Liquid discharge head and image formation device

Abstract

To provide a liquid discharge head which can suppress flowing of an adhesive agent to a vibration plate.SOLUTION: A liquid discharge head comprises: a pressure chamber substrate which forms a pressure chamber in which discharged liquid is stored; a channel formation substrate for forming a channel in which the liquid flows; a pressure part for applying a pressure to the liquid in the pressure chamber; and a vibration plate which is joined to the pressure part, and vibrates in linkage with displacement of the pressure part. The pressure chamber substrate is joined to the channel formation substrate by the adhesive agent, and in a normal direction of a surface of the vibration plate, the pressure chamber substrate has: an inclined part which has one or more inclined surfaces being inclined so as to, as approaching the vibration plate, a width of the pressure chamber becomes smaller.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Image forming apparatuses equipped with liquid ejection heads that eject liquid such as ink onto a medium such as printing paper have been proposed. In recent years, image forming apparatuses have been attracting attention not only for printing purposes but also as devices that can apply liquefiable materials to any location. As a liquid ejection head provided in an image forming apparatus, a head that ejects liquid filled in a pressure chamber from a nozzle by vibrating a vibration plate that constitutes the wall surface of the pressure chamber using a piezoelectric element is known.

[0003] The liquid ejection head described in Patent Document 1 has an actuator substrate and a holding substrate bonded to the actuator substrate with an adhesive. The actuator substrate has a flow path forming portion, a vibration plate, a piezoelectric element, and a joint portion. The flow path forming substrate has a liquid chamber. The vibration plate forms one wall surface of the liquid chamber. The piezoelectric element is disposed on the surface of the vibration plate opposite the liquid chamber. The joint portion is a portion bonded to the holding substrate via an adhesive.

[0004] In the connection between the joint and the holding substrate using an adhesive, the softened excess adhesive may flow out of the joint and reach the diaphragm. If the adhesive hardens on the diaphragm, the hardened adhesive may hinder the diaphragm from displacing, which may cause variations in the ink ejection. In this document, the adhesive is blocked by providing a convex structure near the joint. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-172328 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional technology, the step formed by the convex structure is parallel to the vertical direction. This makes it easy for the adhesive to flow vertically downward. For this reason, further ingenuity is required to prevent the adhesive from flowing out onto the diaphragm. [Means for solving the problem]

[0007] A liquid ejection head according to a preferred embodiment of the present invention comprises a pressure chamber substrate forming a pressure chamber in which the ejected liquid is stored, a flow path forming substrate forming a flow path through which the liquid flows, a pressure section which applies pressure to the liquid in the pressure chamber, and a vibration plate which is joined to the pressure section and vibrates in response to displacement of the pressure section, wherein the pressure chamber substrate is joined to the flow path forming substrate with an adhesive and comprises an inclined portion having one or more inclined surfaces which incline in a direction normal to the surface of the vibration plate so that the width of the pressure chamber narrows as it approaches the vibration plate. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of the liquid ejection head shown in FIG. [Diagram 3] 2 is a cross-sectional view of a portion of the liquid ejection head shown in FIG. [Figure 4] 4 is an enlarged view of a portion of the liquid ejection head of FIG. 3. [Diagram 5] 4 is an enlarged view of a portion of the liquid ejection head of FIG. 3. [Figure 6] 6 is a perspective view showing a part of the pressure chamber substrate of FIG. 5. [Figure 7] 6A and 6B are diagrams for explaining bonding between a pressure chamber substrate and a flow path forming substrate. [Figure 8] 6A and 6B are diagrams for explaining bonding between a pressure chamber substrate and a flow path forming substrate. [Figure 9] FIG. 13 is a diagram for explaining the outflow of adhesive in a comparative example. [Figure 10] 11A and 11B are diagrams for explaining the outflow of adhesive in the present embodiment. [Figure 11] FIG. 6 is an enlarged view of the inclined portion of FIG. 5. [Figure 12] 12 is a diagram for explaining the outflow of adhesive at the inclined portion in FIG. 11. FIG. [Figure 13] FIG. 11 is a diagram showing an inclined portion of the second embodiment. [Figure 14] 13 is a diagram for explaining the outflow of an adhesive in the second embodiment. FIG. [Figure 15] 13 is a diagram for explaining another example of adhesive outflow in the second embodiment. FIG. [Figure 16] FIG. 13 is a diagram showing an inclined portion of a modified example. [Figure 17] 13A and 13B are diagrams illustrating an inclined portion of another modified example. [Figure 18] 6A and 6B are diagrams for explaining bonding between a pressure chamber substrate and a flow path forming substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Note that the dimensions or scale of each part in the drawings may differ from the actual dimensions, and some parts are shown diagrammatically to facilitate understanding. The scope of the present invention is not limited to these forms unless otherwise specified in the following description to the effect that the present invention is limited. Furthermore, "element β on element γ" is not limited to a configuration in which element γ and element β are in direct contact with each other, and also includes a configuration in which element γ and element β are not in direct contact with each other. "Element γ and element β are the same" means that element γ and element β are substantially the same, and includes manufacturing errors and the like.

[0010] 1. First embodiment 1-1. Overall configuration of image forming apparatus 100 FIG. 1 is a schematic diagram illustrating the configuration of an image forming apparatus 100 according to a first embodiment. In the following, for convenience of explanation, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other will be appropriately used. Moreover, one direction along the X-axis will be referred to as the X1 direction, and the direction opposite to the X1 direction will be referred to as the X2 direction. Similarly, one direction along the Y-axis will be referred to as the Y1 direction, and the direction opposite to the Y1 direction will be referred to as the Y2 direction. One direction along the Z-axis will be referred to as the Z1 direction, and the direction opposite to the Z1 direction will be referred to as the Z2 direction.

[0011] The image forming apparatus 100 in FIG. 1 is an inkjet printing apparatus that ejects ink, which is an example of a liquid, onto a medium 90. The medium 90 is typically printing paper, but any printing target made of any material, such as a resin film or fabric, can be used as the medium 90. As illustrated in FIG. 1, the image forming apparatus 100 is provided with a liquid container 9 that stores ink. For example, a cartridge that can be detached from the image forming apparatus 100, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink can be used as the liquid container 9.

[0012] The image forming apparatus 100 includes a control unit 20, a medium conveying mechanism 22, a moving mechanism 24, and a liquid ejection head 3. The control unit 20 includes 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 performs overall control of each element of the image forming apparatus 100.

[0013] The medium transport mechanism 22 transports the medium 90 in a direction along the Y axis under the control of the control unit 20. The movement mechanism 24 reciprocates the liquid ejection head 3 along the X axis under the control of the control unit 20. The movement mechanism 24 includes a substantially box-shaped transport body 242 that houses the liquid ejection head 3, and a transport belt 244 to which the transport body 242 is fixed. Note that a configuration in which a plurality of liquid ejection 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 ejection head 3, may also be employed.

[0014] The liquid ejection heads 3 eject ink supplied from a liquid container 9 onto the medium 90 from multiple nozzles under the control of the control unit 20. An image is formed on the surface of the medium 90 by each liquid ejection head 3 ejecting ink onto the medium 90 in parallel with the transport of the medium 90 by the medium transport mechanism 22 and the repeated reciprocating motion of the transport body 242.

[0015] The image forming apparatus 100 has a liquid ejection head 3 having the characteristics described below, which makes it possible to suppress deterioration in print quality.

[0016] 1-2. Overall configuration of liquid ejection head 3 Fig. 2 is an exploded perspective view of the liquid ejection head 3 shown in Fig. 1. Fig. 3 is a cross-sectional view of a portion of the liquid ejection head shown in Fig. 1, taken along line aa in Fig. 2. The cross section shown in Fig. 3 is a cross section parallel to the XZ plane. The Z axis is an axis along the direction in which ink is ejected by the liquid ejection head 3. The "first direction" that intersects with the Z2 direction is, for example, a direction along the X axis, and is the X1 direction or the X2 direction.

[0017] As illustrated in FIG. 2, 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 row La and a second row Lb arranged side by side at intervals along the X axis. Each of the first row La and the second row Lb is a collection of a plurality of nozzles N arranged linearly along the Y axis. The liquid ejection head 3 has a structure in which elements related to each nozzle N in the first row La and elements related to each nozzle N in the second row Lb are arranged substantially symmetrically with respect to a plane. In the following description, the elements corresponding to the first row La will be mainly described, and descriptions of the elements corresponding to the second row Lb will be omitted as appropriate.

[0018] 2 and 3, the liquid ejection head 3 includes a flow path forming substrate 31, a pressure chamber substrate 32, a vibration plate 33, a nozzle plate 37, a vibration absorber 38, a plurality of pressure sections 34, a sealant 35, a housing section 36, and a wiring substrate 40. Each of the flow path forming substrate 31, the pressure chamber substrate 32, the vibration plate 33, the nozzle plate 37, the vibration absorber 38, the sealant 35, and the housing section 36 is a long plate-like member along the Y axis. Moreover, the nozzle plate 37, the flow path forming substrate 31, the pressure chamber substrate 32, the vibration plate 33, and the sealant 35 are arranged in this order in the Z2 direction.

[0019] The nozzle plate 37 is a plate-like member in which a plurality of nozzles N are formed. 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 by, for example, an adhesive.

[0020] The flow path forming substrate 31 forms a flow path through which the ink flows. Specifically, the flow path forming substrate 31 is formed with a space Ra, a relay liquid chamber Rb, a plurality of supply flow paths 312, and a plurality of communication flow paths 314. The space Ra is an opening formed in an elongated shape along the Y axis. Each of the supply flow paths 312 and the communication flow paths 314 is a through hole formed for each nozzle N. Each communication flow path 314 overlaps with a corresponding nozzle N in a plan view seen from the Z1 direction. The relay liquid chamber Rb is a space formed in an elongated shape along the Y axis across the plurality of nozzles N, and connects the space Ra and the plurality of supply flow paths 312 to each other. A pressure chamber substrate 32 is bonded to the Z2-direction surface of the flow path forming substrate 31 with an adhesive.

[0021] 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. A pressure chamber C1 is formed for each nozzle N. The pressure chamber C1 is an elongated space and extends in the X1 direction. The plurality of pressure chambers C1 are aligned along the Y axis. Each pressure chamber C1 communicates with the communication flow path 314 and the supply flow path 312. Therefore, the pressure chamber C1 communicates with the nozzle N via the communication flow path 314, and also communicates with the space Ra via the supply flow path 312 and the relay liquid chamber Rb.

[0022] The nozzle plate 37, the flow path forming substrate 31, and the pressure chamber substrate 32 are manufactured by processing a single crystal substrate of silicon (Si) using semiconductor manufacturing techniques such as photolithography, etching, etc. However, the nozzle plate 37, the flow path forming substrate 31, and the pressure chamber substrate 32 may be manufactured using any known material or method.

[0023] The vibration plate 33 is connected to the surface of the pressure chamber substrate 32 opposite to the flow path forming substrate 31. The vibration plate 33 is disposed on the pressure chamber C1 and is elastically deformable. The vibration plate 33 is a plate-like member formed in an elongated rectangular shape along the Y axis in a plan view. The vibration plate 33 and the pressure chamber may be integrally configured, or may be configured as separate bodies and joined with an adhesive or the like.

[0024] A pressure section 34 is formed on the surface of the vibration plate 33 opposite to the pressure chamber C1. A pressure section 34 is provided for each pressure chamber C1. The pressure section 34 has an elongated shape along the X-axis in a plan view. The pressure section 34 is a piezoelectric element that applies pressure to the ink in the pressure chamber C1. The pressure section 34 is also a drive element that is driven by application of a drive signal.

[0025] The sealing body 35 is bonded to the diaphragm 33 by, for example, an adhesive. The sealing body 35 is a structure that protects the multiple pressure portions 34 and reinforces the mechanical strength of the pressure chamber substrate 32 and the diaphragm 33. A recess is formed in the sealing body 35 on the surface facing the diaphragm 33. The multiple pressure portions 34 are housed inside the recess. The sealing body 35 also has a space 353 through which the wiring board 40 is inserted.

[0026] The housing 36 is bonded to the flow passage forming substrate 31 by, for example, an adhesive. The housing 36 is a case for storing ink to be supplied to the multiple pressure chambers C1. The housing 36 is formed by, for example, 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 through which ink is supplied from the liquid container 9, and communicates with the space Rc. The space Rc communicates with the space Ra of the flow passage forming substrate 31. The space formed by the space Rc and the space Ra functions as a liquid storage chamber R that stores ink to be 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 flow passage 312 and is supplied in parallel to the multiple pressure chambers C1. The space 362 overlaps with the space 353 of the sealing body 35 in a plan view. The wiring board 40 is inserted through the space 353 and the space 362 .

[0027] The wiring board 40 is connected to the vibration plate 33. The wiring board 40 is a mounting component on which a plurality of wirings are formed for electrically connecting the control unit 20 and the liquid ejection head 3. For example, a flexible wiring board 40 such as an FPC (Flexible Printed Circuit) or an FFC (Flexible Flat Cable) is preferably used. A drive signal and a reference voltage for driving the pressure units 34 are supplied to each pressure unit 34 from the wiring board 40.

[0028] Furthermore, a vibration absorber 38 is bonded, for example, by an adhesive to the Z1 direction surface of the flow path forming substrate 31. The vibration absorber 38 is a flexible film that constitutes the wall surface of the space Ra, and absorbs pressure fluctuations of the ink in the liquid storage chamber R.

[0029] 1-3. Specific configuration of part of liquid ejection head 3 Fig. 4 and Fig. 5 are enlarged views of a portion of the liquid ejection head 3 of Fig. 3. The cross section shown in Fig. 4 is parallel to the YZ plane. The cross section shown in Fig. 5 is parallel to the XZ plane.

[0030] 4 and 5, the pressure unit 34 is generally a structure in which a first electrode 341, a piezoelectric body 343, and a second electrode 342 are laminated in this order from the vibration plate 33 side. The first electrode 341 and the second electrode 342 have different electric potentials.

[0031] The first electrode 341 is formed on the surface of the vibration plate 33. The first electrodes 341 are individual electrodes formed at a distance from each other for each pressure portion 34. A drive signal with a fluctuating voltage is applied to the first electrodes 341. The first electrodes 341 are elongated along the X-axis. The multiple first electrodes 341 are arranged along the Y-axis at intervals from each other. The first electrodes 341 are formed of a conductive material such as platinum (Pt) or iridium (Ir).

[0032] The piezoelectric body 343 is provided on the first electrode 341. The piezoelectric body 343 is, for example, a strip-shaped dielectric film that is continuous along the Y axis across the multiple pressure portions 34. The piezoelectric body 343 is, for example, strip-shaped extending along the Y axis, and is separated into each pressure portion 34 by forming multiple notches. The piezoelectric body 343 is formed of a known piezoelectric material, for example, lead zirconate titanate (Pb(Zr,Ti)O3).

[0033] The second electrode 342 is provided on the piezoelectric body 343. The second electrode 342 is a band-shaped common electrode extending along the Y axis so as to be continuous across the multiple pressure units 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.

[0034] A voltage corresponding to the difference between a reference voltage applied to the second electrode 342 and a drive signal corresponding to the ejection amount supplied to the first electrode 341 is applied to the piezoelectric body 343. The application of a voltage between the first electrode 341 and the second electrode 342 deforms the piezoelectric body 343. This deformation causes the pressure unit 34 to flexibly deform, i.e., vibrate, the vibration plate 33. The vibration of the vibration plate 33 changes the pressure in the pressure chamber C1, and the ink in the pressure chamber C1 is ejected from the nozzle N.

[0035] The vibration plate 33 vibrates when driven by the pressure unit 34. In the illustrated example, the vibration plate 33 is composed of a laminate including a first layer 331 and a second layer 332. The first layer 331 contacts 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 part of the pressure chamber substrate 32. The second layer 332 is formed, for example, by a known film formation technique such as sputtering. The vibration plate 33 may be composed of one layer, or may be composed of three or more layers.

[0036] A recess 330 is provided on the vibration plate 33 facing the pressure chamber substrate 32. The recess 330 is a recess formed by removing a portion of the vibration plate 33. In the illustrated example, the recess 330 is provided in the first layer 331. Note that the recess 330 does not penetrate the first layer 331, but it may penetrate therethrough. In this case, the bottom surface of the recess 330 is formed by the second layer 332. Also, a portion of the recess 330 may be formed by removing a portion of the second layer 332.

[0037] The recessed portion 330 has a recess 335 at a portion that is joined to the pressure chamber substrate 32. The recessed portion 335 corresponds to an outer periphery of the recessed portion 330, and is provided around the entire circumference of the recessed portion 330 in plan view. As will be described later, the recessed portion 335 has a portion that overlaps with the inclined portion 320 of the pressure chamber substrate 32 in plan view. Therefore, the recessed portion 335 has a recess that is recessed along the X1 direction and a recess that is recessed along the X2 direction.

[0038] Fig. 6 is a perspective view showing a part of the pressure chamber substrate 32 of Fig. 5. As shown in Fig. 5 and Fig. 6, 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. The inclined portions 320 are also provided at a portion of the pressure chamber substrate 32 that is joined to the vibration plate 33.

[0039] Each inclined portion 320 includes an inclined surface 325. The inclined surface 325 is a flat surface and is inclined with respect to a normal line A1 to the surface 33a of the vibration plate 33. The inclined surface 325 is also inclined such that the width of the pressure chamber C1 narrows toward the vibration plate 33 in the Z2 direction.

[0040] 7 and 8 are diagrams for explaining the bonding between the pressure chamber substrate 32 and the flow path forming substrate 31. As shown in FIG. 7, first, adhesive 5 is applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33. The adhesive 5 is a thermosetting resin. Therefore, before hardening, the adhesive 5 has fluidity. Therefore, when the adhesive 5 is applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33, there is a possibility that the adhesive 5 will flow down vertically downward, i.e., in the Z2 direction, from the opposite surface. Note that the Z2 direction corresponds to the vertical downward direction when the adhesive 5 is applied.

[0041] 8, after applying the adhesive 5 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 by the adhesive 5.

[0042] 9 is a diagram for explaining the flow of adhesive 5 in a comparative example. In the comparative example of FIG. 9, a case is considered in which the pressure chamber substrate 32 does not have an inclined surface 325, and the inner wall surface 32a forming the pressure chamber C1 of the pressure chamber substrate 32 is aligned along the vertical axis, i.e., the inner wall surface is aligned along the Z2 direction. In this case, the excess of adhesive 5 applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33 tends to flow in the Z2 direction along the inner wall surface 32a of the pressure chamber substrate 32. For this reason, as shown by the arrow Ax, the adhesive 5 tends to flow in the Z2 direction.

[0043] When the adhesive 5 flows over the inner wall surface 32a and reaches the vibration plate 33, the adhesive 5 may hinder the displacement of the vibration plate 33, causing a risk of variation in vibration characteristics. As a result, there is a risk of variation in the ejection characteristics, and a risk of deterioration in print quality.

[0044] FIG. 10 is a diagram for explaining the flow of adhesive 5 in this embodiment. In this embodiment of FIG. 10, 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 an inclined surface 325. The inclined surface 325 is inclined with respect to the Z2 direction so that the width of the pressure chamber C1 narrows toward the vibration plate 33 in the Z2 direction. Therefore, the excess of adhesive 5 applied to the surface of the pressure chamber substrate 32 opposite the vibration plate 33 flows on the inclined surface 325. Therefore, the adhesive 5 flows as shown by the arrow A0. By having the inclined surface 325, it is possible to suppress the flow of adhesive 5 to the vibration plate 33 compared to the case where the inclined surface 325 is not provided. Therefore, it is possible to suppress the flow of adhesive 5 to the vibration plate 33 with a simple configuration compared to the conventional configuration.

[0045] The existence of the inclined surface 325 can suppress the adhesive 5 from flowing out onto the vibration plate 33, and therefore can suppress the occurrence of variations in the vibration characteristics of the vibration plate 33 caused by the existence of the adhesive 5. This can suppress variations in the ejection characteristics, and therefore suppress the deterioration of the print quality.

[0046] FIG. 11 is an enlarged view of the inclined portion 320 in FIG. 5. As shown in FIG. 11, the inclined surface 325 is inclined with respect to the Z2 direction, which is the normal direction of the surface 33a of the vibration plate 33. That is, the inclined surface 325 is inclined with respect to the normal A1 of the surface 33a of the vibration plate 33. The inclination angle of the inclined surface 325 with respect to the normal A1 is not particularly limited, but is preferably greater than 0 degrees and equal to or less than 45 degrees. When the inclination angle is equal to or less than 45 degrees, the gravity of the adhesive 5 acting in the direction in which the adhesive 5 flows out becomes equal to or less than 1 / 2. Therefore, when the inclination angle is within this range, the adhesive 5 can be more effectively prevented from flowing onto the vibration plate 33 compared to when the inclination angle is outside the range.

[0047] In this embodiment, the pressure chamber substrate 32 has two inclined portions 320 for each pressure chamber C1. The inclined surfaces 325 of the two inclined portions 320 may have the same inclination angle θ or may have different inclination angles θ.

[0048] The inclined portion 320 is provided at a portion of the pressure chamber substrate 32 which is bonded to the vibration plate 33. The inclined surface 325 is provided from the surface of the pressure chamber substrate 32 opposite the vibration plate 33 to the portion which is bonded to the vibration plate 33. Therefore, it is possible to suppress the adhesive 5 from flowing out onto the vibration plate 33, compared to a case in which the inclined surface 325 is provided only halfway in the Z2 direction of the pressure chamber substrate 32.

[0049] FIG. 12 is a diagram for explaining the flow of adhesive 5 at the inclined portion 320 in FIG. 11. As described above, the vibration plate 33 has a recessed portion 330, and when the vibration plate 33 is viewed in a plan view, the inclined portion 320 overlaps with a recessed portion 335 of the recessed portion 330. In other words, when the vibration plate 33 is viewed in the Z2 direction, the inclined portion 320 and the recessed portion 335 appear to overlap in the X direction and the Y direction. As shown in FIG. 12, by providing the recessed portion 335, the adhesive 5 is likely to remain at the tip portion 320x of the inclined portion 320 due to surface tension. Therefore, the adhesive 5 can be prevented from flowing onto the vibration plate 33.

[0050] When the vibration plate 33 is viewed in plan, the recess 335 preferably overlaps with the inclined portion 320 in a range of 50 nm to 2000 nm, and more preferably overlaps with the inclined portion 320 in a range of 50 nm to 1000 nm. The overlap range is indicated by H1 in FIG. 11. When the overlap range is less than 50 nm, the adhesive 5 may not remain at the tip portion 320x and may wrap around the recess 335, compared to when the overlap range is 50 nm or more. In addition, when the overlap range is 2000 nm or less, the recess 335 is easily formed even when the vibration plate 33 and the pressure chamber substrate 32 are integrated. From this viewpoint, it is more preferable that the overlap range is 1000 nm or less. Note that the overlap range is not limited to the above range.

[0051] 5, the inclined portion 320 overlaps with the pressure portion 34 when the vibration plate 33 is viewed in a plan view. In particular, the inclined portion 320 overlaps with the piezoelectric body 343 when viewed in a plan view. The tip portion 320x of the inclined portion 320 has low rigidity and may be cracked due to distortion of the vibration plate 33. Therefore, by overlapping the inclined portion 320 with the pressure portion 34 when viewed in a plan view, the risk of the tip portion 320x of the inclined portion 320 cracking can be suppressed. The inclined portion 320 may be provided at a position overlapping the portion of the piezoelectric body 343 sandwiched between the first electrode 341 and the second electrode 342 in a plan view. This can further reduce the risk of the tip portion 320x cracking. The inclined portion 320 does not have to overlap with the pressure portion 34.

[0052] 4, the pressure chamber substrate 32 does not have the inclined portion 320 in the short-side direction of the pressure chamber C1, but may have the inclined portion 320. Therefore, the inclined surface 325 of the inclined portion 320 may be provided over the entire periphery of the inner wall surface that forms the pressure chamber C1 of the pressure chamber substrate 32. By providing the inclined surface 325 over the entire periphery, it is possible to particularly effectively suppress the adhesive 5 from flowing out onto the vibration plate 33.

[0053] Furthermore, even if 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 recess 335 makes it possible to suppress the adhesive 5 from flowing out onto the vibration plate 33. The presence of the recess 335 in the short-side direction of the pressure chamber C1 makes it possible to cause the adhesive 5 to remain by surface tension at the tip portion that overlaps with the recess 335 of the pressure chamber substrate 32 in a plan view. Therefore, it is possible to suppress the adhesive 5 from flowing out onto the vibration plate 33 compared to a case in which the recess 335 is not provided.

[0054] 2. Second embodiment A second embodiment will be described. In the following exemplary embodiment, for elements having the same actions and functions as those in the first embodiment, the reference numerals used in the description of the first embodiment will be used and detailed descriptions of each will be omitted as appropriate.

[0055] Fig. 13 is a diagram showing an inclined portion 320A of the second embodiment. The inclined portion 320A shown in Fig. 13 differs from the inclined portion 320 of the first embodiment in that it has a plurality of inclined surfaces.

[0056] The inclined portion 320A includes a first inclined surface 321, a second inclined surface 322, and a horizontal surface 323. The first inclined surface 321 and the second inclined surface 322 are inclined with respect to the normal line A1. The second inclined surface 322 is provided closer to the diaphragm 33 in the Z2 direction than the first inclined surface 321. The horizontal surface 323 connects the first inclined surface 321 and the second inclined surface 322. The horizontal surface 323 is perpendicular to the Z2 direction.

[0057] The first inclined surface 321 is inclined at a first inclination angle θ1, which is an inclination angle with respect to the normal line A1. The second inclined surface 322 is inclined at a second inclination angle θ2, which is an inclination angle with respect to the normal line A1. The first inclination angle θ1 and the second inclination angle θ2 are different from each other. Thus, the inclined portion 320A has a plurality of inclined surfaces with different inclination angles. By providing a plurality of inclined surfaces with different inclination angles, it is possible to more effectively prevent the adhesive 5 from flowing onto the vibration plate 33, compared to the first embodiment.

[0058] In particular, the second inclination angle θ2 is larger than the first inclination angle θ1. Therefore, the second inclination surface 322, which is closer to the diaphragm 33 than the first inclination surface 321, is gentler. Therefore, compared to a case where the second inclination angle θ2 is smaller than the first inclination angle θ1, it is possible to more effectively prevent the adhesive 5 from flowing onto the diaphragm 33.

[0059] 14 is a diagram for explaining the flow of adhesive 5 in the second embodiment. As shown in FIG. 14, when second inclined surface 322 is gentler than first inclined surface 321, adhesive 5 flows as indicated by arrow A5 and tends to remain on second inclined surface 322. Adhesive 5 tends to remain at the tip of second inclined surface 322, that is, tip portion 320x of inclined portion 320. For this reason, it is possible to suppress the flow of adhesive 5 onto vibration plate 33.

[0060] 15 is a diagram for explaining another example of the flow of adhesive 5 in the second embodiment. As shown in FIG. 15, adhesive 5 may flow as indicated by arrow A6 and remain on horizontal surface 323. Since horizontal surface 323 is horizontal, adhesive 5 is likely to remain on horizontal surface 323. Therefore, the presence of horizontal surface 323 can suppress the flow of adhesive 5 onto vibration plate 33.

[0061] Although not shown, the adhesive 5 may remain on the first inclined surface 321. For example, by making the second inclination angle θ2 smaller than the first inclination angle θ1, the first inclined surface 321 becomes gentler than the second inclined surface 322. This makes it possible for the adhesive 5 to remain on the first inclined surface 321 more easily.

[0062] The second inclination angle θ2 may be the same as the first inclination angle θ1. Even in this case, by having the inclined portion 320 have a plurality of inclined surfaces, it is possible to more effectively prevent the adhesive 5 from flowing onto the diaphragm 33, compared to the case where the inclined portion 320 has a single inclined surface.

[0063] 3. Variations The above-described embodiment may be modified in various ways. Specific modified aspects that may be applied to the above-described embodiment are illustrated below. Two or more aspects selected from the following examples may be combined as appropriate to the extent that they are not mutually contradictory.

[0064] The inclined surface 325 does not have to be a flat surface, and may include, for example, irregularities or a curved surface that is convex toward the diaphragm 33.

[0065] Fig. 16 is a diagram showing a modified example of inclined portion 320B. In the example shown in Fig. 16, inclined portion 320B does not overlap recessed portion 330 of diaphragm 33 in plan view. Therefore, recessed portion 330 does not have recess 335. Even in the example shown in Fig. 16, it is possible to suppress the adhesive 5 from flowing out onto diaphragm 33.

[0066] FIG. 17 is a diagram showing an inclined portion 320C of another modified example. In the example shown in FIG. 17, the inclined portion 320C does not overlap the recessed portion 330 of the vibration plate 33 in a plan view. The tip 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 between them. Even in the example shown in FIG. 17, it is possible to suppress the adhesive 5 from flowing out onto the vibration plate 33.

[0067] Fig. 18 is a diagram for explaining bonding between the pressure chamber substrate 32 and the flow path forming substrate 31. In the example shown in Fig. 18, adhesive 5 is applied onto the flow path forming substrate 31, and the pressure chamber substrate 32 is brought close to the flow path forming substrate 31 as shown by arrow A3, and the pressure chamber substrate 32 is disposed on the flow path forming substrate 31. By applying the adhesive 5 onto the flow path forming substrate 31, it is possible to prevent the adhesive 5 from flowing out onto the vibration plate 33, compared to the case where the adhesive 5 is applied onto the pressure chamber substrate 32.

[0068] Furthermore, the "liquid ejection head" may be a circulation type head having a so-called circulation flow path.

[0069] An "image forming apparatus" may be employed in various devices such as facsimile machines and copy machines, in addition to devices dedicated to printing. The uses of an image forming apparatus are not limited to printing. For example, an image forming apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus that forms color filters for display devices such as liquid crystal display panels. Also, an image forming apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms wiring and electrodes for wiring boards. Also, an image forming apparatus that ejects a solution of an organic substance related to a living organism is used as a manufacturing apparatus that manufactures biochips, for example.

[0070] Although the present invention has been described based on the preferred embodiment, the present invention is not limited to the above-mentioned embodiment. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above-mentioned embodiment, and any configuration can be added. [Explanation of symbols]

[0071] 3...liquid ejection head, 5...adhesive, 9...liquid container, 20...control unit, 22...medium conveying mechanism, 24...movement mechanism, 25...sealing member, 31...flow path forming substrate, 32...pressure chamber substrate, 32a...inner wall surface, 33...vibration plate, 33a...surface, 34...pressure section, 35...sealing body, 36...casing section, 37...nozzle plate, 38...vibration absorber, 40...wiring board, 90...medium, 100...image forming apparatus, 242...conveyor, 244...conveyor belt, 312...supply flow path, 314...communicating flow path, 320...inclined portion, 320A...inclined portion, 320B...inclined portion, 320C...inclined portion, 321... First inclined surface, 322...second inclined surface, 323...horizontal surface, 324...vertical surface, 325...inclined surface, 330...recessed portion, 331...first layer, 332...second layer, 335...recess, 341...first electrode, 342...second electrode, 343...piezoelectric body, 353...space, 361...supply port, 362...space, A0...arrow, A1...normal, A3...arrow, A5...arrow, A6...arrow, Ax...arrow, C1...pressure chamber, La...first row, Lb...second row, N...nozzle, R...liquid storage chamber, Ra...space, Rb...relay liquid chamber, Rc...space, θ...incline angle, θ1...first inclination angle, θ2...second inclination angle.

Claims

1. a pressure chamber substrate that forms a pressure chamber in which the liquid to be ejected is stored; a flow path forming substrate that forms a flow path through which a liquid flows; a pressure unit that applies pressure to the liquid in the pressure chamber; a vibration plate joined to the pressure portion and vibrating in response to the displacement of the pressure portion; Equipped with The pressure chamber substrate is The flow path forming substrate is bonded to the flow path forming substrate by an adhesive, a sloped portion having one or more sloped surfaces that slope in a normal direction of the surface of the vibration plate so that the width of the pressure chamber narrows toward the vibration plate; A liquid ejection head comprising:

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

3. the one or more inclined surfaces are a plurality of inclined surfaces, The plurality of inclined surfaces have different inclination angles. The liquid ejection head according to claim 2 .

4. the one or more inclined surfaces include a first inclined surface and a second inclined surface provided closer to the diaphragm in the normal direction than the first inclined surface, a second inclination angle, which is an inclination angle of the second inclined surface with respect to the normal direction, is larger than a first inclination angle, which is an inclination angle of the first inclined surface with respect to the normal direction; The liquid ejection head according to claim 3 .

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

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

7. the vibration plate is provided at a portion where the vibration plate is joined to the pressure chamber substrate, and includes a recess that is recessed along a first direction that intersects with the normal direction, The inclined portion overlaps the recessed portion when the diaphragm is viewed in a plan view. The liquid ejection head according to claim 1 .

8. When the vibration plate is viewed in a plan view, the recess overlaps the inclined portion by a range of 50 nm to 1000 nm.

8. A liquid ejection head according to claim 7.

9. The inclined portion overlaps the pressure portion when the diaphragm is viewed in a plan view. The liquid ejection head according to claim 1 .

10. In an image forming apparatus having 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.

1. An image forming apparatus comprising:

Images