Liquid ejecting head and method of inspecting liquid ejecting head

Abstract

To provide a liquid jet head which can be easily inspected, and to provide a method of inspecting the liquid jet head.SOLUTION: A liquid ejecting head includes a first head chip having a plurality of first nozzles configured to eject a liquid in a first direction, a fixing plate including a first surface which is a surface perpendicular to the first direction and faces the first direction, a second surface which faces a second direction opposite to the first direction and is a surface opposite to the first surface, and a first opening which exposes the plurality of first nozzles, and a holder which includes a base portion, a wall portion protruding from the base portion in the first direction, and accommodates the first head chip in an accommodation space defined by the base portion, the wall portion, and the fixing plate. The holder has a third surface that is formed continuously so as to surround an outer periphery of the fixing plate and is a plane perpendicular to the first direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a liquid jet head and a method for inspecting a liquid jet head. [Background technology]

[0002] 2. Description of the Related Art Liquid ejection apparatuses equipped with liquid ejection heads that eject liquid such as ink onto a medium such as printing paper have been proposed.

[0003] Patent Document 1 discloses a liquid jet head body capable of ejecting liquid droplets from a nozzle, a holder that houses the liquid jet head body, and a fixing plate to which the liquid jet head body is fixed. The fixing plate is bonded to both the holder and the liquid jet head body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-130026 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, before using a liquid ejection apparatus, it is desirable to check for defective sealing of the fixing plate as an initial defect, for example, by a leak test.

[0006] In the device described in Patent Document 1, the liquid jet head main body is covered from above by a holder, and a fixing plate is disposed below the liquid jet head main body and adhered to the holder. The device described in Patent Document 1 does not have a flat surface that surrounds the entire periphery of the adhesive portion between the fixing plate and the holder. Therefore, it was difficult to abut a member for leak testing so that the fixing plate was covered from below the liquid jet head main body. [Means for solving the problem]

[0007] A liquid ejection head according to one embodiment of the present disclosure comprises: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction; a second surface that faces a second direction opposite the first direction and is the surface opposite the first surface; and a first opening that exposes the plurality of first nozzles; a holder having a base and a wall protruding from the base in the first direction, and that accommodates the first head chip in an accommodation space defined by the base, the wall, and the fixing plate; and a first adhesive layer that is arranged continuously to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder; and the holder has a third surface that is formed continuously to surround the outer periphery of the fixing plate and is a plane perpendicular to the first direction.

[0008] A liquid ejection head according to one embodiment of the present disclosure comprises: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction; a second surface that faces a second direction opposite the first direction and is a surface opposite the first surface; and a first opening that exposes the plurality of first nozzles; a holder having a base portion and a wall portion protruding from the base portion in the first direction, and that accommodates the first head chip in an accommodation space defined by the base portion, the wall portion, and the fixing plate; and a first adhesive layer that is arranged continuously to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder, and the holder has an elastic portion that is arranged continuously to surround the entire outer periphery of the fixing plate when viewed in the second direction, and that has higher elasticity than other areas of the holder.

[0009] According to one embodiment of the present disclosure, there is provided a method for inspecting a liquid jet head, the method comprising: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction, a second surface that faces a second direction opposite the first direction and is opposite the first surface, and a first opening that exposes the plurality of first nozzles; a holder that accommodates the first head chip; and a first adhesive layer that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate to the holder, the method comprising: a first step of forming a space to accommodate the fixing plate between the cover member and the holder by abutting a cover member against the holder so as to surround the entire circumference of the fixing plate when viewed in the second direction; and a second step of, after the first step, reducing or pressurizing the space through the opening formed in the cover member while closing a flow path of the liquid jet head that is connected to the first nozzles. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating the configuration of a liquid ejecting apparatus according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the liquid jet head shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view of the liquid jet head shown in FIG. [Figure 4] FIG. 2 is a bottom view of the liquid jet head shown in FIG. [Figure 5] 4 is an enlarged view of a portion of the liquid jet head shown in FIG. [Figure 6] 4 is a cross-sectional view of a first head chip included in the liquid jet head shown in FIG. [Figure 7] FIG. 3 is a diagram for explaining a leak test according to the first embodiment. [Figure 8] FIG. 10 is a diagram for explaining a leak test in a comparative example. [Figure 9] 4 is a flowchart illustrating an inspection method for the liquid jet head according to the first embodiment. FIG. [Figure 10] FIG. 10 is a cross-sectional view of a portion of a liquid jet head according to a second embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a portion of a liquid jet head according to a third embodiment. [Figure 12] FIG. 10 is a bottom view of a liquid jet head according to a third embodiment. [Figure 13] FIG. 10 is a cross-sectional view of a portion of a liquid jet head according to a fourth embodiment. [Figure 14] FIG. 10 is a bottom view of a liquid jet head according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The dimensions and scale of each part in the drawings may differ from the actual dimensions, and some parts are shown schematically to facilitate understanding. The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited to these embodiments. Furthermore, the term "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, but also includes a configuration in which element γ and element β are not in direct contact with each other. The term "element γ and element β are equal" means that element γ and element β are substantially equal, and includes measurement errors, manufacturing errors, and the like.

[0012] 1. First embodiment 1-1. Overall configuration of the liquid ejection device 100 FIG. 1 is a schematic diagram illustrating the configuration of a liquid ejection device 100 according to a first embodiment. For ease of explanation, the following description will appropriately use mutually perpendicular X, Y, and Z axes. A direction along the X axis will be referred to as the X1 direction, and a direction opposite to the X1 direction will be referred to as the X2 direction. Similarly, a direction along the Y axis will be referred to as the Y1 direction, and a direction opposite to the Y1 direction will be referred to as the Y2 direction. A direction along the Z axis will be referred to as the Z1 direction, and a direction opposite to the Z1 direction will be referred to as the Z2 direction. The Z1 direction relative to a certain point is referred to as "downward," and the Z2 direction from a certain point is referred to as "upward." Viewing in the Z1 or Z2 direction is referred to as a "planar view." The Z1 direction corresponds to the "first direction." The Z2 direction corresponds to the "second direction."

[0013] As shown in FIG. 1, the liquid ejecting device 100 includes a liquid storage section 9, a control unit 91, a conveying section 92, a head unit 10, and a movement mechanism 93.

[0014] The liquid storage unit 9 is a container that stores ink. Specific examples of the liquid storage unit 9 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of flexible film, and an ink tank that can be refilled with ink. The type of ink stored in the liquid storage unit 9 is not particularly limited and can be any type.

[0015] The control unit 91 controls the operation of each element of the liquid ejection device 100. The control unit 91 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls the operation of each element of the liquid ejection device 100.

[0016] The transport unit 92 transports the medium 90 in a direction DM under the control of the control unit 91. In this embodiment, the direction DM is the Y1 direction. In the example shown in FIG. 1, the transport unit 92 includes a long transport roller along the X axis and a motor that rotates the transport roller. Note that the transport unit 92 is not limited to a configuration using a transport roller, and may be configured, for example, to use a drum or endless belt that transports the medium 90 while adsorbing it to its outer peripheral surface using electrostatic force or the like.

[0017] The head unit 10 has a unit base 11 and a liquid ejection head 1. The liquid ejection head 1 ejects ink from nozzles toward a medium 90. The unit base 11 holds the liquid ejection head 1.

[0018] The movement mechanism 93 has a conveyor belt to which the unit base 11 is fixed, and moves the head unit 10 back and forth in the X1 direction and the X2 direction under the control of the control unit 91. Under the control of the control unit 91, the head unit 10 ejects ink supplied from the liquid storage section 9 from each of the multiple nozzles onto the medium 90 in the Z1 direction. The ejection of ink from the head unit 10 is performed in parallel with the movement of the head unit 10 by the movement mechanism 93, so that an ink image is formed on the surface of the medium 90.

[0019] The number and arrangement of the multiple liquid jet heads 1 included in the head unit 10 are not limited to the example shown in Fig. 1 and are arbitrary. Furthermore, if the head unit 10 is configured to be able to circulate ink, the head unit 10 may be connected to the liquid storage section 9 via a circulation mechanism for circulating the ink within the head unit 10.

[0020] 1-2. Liquid jet head 1 2 and 3 are cross-sectional views of the liquid jet head 1 shown in FIG. 1. FIG. 4 is a bottom view of the liquid jet head 1 shown in FIG. 1. In FIG. 4, components that are not directly visible when the liquid jet head 1 is viewed in the Z2 direction are indicated by dotted lines, dashed lines, or dashed-dotted lines. FIG. 5 is an enlarged view of a portion of the liquid jet head 1 shown in FIG. 3. Note that FIG. 2 corresponds to the cross section taken along line A1-A1 in FIG. 4, and FIG. 3 corresponds to the cross section taken along line A2-A2 in FIG. 4.

[0021] 2 and 3, the liquid jet head 1 includes a first head chip 2a, an intermediate substrate 7, a fixing plate 3, a holder 4, and a flow path connection portion 6. Furthermore, as shown in Fig. 5, the liquid jet head 1 includes a first adhesive layer 51 and a second adhesive layer 52. Note that in Fig. 4, the first adhesive layer 51 is represented as an area surrounded by two dashed lines, and the second adhesive layer 52 is represented as an area surrounded by two broken lines.

[0022] As shown in Figures 2 and 3, the flow path connection part 6 is arranged in the Z2 direction of the first head chip 2a. The flow path connection part 6 has a flow path (not shown) for supplying liquid to the first head chip 2a. The flow path connection part 6 has a main body part 61 and a protrusion part 62. The main body part 61 is a plate-shaped part extending in the XY plane. The main body part 61 is connected to the holder 4. The main body part 61 and the holder 4 are connected by, for example, screws 71. The main body part 61 and the holder 4 may be connected by, for example, an adhesive or may be fixed by a fixing member other than the screws 71.

[0023] The protrusion 62 protrudes in the Z2 direction from the main body 61. The liquid storage section 9 described above is indirectly or directly connected to the protrusion 62. The protrusion 62 has a flow path for supplying the liquid in the liquid storage section 9 to the liquid jet head 1. In the example of FIG. 3, the number of protrusions 62 is four, but it may be one to three, or five or more. The material of the flow path connection section 6 is, for example, a resin or a metal such as stainless steel.

[0024] First head chip 2a has multiple first nozzles Na that spray liquid in the Z1 direction. In Fig. 4, the outer edge of first head chip 2a is indicated by a dotted line. The outer edge of first head chip 2a is located inside first adhesive layer 51 and wall portion 42. First head chip 2a will be described in detail later.

[0025] Holder 4 is a member that houses and holds first head chip 2a. Although not shown, holder 4 also has a flow path for supplying liquid from flow path connection portion 6 to first head chip 2a. Holder 4 is made of a material such as resin or a metal such as stainless steel.

[0026] The holder 4 has a base portion 41, a wall portion 42, and a protrusion 43. The base portion 41 is a plate-like portion extending along the XY plane. The base portion 41 has a side surface 410. The side surface 410 is the outermost surface of the holder 4 as viewed in the Z1 direction. The base portion 41 also includes a flange portion 44 that protrudes outward beyond the wall portion 42 as viewed in the Z1 direction. The flange portion 44 has a rectangular frame shape that surrounds the wall portion 42 as viewed in the Z2 direction. The flange portion 44 also has a through hole 40H. The through hole 40H is a screw hole into which a screw 71 is inserted to connect the flow path connection portion 6 and the holder 4. In FIG. 4, the wall portion 42 is represented as a region surrounded by two dashed dotted lines. When the liquid jet head 1 is viewed in the Z2 direction, the wall portion 42 and the first adhesive layer 51 overlap.

[0027] Wall portion 42 protrudes from base portion 41 in the Z1 direction and surrounds first head chip 2a from the side. The planar shape of wall portion 42 is a quadrangular frame shape that surrounds first head chip 2a. Furthermore, protrusion 43 protrudes from flange portion 44 in the Z1 direction. The planar shape of protrusion 43 is a quadrangular frame shape. The surface of protrusion 43 facing the Z1 direction is third surface 401. Note that protrusion height T1 (see FIG. 5) of protrusion 43 is sufficiently smaller than the length of wall portion 42 in the Z1 direction.

[0028] 3, 4, etc., when viewed in the Z1 direction, the protrusion 43 does not overlap with any part other than the part that constitutes the third surface 401, such as the fixing plate 3 or the holder 4 that does not constitute the third surface 401. Furthermore, as shown in Fig. 2, etc., at least a part of the protrusion 43 overlaps with the relay board 7 when viewed in the Z2 direction.

[0029] Holder 4 has an accommodation space S0a for accommodating first head chip 2a together with fixing plate 3, which will be described later. Specifically, first head chip 2a is accommodated in accommodation space S0a defined by base portion 41, wall portion 42, and fixing plate 3.

[0030] The fixed plate 3 is a plate-shaped member. The fixed plate 3 is arranged in the Z1 direction of the holder 4. As shown in FIG. 5 , the fixed plate 3 has a first surface 301 and a second surface 302. The first surface 301 is a surface perpendicular to the Z1 direction and is the surface of the fixed plate 3 facing the Z1 direction. The second surface 302 is a surface facing the Z2 direction and is the surface opposite to the first surface 301.

[0031] The fixed plate 3 has a first opening 3Ha. The first opening 3Ha is a through-hole that penetrates from the first surface 301 to the second surface 302. The first opening 3Ha is a hole that exposes a plurality of first nozzles Na, which are part of the first head chip 2a, from the fixed plate 3. The material of the fixed plate 3 is, for example, a resin or a metal such as stainless steel.

[0032] The relay board 7 is placed on the base portion 41 of the holder 4. The base portion 41 has a recess for placing the relay board 7. The relay board 7 is a board on which mounted components are mounted for electrically connecting the control unit 91 and the first head chip 2a. As shown in FIG. 2, the surface of the relay board 7 facing the Z2 direction is flat, and a connector 70 is connected to the surface of the relay board 7 facing the Z1 direction. The connector 70 is a member for electrically connecting the relay board 7 and the first head chip 2a.

[0033] 5, the first adhesive layer 51 bonds the second surface 302 of the fixing plate 3 and the holder 4. As shown in Fig. 4, the first adhesive layer 51 is disposed continuously so as to surround the first opening 3Ha when viewed in the Z2 direction. Specifically, the first adhesive layer 51 bonds the end surface of the wall portion 42 in the Z1 direction and the second surface 302.

[0034] As shown in Fig. 5, the second adhesive layer 52 bonds the second surface 302 of the fixing plate 3 to a nozzle plate 201 (described later) of the first head chip 2a. As shown in Fig. 4, the second adhesive layer 52 is continuously disposed so as to surround the first opening 3Ha when viewed in the Z2 direction. The planar shape of the second adhesive layer 52 is a quadrangular frame that surrounds the first adhesive layer 51. The second adhesive layer 52 is spaced apart from the first adhesive layer 51 and is located inside the first adhesive layer 51 when viewed in the Z2 direction.

[0035] Each of the first adhesive layer 51 and the second adhesive layer 52 is formed of, for example, an adhesive containing a thermosetting resin.

[0036] 1-3. First head chip 2a Fig. 6 is a cross-sectional view of the first head chip 2a included in the liquid jet head 1 shown in Fig. 3. As shown in Fig. 6, the first head chip 2a includes, for example, a communication plate 202, a pressure chamber substrate 203, a vibration plate 204, a nozzle plate 201, a flow path opening forming member 208, a plurality of drive elements E, and a sealing substrate 205.

[0037] The communicating plate 202, pressure chamber substrate 203, vibration plate 204, nozzle plate 201, sealing substrate 205, and flow path opening forming member 208 are each a long plate-like member extending along the Y axis. The pressure chamber substrate 203 is placed on the surface of the communicating plate 202 facing the Z2 direction. The nozzle plate 201 is placed on the surface of the communicating plate 202 facing the Z1 direction. The respective members are fixed together by, for example, an adhesive.

[0038] The nozzle plate 201 is a plate-like member in which a plurality of first nozzles Na are formed. The nozzle plate 201 is the member of the first head chip 2a that is located furthest in the Z1 direction. The surface of the nozzle plate 201 facing the Z1 direction is the nozzle surface. Each of the plurality of first nozzles Na is a circular through-hole that ejects ink. For example, the nozzle plate 201 is manufactured by processing a silicon (Si) single crystal substrate using semiconductor manufacturing techniques such as photolithography and etching.

[0039] The communicating plate 202 is formed with a plurality of throttle portions R1, a plurality of communicating channels R2, a communicating space Ra, and a common channel Rb. Each of the throttle portions R1 and the communicating channels R2 extends in the Z1 direction and is a through-hole formed for each nozzle N. The communicating channel R2 overlaps with the first nozzle Na in plan view. The communicating space Ra is an opening formed in an elongated shape along the Y axis. The common channel Rb communicates with the communicating space Ra and overlaps with the communicating space Ra in plan view. The common channel Rb extends along the Y axis. The common channel Rb communicates with the plurality of throttle portions R1.

[0040] A plurality of pressure chambers C are formed in the pressure chamber substrate 203. The pressure chambers C are located between the communication plate 202 and the vibration plate 204, and are spaces formed by the wall surfaces of the pressure chamber substrate 203. A pressure chamber C is formed for each first nozzle Na. The pressure chamber C is an elongated space extending in the X1 direction. The plurality of pressure chambers C are arranged along the Y axis.

[0041] The communication plate 202 and the pressure chamber substrate 203 are manufactured by processing a semiconductor substrate such as a silicon single crystal substrate.

[0042] An elastically deformable vibration plate 204 is disposed above the pressure chamber C. The vibration plate 204 is laminated on the pressure chamber substrate 203 and contacts the surface of the pressure chamber substrate 203 opposite the surface from the communicating plate 202. The vibration plate 204 is a long, rectangular plate-like member extending along the Y-axis in a plan view. The pressure chamber C communicates with the communicating flow path R2 and the throttle portion R1. Therefore, the pressure chamber C communicates with the first nozzle Na via the communicating flow path R2, and also communicates with the communicating space Ra via the throttle portion R1. Note that the first nozzle Na, the communicating flow path R2, the pressure chamber C, and the throttle portion R1 form an individual flow path for each nozzle N. Also, for ease of explanation, the pressure chamber substrate 203 and the vibration plate 204 are illustrated in FIG. 6 as separate substrates, but in reality they are laminated on a single silicon substrate.

[0043] A driving element E is formed for each pressure chamber C on the surface of the vibration plate 204 opposite to the pressure chamber C. The driving element E is an elongated piezoelectric element extending along the X-axis in a plan view. The driving element E includes, for example, a pair of electrodes and a piezoelectric body sandwiched between the pair of electrodes. The driving element E may also be an electrothermal conversion element that generates thermal energy.

[0044] The sealing substrate 205 is a structure that protects the multiple drive elements E. The sealing substrate 205 is fixed to the surface of the diaphragm 204 with, for example, an adhesive. The multiple drive elements E are housed inside a recess formed on the surface of the sealing substrate 205 that faces the diaphragm 204. The sealing substrate 205 also has a through hole 20H for inserting a wiring substrate 209 therethrough.

[0045] The flow path opening forming member 208 is disposed in the Z2 direction of the sealing substrate 205. The flow path opening forming member 208 has a space Rc. The space Rc is connected to the aforementioned communication space Ra. The communication space Ra, the common flow path Rb, and the space Rc form a common space R that is shared by multiple first nozzles Na. The common space R functions as an ink reservoir. The ink stored in the common space R branches off into each throttle section R1 and is supplied to and filled in parallel into multiple pressure chambers C. In addition, a through hole 21H is provided in the flow path opening forming member 208. The through hole 21H overlaps with the through hole 20H of the sealing substrate 205 in a plan view. A wiring substrate 209 is inserted into the through hole 21H.

[0046] Wiring board 209 is bonded to diaphragm 204. Wiring board 209 protrudes from diaphragm 204 in the Z2 direction. Wiring board 209 is a mounting component on which a plurality of wires are formed for electrically connecting first head chip 2a and relay substrate 7. Wiring board 209 is connected to connector 70 described above. Wiring board 209 is, for example, a flexible board such as an FPC (Flexible Printed Circuit) or a COF (Chip On Film) or a rigid board. A drive signal and a reference voltage for driving drive elements E are supplied to each drive element E from wiring board 209.

[0047] In this first head chip 2a, when the drive element E contracts due to energization, the vibration plate 204 is bent and deflected in the direction that reduces the volume of the pressure chamber C, and the force inside the pressure chamber C increases, causing an ink droplet to be ejected from the nozzle N. At this time, pressure also propagates from the pressure chamber C toward the throttle portion R1, and ink also flows into the common flow path Rb through the throttle portion R1. After the ink is ejected, the drive element E returns to its original position. At this time, the ink in the common flow path Rb from the nozzle N also vibrates. Then, at the same time as the meniscus of the nozzle N returns to its original position, ink is supplied from the throttle portion R1. Through this series of operations, ink is ejected from the nozzle N.

[0048] 6, the components of first head chip 2a do not necessarily have to include all of the components, and may further include additional components. For example, flow path opening forming member 208 may be a component of holder 4. First head chip 2a preferably includes at least nozzle plate 201, more preferably further includes pressure chamber substrate 203, and particularly preferably further includes communicating plate 202.

[0049] 1-4.Leak inspection FIG. 7 is a diagram illustrating a leak test according to the first embodiment. As shown in FIG. 7, the third surface 401 of the protrusion 43 is a flat surface against which a lid member 8 for a leak test can abut. The lid member 8 is a member used when performing a leak test. In this embodiment, the portion of the lid member 8 that abuts against the third surface 401 is made of a flexible material. The portion of the lid member 8 that abuts against the third surface 401 has lower elasticity than the third surface 401. The portion of the lid member 8 other than the portion that abuts against the third surface 401 is made of, for example, resin or metal. When the lid member 8 abuts against the third surface 401, a sealed space S1 is formed between the third surface 401 and the lid member 8. An opening 801 is formed in the lid member 8.

[0050] The cover member 8 is connected via a connection path Cc to a valve mechanism Va that opens and closes the connection path Cc, and the valve mechanism Va is connected via the connection path Cc to a pump P that performs suction or pressurization. In other words, the sealed space S1 is connected to the pump P via the connection path Cc and the valve mechanism Va. An apparatus including the cover member 8, connection path Cc, valve mechanism Va, and pump P is referred to as a suction apparatus or a pressurization apparatus. Furthermore, a pressure gauge Pg that measures the pressure inside the sealed space S1 is provided in the connection path Cc between the sealed space S1 and the valve mechanism Va.

[0051] A leak test is then performed by using a pump P to suction or pressurize the sealed space S1, and checking whether there is any adhesion failure in the fixing plate 3 based on the pressure value in the sealed space S1 measured by a pressure gauge Pg. Specifically, as shown in FIG. 7 , the accommodation space S0a communicates with the outside via a through hole formed in the holder 4 and a through hole formed in the relay substrate 7. Therefore, if a leak occurs in the first adhesive layer 51 or the second adhesive layer 52, the sealed space S1 communicates with the outside via the accommodation space S0a, the through hole formed in the holder 4, and the through hole formed in the relay substrate 7. Therefore, the pressure value in the sealed space S1 significantly differs depending on whether a leak occurs or not. A detailed method for testing for adhesion failure will be described later.

[0052] The third surface 401 is a surface of the holder 4 facing the Z1 direction, is continuously formed so as to surround the outer periphery of the fixed plate 3, and is a plane perpendicular to the Z1 direction. Here, the term "plane" means that the surface is all on the same plane, and does not include, for example, a surface in which multiple planes of different heights are arranged consecutively. However, the flatness of the plane may be 100 μm or less. More preferably, the flatness is 60 μm or less. According to the third surface 401, the lid member 8 can be suitably attached to the third surface 401. Furthermore, the provision of the third surface 401 allows the lid member 8 to be disposed so as to cover the fixing plate 3 from below the liquid jet head 1. Therefore, a leak test can be performed from below the liquid jet head 1.

[0053] Fig. 8 is a diagram for explaining a leak test in a comparative example. As shown in Fig. 8, when there is no flat surface with a sufficient plane area to allow the lid member 8 to abut against the Z1 direction surface 440 of the liquid jet head 1, it is possible to abut the lid member 8 against the Z2 direction surface of the relay substrate 7, for example, as shown in Fig. 8. By abutting them, a sealed space S2 is formed between the relay substrate 7 and the lid member 8.

[0054] In the comparative example, the accommodation space S0a is connected to the sealed space S2 via a through-hole formed in the holder 4 and a through-hole formed in the relay substrate 7. Therefore, after sealing the nozzle surface, the sealed space S2 is suctioned or pressurized, and a leak test is performed by checking whether there is any adhesion defect in the fixed plate 3 based on the pressure value in the sealed space S2. In the comparative example, in order to perform a leak test on the adhesion of the fixed plate 3, it is necessary to firmly adhere the relay substrate 7 to the holder 4 in order to seal the area between the relay substrate 7 and the fixed plate 3.

[0055] To achieve this strong adhesion, it is necessary to provide a wide adhesive area on both the surface of the relay substrate 7 facing the Z1 direction and the surface of the holder 4 facing the Z2 direction for bonding them together. However, providing wide adhesive areas on each of the relay substrate 7 and the holder 4 increases the size of the liquid jet head 1. Furthermore, an adhesive procedure is required, which increases the number of steps in assembling the liquid jet head 1.

[0056] Furthermore, it is necessary to provide a flat surface on the surface of the relay substrate 7 facing the Z2 direction, against which the cover member 8 abuts. This further increases the size of the relay substrate 7, and the size of the liquid jet head 1 also increases.

[0057] In contrast to this, according to the present embodiment, the cover member 8 can be disposed so as to cover the fixing plate 3 from below the liquid jet head 1, and therefore a leak test can be performed from below the liquid jet head 1. This makes it possible to prevent the liquid jet head 1 from becoming too large, and also makes it easier to perform a leak test.

[0058] Such a leak test is generally performed before using the liquid jet head 1. By performing such a leak test, it is possible to reduce the risk of the fixing plate 3 coming off the holder 4 due to poor adhesion when using the liquid jet head 1. Furthermore, by reducing the poor adhesion, it is possible to suppress the risk of ink entering the first head chip 2a from between the fixing plate 3 and the holder 4.

[0059] As described above, the holder 4 has the protrusion 43. The protrusion 43 protrudes in the Z1 direction from the flange 44. The protrusion 43 is continuously arranged so as to surround the entire outer periphery 31 of the fixing plate 3 when viewed in the Z2 direction. The surface of the protrusion 43 facing the Z1 direction is the third surface 401.

[0060] Possible cases where the third surface 401 is provided other than on the convex portion 43 include a case where the third surface 401 is provided on a flat surface of the flange portion 44 that is not on the convex portion 43, or a case where the bottom of a recess formed on the surface 440 of the flange portion 44 that faces the Z1 direction is the third surface 401. When the third surface 401 is provided other than on the convex portion 43 in this way, there is a risk that the sealing ability of the cover member 8 with respect to the third surface 401 may be reduced compared to a case where the third surface 401 is provided on the convex portion 43. This is because, in a form where the third surface 401 is provided other than on the convex portion 43, it is more difficult to accurately form a highly flat surface by processing or the like compared to a case where the third surface 401 is provided on the convex portion 43.

[0061] For example, if the third surface 401 is provided on a flat surface that is not a convex portion of the flange portion 44, it is necessary to ensure high flatness over the entire surface of the flange portion 44 in the Z1 direction. In other words, flatness must be ensured over a very wide area, and as the area increases, there is a risk that flatness will decrease. In contrast, by providing a convex portion 43 corresponding to the lid member 8, the area that requires flatness can be reduced. As the area decreases, it becomes easier to create, for example, a mold with high flatness accuracy. This also improves yield. In addition, it is very difficult to process the bottom surface of a recess to be flat.

[0062] For this reason, by providing third surface 401 on protrusion 43, it is possible to improve the flatness of third surface 401. Therefore, it is possible to improve the sealing performance of cover member 8, and therefore to improve the reliability of leak testing.

[0063] The third surface 401 may be provided on a surface of the flange portion 44 facing the Z1 direction where there is no protrusion, or on the bottom surface of a recess formed in the flange portion 44.

[0064] 4 and 5, width W1 of third surface 401 in a direction perpendicular to the Z1 direction is not particularly limited, but is preferably greater than 1 mm. When width W1 is greater than 1 mm, it is easier to abut lid member 8 compared to when width W1 is 1 mm or less. For example, even if lid member 8 abuts with a slight deviation in a direction parallel to third surface 401, suction or pressure can be applied accurately.

[0065] Furthermore, since the width W1 of the third surface 401 is greater than 1 mm, there is a sufficient width to press the lid member 8 against the third surface 401 compared to when the width is 1 mm or less, and the contact area can be increased by the deformation of the lid member 8, thereby improving the sealing performance between the third surface 401 and the lid member 8.

[0066] Furthermore, from the above viewpoint, the width W1 is more preferably greater than 1.5 mm, and even more preferably greater than 2.0 mm. The width W1 may or may not be constant.

[0067] Furthermore, width W1 is not particularly limited, but is preferably smaller than 3 mm. When width W1 is smaller than 3 mm, the flatness of third surface 401 can be improved compared to when width W1 is 3 mm or greater, in the case where third surface 401 is the surface of protrusion 43 in the Z1 direction. This can improve the sealing performance of lid member 8.

[0068] As described above, the second adhesive layer 52 is continuously disposed so as to surround the first opening 3Ha when viewed in the Z1 direction, and bonds the second surface 302 of the fixing plate 3 and the first head chip 2a. As described above, according to the present embodiment having the third surface 401, it is possible to inspect for poor adhesion of the second adhesive layer 52 in addition to poor adhesion of the first adhesive layer 51. Therefore, it is possible to inspect whether the fixing plate 3 has detached from the first head chip 2a before use of the liquid jet head 1. Therefore, it is possible to reduce the risk of the fixing plate 3 detaching from the first head chip 2a due to poor adhesion when using the liquid jet head 1. Therefore, it is possible to reduce the risk of ink entering between the fixing plate 3 and the first head chip 2a when using the liquid jet head 1.

[0069] Furthermore, as shown in FIG. 5, for example, when performing nozzle cleaning by abutting the cap member 14 against the fixed plate 3, it is possible to prevent air from leaking between the fixed plate 3 and the first head chip 2a, making it impossible to suck up ink.

[0070] When performing nozzle cleaning of the first nozzle Na, a cap member 14 is used to seal the first nozzle Na. This cap member abuts, for example, against the first surface 301 of the fixed plate 3. As shown in FIG. 5, the first surface 301 of the fixed plate 3 has an abutment portion 303 with which the cap member 14 abuts. This abutment portion 303 is different from the third surface 401 described above. In other words, the third surface 401 does not function as an "abutment portion" with which the cap member 14 abuts.

[0071] Furthermore, the base portion 41, the wall portion 42, and the protrusion portion 43 of the holder 4 are integrally formed. The fact that the base portion 41, the wall portion 42, and the protrusion portion 43 are integrally formed means that no adhesive is provided to bond the base portion 41, the wall portion 42, and the protrusion portion 43 to one another.

[0072] If the holder 4 were not formed as a single unit but formed by bonding multiple members together, an adhesive layer would be required to connect the base 41 and the wall 42, or an adhesive layer to connect the base 41 and the protrusion 43. In this case, when poor adhesion is detected, there is a possibility that the poor adhesion is occurring in the adhesive layer, making it difficult to determine whether the poor adhesion is due to the adhesive layer or to either the first adhesive layer 51 or the second adhesive layer 52. This makes it difficult to determine whether the poor adhesion is related to the fixing plate 3. Therefore, in order to clearly determine that the poor adhesion is related to the fixing plate 3, it is preferable that the base 41, the wall 42, and the protrusion 43 are formed as a single unit.

[0073] As described above, the base 41 includes the flange 44 that projects outward beyond the wall 42 when viewed in the Z2 direction. The protrusion 43 projects from the flange 44.

[0074] Providing the protrusion 43 on the flange portion 44 eliminates the need to provide the protrusion 43 at the tip 42E of the wall portion 42 or outside the first adhesive layer 51, thereby increasing the degree of freedom in designing the wall portion 42. This allows, for example, the thickness of the wall portion 42 in the Y1 direction to be reduced. This also allows a large space to be provided outside the wall portion 42 and in the Z1 direction of the base portion 41. This allows, for example, the paper pressing mechanism, which is part of the transport unit 92 described above, to be disposed in this space, thereby enabling the liquid jet head 1 to be made smaller.

[0075] Although not particularly limited, the protruding height T1 of the convex portion 43 is preferably 2 mm or less. By setting the protruding height T1 to 2 mm or less, compared to when the protruding height T1 exceeds 2 mm, the protruding height T1 of the convex portion 43 becomes larger, which reduces the space required to place the paper pressing mechanism, which is part of the conveying unit 92, making it difficult to place the conveying unit 92. Furthermore, if the protruding height T1 is too large, excessive cure shrinkage may occur during the processing of the convex portion 43, which may reduce the flatness of the third surface 401.

[0076] Moreover, the protrusions 43 are disposed at intervals from the wall portions 42 when viewed in the Z2 direction. Therefore, it is easier to increase the flatness of the third surfaces 401 of the protrusions 43 in processing the protrusions 43 compared to when the protrusions 43 are disposed without any intervals from the wall portions 42.

[0077] Furthermore, the protrusion 43 is located between the wall 42 and the side surface 410 of the base 41 as viewed in the Z2 direction, and is disposed at a position closer to the wall 42 than the side surface 410 as viewed in the Z2 direction. In other words, the distance between the protrusion 43 and the wall 42 is shorter than the distance between the protrusion 43 and the side surface 410. By disposing the protrusion 43 closer to the wall 42, the cover member 8 can be made smaller than when the protrusion 43 is disposed closer to the side surface 410.

[0078] The holder 4 also has through holes 40H into which screws are inserted to secure the holder 4 to the flow path connecting unit 6, which is a member stacked on the holder 4 in the Z2 direction. When viewed in the Z2 direction, the third surface 401 is disposed on the inside of the through holes 40H. By disposing the through holes 40H on the outside of the third surface 401, it is possible to prevent air from leaking from the through holes 40H during a leak test, compared to when the through holes 40H are disposed on the inside of the third surface 401.

[0079] 9 is a flow diagram showing the method for inspecting the liquid jet head 1 according to the first embodiment. As shown in Fig. 9, the method for inspecting the liquid jet head 1 includes a first step S11, a second step S12, and a third step S13.

[0080] The first step S11 is a step of abutting the cover member 8 against the holder 4 so as to surround the entire periphery of the fixed plate 3 when viewed in the Z2 direction, thereby forming an enclosed space S1 for accommodating the fixed plate 3 between the cover member 8 and the holder 4. In other words, as shown in the above-mentioned FIG. 7 , this is a step of closely contacting the cover member 8 with the third surface 401.

[0081] The second step S12 is a step of reducing or pressurizing the inside of the sealed space S1 through the opening 801 formed in the lid member 8, after the first step S11, while the flow path of the liquid jet head 1 that communicates with the first nozzle Na is closed. If the reduction in pressure and the pressurization are not performed while the flow path of the liquid jet head 1 is closed, external air may enter or exit the flow path through the first nozzle Na during reduction in pressure or pressurization, which may cause noise in the leak test. One method of closing the flow path of the liquid jet head 1 that communicates with the first nozzle Na is to seal the nozzle plate 201 with tape, for example.

[0082] In the third step S13, the presence of an adhesion defect in the first adhesive layer 51 is detected based on the pressure value in the sealed space S1 when the pressure in the sealed space S1 is reduced or increased in the second step S12. Specifically, first, the pump P is driven with the valve mechanism Va (see FIG. 7) open to reduce or increase the pressure for a certain period of time. Thereafter, the pump P is stopped and the valve mechanism Va is closed to maintain the pressure in the sealed space S1. After a certain period of time has passed, the pressure value in the sealed space S1 is measured with the pressure gauge Pg. If the pressure value is higher or lower than a preset reference value, the presence of an adhesion defect is detected.

[0083] Therefore, it is possible to prevent the liquid jet head 1 from becoming large.

[0084] Furthermore, according to this leak test, the cover member 8 can be placed so as to cover the fixing plate 3 from below the liquid jet head 1. By performing this leak test, it is possible to reduce the risk of the fixing plate 3 coming off the holder 4 due to poor adhesion when the liquid jet head 1 is in use. Furthermore, by reducing this poor adhesion, it is possible to suppress the risk of ink entering the head chip 2 from between the fixing plate 3 and the holder 4.

[0085] 2. Second embodiment A second embodiment of the present disclosure will be described below. In the following exemplary embodiments, elements whose actions or functions are similar to those of the first embodiment will be designated by the same reference numerals as those used in the description of the first embodiment, and detailed descriptions of each element will be omitted where appropriate.

[0086] Fig. 10 is a cross-sectional view of a portion of a liquid jet head 1A according to a second embodiment. In the second embodiment shown in Fig. 10, elastic portions 46 are provided instead of the convex portions 43. It may be understood that the convex portions 43 are made of an elastic member. In this embodiment, the portion of cover member 8 that comes into contact with third surface 401 does not need to be flexible, and may be made of, for example, resin or metal.

[0087] The elastic portion 46 has elasticity. The elastic portion 46 is provided on a part of a surface 440 of the flange portion 44 of the holder 4 facing the Z1 direction. The surface of the elastic portion 46 facing the Z1 direction is the third surface 401. The elastic portion 46 is made of a flexible member. The elastic portion 46 includes, for example, an elastomer. The portions of the holder 4 other than the elastic portion 46, namely the base portion 41, the wall portion 42, and the flange portion 44, are made of metal or resin having lower elasticity than the elastic portion 46.

[0088] Third surface 401 has higher elasticity than other areas of holder 4. Specifically, third surface 401 has higher elasticity than base portion 41 and wall portion 42. By providing such third surface 401, even if lid member 8 is not made of an elastic material, lid member 8 can be suitably attached to third surface 401. Therefore, air leakage from between third surface 401 and lid member 8 can be prevented during a leak test.

[0089] In this embodiment, the elastic portion 46 protrudes in the Z1 direction from the surface 440 of the flange portion 44 facing the Z1 direction. However, the elastic portion 46 may be disposed, for example, in a recess formed in the surface of the flange portion 44 facing the Z1 direction. Therefore, the elastic portion 46 does not have to protrude in the Z1 direction from the surface of the flange portion 44 facing the Z1 direction. Furthermore, the elastic portion 46 does not have to be a surface perpendicular to the Z axis. The elastic portion 46 may be inclined with respect to the XY plane perpendicular to the Z axis. Furthermore, the third surface 401 does not have to be flat, and may be a surface having projections and recesses. This is because the elastic portion 46 has elasticity, and thus deforms when the cover member 8 is brought into close contact.

[0090] 3. Third embodiment A third embodiment of the present disclosure will be described below. In the following exemplary embodiments, elements that have the same actions or functions as those in the first embodiment will be designated by the same reference numerals as those in the first embodiment, and detailed descriptions of each element will be omitted where appropriate.

[0091] Fig. 11 is a cross-sectional view of a portion of a liquid jet head 1B according to a third embodiment. Fig. 12 is a bottom view of the liquid jet head 1B according to the third embodiment. In the third embodiment shown in Figs. 11 and 12, the protrusion 43 is disposed at a tip 42E of the wall portion 42 in the Z1 direction. The protrusion 43 is spaced apart from the fixed plate 3 and disposed outside the fixed plate 3 when viewed in the Z2 direction. Here, the tip 42E of the wall portion 42 in the Z1 direction is the surface that is bonded to the second surface 302 of the fixed plate 3.

[0092] According to the third embodiment in which the protrusion 43 is provided on the wall 42, the third surface 401 is located in the Z1 direction more than in the first embodiment, and therefore the distance until the cover member 8 comes into contact with the protrusion 43 is shorter when the cover member 8 comes into contact with the protrusion 43 in the Z2 direction. Therefore, the time required for the cover member 8 to come into contact with the protrusion 43 can be shortened, improving operability.

[0093] In this embodiment, elastic portions 46 may be provided instead of the protrusions 43, as in the second embodiment.

[0094] 4. Fourth embodiment A fourth embodiment of the present disclosure will be described below. In the following exemplary embodiments, elements whose actions or functions are similar to those of the first embodiment will be designated by the same reference numerals as those used in the description of the first embodiment, and detailed descriptions of each element will be omitted as appropriate.

[0095] Fig. 13 is a cross-sectional view of a portion of a liquid jet head 1 according to a fourth embodiment. Fig. 14 is a bottom view of a liquid jet head 1C according to the fourth embodiment. In the fourth embodiment shown in Figs. 13 and 14, one holder 4C holds a plurality of head chips 2.

[0096] In the illustrated example, one holder 4C holds a plurality of head chips 2. Specifically, the liquid jet head 1C of this embodiment has a first head chip 2a and a second head chip 2b.

[0097] The second head chip 2b has a plurality of second nozzles Nb that spray liquid in the Z1 direction. The second head chip 2b has the same configuration as the first head chip 2a in Fig. 6. In addition to the first opening 3Ha, the fixed plate 3 has second openings 3Hb that expose the plurality of second nozzles Nb.

[0098] Holder 4C further has a partition wall 45. Partition wall 45 is located between first head chip 2a and second head chip 2b. Wall portion 42 is a portion located outside first head chip 2a and second head chip 2b when viewed in the Z2 direction. Holder 4 also houses second head chip 2b in another storage space S0b different from storage space S0a. If holder 4C does not have partition wall 45, storage spaces S0a and S0b may be integrated to form one and the same space. Wall portion 42 and partition wall 45 correspond to the "wall portion."

[0099] Furthermore, the liquid jet head 1 of this embodiment includes a third adhesive layer 53. The third adhesive layer 53 is disposed continuously so as to surround the outer periphery of the second opening 3Hb when viewed in the Z1 direction, and bonds the second surface 302 of the fixing plate 3 and the second head chip 2b together. Similar to the second adhesive layer 52, the third adhesive layer 53 is formed of an adhesive containing, for example, a thermosetting resin.

[0100] In this embodiment, the first adhesive layer 51 is disposed continuously so as to surround the second adhesive layer 52 and the third adhesive layer 53 when viewed in the Z1 direction. Specifically, the first adhesive layer 51 is located between the wall portion 42 and the fixing plate 3, and also between the partition wall 45 and the fixing plate 3. The first adhesive layer 51 bonds the wall portion 42 and the fixing plate 3, and also bonds the partition wall 45 and the fixing plate 3. The first adhesive layer 51 does not have to be disposed between the partition wall 45 and the fixing plate 3.

[0101] In the present embodiment, as in the first embodiment, the third surface 401 is formed continuously on the surface of the holder 4C facing the Z1 direction so as to surround the outer periphery of the fixing plate 3. By having such a third surface 401, the lid member 8 can be tightly attached to the third surface 401 from below the third surface 401. Therefore, a leak test can be suitably performed from below the liquid jet head 1C.

[0102] 5. Variations The first embodiment exemplified above can be modified in various ways. Specific modified aspects that can be applied to the first embodiment are exemplified below. Two or more aspects arbitrarily selected from the following examples can be combined as appropriate within the scope of not mutually contradicting each other.

[0103] The "third surface" does not have to be the surface of the "protrusion" in the Z1 direction, but may be a part of the surface of the "holder" facing the Z1 direction.

[0104] The fixed plate 3 may have a hole penetrating the fixed plate 3 in addition to the first opening 3Ha. For example, the fixed plate 3 may have a hole for inserting a jig for positioning. When a hole is provided, it is preferable to seal the hole with a filler to prevent gas from leaking from the hole during a leak test.

[0105] The fixed plate 3 may have a bent portion that is a portion bent along the outer surface of the wall portion 42 at the end of the flat plate extending in the XY plane where the opening is formed. Also in this configuration, the third surface 401 is formed continuously so as to surround the outer periphery of the fixed plate 3 including the bent portion.

[0106] "Liquid ejection devices" can be used in various devices such as facsimile machines and copiers, as well as devices dedicated to printing. The uses of liquid ejection devices are not limited to printing. For example, a liquid ejection device that ejects a solution of coloring material is used as a manufacturing device for forming color filters for display devices such as liquid crystal display panels. A liquid ejection device that ejects a solution of conductive material is used as a manufacturing device for forming wiring and electrodes on relay boards. A liquid ejection device that ejects a solution of organic matter related to living organisms is used as a manufacturing device for manufacturing biochips, for example.

[0107] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above-described embodiments, and any configuration can be added.

[0108] 6. Supplementary Notes For example, the following aspects can be understood from the above embodiment and modified examples.

[0109] A liquid ejection head of a first aspect, which is a preferred example of the present disclosure, comprises: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction; a second surface that faces a second direction opposite the first direction and is the surface opposite the first surface; and a first opening that exposes the plurality of first nozzles; a holder having a base portion and a wall portion protruding from the base portion in the first direction, and that accommodates the first head chip in an accommodation space defined by the base portion, the wall portion and the fixing plate; and a first adhesive layer that is arranged continuously to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder, and the holder has a third surface that is formed continuously to surround the outer periphery of the fixing plate and is a plane perpendicular to the first direction.

[0110] According to the first aspect, the lid member for leak testing can be suitably attached to the third surface. Furthermore, the provision of the third surface allows the lid member to be positioned so as to cover the fixing plate from below the liquid ejection head. Therefore, the leak test can be performed from below the liquid ejection head.

[0111] In a second aspect, which is a preferred example of the first aspect, the holder is arranged continuously so as to surround the entire outer periphery of the fixing plate when viewed in the second direction and has a convex portion that protrudes in the first direction, and the third surface is located at the tip of the convex portion.

[0112] According to the second aspect, by providing the third surface on the convex portion, the flatness of the third surface can be improved, thereby improving the sealing performance of the lid member and improving the reliability of leak testing.

[0113] In a third aspect which is a preferred example of the first or second aspect, the width of the third surface in a direction perpendicular to the first direction is greater than 1 mm.

[0114] According to this third aspect, compared to when the width is 1 mm or less, the width is sufficient to press the lid member against the third surface, and the contact area can be increased by deforming the lid member, thereby improving the sealing ability between the third surface and the lid member.

[0115] In a fourth aspect which is a preferable example of the second aspect, the width of the third surface in a direction perpendicular to the first direction is smaller than 3 mm.

[0116] According to the fourth aspect, the flatness of the third surface can be improved compared to when the width is 3 mm or more, thereby improving the sealing performance of the lid member.

[0117] In a fifth aspect, which is a preferred example of any of the first to fourth aspects, a second adhesive layer is provided that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate and the first head chip.

[0118] According to the fifth aspect, it is possible to inspect whether or not the fixing plate is detached from the first head chip.

[0119] In a sixth aspect which is a preferred example of the second aspect, the base portion, the wall portion, and the protrusion portion are integrally formed.

[0120] According to the sixth aspect, it is possible to clearly determine that the adhesion defect is related to the fixing plate.

[0121] In a seventh aspect which is a suitable example of the second aspect, the base portion includes a flange portion that projects outward beyond the wall portion when viewed in the second direction, and the convex portion projects from the flange portion.

[0122] According to the seventh aspect, the paper pressing mechanism, which is part of the transport unit, can be disposed in this space, which makes it possible to reduce the size of the liquid jet head.

[0123] In an eighth aspect which is a preferable example of the second aspect, the protrusion is disposed at a tip of the wall in the first direction.

[0124] According to the eighth aspect, when the lid member is brought into contact with the third surface, the distance until the contact can be shortened, so that the time for the lid member to come into contact with the convex portion can be shortened, improving operability.

[0125] In a ninth aspect which is a preferred example of the first to eighth aspects, a contact portion is provided to which a cap member that seals the plurality of first nozzles can come into contact, and the third surface is different from the contact portion.

[0126] The contact portion is a portion that comes into contact with a cap member that seals the first nozzle when performing nozzle cleaning of the first nozzle Na, and is different from the third surface.

[0127] In a tenth aspect which is a preferred example of any of the first to eighth aspects, the third surface has higher elasticity than other areas of the holder.

[0128] According to the tenth aspect, the lid member can be suitably attached to the third surface, which makes it possible to prevent air from leaking between the third surface and the lid member during a leak test.

[0129] A liquid ejection head according to an eleventh aspect of the present disclosure, which is a preferred example of the present disclosure, comprises: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction; a second surface that faces a second direction opposite the first direction and is the surface opposite the first surface; and a first opening that exposes the plurality of first nozzles; a holder having a base and a wall protruding from the base in the first direction, and that accommodates the first head chip in an accommodation space defined by the base, the wall, and the fixing plate; and a first adhesive layer that is arranged continuously to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder, and the holder has an elastic portion that is arranged continuously to surround the entire outer periphery of the fixing plate when viewed in the second direction, and that has higher elasticity than other areas of the holder.

[0130] According to the eleventh aspect, the lid member can be suitably brought into close contact with the elastic portion, thereby preventing air from leaking between the elastic portion and the lid member during a leak test.

[0131] In the twelfth aspect, which is a preferred example of the fifth aspect, a second head chip having a plurality of second nozzles that spray liquid in the first direction is provided, the fixing plate has a second opening that exposes the plurality of second nozzles, the holder accommodates the second head chip in the accommodation space and is arranged continuously to surround the outer periphery of the second opening when viewed in the first direction, and is provided with a third adhesive layer that bonds the second surface of the fixing plate and the second head chip, and the first adhesive layer is arranged continuously to surround the second adhesive layer and the third adhesive layer when viewed in the first direction.

[0132] According to the twelfth aspect, even when a second head chip is provided, the lid member can be tightly attached to the third surface from below the third surface, so that leak testing can be suitably performed from below the liquid ejection head.

[0133] In a thirteenth aspect which is a preferable example of the seventh aspect, the protrusion is disposed at a distance from the wall when viewed in the second direction.

[0134] According to the twelfth aspect, in processing the convex portion, it is easy to increase the flatness of the third surface of the convex portion.

[0135] In a fourteenth aspect, which is a preferred example of the thirteenth aspect, the convex portion is located between the wall portion and the side surface of the base portion when viewed in the second direction, and is positioned closer to the wall portion than the side surface when viewed in the second direction.

[0136] According to the fourteenth aspect, the cover member can be made smaller.

[0137] In a fifteenth aspect which is a preferred example of the first to tenth aspects, the head device further comprises a relay substrate connected to the first head chip and stacked on the holder.

[0138] In the sixteenth aspect, which is a preferred example of the first to tenth aspects, the holder has a through hole into which a screw is inserted to fix the holder to a member stacked in the second direction of the holder, and the third surface is positioned inside the through hole when viewed in the second direction.

[0139] According to the sixteenth aspect, air can be prevented from leaking from the through-hole during a leak test.

[0140] A seventeenth aspect of the present disclosure is a preferred example of a method for manufacturing a liquid jet head, the method comprising: a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction, a second surface that faces a second direction opposite the first direction and is opposite the first surface, and a first opening that exposes the plurality of first nozzles; a holder that accommodates the first head chip; and a first adhesive layer that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate to the holder, the method comprising: a first step of abutting a cover member against the holder so as to surround the entire circumference of the fixing plate when viewed in the second direction, thereby forming a space to accommodate the fixing plate between the cover member and the holder; and a second step of, after the first step, reducing or pressurizing the space through the opening formed in the cover member while closing a flow path of the liquid jet head that is connected to the first nozzles.

[0141] According to the seventeenth aspect, the cover member 8 can be disposed so as to cover the fixed plate from below the liquid jet head.

[0142] In the 18th embodiment, which is a preferred example of the 17th embodiment, there is provided a step of detecting that there is poor adhesion in the first adhesive layer based on the pressure value in the space when the pressure in the space is reduced or increased in the second step.

[0143] According to the eighteenth aspect, if the pressure value is higher or lower than a preset reference value, it is possible to detect that there is poor adhesion. [Explanation of symbols]

[0144] 1...liquid jet head, 2a...first head chip, 2b...second head chip, 3...fixing plate, 3Ha...first opening, 3Hb...second opening, 4...holder, 7...relay substrate, 8...lid member, 20...flow path member, 31...outer periphery, 40H...through hole, 41...base portion, 42...wall portion, 43...convex portion, 44...flange portion, 45...partition wall, 46...elastic portion, 51...first adhesive layer, 52...second adhesive Adhesion layer, 53...third adhesive layer, 61...main body portion, 62...protrusion portion, 71...screw, 100...liquid injection device, 301...first surface, 302...second surface, 303...contact portion, 401...third surface, 410...side surface, C...pressure chamber, E...driving element, Na...first nozzle, Nb...second nozzle, S0a...accommodation space, S0b...accommodation space, S11...first step, S12...second step, S13...third step.

Claims

1. a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction, a second surface that faces a second direction opposite to the first direction and faces the opposite side of the first surface, and a first opening that exposes the plurality of first nozzles; a holder having a base and a wall protruding from the base in the first direction, the holder accommodating the first head chip in an accommodating space defined by the base, the wall, and the fixing plate; a first adhesive layer that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder; Equipped with the holder is formed continuously around the outer periphery of the fixing plate and has a third surface that is a plane perpendicular to the first direction; A liquid jet head characterized by:

2. the holder has a convex portion that is continuously arranged so as to surround the entire outer periphery of the fixing plate when viewed in the second direction and that protrudes in the first direction; the third surface is located at the tip of the protrusion, The liquid jet head according to claim 1 .

3. The width of the third surface in a direction perpendicular to the first direction is greater than 1 mm. The liquid jet head according to claim 1 .

4. The width of the third surface in a direction perpendicular to the first direction is smaller than 3 mm. The liquid jet head according to claim 2 .

5. a second adhesive layer that is continuously disposed so as to surround the first opening when viewed in the first direction and that bonds the fixing plate and the first head chip; The liquid jet head according to claim 1 .

6. The base portion, the wall portion, and the protrusion portion are integrally formed. The liquid jet head according to claim 2 .

7. the base portion includes a flange portion that protrudes outward beyond the wall portion when viewed in the second direction, The protrusion protrudes from the flange portion. The liquid jet head according to claim 2 .

8. The protrusion is disposed at a tip of the wall portion in the first direction. The liquid jet head according to claim 2 .

9. a contact portion to which a cap member that seals the plurality of first nozzles can contact; the third surface is different from the abutment portion; The liquid jet head according to claim 1 .

10. the third surface has a higher elasticity than other areas of the holder; The liquid jet head according to claim 1 .

11. a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction, a second surface that faces a second direction opposite to the first direction and faces the opposite side of the first surface, and a first opening that exposes the plurality of first nozzles; a holder having a base and a wall protruding from the base in the first direction, the holder accommodating the first head chip in an accommodating space defined by the base, the wall, and the fixing plate; a first adhesive layer that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder; Equipped with the holder has an elastic portion that is continuously arranged so as to surround the entire outer periphery of the fixing plate when viewed in the second direction and has higher elasticity than other regions of the holder. A liquid jet head characterized by:

12. a second head chip having a plurality of second nozzles that eject liquid in the first direction; the fixing plate has a second opening through which the plurality of second nozzles are exposed, the holder accommodates the second head chip in the accommodation space; a third adhesive layer that is continuously disposed so as to surround an outer periphery of the second opening when viewed in the first direction and that bonds the second surface of the fixing plate and the second head chip; the first adhesive layer is disposed continuously so as to surround the second adhesive layer and the third adhesive layer when viewed in the first direction; The liquid jet head according to claim 5 .

13. The protrusion is disposed at a distance from the wall when viewed in the second direction. The liquid jet head according to claim 7 .

14. the protrusion is located between the wall and a side surface of the base as viewed in the second direction, and is disposed at a position closer to the wall than the side surface as viewed in the second direction. The liquid jet head according to claim 13 .

15. a relay substrate connected to the first head chip and stacked on the holder; The liquid jet head according to claim 1 .

16. the holder includes a through hole into which a screw is inserted to fix the holder to a member stacked in the second direction of the holder, The third surface is disposed on the inner side of the through hole when viewed in the second direction. The liquid jet head according to claim 1 .

17. a first head chip having a plurality of first nozzles that eject liquid in a first direction; a fixing plate having a first surface that is perpendicular to the first direction and faces the first direction, a second surface that faces a second direction opposite the first direction and is opposite to the first surface, and a first opening that exposes the plurality of first nozzles; a holder that accommodates the first head chip; and a first adhesive layer that is continuously arranged to surround the first opening when viewed in the first direction and that bonds the fixing plate and the holder, a first step of forming a space for accommodating the fixing plate between the cover member and the holder by bringing a cover member into contact with the holder so as to surround the entire periphery of the fixing plate when viewed in the second direction; a second step of decompressing or pressurizing the space through an opening formed in the lid member after the first step, while a flow path of the liquid ejection head communicating with the first nozzle is closed; A liquid ejection head inspection method comprising:

18. and detecting an adhesive defect in the first adhesive layer based on a pressure value in the space when the pressure in the space is reduced or increased in the second step.

18. The method for inspecting a liquid jet head according to claim 17.

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