Liquid injection head and liquid injection device

Abstract

Knowing the right time to replace the liquid spray head. [Solution] The liquid spray head comprises a first flow path communicating with one or more nozzles among a plurality of nozzles, a first adhesive portion A that defines the inner wall of the first flow path and is provided so as to surround the first flow path, a first adhesive portion B provided so as to surround the first adhesive portion A, and a first detection means A for detecting a state in which the liquid exceeds the first adhesive portion A but does not exceed the first adhesive portion B.

Description

Technical Field

[0001] The present invention relates to a liquid ejection head and a liquid ejection device.

Background Art

[0002] Conventionally, liquid ejection heads that eject liquids such as ink from nozzles have become widespread. For example, Patent Document 1 discloses that a plurality of flow path members constituting the flow path of a liquid ejection head are joined to each other by an adhesive, thereby hermetically connecting the flow paths formed in each of the plurality of joined flow path members.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The adhesive joining the flow path members deteriorates when it comes into contact with the liquid flowing through the flow path, and there is a risk that the liquid in the flow path will leak out of the flow path member from the joined portion. However, in the conventional technology described above, there has been a problem that the user of the liquid ejection head cannot determine when to replace the liquid ejection head.

Means for Solving the Problems

[0005] A liquid ejection head according to a preferred aspect of the present disclosure includes a plurality of nozzles that eject a liquid, a first flow path that communicates with one or more of the plurality of nozzles, a first adhesive portion A that defines an inner wall of the first flow path and is provided so as to surround the first flow path, a first adhesive portion B that is provided so as to surround the first adhesive portion A, and first detection means A for detecting a state in which the liquid exceeds the first adhesive portion A but does not exceed the first adhesive portion B.

[0006] A liquid spraying device according to a preferred embodiment of the present disclosure comprises the liquid spraying head described above, an acquisition unit for acquiring state information relating to the state of the first detection means A, and an estimation unit for estimating the degree of deterioration of the first adhesive portion A based on the state information. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram showing an example configuration of the inkjet system SYS according to the first embodiment. [Figure 2] A diagram showing the configuration of the processing unit 200. [Figure 3] A block diagram showing an example configuration of inkjet printer 100. [Figure 4] Configuration diagram of inkjet printer 100. [Figure 5] Exploded perspective view of the liquid injection head 30. [Figure 6] Cross-sectional view when the liquid injection head 30 is fractured along the line IV-IV in Figure 5. [Figure 7] A magnified view of the area around the ink hole 322 shown in Figure 6. [Figure 8] Cross-sectional view when the head unit Hn is broken along the X-axis direction, passing through the wiring hole 323. [Figure 9] A schematic plan view showing the inside of head unit Hn. [Figure 10] A plan view illustrating the internal flow channel Sn within the structure. [Figure 11] Side view of the internal supply channel S1a and the internal discharge channel S2a within the structure. [Figure 12] Side view of the internal supply channel S1b and the internal discharge channel S2b within the structure. [Figure 13] A diagram illustrating the detection mechanism 60A. [Figure 14] A diagram illustrating the detection mechanism 60A. [Figure 15] A diagram illustrating the detection mechanism 60A. [Figure 16] A diagram illustrating the functions of the SYS inkjet system. [Figure 17]A diagram showing a flowchart of the operation of the inkjet system SYS. [Figure 18] A block diagram showing a configuration example of the inkjet printer 100a in the second embodiment. [Figure 19] A diagram for explaining the first adhesion part GL1Ba. [Figure 20] A diagram showing a flowchart of the operation of the inkjet system SYS in the second embodiment. [Figure 21] A block diagram showing a configuration example of the inkjet printer 100b in the third embodiment. [Figure 22] A diagram for explaining the detection mechanism 60Ab. [Figure 23] A diagram for explaining the detection mechanism 60Ac in the first modification example. [Figure 24] A diagram for explaining the detection mechanisms 60Ad1 and 60Ad2 in the second modification example. [Figure 25] A block diagram showing a configuration example of the inkjet printer 100e in the third modification example. [Figure 26] A diagram for explaining the detection mechanisms 60Ae and 60B. [Figure 27] A diagram for explaining the detection mechanisms 60Ae and 60B. [Figure 28] A diagram for explaining the first adhesion part GL1Bf in the fourth modification example. [Figure 29] A diagram for explaining the first adhesion part GL1Bf in the fourth modification example. [Figure 30] A diagram for explaining the detection mechanism 60Ag in the fifth modification example.

Modes for Carrying Out the Invention

[0008] The embodiments for implementing this disclosure will be described below with reference to the drawings. However, the dimensions and scale of each part in each drawing have been appropriately altered from those of the actual parts. Furthermore, the embodiments described below are preferred examples of this disclosure and are subject to various technically preferred limitations. However, the scope of this disclosure is not limited to these embodiments unless otherwise stated in the following description.

[0009] For the sake of explanation, in the following, one direction along the X-axis from an arbitrary point will be referred to as the X1 direction, and the opposite direction will be referred to as the X2 direction. The X1 and X2 directions will be collectively referred to as the directions along the X-axis. Similarly, two opposite directions along the Y-axis from an arbitrary point will be referred to as the Y1 and Y2 directions, and two opposite directions along the Z-axis from an arbitrary point will be referred to as the Z1 and Z2 directions. The Y1 and Y2 directions will be collectively referred to as the directions along the Y-axis. The Z1 and Z2 directions will be collectively referred to as the directions along the Z-axis. The directions along the X-axis and the directions along the Y-axis are mutually orthogonal. The directions along the X-axis and the directions along the Z-axis are mutually orthogonal. The directions along the Y-axis and the directions along the Z-axis are mutually orthogonal. The XY plane, which includes the X and Y axes, corresponds to the horizontal plane. The Z-axis is an axis that runs vertically, with Z1 corresponding to the upward vertical direction and Z2 corresponding to the downward vertical direction. Viewing along the Z-axis is sometimes referred to as a "planar view."

[0010] 1. First Embodiment 1-1. Overview of the SYS Inkjet System Figure 1 is a schematic diagram showing an example configuration of the inkjet system SYS according to the first embodiment. The inkjet system SYS is a system that provides a service of forming an image on a medium PP, which will be described later, using an inkjet method. The inkjet system SYS includes an inkjet printer 100 and a processing device 200.

[0011] Here, the inkjet printer 100 is a device provided by the manufacturer of the inkjet printer 100. The inkjet printer 100 is a liquid ejection device that ejects ink, which is an example of a liquid. The manufacturer of the inkjet printer 100 is the company that manufactures the inkjet printer 100. The manufacturer of the inkjet printer 100 may be referred to as the "printer manufacturer." The liquid ejection head 30 incorporated into the inkjet printer 100 is provided by the manufacturer of the liquid ejection head 30. The manufacturer of the liquid ejection head 30 is the company that manufactures the liquid ejection head 30. Hereafter, the manufacturer of the liquid ejection head 30 may be referred to as the "head manufacturer." The printer manufacturer receives the liquid ejection head 30 from the head manufacturer and manufactures the inkjet printer 100 by incorporating the provided liquid ejection head 30 into the inkjet printer 100. The inkjet printer 100 is an example of a "liquid ejection device."

[0012] Figure 1 shows a user U who uses the inkjet printer 100. User U is, for example, an employee belonging to the printer manufacturer who uses the inkjet printer 100. Also, for example, a third party who receives the inkjet printer 100 from the printer manufacturer and uses it is also a user U. In addition to the inkjet printer 100, user U also uses the processing unit 200.

[0013] The inkjet printer 100 receives image data (Img) from the processing unit 200. The inkjet printer 100 forms an image based on the image data (Img) onto the PP medium. Hereinafter, the process of forming an image onto the PP medium may be referred to as the "printing process."

[0014] The inkjet printer 100 has one head module 3, each having one liquid ejection head 30.

[0015] The processing unit 200 is a computer, such as a desktop or notebook computer. The processing unit 200 may also be provided as part of the inkjet printer 100.

[0016] 1-2. Regarding the malfunction of the liquid spray head 30 The liquid jet head 30 included in the inkjet printer 100 may malfunction due to aging or other reasons. One reason for the malfunction of the liquid jet head 30 is that the adhesive joint that connects the two flow path members that constitute the flow path within the liquid jet head 30 to ensure a liquid-tight connection between them may deteriorate due to prolonged contact with ink, wear from the flow rate, and / or leaching of the adhesive into the ink. This can lead to the inability to create a liquid-tight connection between the two flow path members, potentially causing ink to leak out of the flow path from the point where the connection is no longer liquid-tight. Hereinafter, the inability of the adhesive to seal the gap between the flow paths of the two flow path members may be referred to as "seal failure." When a seal failure occurs, ink may leak out of the flow path from the point where the seal failure occurred. If ink leaks out of the flow path, it may adhere to the electronic circuitry inside the liquid jet head 30, causing it to malfunction, or the inside or surrounding area of ​​the inkjet printer 100 may be contaminated with ink.

[0017] Therefore, the present invention provides a liquid spray head 30 that can detect signs of ink leakage from the liquid spray head 30 before the liquid spray head 30 malfunctions due to ink leaking out of the flow path from a point where a sealing failure has occurred. The signs of ink leakage from the liquid spray head 30 include the fact that ink will soon leak from the liquid spray head 30 and estimating the lifespan of the liquid spray head 30, that is, estimating the time when ink will likely leak from the liquid spray head 30.

[0018] 1-3. Configuration of the processing unit 200 Figure 2 shows the configuration of the processing unit 200. The processing unit 200 includes a control circuit 210, a memory circuit 220, an input device 260, and a display device 270. The control circuit 210, the memory circuit 220, the input device 260, and the display device 270 are interconnected by a bus 290 for communicating information.

[0019] The control circuit 210 includes, for example, one or more processors such as CPUs (Central Processing Units). The control circuit 210 may also include programmable logic devices such as FPGAs (Field Programmable Gate Arrays) in place of, or in addition to, the CPUs.

[0020] The memory circuit 220 is composed of a magnetic memory device or flash ROM, etc. The memory circuit 220 is readable by the control circuit 210 and stores multiple programs, including the inkjet program PM1 executed by the control circuit 210, and various information used by the control circuit 210. The memory circuit 220 includes, for example, one or more volatile memories such as RAM and one or more non-volatile memories such as ROM, EEPROM, or PROM, or both, as semiconductor memory. The inkjet program PM1 is, for example, a program that generates image data Img.

[0021] The communication device 240 is a circuit capable of communicating with the inkjet printer 100. For example, the communication device 240 is a network card such as USB (Universal Serial Bus) or Bluetooth. USB and Bluetooth are registered trademarks.

[0022] The input device 260 is a device that outputs operation information in response to user U's actions. The input device 260 is, for example, a mouse and a keyboard.

[0023] The display device 270 displays an image containing some information to the user U. The display device 270 is an organic EL (Electro-Luminescence) display, an LED (Light Emitting Diode) display, or an LCD (Liquid Crystal Display). Alternatively, the input device 260 and the display device 270 may be integrated into a single unit. An example of an integrated configuration of the input device 260 and the display device 270 is a touch panel.

[0024] 1-4. Overview of the Inkjet Printer 100 Figure 3 is a block diagram showing an example configuration of the inkjet printer 100. Figure 4 is a diagram of the inkjet printer 100's configuration. The inkjet printer 100 shown in Figure 4 is an inkjet printing device that sprays ink as droplets onto a medium PP. Ink is an example of a "liquid". The medium PP is, for example, printing paper. However, the medium PP is not limited to printing paper, and may be any material to be printed on, such as resin film or fabric.

[0025] As shown in Figures 3 and 4, the inkjet printer 100 includes a control module CM, a liquid supply system 10, a control circuit 21, a memory circuit 22, a transport mechanism 23, a moving mechanism 24, a head module 3, a communication device 28, and a measurement circuit 29.

[0026] The control module CM includes a power supply circuit 113 and a drive signal generation circuit 114. The power supply circuit 113 receives power from a commercial power supply (not shown) and generates various predetermined potentials. The generated potentials are supplied to various parts of the inkjet printer 100 as appropriate. In the example shown in Figure 3, the power supply circuit 113 generates a power supply potential VHV and an offset potential VBS. The offset potential VBS is supplied to the liquid jet head 30. The power supply potential VHV is supplied to the drive signal generation circuit 114, etc.

[0027] The drive signal generation circuit 114 is a circuit that generates a drive signal Com for driving the liquid injection head 30. Specifically, the drive signal generation circuit 114 includes, for example, a DA conversion circuit and an amplification circuit. In the drive signal generation circuit 114, the DA conversion circuit converts the waveform specification signal dCom from the control circuit 21 (described later) from a digital signal to an analog signal, and the amplification circuit generates the drive signal Com by amplifying the analog signal using the power supply potential VHV from the power supply circuit 113.

[0028] The liquid supply system 10 includes a liquid container 12 and a sub-tank 13. The liquid container 12 stores ink. The sub-tank 13 temporarily stores the ink supplied from the liquid container 12.

[0029] The liquid container 12 includes, for example, a cartridge that can be attached to or removed from the inkjet printer 100, a bag-shaped ink pack made of a flexible film, or an ink tank that can be refilled with ink. The liquid container 12 includes liquid containers 12a and 12b. Liquid containers 12a and 12b store, for example, inks of different colors. Liquid container 12a stores a first ink. Liquid container 12b stores, for example, a second ink of a different color from the first ink.

[0030] Subtank 13 includes subtanks 13a and 13b. Subtank 13a is connected to liquid container 12a and temporarily stores the first ink. Subtank 13b is connected to liquid container 12b and temporarily stores the second ink. A supply tube Ta_in and a discharge tube Ta_out are also connected to subtank 13a. A supply tube Tb_in and a discharge tube Tb_out are connected to subtank 13b. These tubes are connected to the head module 3. The subtank 13 supplies ink to the head module 3 and recovers ink from the head module 3. Thus, ink circulates between the subtank 13 and the head module 3.

[0031] The inks are, for example, water-based pigment inks, solvent inks, or UV-curable inks. Solvent inks are inks that contain an organic solvent. Solvent inks are inks that, after being applied to a medium PP, erode the medium PP to form a receiving layer, and fix the colorant on this receiving layer. UV-curable inks are inks that contain a UV-curing component. Hereinafter, UV-curable inks will be referred to as UV (Ultra Violet) inks. The UV-curing component contains a monomer or oligomer. UV inks are inks that, after being applied to a medium PP, are irradiated with ultraviolet light, causing the UV-curing component to harden, and fix the colorant within the film formed by the hardening of the UV-curing component.

[0032] The memory circuit 22 stores various programs, including the control program PM2 executed by the control circuit 21, and various data, such as image data Img, processed by the control circuit 21. The memory circuit 22 includes, for example, one or more volatile memories such as RAM and one or more non-volatile memories such as ROM, EEPROM, or PROM, or both, as semiconductor memory. The memory circuit 22 may be configured as part of the control circuit 21.

[0033] The transport mechanism 23 transports the medium PP along the Y-axis under the control of the control circuit 21. The moving mechanism 24 reciprocates the head module 3 along the X-axis under the control of the control circuit 21.

[0034] The moving mechanism 24 comprises a roughly box-shaped support 241 that houses the head module 3, and an endless belt 242 to which the support 241 is fixed.

[0035] The communication device 28 is a circuit capable of communicating with the processing unit 200. For example, the communication device 28 is a network card such as a USB or Bluetooth card. Alternatively, the communication device 28 may be integrated with the control circuit 21.

[0036] The head module 3 sprays ink supplied from the sub-tank 13 onto the medium PP under the control of the control circuit 21. As the medium PP is transported by the transport mechanism 23 and the support 241 moves back and forth, the head module 3 sprays ink onto the medium PP, forming an image on the surface of the medium PP. Any ink not sprayed from the head module 3 is discharged into the sub-tank 13. The head module 3 is equipped with one liquid spray head 30, but may be equipped with multiple liquid spray heads 30.

[0037] Let's return to the explanation in Figures 3 and 4. The control circuit 21 controls each element of the inkjet printer 100. The control circuit 21 includes, for example, one or more processing circuits such as a CPU or FPGA and one or more storage circuits such as semiconductor memory.

[0038] The control circuit 21 controls the operation of each part of the inkjet printer 100 by executing a program stored in the memory circuit 22. Here, the control circuit 21 generates signals such as control signal Sk1, control signal Sk2, print signal SI, waveform specification signal dCom, and request signal RI as signals to control the operation of each part of the inkjet printer 100.

[0039] Control signal Sk1 is a signal for controlling the drive of the moving mechanism 24. Control signal Sk2 is a signal for controlling the drive of the transport mechanism 23. Printing signal SI is a signal for controlling the drive of the liquid spray head 30. Waveform specification signal dCom is a digital signal for defining the waveform of the drive signal Com generated by the drive signal generation circuit 114.

[0040] The measurement circuit 29 performs a measurement process to measure the current value in the detection mechanism 60A, which is provided in the liquid injection head 30. The request signal RI is a signal that requests the measurement circuit 29 to perform the measurement process. The measurement circuit 29 transmits measurement information JI, which indicates the measurement result, to the control circuit 21. The detection mechanism 60A will be described later in Figures 13, 14, and 15, and will not be shown or described in Figures 6 and 7.

[0041] 1-5. Overall configuration of the liquid injection head 30 Figure 5 is an exploded perspective view of the liquid injection head 30. Figure 6 is a cross-sectional view of the liquid injection head 30 when it is broken along the line IV-IV in Figure 5. The diagram in Figure 6 is a view of the cross-section of the liquid injection head 30 when it is broken along the line IV-IV, as seen in the Y2 direction. The line IV-IV is a virtual line segment that passes through the two ink holes 322 and is aligned with the X-axis direction.

[0042] As shown in Figure 5, the liquid injection head 30 comprises a housing 3α, a flow channel structure 33, a fixing plate 36, and a reinforcing plate 37. The liquid injection head 30 also has a plurality of head units H1, H2, H3, and H4. When head units H1, H2, H3, and H4 are not distinguished, they are referred to as head unit Hn. The liquid injection head 30 also includes electrical elements such as a wiring board 381, wiring members 382, ​​circuit boards 383u, and 383v. The flow channel structure 33 has a laminate 333, supply connection parts 331a and 331b, and discharge connection parts 332a and 332b. The elements of the liquid injection head 30 will be described below with reference to Figures 5 and 6.

[0043] The housing 3α shown in Figures 5 and 6 is a hollow case that houses the head unit Hn and the laminate 333. The housing 3α has a cover member 31 and a holder member 32.

[0044] The cover member 31 houses the laminate 333. The holder member 32 houses a plurality of head units Hn. In this embodiment, the holder member 32 houses four head units Hn. The holder member 32 is positioned in the Z2 direction relative to the cover member 31.

[0045] As shown in Figure 5, the cover member 31 has two first connection holes 311, two second connection holes 312, and a first hole 313. The first hole 313 is a hole through which the wiring member 382 is inserted. One of the supply connection parts 331a and 331b is inserted and fitted into each first connection hole 311. One of the discharge connection parts 332a and 332b is inserted and fitted into each second connection hole 312.

[0046] The holder member 32 has a plurality of recesses 321, a plurality of ink holes 322, and a plurality of wiring holes 323. Each recess 321 is a recess that opens in the Z2 direction. A head unit Hn is placed in each recess 321. Each ink hole 322 is a hole through which ink flows between the flow path structure 33 and the head unit Hn. Each wiring hole 323 communicates with the recess 321. Each wiring hole 323 is a hole through which the flexible substrate 51 shown in Figure 8 passes. A flexible substrate 51 is provided for each head unit Hn and is electrically connected to the head unit Hn. Also, as shown in Figure 5, the holder member 32 has a flange 324 for fixing the holder member 32 to the support 241.

[0047] As shown in Figure 6, the housing 3α has an upper wall portion 34 and a side wall portion 35. The side wall portion 35 has side walls 351u and 351v.

[0048] As shown in Figure 5, the laminated body 333 of the channel structure 33 has multiple channel plates Su1, Su2, Su3, Su4, and Su5, which are referred to as channel plates Su when not distinguished. Each channel plate Su is formed, for example, by injection molding of resin, but may also be formed of metal.

[0049] The flow path plates Su1 to Su5 are bonded to each other by adhesives that form bonding sections GL12, GL23, GL34, and GL45. Flow path plate Su5 is bonded to the holder member 32 in the Z1 direction by adhesives that form bonding section GL56. In the following description, the layers formed by adhesives within the liquid injection head 30 are collectively referred to as bonding sections GL. The bonding sections GL connect the two members in a liquid-tight manner. The adhesive that forms the bonding sections GL is, for example, an epoxy-based adhesive mainly composed of epoxy resin, but a silicone-based adhesive may also be used.

[0050] The liquid injection head 30 has a flow path SF inside that communicates with the nozzle Nz. The flow path SF includes internal supply flow paths S1a, S1b, internal discharge flow paths S2a, S2b, internal supply flow paths R1a, R1b, internal discharge flow paths R2a, R2b, a first liquid storage chamber Ra, a second liquid storage chamber Rb, second communication flow paths R4a, R4b, pressure chambers Ca, Cb, and first communication flow paths R3a, R3b. Note that the flow path SF is an example of a "flow path communicating with the nozzle".

[0051] The laminate 333 has internal supply channels S1a and S1b, and internal discharge channels S2a and S2b. When the internal supply channels S1a, S1b, S2a, and S2b are not distinguished, they are referred to as internal channel Sn. Each internal channel Sn is a space formed within the laminate 333. Ink flows through each internal channel Sn. Each internal channel Sn is formed by one or both of the grooves along the XY plane provided in each of two adjacent channel plates Su, and by holes extending in the Z axis direction within the channel plate Su. Note that in Figure 6, the internal channel Sn is omitted to avoid complexity in the drawing.

[0052] Specifically, the internal supply channel S1a supplies the first ink stored in the sub-tank 13a to the multiple head units Hn. The internal supply channel S1b supplies the second ink stored in the sub-tank 13b to the multiple head units Hn. The internal discharge channel S2a discharges the first ink that was not ejected from the multiple head units Hn to the sub-tank 13a. The internal discharge channel S2b discharges the second ink that was not ejected from the multiple head units Hn to the sub-tank 13b. Each internal channel Sn may be equipped with a filter section Fa having a filter for collecting foreign matter or air bubbles mixed in the ink.

[0053] Each of the supply connection parts 331a, 331b and discharge connection parts 332a, 332b is provided in the Z1 direction of the laminate 333 and protrudes from the laminate 333 in the Z1 direction. Each of the supply connection parts 331a, 331b and discharge connection parts 332a, 332b is a connecting pipe for connecting the flow path Sn within each structure to the outside of the housing 3α.

[0054] Specifically, the supply connection section 331a is a supply pipe that supplies first ink from the sub-tank 13a to the internal supply channel S1a, and is provided with a supply port S1a_in for supplying first ink to the laminate 333. The supply connection section 331b is a supply pipe that supplies second ink from the sub-tank 13b to the internal supply channel S1b, and is provided with a supply port S1b_in for supplying second ink to the laminate 333. The discharge connection section 332a is a discharge pipe that discharges first ink from the internal discharge channel S2a to the sub-tank 13a, and is provided with a discharge port S2a_out for discharging first ink from the laminate 333. The discharge connection section 332b is a discharge pipe that discharges second ink from the internal discharge channel S2b to the sub-tank 13b, and is provided with a discharge port S2b_out for discharging second ink from the laminate 333.

[0055] The head unit Hn has internal supply channels R1a and R1b, internal discharge channels R2a and R2b, and a liquid injection section Q for ejecting ink. The first liquid storage chamber Ra, the second liquid storage chamber Rb, the second communication channels R4a and R4b, the pressure chambers Ca and Cb, and the first communication channels R3a and R3b are included in the liquid injection section Q. The channels included in the liquid injection section Q are shown in Figure 8.

[0056] In Figure 6, the detailed shape of the liquid injection unit Q is omitted to avoid complexity in the drawing. The detailed shape of the liquid injection unit Q will be described later in Figure 8. Each head unit Hn has a plurality of nozzles Nz, as shown in Figure 6. Each nozzle Nz is a through-hole that sprays ink in the Z2 direction. Specifically, each head unit Hn has a plurality of nozzles Nz that spray first ink and a plurality of nozzles Nz that spray second ink. In addition, each head unit Hn defines the in-head supply passages R1a, R1b and the in-head discharge passages R2a, R2b.

[0057] The internal supply channels R1a and R1b are channels that extend from the Z1-direction end of the head unit Hn to the liquid injection section Q. The internal discharge channels R2a and R2b are channels that extend from the liquid injection section Q to the Z1-direction end of the head unit Hn. When the internal supply channels R1a and R1b and the internal discharge channels R2a and R2b are not distinguished, they are referred to as the internal channel Rn.

[0058] The head unit Hn has a case 335 that defines the internal flow path Rn within the head.

[0059] Figure 7 is a magnified view of the area around the ink hole 322 shown in Figure 6. The flow path plate Su5 has columnar protrusions 334a and 334b ​​that project in the Z2 direction. The protrusions 334a and 334b ​​are bonded to the holder member 32 in the Z1 direction by an adhesive that forms the bonding portion GL56.

[0060] The flow path plate Su5 has flow path plate side connecting pipes 330a and 330b. The flow path plate side connecting pipes 330a and 330b are collectively referred to as the flow path plate side connecting pipe 330. The flow path plate side connecting pipe 330 protrudes from the flow path plate Su5 toward the case 335 and is inserted into the ink hole 322.

[0061] Case 335 has case-side connecting pipes 336a and 336b. Case-side connecting pipes 336a and 336b are collectively referred to as case-side connecting pipe 336. Case-side connecting pipe 336 protrudes from case 335 toward the flow path plate Su5 and is inserted into the ink hole 322.

[0062] Adhesive is applied to the top surface of the flow path plate side connecting pipe 330 and the top surface of the case side connecting pipe 336 to form the adhesive joint GL57.

[0063] The direction of ink flow in the print head supply channels R1a and R1b is in the Z2 direction. The top surface of the channel plate side connecting pipe 330 and the top surface of the case side connecting pipe 336 are perpendicular to the direction of ink flow.

[0064] Let's return to the explanation in Figures 5 and 6. As shown in Figure 5, the fixing plate 36 is a plate member for fixing a plurality of head units Hn to the holder member 32. The fixing plate 36 has a plurality of openings 361 for exposing the nozzles Nz of the plurality of head units Hn.

[0065] The reinforcing plate 37 is positioned between the holder member 32 and the fixing plate 36 and is fixed to the fixing plate 36 with adhesive. The reinforcing plate 37 has a plurality of openings 371 in which the plurality of head units Hn are positioned.

[0066] The wiring board 381 is a mounting component for electrically connecting the liquid injection head 30 to the control circuit 21 shown in Figure 4. The wiring board 381 is placed on the laminate 333. A wiring member 382 is installed on the wiring board 381. The wiring member 382 is a component for electrically connecting the liquid injection head 30 and the control circuit 21. The wiring member 382 is, for example, a connector. Note that the wiring member 382 may also be a signal cable such as an FFC (Flexible Flat Cable).

[0067] Circuit boards 383u and 383v are arranged so as to sandwich the laminate 333 and are electrically connected to the wiring board 381. Flexible circuit boards 51 mounted on head units H1 and H3 are electrically connected to circuit board 383u via an intermediate board (not shown). Flexible circuit boards 51 mounted on head units H2 and H4 are electrically connected to circuit board 383v via an intermediate board (not shown).

[0068] 1-6. Head Unit Hn Figure 8 is a cross-sectional view of the head unit Hn when it is broken along the X-axis direction, passing through the wiring hole 323. The diagram in Figure 8 is a view of the cross-section of the head unit Hn when it is broken along the X-axis direction, passing through the wiring hole 323, as seen in the Y2 direction. Figure 9 is a schematic plan view of the inside of the head unit Hn. The diagram in Figure 9 is a plan view of the inside of the head unit Hn as seen in the Z2 direction. Figures 8 and 9 each show the portion of the head unit Hn shown in Figure 6 near the fixing plate 36.

[0069] As shown in Figure 8, the head unit Hn comprises a nozzle plate 40, a communication plate 42, a pressure chamber substrate 43, a diaphragm 44, a plurality of drive elements E, a protective section 46, a compliance substrate 45, and the case 335 described above.

[0070] The nozzle plate 40, communication plate 42, pressure chamber substrate 43, and diaphragm 44 are each elongated plate-shaped members along the Y-axis. The pressure chamber substrate 43 and case 335 are positioned in the Z1 direction relative to the communication plate 42. On the other hand, the nozzle plate 40 and compliance substrate 45 are positioned in the Z2 direction relative to the communication plate 42. Furthermore, each component of the head unit Hn is joined to each other by adhesive. Although not shown in Figure 8, the layer formed by the adhesive that joins each component of the head unit Hn to each other is also included in the adhesive portion GL.

[0071] As shown in Figure 9, the multiple nozzles Nz are divided into a first nozzle row La and a second nozzle row Lb. Each of the first nozzle row La and the second nozzle row Lb is a set of multiple nozzles Nz arranged linearly along the Y axis. The first nozzle row La and the second nozzle row Lb are spaced apart from each other and aligned in the X axis direction. Here, the liquid injection unit Q has a first liquid injection unit Qa which includes multiple nozzles Nz belonging to the first nozzle row La, and a second liquid injection unit Qb which includes multiple nozzles Nz belonging to the second nozzle row Lb. The first liquid injection unit Qa injects first ink supplied from sub-tank 13a from each nozzle Nz of the first nozzle row La. The second liquid injection unit Qb injects second ink supplied from sub-tank 13b from each nozzle Nz of the second nozzle row Lb.

[0072] In the following description, the subscript 'a' is added to the symbols of elements related to the first nozzle row La, and the subscript 'b' is added to the symbols of elements related to the second nozzle row Lb. Furthermore, the elements related to the first liquid injection section Qa and the elements related to each nozzle Nz of the second liquid injection section Qb are arranged in a substantially plane-symmetrical manner. Therefore, in the following description, the elements corresponding to the first liquid injection section Qa will be explained in detail, and the explanation of the elements corresponding to the second liquid injection section Qb will be omitted as appropriate.

[0073] As shown in Figure 8, the communication plate 42 is provided with a first communication channel R3a and a second communication channel R4a. Each of the first communication channel R3a and the second communication channel R4a is provided for each nozzle Nz. The first communication channel R3a connects the nozzle Nz to the pressure chamber Ca described later. The second communication channel R4a connects the nozzle Nz to the first liquid storage chamber Ra described later. The compliance substrate 45 also constitutes a part of the wall surface of the first liquid storage chamber Ra. The compliance substrate 45 has, for example, a flexible resin film 45a and a metal plate 45b such as stainless steel.

[0074] Multiple pressure chambers Ca are provided in the pressure chamber substrate 43. Each pressure chamber Ca is a space that communicates with a nozzle Nz via a first communication channel R3a. An elastically deformable diaphragm 44 is positioned above each pressure chamber Ca. Part or all of the diaphragm 44 may be a separate component from the pressure chamber substrate 43, or it may be integrated with it. A drive element Ea is formed on the surface of the diaphragm 44 opposite to each pressure chamber Ca. Multiple drive elements Ea are arranged in a one-to-one correspondence with multiple nozzles Nz. The drive elements Ea generate energy for ejecting ink. Specifically, when a drive signal is applied to the drive element Ea, ink is ejected from the nozzle Nz. For example, the drive element Ea is a piezoelectric element that changes the volume of the pressure chamber Ca.

[0075] A protective section 46 is positioned on the diaphragm 44. A flexible substrate 51 is bonded to the surface of the diaphragm 44. Multiple wires for electrically connecting the control circuit 21 and the head unit Hn are formed on the flexible substrate 51. A drive circuit 50 for driving the drive elements E is also mounted on the flexible substrate 51. Based on the signal output from the control circuit 21, the drive circuit 50 selects whether or not to supply various signals, such as drive signals, to each drive element Ea to drive each drive element Ea.

[0076] Case 335 has a first liquid storage chamber Ra for storing ink. Case 335 also has parts of the head supply channels R1a, R1b, and R2a, R2b described above. As shown in Figure 8, the head supply channel R1a and the head discharge channel R2a are each connected to the first liquid storage chamber Ra. Also as shown in Figure 8, case 335 has a substrate hole 411 through which the flexible substrate 51 is inserted.

[0077] 1-7. Shape of the channel Sn within the structure Figure 10 is a plan view illustrating an internal flow path Sn within the structure. Figure 11 is a side view of the internal supply flow path S1a and the internal discharge flow path S2a within the internal flow path Sn through which the first ink flows. Figure 12 is a side view of the internal supply flow path S1b and the internal discharge flow path S2b within the internal flow path Sn through which the second ink flows. In Figures 11 and 12, the first liquid storage chamber Ra of each head unit Hn is indicated by the symbol "Ra / Hn", and the second liquid storage chamber Rb of each head unit Hn is indicated by the symbol "Rb / Hn". Note that the configuration of the internal flow path Sn is not limited to the following configurations.

[0078] The flow path structure 33 is provided with internal supply flow paths S1a and S1b, and internal discharge flow paths S2a and S2b, as illustrated in Figures 10, 11, and 12. The internal supply flow path S1a is a flow path from the supply port S1a_in to the internal supply flow path R1a of each head unit Hn, and the internal discharge flow path S2a is a flow path from the internal discharge flow path R2a of each head unit Hn to the discharge port S2a_out. The internal supply flow path S1b is a flow path from the supply port S1b_in to the internal supply flow path R1b of each head unit Hn, and the internal discharge flow path S2b is a flow path from the internal discharge flow path R2b of each head unit Hn to the discharge port S2b_out.

[0079] As illustrated in Figures 12 and 11, the internal supply channel S1a is a channel that includes a supply section Pa1, a connecting section Pa2, and four filter sections Fa_1-Fa_4. As illustrated in Figure 11, the supply section Pa1 is formed between the channel plates Su1 and Su2. The supply section Pa1 has a shape that extends along the Y axis. The end of the supply section Pa1 in the Y2 direction communicates with the supply port S1a_in.

[0080] As illustrated in Figures 10 and 11, the internal supply channel S1a is a channel that includes a supply section Pa1, a connecting section Pa2, and four filter sections Fa_1-Fa_4. As illustrated in Figure 11, the supply section Pa1 is formed between the channel plates Su1 and Su2. The supply section Pa1 has a shape that extends along the Y axis. The end of the supply section Pa1 in the Y2 direction communicates with the supply port S1a_in.

[0081] The connecting section Pa2 and the four filter sections Fa_1 to Fa_4 are formed between the flow path plates Su2 and Su3. The connecting section Pa2 communicates with the supply section Pa1 through a through hole formed in the flow path plate Su2. The connecting section Pa2 extends in the Y2 direction from the connection point with the supply section Pa1, and branches into two systems that communicate with the filter sections Fa_1 and Fa_3.

[0082] Filter section Fa_2 communicates with supply section Pa1 through a through-hole formed in flow path plate Su2. Filter section Fa_4 communicates with supply section Pa1 through a through-hole formed in flow path plate Su2. Each filter section Fa_1-Fa_4 communicates with the in-head supply flow path R1a of each head unit Hn through through-holes that penetrate flow path plates Su3-Su5.

[0083] As illustrated in Figures 10 and 12, the internal supply channel S1b is a channel that includes a supply section Pb1, a connecting section Pb2, and four filter sections Fb_1 to Fb_4. The supply section Pb1 is formed between the channel plates Su1 and Su2. The supply section Pb1 has a shape that extends along the Y axis. The supply port S1b_in is connected to the Y2 end of the supply section Pb1. Here, the supply sections Pa1 and Pb1 are installed side by side between the channel plates Su1 and Su2.

[0084] The connecting section Pb2 and the four filter sections Fb_1-Fb_4 are formed between the flow path plates Su2 and Su3. The connecting section Pb2 communicates with the supply section Pb1 through a through hole formed in the flow path plate Su2. The connecting section Pb2 extends in the Y1 direction from the connection point with the supply section Pb1, and branches into two systems that communicate with the filter sections Fb_2 and Fb_4. Here, the connecting section Pb2 extends in the opposite direction from the connecting section Pa2 from the connection point with the supply section Pb1.

[0085] Filter section Fb_1 communicates with supply section Pb1 through a through-hole formed in flow path plate Su2. Filter section Fb_3 communicates with supply section Pb1 through a through-hole formed in flow path plate Su2. Each filter section Fb_1-Fb_4 communicates with the in-head supply channel R1b of each head unit Hn through through-holes that penetrate flow path plates Su3-Su5.

[0086] As illustrated in Figures 10 and 11, the internal discharge channel S2a of the structure is a channel that includes a discharge section Pa3. The discharge section Pa3 is formed between the channel plates Su4 and Su5. The discharge section Pa3 has a shape that extends along the Y-axis over a wider area than the supply section Pa1. The vicinity of the end of the discharge section Pa3 in the Y1 direction communicates with the discharge port S2a_out. The internal discharge channel R2a of each head unit Hn communicates with the discharge section Pa3 through a through hole that penetrates the channel plate Su5.

[0087] As illustrated in Figures 10 and 12, the internal discharge channel S2b of the structure is a channel that includes a discharge section Pb3. The discharge section Pb3 is formed between the channel plates Su3 and Su4. The discharge section Pb3 has a shape that extends along the Y-axis over a wider area than the supply section Pb1. The vicinity of the end of the discharge section Pb3 in the Y1 direction communicates with the discharge port S2b_out. The internal discharge channel R2b of each head unit Hn communicates with the discharge section Pb3 through through holes that penetrate the channel plates Su4 and Su5.

[0088] 1-8. Detection mechanism 60A and measurement circuit 29 A detection mechanism 60A is provided near the bonding portion GL where two flow path members are bonded together in order to detect signs of ink leakage from the liquid spray head 30. The pair of two flow path members can be any two members that constitute the liquid spray head 30, form part of the flow path SF, and are bonded together with some kind of adhesive. Specifically, the pair of two flow path members can be a pair of two adjacent flow path plates Su within the flow path structure 33, a pair of flow path plate Su5 and case 335, or a pair of two members that constitute the head unit Hn, form part of the flow path SF, and are bonded together with some kind of adhesive. Specifically, the pair of two members within the head unit Hn can be a pair of case 335 and communication plate 42, a pair of communication plate 42 and pressure chamber substrate 43, a pair of communication plate 42 and compliance substrate 45, a pair of communication plate 42 and nozzle plate 40, or a pair of pressure chamber substrate 43 and diaphragm 44. The detection mechanism 60A will be explained using Figures 13, 14, and 15.

[0089] Figures 13, 14, and 15 are diagrams illustrating the detection mechanism 60A. The detection mechanism 60A may be installed in any of the two sets of flow path members described above, or it may be installed in multiple sets. Figures 13, 14, and 15 show an example in which the detection mechanism 60A is installed in the region RG1 shown in Figure 12. Region RG1 includes a supply flow path Sh1 which is part of the internal supply flow path S1b and is formed by flow path plates Su4 and Su5. Furthermore, in the following figures, the flow path structure 33 and the shape of the flow path inside the flow path structure 33 are shown in a simplified manner to avoid complexity in the drawings. Figure 13 shows an enlarged view of region RG1. Figures 14 and 15 show a cross-section when the liquid injection head 30 is broken along the line aa shown in Figure 13.

[0090] As shown in Figure 13, the supply channel Sh1 has a vertical channel Sh11 extending along the Z axis, a horizontal channel Sh12 extending perpendicular to the Z axis, and a vertical channel Sh13 extending along the Z axis. In Figures 14 and 15, the position of the vertical channel Sh11 is shown to illustrate the positional relationship. The Z2 end of the vertical channel Sh11 communicates with the Y2 end of the horizontal channel Sh12. The Y1 end of the horizontal channel Sh12 communicates with the Z1 end of the vertical channel Sh13. In the first embodiment, a detection mechanism 60A is provided at the location where the horizontal channel Sh12 is present, but the detection mechanism 60A may also be provided at the location where the horizontal channel Sh12 is not present. The supply channel Sh1 communicates with the nozzle Nz of the head unit H1, which is one of the multiple nozzles Nz of the liquid injection head 30. Note that the supply channel Sh1 is an example of a "first channel," and the nozzle Nz of the head unit H1 is an example of "one or more nozzles among multiple nozzles."

[0091] Figure 13 shows the area near region RG1. Figures 14 and 15 show the locations where the detection mechanism 60A is installed.

[0092] As shown in Figure 14, the detection mechanism 60A includes a detection wire 61 and detection wirings 621 and 622. In the first embodiment, signs of ink leakage from the liquid spray head 30 can be detected based on the magnitude of the current in the detection wire 61. In the first embodiment, it is assumed that the ink is conductive. Conductive ink is, for example, a water-based ink containing an electrolyte. However, conductive ink is not limited to water-based ink containing an electrolyte, but may also be UV ink containing an electrolyte.

[0093] As shown in Figure 13, the adhesive portion GL45 has first adhesive portions GL1A and GL1B. The first adhesive portions GL1A and GL1B join the surface S51 of the flow channel plate Su5 facing in the Z1 direction and the surface S42 of the flow channel plate Su4 facing in the Z2 direction. The first adhesive portion GL1A defines the inner wall SY of the supply channel Sh1 and is provided so as to surround the supply channel Sh1. The first adhesive portion GL1B is provided at a distance from the first adhesive portion GL1A and so as to surround the first adhesive portion GL1A. As shown in Figures 14 and 15, in plan view, the shapes of the first adhesive portions GL1A and GL1B are annular. The adhesives forming the first adhesive portions GL1A and GL1B may be of the same type or of different types. In the first embodiment, it is assumed that the adhesives forming the first adhesive portions GL1A and GL1B are of the same type.

[0094] Figure 14 shows the initial state of the liquid spray head 30. In this specification, the initial state of the liquid spray head 30 means the state after the liquid spray head 30 has been manufactured but before it has been filled with ink. Alternatively, the initial state of the liquid spray head 30 can be described as the state in which the adhesive portion GL has never come into contact with ink. Figure 15 shows a portion of the first adhesive portion GL1A that has deteriorated, and the area RG2 where ink is present.

[0095] As can be seen from Figures 13, 14, and 15, in the initial state of the liquid spray head 30 and immediately after the liquid spray head 30 is filled with ink, only the first adhesive part GL1A of the first adhesive parts GL1A and GL1B is in contact with the ink. If the first adhesive part GL1A deteriorates and ink leaks from the first adhesive part GL1A, then both the first adhesive parts GL1A and GL1B will be in contact with the ink.

[0096] Figure 14 shows the initial state of the liquid spray head 30. Figure 15 shows the state in which the first adhesive part GL1A has deteriorated and ink has leaked from the first adhesive part GL1A.

[0097] The detection wire 61 is positioned on surface S51. The detection wire 61 has wire portions 611, 612, and 613. Wire portions 611 and 612 extend in the direction along the X axis. However, the direction of extension of wire portions 611 and 612 is not limited to the direction along the X axis, but may be in the direction toward the side surface of the flow channel structure 33. The end of wire portion 611 in the X1 direction is connected to one end OE1 of wire portion 613. The end of wire portion 612 in the X1 direction is connected to one end OE2 of wire portion 613. The end of wire portion 611 in the X2 direction is connected to one end of detection wiring 621. The end of wire portion 612 in the X2 direction is connected to one end of detection wiring 622. Detection wirings 621 and 622 function as lead wires of the detection wire 61. Detection wires 621 and 622 are connected to the measurement circuit 29 via wiring components not shown.

[0098] As can be seen from Figure 13, the conductor portion 613 is housed in a first space SP1A formed by cutting out the surface S42 of the flow path plate Su4 in the Z1 direction. In plan view, the first space SP1A corresponds to the distance between the first adhesive portions GL1A and GL1B. In plan view, the shape of the first space SP1A is annular. However, the shape of the first space SP1A does not have to be annular, and in plan view, the first space SP1A does not have to exist in areas where the conductor portion 613 does not exist, specifically between one end OE1 and the other end OE2. The first adhesive portion GL1B is provided at a distance from the conductor portion 613 and surrounding the conductor portion 613. As can be seen from Figures 14 and 15, the conductor portion 613 is positioned between the first adhesive portions GL1A and GL1B. The conductor portion 613 is provided to detect a state in which the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B. In this specification, "ink exceeding the adhesive portion GL" means a state in which ink has leaked from the adhesive portion GL, and even if ink comes into contact with the adhesive portion GL and enters the adhesive portion GL, if ink has not leaked from the adhesive portion GL, the state in which the ink has not exceeded the adhesive portion GL is considered to be. The state in which the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B can also be said to be a state in which ink is present in the first space SP1A between the first adhesive portions GL1A and GL1B, or it can be said to be an indication that ink is leaking from the liquid spray head 30. The conductor portion 613 is an example of the "first detection means A". The first space SP1A is an example of the "first region A", and the flow path plate Su4 is an example of the "flow path member". Note that "Region A" may be a two-dimensional space, i.e., a plane, or a three-dimensional space; however, in this specification, when simply referred to as "space," it indicates a three-dimensional space.

[0099] By providing the first space SP1A, if the ink exceeds the first adhesive portion GL1A, the ink leaking from the first adhesive portion GL1A can be contained in the first space SP1A. Compared to the configuration in which the first space SP1A is not provided, the timing of ink leakage from the liquid spray head 30 can be delayed. In the first embodiment, the first space SP1A is formed by cutting out the surface S42 in the Z1 direction, but this is not limited to this. For example, the first space SP1A may be formed by cutting out the surface S51 of the flow path plate Su5 in the Z2 direction. Furthermore, the first space SP1A may not be provided at all.

[0100] In the example shown in Figure 14, the width L1B of the first adhesive portion GL1B is narrower than the width L1A of the first adhesive portion GL1A. The width L1A can also be described as the minimum distance from the supply channel Sh1 to the inner edge of the first space SP1A. Similarly, the width L1B can be described as the minimum distance from the outer edge of the first space SP1A to the outer edge of the first adhesive portion GL1B.

[0101] The state in which the ink does not exceed the first adhesive part GL1A means that the first adhesive part GL1A has not deteriorated to the extent that it does not leak ink. Therefore, in the following description, the state in which the ink does not exceed the first adhesive part GL1A may be described as "no deterioration state". On the other hand, the state in which the ink exceeds the first adhesive part GL1A but does not exceed the first adhesive part GL1B means that it has deteriorated to the extent that ink leaks from the first adhesive part GL1A. Therefore, in the following description, the state in which the ink exceeds the first adhesive part GL1A but does not exceed the first adhesive part GL1B may be described as "deteriorated state". Furthermore, the state in which there is no deterioration and the state in which there is deterioration may be collectively referred to as "adhesive deterioration state".

[0102] In Figures 14 and 15, the shape of the conductor portion 613 is simplified to avoid complexity in the drawings. In Figures 14 and 15, vertical shading is applied to the areas where the shape of the wiring has been simplified. The actual shape of the conductor portion 613 is a meandering shape in which the direction of extension changes periodically, as shown in the enlarged region ER1 in Figures 14 and 15, which is an enlarged view of the end of the conductor portion 613 in the Y1 direction. The conductor portion 613 is arranged to surround the first adhesive portion GL1A while meandering.

[0103] Using Figures 14 and 15, a method for detecting a state in which the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B will be explained. The measurement circuit 29 measures the magnitude of the current between detection wiring 621 and detection wiring 622. Based on the magnitude of the current measured by the measurement circuit 29, the control circuit 21 determines whether or not the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B. Compared to the initial state of the liquid spray head 30 as shown in Figure 14, in the state in which ink has leaked from the first adhesive portion GL1A as shown in Figure 15, a part of the conductor portion 613 is short-circuited by the ink, as shown in Figure 15, and the resistance between detection wiring 621 and 622 decreases. Therefore, the current value between detection wiring 621 and 622 in the state in which ink has leaked from the first adhesive portion GL1A is greater than the current value between detection wiring 621 and 622 in the initial state of the liquid spray head 30. Therefore, the measurement circuit 29 measures the current value between detection wiring 621 and detection wiring 622 as part of the measurement process. The measurement circuit 29 then generates measurement information JI indicating the measured current value and transmits the measurement information JI to the control circuit 21. The measurement information JI indicating the current value of the conductor portion 613 is an example of "state information" regarding the state of the conductor portion 613.

[0104] 1-9. Function of the First Embodiment The detection mechanism 60A and the measurement circuit 29 make it possible to estimate the deterioration state of the adhesive portion. Furthermore, it is preferable to replace the liquid spray head 30 before ink leaks from it. Therefore, in the inkjet system SYS according to this embodiment, a function is provided to prompt the user U to replace the liquid spray head 30 if the first adhesive portion GL1A of the liquid spray head 30 is in a deteriorated state.

[0105] Figure 16 is a diagram showing the functions of the inkjet system SYS. Figure 17 is a flowchart showing the operation of the inkjet system SYS. The control circuit 21 functions as an acquisition unit 71, an estimation unit 73, and a notification unit 75 by executing the read control program PM2.

[0106] The series of processes shown in Figure 17 are performed periodically. For example, the inkjet system SYS performs the series of processes shown in Figure 17 daily, weekly, or monthly. However, the series of processes shown in Figure 17 may be performed irregularly. For example, when the inkjet system SYS receives image data Img from the processing unit 200, it may perform the series of processes shown in Figure 17 before the printing process, or it may perform the series of processes shown in Figure 17 at the instruction of user U.

[0107] In step SC2, the control circuit 21 transmits the request signal RI to the measurement circuit 29. After the processing of step SC2 is completed, the control circuit 21 waits for a response from the measurement circuit 29.

[0108] When the measurement circuit 29 receives the request signal RI, the measurement circuit 29 performs the measurement process in step SR2. After the processing in step SR2 is completed, the measurement circuit 29 transmits measurement information JI, which indicates the measurement result, to the control circuit 21 in step SR4. After the processing in step SR4 is completed, the measurement circuit 29 terminates the series of processes shown in Figure 17.

[0109] In step SC4, the control circuit 21 functions as an acquisition unit 71 to acquire measurement information JI from the measurement circuit 29. Next, in step SC6, the control circuit 21 functions as an estimation unit 73 to estimate the degree of deterioration of the first adhesive part GL1A based on the measurement information JI. Specifically, the control circuit 21 estimates that the state of the first adhesive part GL1A is undeteriorated if the current value of the detection mechanism 60A is less than a predetermined threshold. On the other hand, if the current value measured by the detection mechanism 60A is less than a predetermined threshold, the control circuit 21 estimates that the state of the first adhesive part GL1A is deteriorated. The predetermined threshold is set in advance by the head maker based on experiments and experience.

[0110] After the processing in step SC6 is completed, in step SC8, the control circuit 21 determines, based on the estimation result, whether or not it is a condition that should notify the user U. More specifically, the control circuit 21 determines that it is a condition that should notify the user U if there is a liquid spray head 30 in which the state of the first adhesive part GL1A is in a deteriorated state.

[0111] If the determination result in step SC8 is positive, the control circuit 21 functions as a notification unit 75 in step SC10 to generate notification information CI based on the estimation result and notifies the user U of the generated notification information CI. The notification information CI is information that prompts the replacement of the liquid spray head 30 which shows signs of ink leakage. For example, let's assume that the estimation result estimates that the state of the first adhesive part GL1A is in a deteriorated state. Under this premise, the notification information CI is the string "There are signs that the liquid spray head is malfunctioning. Specifically, there are signs that ink is leaking from this liquid spray head. Please replace the liquid spray head." However, the notification information CI is not limited to a string. For example, the notification information CI may be information that shows an image in which an enhanced image highlighting the liquid spray head 30 which shows signs of ink leakage is superimposed on an image showing the head module 3. The highlighted image is, for example, an image in which the color of a liquid spray head 30 showing signs of ink leakage is different from the color of a liquid spray head 30 that does not show signs of ink leakage, or an image in which a speech bubble is provided pointing to a liquid spray head 30 showing signs of ink leakage, and the text "We recommend replacing this liquid spray head." is contained within the speech bubble.

[0112] After the processing in step SC10 is completed, the control circuit 21 terminates the series of processes shown in Figure 17. Also, if the determination result in step SC8 is negative, the control circuit 21 terminates the series of processes shown in Figure 17.

[0113] When the processing unit 200 receives notification information CI, the control circuit 210 of the processing unit 200 notifies the user U of the notification information CI in step SS2. Specifically, the control circuit 210 causes the display device 270 to display the string or image indicated by the notification information CI.

[0114] In Figures 16 and 17, the control circuit 21 functions as the estimation unit 73 and the notification unit 75, but this is not limited to this configuration. For example, the control circuit 21 may transmit the measurement information JI to the processing unit 200, and the control circuit 210 of the processing unit 200 may function as the estimation unit 73 and the notification unit 75.

[0115] 1-10. Summary of the First Embodiment As described above, the liquid spray head 30 in the first embodiment includes a plurality of nozzles Nz for spraying ink, a supply channel Sh1 communicating with one or more of the plurality of nozzles Nz, a first adhesive portion GL1A that defines the inner wall SY of the supply channel Sh1 and surrounds the supply channel Sh1, a first adhesive portion GL1B that surrounds the first adhesive portion GL1A, and a conductor portion 613 for detecting a state in which the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B. According to the first embodiment, the conductor portion 613 can detect that the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1B, thus allowing for the detection of signs of ink leakage from the liquid spray head 30. The user U can know the time when signs of ink leakage from the liquid spray head 30 are detected as an appropriate time to replace the liquid spray head 30.

[0116] Furthermore, the adhesive forming the first adhesive portion GL1A and the adhesive forming the first adhesive portion GL1B are of the same type, and the width L1B of the first adhesive portion GL1B is narrower than the width L1A of the first adhesive portion GL1A. Since the adhesive forming the first adhesive portion GL1A and the adhesive forming the first adhesive portion GL1B are of the same type, the deterioration conditions of the first adhesive portion GL1A and GL1B can be made the same for various inks. As a result of being able to make the deterioration conditions the same, in the first embodiment, compared to the embodiment in which the adhesives are of different types, the degree of deterioration of the first adhesive portion GL1A and the first adhesive portion GL1B when in contact with ink is said to be similar. Furthermore, compared to the embodiment in which the width L1B is wider than the width L1A, signs of ink leakage from the liquid spray head 30 can be detected at a timing closer to the point in time when ink actually leaks from the liquid spray head 30.Therefore, if the liquid spray head 30 is replaced when it is detected that the first adhesive portion GL1A is in a deteriorated state, the lifespan of the liquid spray head 30 can be extended compared to the embodiment in which the width L1B is wider than the width L1A.

[0117] Furthermore, the ink flowing through the supply channel Sh1 is conductive, and the first detection means A is a conductive wire portion 613 located in the first space SP1A between the first adhesive portions GL1A and GL1B. According to the first embodiment, the change in the electrical resistance of the conductive wire portion 613 due to ink contact with the conductive wire portion 613 can be used to detect signs of ink leakage from the liquid spray head 30.

[0118] The inkjet printer 100 also includes a liquid jet head 30 and a control circuit 21. The control circuit 21 functions as an acquisition unit 71 that acquires measurement information JI and an estimation unit 73 that estimates the degree of deterioration of the first adhesive part GL1A based on the measurement information JI. According to the first embodiment, by estimating the degree of deterioration of the first adhesive portion GL1A, the user U can be notified that there are signs of ink leakage from the liquid spray head 30. Therefore, signs of ink leakage from the liquid spray head 30 can be detected without damaging the liquid spray head 30.

[0119] The control circuit 21 also functions as a notification unit 75. Based on the estimated degree of deterioration of the first adhesive part GL1A based on the measurement information JI, the notification unit 75 prompts the replacement of the liquid spray head 30. According to the first embodiment, user U can replace the liquid spray head 30 before ink leaks from it by replacing the liquid spray head 30 in accordance with the instruction to replace the liquid spray head 30.

[0120] The notification unit 75 may also add life information indicating the lifespan of the liquid spray head 30 to the notification information CI, which indicates a prompt to replace the liquid spray head 30 that shows signs of ink leakage. The lifespan information is, for example, a string of characters such as "The expected date of failure of the liquid spray head 30 is yyyy / mm / dd." where yyyy is a four-digit number, mm is an integer from 1 to 12, and dd is an integer from 1 to 31. In order to generate the lifespan information, the memory circuit 22 stores information indicating the date the liquid spray head 30 was put into use, information indicating the length of the width L1A of the first adhesive part GL1A, and information indicating the length of the width L1B of the first adhesive part GL1B. The notification unit 75 assumes that the notification information CI indicates that the liquid spray head 30 shows signs of ink leakage. The notification unit 75 calculates the lifespan of the liquid spray head 30 using the following formula (1). Lifespan of liquid spray head 30 = (Current date - Date when liquid spray head 30 was first used) × (Width L1A + Width L1B) / Width L1A + Current date (1)

[0121] If lifespan information is generated, the notification unit 75 may notify the user U of the notification information CI immediately after generating the lifespan information, or it may notify the notification information CI a predetermined number of days before the date indicated in the lifespan information.

[0122] 2. Second Embodiment The method for estimating the degree of deterioration of the first adhesive portion GL1A is not limited to the method of providing the conductive wire portion 613. In the second embodiment, an adhesive that changes color when it comes into contact with ink is used. The second embodiment will be described below. In the second embodiment, the third embodiment described later, and modifications based on the second or third embodiment, the ink does not need to be conductive.

[0123] 2-1. Configuration and Operation of the Second Embodiment Figure 18 is a block diagram showing an example configuration of the inkjet printer 100a in the second embodiment. The inkjet printer 100a has a liquid ejection head 30a instead of the liquid ejection head 30, a control circuit 21a instead of the control circuit 21, a memory circuit 22a instead of the memory circuit 22, and an imaging device 90 instead of the measurement circuit 29.

[0124] Figure 19 is a diagram illustrating the first adhesive portion GL1Ba. Figure 19 shows a cross-section of the liquid injection head 30a when it is broken along the line aa shown in Figure 13.

[0125] In the second embodiment, the adhesive portion GL45a has a first adhesive portion GL1Ba instead of the first adhesive portion GL1B. The first adhesive portion GL1Ba is provided so as to surround the first adhesive portion GL1A so as to be in close contact with the first adhesive portion GL1A.

[0126] The first adhesive portion GL1Ba has a protrusion 64. The protrusion 64 is a portion of the first adhesive portion GL1Ba that protrudes in the X2 direction from the annular portion surrounding the first adhesive portion GL1A. In the example of Figure 19, the detection surface S6 of the protrusion 64 facing in the X2 direction is flush with the wall surface SW2 of the flow channel structure 33 facing in the X2 direction. However, the detection surface S6 does not have to be flush with the wall surface SW2, and may be recessed relative to the wall surface SW2 to the extent that it is visible from outside the flow channel structure 33.

[0127] In the second embodiment, the flow path plate Su4 is an example of a "first flow path member," the flow path plate Su5 is an example of a "second flow path member," and the detection surface S6, which is part of the first adhesive portion GL1Ba, is an example of a "first detection means A." The fact that the detection surface S6 is positioned in a location recessed from the wall surface SW2 to the extent that it is visible from outside the flow path structure 33 is an example of "part of the first detection means A being positioned near the outer surface of the first flow path member."

[0128] The first adhesive portion GL1Ba has the property of changing color when it comes into contact with ink. There are two types of discoloration when it comes into contact with ink, as shown below. The first type of discoloration is a type in which the pigment of the adhesive changes when it comes into contact with ink. For example, the adhesive forming the first adhesive portion GL1Ba contains anthocyanin pigment. The color of anthocyanin pigment is red in acidic conditions and blue in alkaline conditions. Therefore, in the first type of discoloration, when manufacturing the liquid spray head 30, the head manufacturer forms the first adhesive portion GL1Ba so that it is alkaline if the liquid pH of the ink is acidic. On the other hand, if the liquid pH of the ink is alkaline, the first adhesive portion GL1Ba is formed so that it is acidic. As a result, when the first adhesive portion GL1Ba comes into contact with ink, the anthocyanin pigment changes color, and the first adhesive portion GL1Ba has the property of changing color when it comes into contact with ink. The pigment that changes color depending on the liquid pH is not limited to anthocyanin pigment, but may also be a flavonoid pigment.

[0129] The second discoloration mode is one in which the first adhesive portion GL1Ba is transparent or translucent, and ink containing a colorant penetrates into the inside of the first adhesive portion GL1Ba, causing the first adhesive portion GL1Ba to discolor due to the colorant contained in the ink.

[0130] In the second embodiment, a method for detecting a state in which the ink exceeds the first adhesive portion GL1A but does not exceed the first adhesive portion GL1Ba will be described. From the initial state of the liquid spray head 30a to immediately after the liquid spray head 30a is filled with ink, only the first adhesive portion GL1A is in contact with the ink, but the first adhesive portion GL1Ba is not in contact with the ink, so the first adhesive portion GL1Ba does not change color. When the ink exceeds the first adhesive portion GL1A, the first adhesive portion GL1Ba comes into contact with the ink, and the first adhesive portion GL1Ba changes color. When the first adhesive portion GL1Ba changes color, the detection surface S6 of the first adhesive portion GL1Ba also changes color.

[0131] The explanation returns to Figure 18. The imaging device 90 images the detection surface S6. The imaging device 90 has an imaging optical system and an image sensor. The imaging optical system is an optical system that includes at least one imaging lens and may include various optical elements such as prisms, or it may include a zoom lens or a focus lens. From the viewpoint of making it easy to image the detection surface S6 with the image sensor, the imaging optical system is preferably configured to include a wide-angle lens or a fisheye lens. The image sensor is composed of, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor. The image sensor images via the imaging optical system and transmits image information GI indicating the captured image to the control circuit 21a.

[0132] To enable the imaging device 90 to image the detection surface, a through hole or transparent member is provided in the portion of the side wall of the cover member 31 in the Y2 direction that overlaps with the detection surface when viewed along the Y axis, so that the detection surface S6 is visible from outside the liquid spray head 30a. In addition, the imaging device 90 may have a light source that illuminates the detection surface S6 in order to make the image of the detection surface S6 clearer.

[0133] The memory circuit 22a stores the control program PM2a in place of the control program PM2. As shown in Figure 18, the control circuit 21a functions as an acquisition unit 71a, an estimation unit 73a, and a notification unit 75 by executing the read control program PM2a.

[0134] Figure 20 is a flowchart showing the operation of the inkjet system SYS in the second embodiment. Only the differences from the flowchart shown in Figure 17 are described below.

[0135] In step SC2a, the control circuit 21a transmits the request signal RI to the imaging device 90. After the processing of step SC2a is completed, the control circuit 21a waits for a response from the imaging device 90.

[0136] When the measurement circuit 29 receives the request signal RI, the imaging device 90 captures an image of the detection surface S6 in step SK2. Then, in step SK4, the imaging device 90 transmits image information GI, which represents the image of the detection surface S6, to the control circuit 21a. After the processing in step SK4 is completed, the imaging device 90 terminates the series of processes shown in Figure 20.

[0137] In step SC4a, the control circuit 21a functions as an acquisition unit 71a to acquire image information GI from the imaging device 90. Next, in step SC6a, the control circuit 21a functions as an estimation unit 73a to estimate the degree of deterioration of the first adhesive part GL1A based on the image information GI. Specifically, the memory circuit 22a stores pre-discoloration image information showing the image of the detection surface S6 before discoloration, and post-discoloration image information showing the image after discoloration. The control circuit 21a determines whether the image captured of the detection surface S6 is closer to the image shown by the pre-discoloration image information or the image shown by the post-discoloration image information. If the control circuit 21a determines that the image captured of the detection surface is closer to the image shown by the pre-discoloration image information, the control circuit 21a estimates that the state of the first adhesive part GL1A is undeteriorated. On the other hand, if the control circuit 21a determines that the image captured of the detection surface is closer to the image shown by the post-discoloration image information, the control circuit 21a estimates that the state of the first adhesive part GL1A is deteriorated. The image information before and after discoloration is pre-stored in the memory circuit 22a by the head manufacturer based on experiments.

[0138] In the second embodiment, the image information GI showing an image of the detection surface is an example of "state information" relating to the state of the detection surface S6.

[0139] 2-2. Summary of the Second Embodiment As described above, the liquid injection head 30a in the second embodiment further comprises flow path plates Su4 and Su5 that constitute the supply flow path Sh1. The first adhesive portions GL1A and GL1Ba adhere to the flow path plates Su4 and Su5. The detection surface S6, which is part of the first adhesive portion GL1Ba and serves as the first detection means A in the second embodiment, is positioned near the wall surface SW2 of the flow path plate Su4. The first adhesive portion GL1Ba has the property of changing color when it comes into contact with the ink flowing in the supply flow path Sh1. According to the second embodiment, when ink leaks from the first adhesive portion GL1A and comes into contact with the first adhesive portion GL1Ba, the first adhesive portion GL1Ba changes color, which indicates that ink is leaking from the liquid spray head 30a.

[0140] Furthermore, the inkjet printer 100a includes a liquid jet head 30a and a control circuit 21a. The control circuit 21a functions as an acquisition unit 71a that acquires image information GI from the imaging device 90 and an estimation unit 73a that estimates the degree of deterioration of the first adhesive part GL1A based on the image information GI. According to the second embodiment, similar to the first embodiment, the user U can be notified if there are signs of ink leakage from the liquid spray head 30a.

[0141] In the second embodiment, the inkjet printer 100a does not need to have an imaging device 90. The user U can detect signs of ink leakage from the liquid ejection head 30a by directly visually inspecting the detection surface S6. The liquid ejection head 30a may also have both a detection surface S6 for visual inspection by the user U and a detection surface S6 for imaging by the imaging device 90. Furthermore, the detection surface S6 may be provided around the entire circumference of the wall surface SW2 of the flow path plate Su4 in a plan view.

[0142] 3. Third Embodiment In the second embodiment, the discoloration of the first adhesive portion GL1Ba indicates that ink is leaking from the liquid spray head 30a, but the embodiment is not limited to this. In the third embodiment, the configuration allows for direct visual inspection of the ink that has exceeded the first adhesive portion GL1A.

[0143] 3-1. Configuration and Operation of the Third Embodiment Figure 21 is a block diagram showing an example configuration of the inkjet printer 100b in the third embodiment. The inkjet printer 100b has a liquid jet head 30b instead of a liquid jet head 30a, a control circuit 21a instead of a control circuit 21a, a memory circuit 22b instead of a memory circuit 22a, and an imaging device 90b instead of an imaging device 90. The liquid jet head 30b has a detection mechanism 60Ab.

[0144] Figure 22 is a diagram illustrating the detection mechanism 60Ab. In Figure 22, the region RG1 shown in Figure 12 is shown enlarged, with the liquid injection head 30 replaced by the liquid injection head 30b.

[0145] The liquid injection head 30b has a flow channel plate Su4b instead of the flow channel plate Su4. The flow channel plate Su4b has a detection mechanism 60Ab. The detection mechanism 60Ab is a translucent portion provided on the flow channel plate Su4b to make the first space SP1A visible from the outside. In this specification, translucency means that the member has a thickness of 10 mm or less and a visible light transmittance of 50% or more. However, a high transmittance is preferred, specifically, for a member with a thickness of 10 mm or less, a visible light transmittance of 70% or more is preferred, and a transmittance of 90% or more is even more preferred. The translucent member is formed from glass, and transparent resin materials such as transparent epoxy resin or transparent acrylic resin. As for the manufacturing method of the flow channel plate Su4b, for example, the detection mechanism 60Ab, which is the translucent portion, and a non-translucent resin may be integrated by insert molding, or the detection mechanism 60Ab may be bonded to the non-translucent resin with some adhesive.

[0146] In the third embodiment, the flow path plate Su4b is an example of a "flow path member," and the first space SP1A defined by the flow path plate Su4b is an example of a "first region A."

[0147] As can be seen from Figure 21, in plan view, the detection mechanism 60Ab overlaps with the first space SP1A and the first adhesive portion GL1B. Therefore, the shape of the detection mechanism 60Ab is annular, similar to the first space SP1A and the first adhesive portion GL1B.

[0148] If the ink exceeds the first adhesive portion GL1A, the ink leaking from the first adhesive portion GL1A is contained in the first space SP1A. Therefore, by viewing the detection mechanism 60Ab in a direction perpendicular to the Z-axis, it is possible to determine whether or not the ink has exceeded the first adhesive portion GL1A based on whether or not ink is present in the first space SP1A.

[0149] Although not shown in Figure 22, similar to the first embodiment, in the third embodiment, the adhesive forming the first adhesive portion GL1A and the adhesive forming the first adhesive portion GL1B may be of the same type or different types. The width of the first adhesive portion GL1B is narrower than the width of the first adhesive portion GL1A.

[0150] Let's return to the explanation in Figure 21. The imaging device 90b captures an image of the detection mechanism 60Ab in a direction perpendicular to the Z-axis and transmits image information GIb, which represents the captured image, to the control circuit 21b.

[0151] In order for the imaging device 90b to image the first space SP1A, similar to the second embodiment, a through hole or transparent member is provided in the portion of the side wall of the cover member 31 in the Y2 direction that overlaps with the first space SP1A when viewed along the Y axis, so that the first space SP1A is visible from outside the liquid spray head 30b. Furthermore, the imaging device 90b may have a light source that illuminates the first space SP1A in order to make the image of the first space SP1A clearer.

[0152] The memory circuit 22b stores the control program PM2b in place of the control program PM2a. As shown in Figure 21, the control circuit 21b functions as the acquisition unit 71b, the estimation unit 73b, and the notification unit 75 by executing the read control program PM2b.

[0153] The acquisition unit 71b acquires image information GIb from the imaging device 90b. The estimation unit 73b estimates the degree of deterioration of the first adhesive part GL1A based on the image information GIb. Specifically, the memory circuit 22b stores pre-deterioration image information, which shows an image of the detection mechanism 60A taken perpendicular to the Z-axis when no ink is present in the first space SP1A, and post-deterioration image information, which shows an image of the detection mechanism 60A taken perpendicular to the Z-axis when ink is present in the first space SP1A. The estimation unit 73b determines whether the image of the detection surface of the detection mechanism 60Aa is closer to the image shown by the pre-deterioration image information or the image shown by the post-deterioration image information. If the image shown by the image information GIb is determined to be closer to the image shown by the pre-deterioration image information, the estimation unit 73b estimates that the state of the first adhesive part GL1A is undeteriorated. On the other hand, if the image information GIb is determined to be close to the image information after degradation, the estimation unit 73b estimates that the state of the first adhesive part GL1A is in a degraded state. The pre-degradation image information and the post-degradation image information are stored in the memory circuit 22b in advance by the head maker based on experiments.

[0154] In the third embodiment, the image information GIb, which is obtained by imaging the detection mechanism 60Ab in a direction perpendicular to the Z-axis, is an example of "state information" relating to the state of the detection mechanism 60Ab.

[0155] 3-2. Summary of the Third Embodiment As described above, the liquid injection head 30b in the third embodiment further comprises a flow path plate Su4b that defines the first space SP1A between the first adhesive portion GL1A and GL1B, and the detection mechanism 60Ab, which is the first detection means A in the third embodiment, is a translucent portion provided on the flow path plate Su4b to make the first space SP1A visible from the outside. If ink leaks from the first adhesive portion GL1A, the first space SP1A can be made visible from the outside, allowing the ink inside the first space SP1A to be seen, thus enabling detection of signs of ink leakage from the liquid spray head 30b.

[0156] Furthermore, the inkjet printer 100b includes a liquid jet head 30b and a control circuit 21b. The control circuit 21b functions as an acquisition unit 71a that acquires image information GIb from the imaging device 90b, and an estimation unit 73b that estimates the degree of deterioration of the first adhesive part GL1A based on the image information GIb. According to the third embodiment, similar to the first embodiment, the user U can be notified of a liquid spray head 30b that shows signs of ink leakage.

[0157] In the third embodiment, the inkjet printer 100b does not need to have an imaging device 90b. The user U can directly visually inspect the detection mechanism 60Ab of the liquid ejection head 30a and determine whether or not ink is present in the first space SP1A, thereby detecting signs of ink leakage from the liquid ejection head 30b.

[0158] In the third embodiment, the liquid spray head 30b does not necessarily have the first space SP1A. Even without the first space SP1A, signs of ink leakage from the liquid spray head 30b can be detected by determining whether or not ink is present in the region between the first adhesive portion GL1A and the first adhesive portion GL1B. The region between the first adhesive portion GL1A and GL1B is an example of the "first region A". However, it is preferable that the liquid spray head 30b has the first space SP1A because it makes it easier to check for ink.

[0159] Furthermore, in the third embodiment, a portion of the flow channel plate Su4b is the detection mechanism 60Ab, i.e., the light-transmitting portion, but the entire flow channel plate Su4 may be a light-transmitting portion. However, if the ink is UV ink, there is a risk that the ink in the supply channel Sh1 will harden if the entire flow channel plate Su4 is a light-transmitting portion. Therefore, if the ink is UV ink, it is preferable that, in a plan view, the portion of the flow channel plate Su4b that overlaps with the supply channel Sh1 and the first adhesive portion GL1A is not a light-transmitting portion.

[0160] 4. Variations Each of the embodiments exemplified above can be modified in various ways. Specific examples of modifications that can be applied to each of the embodiments described above are given below. Two or more embodiments arbitrarily selected from the following examples can be merged as appropriate, provided they do not contradict each other.

[0161] 4-1. First and Second Variant Examples In the first embodiment, when the flow channel member has multiple flow channels, a first detection mode is considered in which the multiple flow channels are surrounded by a single detection mechanism 60A, and a second detection mode is considered in which each of the multiple flow channels is surrounded by its own detection mechanism 60A. The first detection mode will be described below using Figure 23 as a first modified example, and the second detection mode will be described using Figure 24 as a second modified example.

[0162] Figure 23 is a diagram illustrating the detection mechanism 60Ac in the first modified example. In the first modified example, the liquid injection head 30c has a detection mechanism 60Ac instead of a detection mechanism 60A. The flow path plates Sux1 and Suy1 shown in Figure 23 have a first flow path Rh1 and a second flow path Rh2 formed therein. Flow path plate Sux1 is one of the flow path plates Su1 to Su4. Flow path plate Suy1 is located in the Z2 direction relative to flow path plate Sux1 and is a member joined to flow path plate Sux1.

[0163] The first channel Rh1 and the second channel Rh2 are any two channels present in the laminate 333. However, in the first modified example, the ink flowing through the first channel Rh1 and the second channel Rh2 is of the same type. In the example shown in Figure 23, the first channel Rh1 has a vertical channel Rh11 extending along the Z-axis, a horizontal channel Rh12 extending perpendicular to the Z-axis, and a vertical channel Rh13 extending along the Z-axis. Similarly, the second channel Rh2 has a vertical channel Rh21 extending along the Z-axis, a horizontal channel Rh22 extending perpendicular to the Z-axis, and a vertical channel Rh23 extending along the Z-axis. In Figure 23, the positions of the vertical channels Rh11 and Rh21 are shown to illustrate their relative positions. Furthermore, in the example shown in Figure 23, the Z2 end of the vertical channel Rh11 communicates with the Y2 end of the horizontal channel Rh12. The Y1 end of the horizontal channel Rh12 communicates with the Z1 end of the vertical channel Rh13. Also, the Z2 end of the vertical channel Rh21 communicates with the Y2 end of the horizontal channel Rh22. The Y1 end of the horizontal channel Rh22 communicates with the Z1 end of the vertical channel Rh23. In the example shown in Figure 23, both the horizontal channel Rh12 and the horizontal channel Rh22 extend along the Y axis, but they are not limited to this and may extend in a direction intersecting the Y axis. Furthermore, the first channel Rh1 does not have to have the horizontal channel Rh12. Similarly, the second channel Rh2 does not have to have the horizontal channel Rh22. Furthermore, the first channel Rh1 and the second channel Rh2 may have distribution channels that distribute to multiple channels, or they may have confluence channels where multiple channels merge.

[0164] The first flow path Rh1 and the second flow path Rh2 may communicate with one or more identical nozzles Nz among the multiple nozzles Nz of the liquid spray head 30c, or they may communicate with one or more different nozzles Nz. In an example where the ink flowing through the first flow path Rh1 and the second flow path Rh2 is of the same type, and the first flow path Rh1 and the second flow path Rh2 communicate with one or more identical nozzles Nz, the first flow path Rh1 is a supply flow path that supplies ink to one or more nozzles Nz, and the second flow path Rh2 is a recovery flow path that recovers ink from the one or more nozzles Nz to which the first flow path Rh1 supplied ink. In the first modified example, the first flow path Rh1 is an example of the "first flow path," and the second flow path Rh2 is an example of the "second flow path."

[0165] The flow path plates Sux1 and Suy1 are joined to each other by a first adhesive portion GL1Ac, a second adhesive portion GL2A, and a first adhesive portion GL1Bc. The first adhesive portion GL1Ac defines the inner wall of the first flow path Rh1 and is provided so as to surround the first flow path Rh1. The second adhesive portion GL2A defines the inner wall of the second flow path Rh2 and is provided so as to surround the second flow path Rh2. The first adhesive portion GL1Bc is provided so as to surround the first adhesive portion GL1Ac and the second adhesive portion GL2A with a gap between them.

[0166] The detection mechanism 60Ac has a detection wire 61c instead of a detection wire 61. The detection wire 61c has a wire portion 613c instead of a wire portion 613. The wire portion 613c is provided to detect a state in which the ink exceeds at least one of the first adhesive portion GL1Ac and the second adhesive portion GL2A but does not exceed the first adhesive portion GL1Bc. As can be seen from Figure 23, the wire portion 613c is meandering in shape, similar to the wire portion 613. The wire portion 613c is arranged to meander around the first adhesive portion GL1Ac and the second adhesive portion GL2A. In the first modified example, the wire portion 613c is an example of the "first detection means A". The second adhesive portion GL2A is an example of the "second adhesive portion A".

[0167] The state in which the ink does not exceed both the first adhesive portion GL1Ac and the second adhesive portion GL2A means that the first adhesive portion GL1Ac and the second adhesive portion GL2A have not deteriorated to the extent that they leak ink. The state in which the ink exceeds at least one of the first adhesive portion GL1Ac and the second adhesive portion GL2A means that at least one of the first adhesive portion GL1Ac and the second adhesive portion GL2A has deteriorated to the extent that it leaks ink. When ink leaks from at least one of the first adhesive portion GL1Ac and the second adhesive portion GL2A, and the leaked ink comes into contact with the conductive portion 613c, the current value between the detection wiring 621 and 622 increases.

[0168] In the first modified example described above, the liquid spray head 30c, unlike the first flow path Rh1, further comprises a second flow path Rh2 communicating with one or more nozzles Nz among a plurality of nozzles Nz, and a second adhesive portion GL2A that defines the inner wall of the second flow path Rh2 and is provided to surround the second flow path Rh2. The conductor portion 613c, which is the first detection means A, is provided to detect a state in which the ink exceeds at least one of the first adhesive portion GL1Ac and the second adhesive portion GL2A but does not exceed the first adhesive portion GL1Bc. The first adhesive portion GL1Bc is provided to surround the first adhesive portion GL1Ac and the second adhesive portion GL2A with a gap between them. According to the first modification, compared to the second modification in which a conductor portion 613c, which is the first detection means A, is provided in both the first channel Rh1 and the second channel Rh2, the number of conductor portions 611, 612 and detection wirings 621, 622 can be reduced. Furthermore, even if ink leaks from both the first adhesive portion GL1Ac and the second adhesive portion GL2A, the ink flowing through the first channel Rh1 and the second channel Rh2 is the same, thus preventing the mixing of different types of ink.

[0169] Figure 24 is a diagram illustrating the detection mechanisms 60Ad1 and 60Ad2 in the second modified example. In the first modified example, the liquid injection head 30d has detection mechanisms 60Ad1 and 60Ad2 instead of detection mechanism 60Ac. The flow path plates Sux2 and Suy2 shown in Figure 24 have a first flow path Rh1 and a second flow path Rh2 formed therein, similar to the first modified example. Flow path plate Sux2 is one of the flow path plates Su1 to Su4. Flow path plate Suy2 is located in the Z2 direction relative to flow path plate Sux2 and is a member joined to flow path plate Sux1.

[0170] In the second modified example, the types of ink flowing through the first channel Rh1 and the second channel Rh2 may be different. In the second modified example, the first channel Rh1 is an example of the "first channel," and the second channel Rh2 is an example of the "second channel."

[0171] The flow path plates Sux2 and Suy2 are joined to each other by first adhesive portions GL1Ad and GL1Bd and second adhesive portions GL2Ad and GL2B. The first adhesive portion GL1Ad defines the inner wall of the first flow path Rh1 and is provided so as to surround the first flow path Rh1. The first adhesive portion GL1Bd is provided so as to surround the first adhesive portion GL1Ad with a gap between them. The second adhesive portion GL2Ad defines the inner wall of the second flow path Rh2 and is provided so as to surround the second flow path Rh2. The second adhesive portion GL2B is provided so as to surround the first adhesive portion GL1Ad with a gap between it and the second adhesive portion GL2Ad.

[0172] The detection mechanism 60Ad1 is provided for the first flow path Rh1, and the detection mechanism 60Ad2 is provided for the second flow path Rh2. Specifically, the wire portion 613 of the detection mechanism 60Ad1 is provided to detect a state in which the ink exceeds the first adhesive portion GL1Ad but does not exceed the first adhesive portion GL1Bd. The wire portion 613 of the detection mechanism 60Ad1 is provided so as to surround the first adhesive portion GL1Ad. The wire portion 613 of the detection mechanism 60Ad2 is provided to detect a state in which the ink exceeds the second adhesive portion GL2Ad but does not exceed the second adhesive portion GL2B. The wire portion 613 of the detection mechanism 60Ad2 is provided so as to surround the second adhesive portion GL2Ad. In the second modified example, the wire portion 613 of the detection mechanism 60Ad1 is an example of the "first detection means A", and the wire portion 613 of the detection mechanism 60Ad2 is an example of the "second detection means". The second adhesive portion GL2B is an example of "second adhesive portion B".

[0173] In the second modified example, the liquid spray head 30d, unlike the first flow path Rh1, further comprises a second flow path Rh2 communicating with one or more nozzles Nz among a plurality of nozzles Nz, a second adhesive portion GL2Ad that defines the inner wall of the second flow path Rh2 and surrounds the second flow path Rh2, a second adhesive portion GL2B that is spaced apart from the second adhesive portion GL2Ad and surrounds the second adhesive portion GL2Ad, and a conductor portion 613 of a detection mechanism 60Ad2, which is a second detection means for detecting a state in which the ink exceeds the second adhesive portion GL2Ad but does not exceed the second adhesive portion GL2B. In the first modification, if the types of ink flowing through the first channel Rh1 and the second channel Rh2 are different, and ink leaks from both the first adhesive part GL1Ac and the second adhesive part GL2A, the different types of ink will mix. If the mixed ink flows back into either the first channel Rh1 or the second channel Rh2, the color of the ink ejected from the nozzle Nz will change, and the quality of the image formed on the medium PP will deteriorate. On the other hand, in the second modification, even if ink leaks from the first adhesive part GL1Ad, the leakage is suppressed by the first adhesive part GL1Bd. Similarly, even if ink leaks from the second adhesive part GL2A, the leakage is suppressed by the second adhesive part GL2B. Therefore, in the second modification, even if ink leaks from both the first adhesive part GL1Ad and the second adhesive part GL2A, the mixing of different types of ink can be suppressed. Therefore, according to the second modification, compared to the first modification in which a common first detection means A is provided for the first channel Rh1 and the second channel Rh2, even when the types of ink flowing through the first channel Rh1 and the second channel Rh2 are different, it is possible to detect signs of ink leakage from the liquid spray head 30d while maintaining the quality of the image formed on the medium PP.

[0174] Furthermore, in the example shown in Figure 24, the first adhesive portion GL1Bd and the second adhesive portion GL2B were independent of each other, but parts of the first adhesive portion GL1Bd and the second adhesive portion GL2B may be common. To explain using the example in Figure 24, the portion of the first adhesive portion GL1Bd in the X2 direction and the portion of the second adhesive portion GL2B in the X1 direction may be common.

[0175] Although the descriptions above apply the first and second modified embodiments to the first embodiment, it is also possible to apply the first modified embodiment to the second and third embodiments, respectively, or to the second modified embodiment.

[0176] 4-2. Third Variation In the third modification, signs of ink leakage from the liquid spray head 30 can be detected in multiple stages.

[0177] Figure 25 is a block diagram showing an example configuration of the inkjet printer 100e in the third modified example. The inkjet printer 100e has a liquid jet head 30e instead of the liquid jet head 30, a control circuit 21e instead of the control circuit 21, a memory circuit 22e instead of the memory circuit 22, and a measurement circuit 29e instead of the measurement circuit 29. The liquid jet head 30e has detection mechanisms 60Ae and 60B instead of the detection mechanism 60A. The detection mechanisms 60Ae and 60B will be explained using Figures 26 and 27.

[0178] Figures 26 and 27 are diagrams illustrating the detection mechanisms 60Ae and 60B. In Figure 26, the region RG1 shown in Figure 12 is shown enlarged, with the liquid injection head 30 replaced by the liquid injection head 30e in the third modified example. In Figure 27, a cross-section is shown when the liquid injection head 30 is fractured along the line bb shown in Figure 26.

[0179] In the third modified example, the flow path plates Su4 and Su5 are joined by an adhesive portion GL45e. The adhesive portion GL45e includes the first adhesive portions GL1Ae and GL1Be, as well as the first adhesive portion GL1C. The first adhesive portion GL1C is positioned between the first adhesive portions GL1Ae and GL1Be and is provided so as to surround the first adhesive portion GL1Ae. In the third modified example, the first adhesive portion GL1Ae is an example of "first adhesive portion A", the first adhesive portion GL1Be is an example of "first adhesive portion B", and the first adhesive portion GL1C is an example of "first adhesive portion C".

[0180] The detection mechanism 60Ae has a detection wire 61Ae instead of the detection wire 61. The detection wire 61Ae has a wire portion 613Ae instead of the wire portion 613. The wire portion 613Ae is provided to detect a state where the wire exceeds the first adhesive portion GL1Ae but does not exceed the first adhesive portion GL1C. As can be seen from Figures 26 and 27, the wire portion 613Ae is positioned between the first adhesive portion GL1Ae and GL1C. In the third modified example, the wire portion 613Ae is an example of the "first detection means A".

[0181] The detection mechanism 60B includes a detection conductor 61B and detection wirings 621B and 622B. The detection conductor 61B is arranged on the surface S51. The detection conductor 61B has conductor portions 611B, 612B, and 613B. Conductor portions 611B and 612B extend parallel to conductor portions 611 and 612, specifically in the direction along the X axis. As shown in Figure 27, conductor portions 611 and 612 are arranged between conductor portions 611B and 612B. The X1 end of conductor portion 611B is connected to one end OE1B of conductor portion 613B. The X1 end of conductor portion 612B is connected to one end OE2B of conductor portion 613B. The X2 end of conductor portion 611B is connected to one end of detection wiring 621B. The end of the conductor portion 612B in the X2 direction is connected to one end of the detection wiring 622B. The detection wirings 621B and 622B function as lead wires of the detection conductor 61B. The detection wirings 621B and 622B are connected to the measurement circuit 29 via wiring members (not shown).

[0182] As can be seen from Figure 26, the conductor portion 613B is housed in the first space SP1B formed by cutting out the surface S42 in the Z1 direction. As can be seen from Figures 26 and 27, the conductor portion 613B is positioned between the first adhesive portion GL1C and GL1Be. In the third modified example, the conductor portion 613B is an example of the "first detection means B".

[0183] Returning to the explanation in Figure 25, the measurement circuit 29e measures the current values ​​between detection wiring 621 and 622 of the detection mechanism 60Ae and between detection wiring 621B and 622B of the detection mechanism 60B. The measurement circuit 29e transmits measurement information JIe, which indicates the measurement results, to the control circuit 21e.

[0184] The memory circuit 22e stores the control program PM2e in place of the control program PM2. As shown in Figure 25, the control circuit 21e functions as an acquisition unit 71e, an estimation unit 73e, and a notification unit 75e by executing the read control program PM2e.

[0185] The acquisition unit 71e acquires measurement information JIe from the control circuit 21e. The estimation unit 73e estimates the degree of deterioration of the first adhesive part GL1Ae and the degree of deterioration of the first adhesive part GL1C based on the measurement information JIe. As can be seen from Figure 27, the lengths of the wiring from detection wiring 621 to 622 and the lengths of the wiring from detection wiring 621B to 622B are different. Therefore, the resistance values ​​between detection wiring 621 and 622 in the initial state of the liquid spray head 30e are different from the resistance values ​​between detection wiring 621 and 622. Therefore, it is preferable that the threshold for estimating the degree of deterioration of the first adhesive part GL1Ae and the threshold for estimating the degree of deterioration of the first adhesive part GL1C are different. Hereinafter, the threshold for estimating the degree of deterioration of the first adhesive part GL1Ae will be referred to as the "first threshold," and the threshold for estimating the degree of deterioration of the first adhesive part GL1C will be referred to as the "second threshold." The estimation unit 73e estimates that the state of the first adhesive parts GL1Ae and GL1C is undegraded if the current value of the detection mechanism 60Ae is less than a first threshold. Furthermore, if the current value of the detection mechanism 60Ae is greater than or equal to the first threshold, and the current value of the detection mechanism 60B is less than a second threshold, the estimation unit 73e estimates that the state of the first adhesive part GL1A is degraded, and the state of the first adhesive part GL1C is undegraded. Furthermore, if the current value of the detection mechanism 60B is greater than or equal to the second threshold, the estimation unit 73e estimates that the state of the first adhesive parts GL1A and GL1C is degraded.

[0186] The notification unit 75e generates notification information CI in the third modified example based on the estimation result of the estimation unit 73e, and notifies the user U of the notification information CI in the third modified example. The notification information CI in the third modified example is information about the liquid spray head 30e that shows signs of ink leakage. However, the notification information CI in the third modified example includes information indicating the degree of the signs of ink leakage from the liquid spray head 30e. For example, if the estimation unit 73e estimates that the state of the first adhesive part GL1A is deteriorated and the state of the first adhesive part GL1C is not deteriorated, the notification information CI is a first sign string indicating the first stage of ink leakage from the liquid spray head 30e. The first sign string is the string, "There are signs of ink leakage from the liquid spray head. Please consider replacing the liquid spray head." Furthermore, if the estimation unit 73e estimates that the first adhesive parts GL1A and GL1C of the liquid spray head 30e are in a deteriorated state, the notification information CI is a second warning string indicating the second stage of ink leakage from the liquid spray head 30e. The second stage of ink leakage from the liquid spray head 30e occurs more quickly than the first stage of ink leakage from the liquid spray head 30e. The second warning string is the string, "The signs of ink leakage from the liquid spray head have increased. We recommend replacing the liquid spray head."

[0187] As described above, the liquid spray head 30e in the third modified example further comprises a first adhesive portion GL1C positioned between the first adhesive portions GL1Ae and GL1Be and provided so as to surround the first adhesive portion GL1Ae, and a conductor portion 613B for detecting a state in which the ink exceeds the first adhesive portion GL1C but does not exceed the first adhesive portion GL1Be, wherein the conductor portion 613Ae is provided for detecting a state in which the ink exceeds the first adhesive portion GL1Ae but does not exceed the first adhesive portion GL1C. According to the third modification, signs of ink leakage from the liquid spray head 30e can be detected in multiple stages. User U can take appropriate action according to each notification information CI. Specifically, user U can use the liquid spray head 30e until just before it fails, while ensuring that time is available to prepare a replacement liquid spray head 30e. For example, if the first sign string is notified to user U as the notification information CI in the third modification, user U orders a liquid spray head 30e from the head manufacturer. Then, if the second sign string is notified to user U as the notification information CI in the third modification, user U replaces the liquid spray head 30 with the liquid spray head 30e obtained from the head manufacturer.

[0188] Although the description above applies the third modification to the first embodiment, it is also possible to apply the first modification to the second and third embodiments, respectively.

[0189] 4-3. Fourth Variation In the second embodiment, the first adhesive portion GL1Ba was provided so as to be in close contact with the first adhesive portion GL1A, but it may also be positioned at a distance from the first adhesive portion GL1A.

[0190] Figures 28 and 29 are diagrams illustrating the first adhesive portion GL1Bf in the fourth modified example. In Figure 28, the region RG1 shown in Figure 12 is shown enlarged, with the liquid injection head 30 replaced by a liquid injection head 30f. In Figure 29, a cross-section is shown when the liquid injection head 30f is broken along the cc line shown in Figure 28.

[0191] The liquid injection head 30f has a flow path plate Su4f instead of the flow path plate Su4. A first space SP1Af is formed in the flow path plate Su4f by cutting out a surface S42f of the flow path plate Su4f in the Z1 direction. Thus, the first space SP1Af is defined by the flow path plates Su4f and Su5.

[0192] In the fourth modified example, the adhesive portion GL45f has a first adhesive portion GL1Bf instead of the first adhesive portion GL1Ba. The first adhesive portion GL1Bf is provided with a gap between it and the first adhesive portion GL1A, surrounding the first adhesive portion GL1A. The annular portion SPr, which is part of the first space SP1Af, coincides with the gap between the first adhesive portion GL1Bf and the first adhesive portion GL1A.

[0193] In the examples shown in Figures 28 and 29, the first adhesive portion GL1Bf has a protrusion 64f that projects in the Y1 direction from the annular portion of the first adhesive portion GL1Bf surrounding the first adhesive portion GL1A. The protrusion 64f has a detection surface S6f facing in the Y1 direction. Similar to the second embodiment, in the example shown in Figure 29, the detection surface S6f is flush with the wall surface SW1 of the flow channel structure 33 facing in the Y1 direction. However, the detection surface S6f does not have to be flush with the wall surface SW1, and may be recessed relative to the wall surface SW1 to the extent that it is visible from outside the flow channel structure 33.

[0194] The first space SP1Af has an annular portion SPr and a groove SPp protruding from the annular portion SPr in the Y1 direction. The groove SPp is formed by the communication between the space formed by the Y1 direction notch of the aforementioned annular portion of the first adhesive portion GL1Bf and the space formed by the Y1 direction recess of the convex portion 64f. The groove SPp can guide ink from the first adhesive portion GL1A toward the outer surface wall SW1 of the flow path plate Su4f, more specifically toward the detection surface S6f. The width of the groove SPp in the direction along the X axis is, for example, the width over which capillary force acts. Because the width of the groove SPp in the direction along the X axis is the width over which capillary force acts, the ink can be actively moved toward the vicinity of the detection surface S6f.

[0195] In the fourth modified example, the flow path plate Su4f is an example of a "first flow path member," the flow path plate Su5 is an example of a "second flow path member," the first space SP1Af is an example of a "first region A," and the detection surface S6f, which is part of the first adhesive portion GL1Bf, is an example of a "first detection means A."

[0196] Similar to the second embodiment, the first adhesive portion GL1Bf has the property of changing color when it comes into contact with ink.

[0197] As described above, according to the fourth modification, the first adhesive portion GL1Bf is positioned with a gap between it and the first adhesive portion GL1A, and the flow path plates Su4f and Su5 define a first space SP1Af between the first adhesive portion GL1A and GL1Bf. Within the first space SP1Af, grooves SPp are arranged that can guide ink from the first adhesive portion GL1A toward the wall surface SW1 of the flow path plate Su4f. According to the fourth modification, since the groove SPp guides the ink toward the outer surface of the flow channel plate Su4f, it is no longer necessary to position the supply channel Sh1 itself near the outer wall of the flow channel structure 33, thus ensuring greater flexibility in the layout of the supply channel Sh1.

[0198] 4-4. Fifth variation In the first embodiment, the first modified example based on the first embodiment, the second modified example based on the first embodiment, and the third modified example based on the first embodiment, the conductor portion 613 is a meandering wiring, but is not limited to this.

[0199] Figure 30 is a diagram illustrating the detection mechanism 60Ag in the fifth modified example. In Figure 19, the line aa shown in Figure 13 indicates a cross-section of the liquid spray head 30g when it is broken in the fifth modified example. The liquid spray head 30g has a detection mechanism 60Ag instead of a detection mechanism 60A.

[0200] The detection mechanism 60Ag has a detection wire 61g instead of the detection wire 61. The detection wire 61g has wire sections 611g, 612g, 613g, and wire section 614. Wire section 611g is connected to one end OE1g of wire section 613g at its end in the X1 direction. Wire section 612g is connected to one end OE2g of wire section 614 at its end in the X1 direction.

[0201] The conductor portions 613g and 614 are each formed in a C shape with a part of a circle cut out, and have a notch in the X1 direction. As can be seen from Figure 30, the conductor portion 614 is positioned between the conductor portion 613g and the first adhesive portion GL1A. In the fifth modified example, the conductor portions 613g and 614 are examples of the "first detection means A" and examples of "one or more conductors positioned in the first region A between the first adhesive portion A and the first adhesive portion B".

[0202] In the fifth modified example, the measurement circuit 29 measures the current value between detection wires 621 and 622. In the initial state of the liquid spray head 30g, detection wires 621 and 622 are not conductive, and the current value is approximately 0. On the other hand, if ink leaks from the first adhesive part GL1A, detection wires 621 and 622 become electrically connected by the ink, so the current value between detection wires 621 and 622 becomes greater than 0.

[0203] 4-5. Sixth variation In the first embodiment, the width L1B of the first adhesive portion GL1B is narrower than the width L1A of the first adhesive portion GL1A, but the width L1B may be wider than the width L1B.

[0204] 4-6. Seventh Variation In each of the embodiments described above, the control circuit 21 functions as an acquisition unit 71, an estimation unit 73, and a notification unit 75, but it may also function as an acquisition unit 71 and an estimation unit 73, and not as a notification unit 75. For example, when a service support person from the head manufacturer visits the printer manufacturer or user U and performs the series of processes shown in Figure 16, the control circuit 21 may not function as a notification unit 75. The service support person provides appropriate support based on the estimated degree of deterioration of the first adhesive part GL1A. For example, if the estimated degree of deterioration of the first adhesive part GL1A indicates that the first adhesive part GL1A is deteriorated, the service support person may suggest to user U that the liquid spray head 30 be replaced. [Explanation of Symbols]

[0205] 3...Head module, 21, 21a, 21b, 21e...Control circuit, 22, 22a, 22b, 22e...Memory circuit, 23...Transport mechanism, 24...Movement mechanism, 28...Communication device, 29, 29e...Measurement circuit, 30, 30a, 30b, 30c, 30d, 30e, 30f, 30g...Liquid injection head, 31...Cover member, 32...Holder member, 33...Flow channel structure, 40...Nozzle plate, 42...Communication plate, 43...Pressure chamber substrate, 44...Vibrator, 50...Drive circuit, 51...Flexible substrate, 60A 60Aa,60Ab,60Ac,60Ad1,60Ad2,60Ae,60Af,60Ag,60B…Detection mechanism, 61,61Ae,61B,61c,61g…Detection wire, 64n…Protrusion, 71,71a,71b,71e…Acquisition unit, 73,73a,73b,73e…Estimation unit, 75,75e…Notification unit, 90,90b…Imaging device, 100,100a,100b,100e…Inkjet printer, 200…Processing device, 210…Control circuit, 220…Memory circuit, 240…Communication Device, 242…Endless belt, 260…Input device, 270…Display device, 333…Laminate, 334a,334b…Protrusions, 335…Case, 336,336a,611,611B,611g,612,612B,612g,613,613Ae,613B,613c,613g,614…Conducting wire portion, 621,621B,622,622B…Detection wiring, CI…Notification information, CM…Control module, Ca,Cb…Pressure chamber, Com…Drive signal, E…Drive element, ER1…Enlarged area, Ea… Driving element, GL1B, GL1Ba, GL1Bc, GL1Bd, GL1Be, GL1Bf, GL1C... First bonding part, GL23, GL34, GL45, GL45a, GL45e, GL45f, GL56, GL57... Bonding part, GL2A, GL2Ad, GL2B... Second bonding part, Nz... Nozzle, OE1, OE1B, OE1g, OE2, OE2B, OE2g... One end, R1a, R1b... Supply channel inside the head, R2a, R2b... Discharge channel inside the head, R3a, R3b... First communication channel, R4a,R4b...Second communication channel, RG1...Region, RG2...Range, RI...Request signal, Ra...First liquid storage chamber, Rb...Second liquid storage chamber, Rh1...First channel, Rh11...Vertical channel, Rh12...Horizontal channel, Rh13...Vertical channel, Rh2...Second channel, Rh21...Vertical channel, Rh22...Horizontal channel, Rh23...Vertical channel, Rn...In-head channel, S1a...In-structure supply channel, S1b...In-structure supply channel, S2a...In-structure discharge channel, S2b...In-structure discharge channel, S42, S42f, S 51...plane, S6, S6f...detection surface, SF...flow channel, SI...printed signal, SP1A, SP1Af, SP1B...first space, SPp...groove, SPr...annular portion, SW1, SW2...wall surface, SY...inner wall, Sh1...supply flow channel, Sh11...vertical flow channel, Sh12...horizontal flow channel, Sh13...vertical flow channel, Sk1, Sk2...control signal, Sn...intrastructure flow channel, Su, Su1, Su2, Su3, Su4, Su4b, Su4f, Su5, Sux1, Sux2, Suy1, Suy2...flow channel plate.

Claims

1. Multiple nozzles for spraying liquid, A first channel communicating with one or more of the aforementioned plurality of nozzles, A first adhesive portion A is provided to define the inner wall of the first flow path and to surround the first flow path, A first adhesive portion B is provided so as to surround the first adhesive portion A, A first detection means A for detecting a state in which the liquid exceeds the first adhesive portion A but does not exceed the first adhesive portion B, A liquid spray head characterized by having the following features.

2. Unlike the first channel, a second channel is provided that communicates with one or more of the multiple nozzles, A second adhesive portion A is provided to define the inner wall of the second flow path and to surround the second flow path, Furthermore, The first detection means A is provided to detect a state in which the liquid exceeds at least one of the first adhesive portion A and the second adhesive portion A but does not exceed the first adhesive portion B. The first adhesive portion B is provided so as to surround the first adhesive portion A and the second adhesive portion A, with a gap between them. The liquid spray head according to feature 1.

3. Unlike the first channel, a second channel is provided that communicates with one or more of the multiple nozzles, A second adhesive portion A is provided to define the inner wall of the second flow path and to surround the second flow path, A second adhesive portion B is provided at a distance from the second adhesive portion A and surrounding the second adhesive portion A, A second detection means for detecting a state in which the liquid exceeds the second adhesive portion A but does not exceed the second adhesive portion B, The liquid spray head according to claim 1, further comprising the following:

4. A first adhesive portion C is provided between the first adhesive portion A and the first adhesive portion B, and is positioned to surround the first adhesive portion A. A first detection means B for detecting a state in which the liquid exceeds the first adhesive portion C but does not exceed the first adhesive portion B, Furthermore, The first detection means A is provided to detect a state in which the adhesive portion exceeds the first adhesive portion A but does not exceed the first adhesive portion C. The liquid spray head according to feature 1.

5. The adhesive forming the first adhesive portion A and the adhesive forming the first adhesive portion B are of the same type. The width of the first adhesive portion B is narrower than the width of the first adhesive portion A. The liquid spray head according to feature 1.

6. The first detection means A is one or more conductors arranged within the first region A between the first adhesive portion A and the first adhesive portion B. The liquid spray head according to feature 1.

7. The device further includes a flow channel member that defines a first region A between the first adhesive portion A and the first adhesive portion B, The first detection means A is a light-transmitting portion provided in the flow channel member to make the first region A visible from the outside. The liquid spray head according to feature 1.

8. The first flow path further comprises a first flow path member and a second flow path member, The first adhesive portion A and the first adhesive portion B bond the first flow channel member and the second flow channel member, A portion of the first adhesive portion B, which serves as the first detection means A, is positioned near the outer surface of the first flow channel member. The first adhesive portion B has the property of changing color when it comes into contact with the liquid flowing in the first channel. The liquid spray head according to feature 1.

9. The first adhesive portion B is positioned with a gap between it and the first adhesive portion A. The first flow channel member and the second flow channel member define the first region A between the first adhesive portion A and the first adhesive portion B, Within the first region A, grooves are provided that can guide liquid from the first adhesive portion A toward the outer surface of the first flow channel member. The liquid spray head according to feature 8.

10. A liquid spray head according to any one of claims 1 to 9, An acquisition unit that acquires state information relating to the state of the first detection means A, An estimation unit that estimates the degree of deterioration of the first adhesive portion A based on the aforementioned state information, A liquid injection device characterized by being equipped with the following features.

11. The system further includes a notification unit that prompts the replacement of the liquid spray head based on the estimated degree of deterioration of the first adhesive portion A based on the aforementioned state information. The liquid injection device according to claim 10.

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