the outflow of the adhesive 5 toward the vibration plate 33.

[0074] Furthermore, even when the pressure chamber substrate 32 does not have the inclined portion 320 in the short-side direction of the pressure chamber C1, as in this embodiment, the provision of the recessed portion 335 can suppress the outflow of the adhesive 5 toward the diaphragm 33. The presence of the recessed portion 335 in the short-side direction of the pressure chamber C1 allows the adhesive 5 to be retained by surface tension at the top portion of the pressure chamber substrate 32 that overlaps with the recessed portion 335 when viewed from above. Consequently, compared to a case where the recessed portion 335 is not provided, the outflow of the adhesive 5 toward the diaphragm 33 can be suppressed.

[0075] 2. Second Implementation

[0076] In the following exemplary embodiment, elements having the same effects or functions as those in the first embodiment described above will be assigned the same reference numerals as those used in the first embodiment, and detailed descriptions thereof will be omitted as appropriate.

[0077] Figure 13 3 is a diagram showing an inclined portion 320A according to the second embodiment. Figure 13 The inclined portion 320A shown has a plurality of inclined surfaces, which is different from the inclined portion 320 of the first embodiment.

[0078] The inclined portion 320A includes a first inclined surface 321, a second inclined surface 322, and a horizontal surface 323. The first and second inclined surfaces 321 and 322 are inclined relative to the normal line A1. The second inclined surface 322 is located closer to the vibration plate 33 in the Z2 direction than the first inclined surface 321. The horizontal surface 323 connects the first and second inclined surfaces 321 and 322. The horizontal surface 323 is perpendicular to the Z2 direction.

[0079] The first inclined surface 321 is inclined at a first inclination angle θ1 relative to the normal line A1. The second inclined surface 322 is inclined at a second inclination angle θ2 relative to the normal line A1. The first inclination angle θ1 and the second inclination angle θ2 are different from each other. Therefore, the inclined portion 320A has multiple inclined surfaces with different inclination angles. By having multiple inclined surfaces with different inclination angles, the adhesive 5 can be further prevented from flowing onto the vibration plate 33 compared to the first embodiment.

[0080] In particular, the second inclination angle θ2 is greater than the first inclination angle θ1. Therefore, the slope of the second inclination surface 322, which is closer to the vibration plate 33 than the first inclination surface 321, is gentler. Consequently, compared to a case where the second inclination angle θ2 is smaller than the first inclination angle θ1, the adhesive 5 can be more effectively prevented from flowing onto the vibration plate 33.

[0081] Figure 14 , which is a diagram for explaining the outflow of the adhesive 5 in the second embodiment. Figure 14 As shown, when the second inclined surface 322 has a gentler slope than the first inclined surface 321, the adhesive 5 flows as indicated by arrow A5 and tends to stay on the second inclined surface 322. The adhesive 5 tends to stay at the top end of the second inclined surface 322, that is, the top end 320x of the inclined portion 320. Therefore, the adhesive 5 can be prevented from flowing out toward the vibration plate 33.

[0082] Figure 15 FIG. 2 is a diagram for explaining another example of the outflow of the adhesive 5 in the second embodiment. Figure 15 As shown, the adhesive 5 can also flow as indicated by arrow mark A6 and stay on the horizontal surface 323. Since the horizontal surface 323 is horizontal, the adhesive 5 is easy to stay. Therefore, the existence of the horizontal surface 323 can suppress the adhesive 5 from flowing out to the vibration plate 33.

[0083] Although not shown, the adhesive 5 may also stay on the first inclined surface 321. For example, by making the second inclined angle θ2 smaller than the first inclined angle θ1, the first inclined surface 321 is made flatter than the second inclined surface 322. This makes it easier for the adhesive 5 to stay on the first inclined surface 321.

[0084] The second inclination angle θ2 may be the same as the first inclination angle θ1. Even in this case, the plurality of inclined surfaces of the inclined portion 320 can further suppress the adhesive 5 from flowing onto the vibration plate 33 compared to a case where the inclined portion 320 has a single inclined surface.

[0085] 3. Modifications

[0086] The embodiments illustrated above can be modified in various ways. Specific modifications applicable to the embodiments described above will be illustrated below. Two or more embodiments arbitrarily selected from the following examples can be appropriately combined within the scope of non-contradiction.

[0087] The inclined surface 325 does not need to be a flat surface, and may include, for example, projections and depressions, or a curved surface that is convex toward the vibration plate 33 .

[0088] Figure 16 , which is a diagram showing an inclined portion 320B of a modified example. Figure 16 In the example shown, the inclined portion 320B does not overlap with the recessed portion 330 of the vibration plate 33 when viewed from above. Therefore, the recessed portion 330 does not have the recessed portion 335. Figure 16 In the example shown, it is also possible to suppress the adhesive 5 from flowing out to the vibration plate 33 .

[0089] Figure 17 FIG. 3 is a diagram showing an inclined portion 320C according to another modified example. Figure 17 In the example shown, the inclined portion 320C does not overlap with the recessed portion 330 of the vibration plate 33 when viewed from above. The top of the inclined portion 320B is removed. Therefore, the inclined portion 320 has an inclined surface 325 and a vertical surface 324. The vertical surface 324 connects the inclined surface 325 and the vibration plate 33. Even in Figure 17 In the example shown, it is also possible to suppress the adhesive 5 from flowing out to the vibration plate 33 .

[0090] Figure 18 3 is a diagram for explaining the bonding between the pressure chamber substrate 32 and the flow path forming substrate 31. Figure 18 In the example shown, the adhesive 5 is applied to the flow channel forming substrate 31, and the pressure chamber substrate 32 is brought close to the flow channel forming substrate 31 as indicated by arrow A3, thereby placing the pressure chamber substrate 32 on the flow channel forming substrate 31. By applying the adhesive 5 to the flow channel forming substrate 31, it is possible to suppress the adhesive 5 from flowing out to the vibration plate 33, compared to the case where the adhesive 5 is applied to the pressure chamber substrate 32.

[0091] Furthermore, the “liquid ejection head” may be a so-called circulation-type head having a circulation flow path.

[0092] The term "image forming device" refers to a device that is used specifically for printing and can be used in various devices such as fax machines and copiers. The use of image forming devices is not limited to printing. For example, an image forming device that ejects a solution of a color material can be used as a manufacturing device for forming a color filter of a display device such as a liquid crystal display panel. In addition, an image forming device that ejects a solution of a conductive material can be used as a manufacturing device for forming wiring or electrodes of a wiring substrate. In addition, an image forming device that ejects a solution of an organic substance related to a living organism can be used as a manufacturing device for manufacturing a biochip, for example.

[0093] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments. In addition, the structure of each part of the present invention can be replaced with any structure that performs the same function as the above-described embodiments, and any structure can be added.

[0094] Explanation of symbols

[0095] 3…Liquid ejection head; 5…Adhesive; 9…Liquid container; 20…Control unit; 22…Medium conveying mechanism; 24…Moving mechanism; 31…Flow path forming substrate; 32…Pressure chamber substrate; 32a…Inner wall surface; 33…Vibration plate; 33a…Surface; 34…Pressure portion; 35…Sealing member; 36…Casing portion; 37…Nozzle plate; 38…Vibration absorber; 40…Wiring substrate; 90…Medium; 100…Image forming device; 242…Conveyor; 244…Conveyor belt; 312…Supply flow path; 314…Connecting flow path; 320…Inclined portion; 320A…Inclined portion; 320B…Inclined portion; 320C…Inclined portion; 321…First inclined surface; 322…Second inclined surface Slanted surface; 323…horizontal surface; 324…vertical surface; 325…inclined surface; 330…recessed portion; 331…first layer; 332…second layer; 335…recessed portion; 341…first electrode; 342…second electrode; 343…piezoelectric body; 353…space; 361…supply port; 362…space; A0…arrow mark; A1…normal line; A3…arrow mark; A5…arrow mark; A6…arrow mark; Ax…arrow mark; C1…pressure chamber; La…first column; Lb…second column; N…nozzle; R…liquid storage chamber; Ra…space; Rb…relay liquid chamber; Rc…space; θ…angle of inclination; θ1…first angle of inclination; θ2…second angle of inclination.

Claims

1. A liquid ejection head, characterized in that: have: a pressure chamber substrate forming a pressure chamber in which the ejected liquid is stored; a flow channel forming substrate, which forms a flow channel for liquid to flow; a pressure portion that applies pressure to the liquid in the pressure chamber; a vibration plate which is engaged with the pressure portion and vibrates in conjunction with the displacement of the pressure portion, The pressure chamber substrate is bonded to the flow path forming substrate by an adhesive. The pressure chamber substrate includes an inclined portion having one or more inclined surfaces inclined in a normal direction of a surface of the vibration plate so as to narrow the width of the pressure chamber toward the vibration plate.

2. The liquid ejection head according to claim 1, wherein The inclination angle of the one or more inclined surfaces relative to the normal direction is greater than 0 degree and less than 45 degrees.

3. The liquid ejection head according to claim 2, wherein: The more than one inclined surface is a plurality of inclined surfaces, The inclination angles of the plurality of inclined surfaces are different from each other.

4. The liquid ejection head according to claim 3, wherein: The one or more inclined surfaces include a first inclined surface and a second inclined surface, wherein the second inclined surface is provided closer to the vibration plate in the normal direction than the first inclined surface. The second inclination angle, which is an inclination angle of the second inclination surface relative to the normal direction, is greater than the first inclination angle, which is an inclination angle of the first inclination surface relative to the normal direction.

5. The liquid ejection head according to claim 1, wherein The pressure chamber is extended in a first direction intersecting the normal direction, The inclined portions are provided at both ends of the pressure chamber in the first direction.

6. The liquid ejection head according to claim 1, wherein The inclined portion is provided on a portion of the pressure chamber substrate that is joined to the vibration plate.

7. The liquid ejection head according to any one of claims 1 to 6, wherein: The vibration plate includes a recessed portion, the recessed portion being provided in a portion joined to the pressure chamber substrate and being concave along a first direction intersecting the normal direction. The inclined portion overlaps the recessed portion when the vibration plate is viewed from above.

8. The liquid ejection head according to claim 7, wherein: The recessed portion and the inclined portion overlap within a range of 50 nm to 1000 nm inclusive when the vibration plate is viewed in a plan view.

9. The liquid ejection head according to claim 1, wherein: The inclined portion overlaps the pressure portion when the vibration plate is viewed in a plan view.

10. An image forming device, characterized in that: In an image forming apparatus including a liquid ejection head for ejecting liquid, The liquid ejection head is the liquid ejection head according to any one of claims 1 to 6.

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