Liquid discharge head, liquid discharge head device, liquid discharge unit, and liquid discharge apparatus

Abstract

To suppress a malfunction that occurs when the electric current due to static electricity flows through a nozzle plate without complicating a manufacturing process of a liquid discharge head.SOLUTION: A liquid discharge head includes: a nozzle plate 10 in which nozzles for discharging liquid are formed; a flow path substrate 20 in which individual liquid chambers communicating with the nozzles are formed; an actuator which generates driving force to discharge liquid in the individual liquid chambers from the nozzles; a conductive shielding layer 26 which is interposed between the flow path substrate and the nozzle plate, and suppresses the flow of the abnormal current input to the nozzle plate into the actuator; and a conductive path 302 which makes the abnormal current having flown into the shielding layer flow toward a conductive nozzle cover 103 provided on the liquid discharge surface 10a side of the nozzle plate in an outer region in the plane direction of the nozzle plate.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a liquid ejection head, a liquid ejection head device, a liquid ejection unit, and a device for ejecting a liquid.

Background Art

[0002] Conventionally, a liquid ejection head having a nozzle plate on which nozzles for ejecting a liquid are formed, a flow path substrate in which individual liquid chambers communicating with the nozzles are formed, and an actuator that generates a driving force for ejecting the liquid in the individual liquid chambers from the nozzles is known.

[0003] For example, Patent Document 1 discloses a head unit (liquid ejection head) having a nozzle plate (nozzle plate), a flow path substrate in which individual liquid chambers are formed, and a piezoelectric element (actuator) formed on a diaphragm constituting the wall surface of the individual liquid chambers of the flow path substrate. In this head unit, the peripheral portion of the liquid ejection surface of the nozzle plate is fixed to a conductive unit fixing plate with a conductive adhesive, and a grounded conductive nozzle cover is further attached to the unit fixing plate with a conductive adhesive. This head unit is for preventing an electric current due to static electricity from flowing from the nozzle plate through the ink in the individual liquid chambers to a drive IC or the like. To prevent this, in this head unit, a conductive film is formed continuously over the liquid ejection surface and the back surface (the surface on the side to which the flow path substrate is joined) of the nozzle plate and the inner peripheral surface of the nozzle. And the conductive film portion on the liquid ejection surface of the nozzle plate is configured to be electrically connected to the nozzle cover via the unit fixing plate. In this head unit, even if an electric current due to static electricity flows from the nozzle plate to the ink, the electric current flows to the nozzle cover through the conductive film in contact with the ink, and problems such as damage or malfunction of the drive IC are prevented.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional liquid ejection head, since it is necessary to form a conductive film over the liquid ejection surface and the back surface of the nozzle plate and the inner peripheral surface of the nozzle, there arises a problem that the manufacturing process of the liquid ejection head becomes complicated.

Means for Solving the Problems

[0005] In order to solve the above-described problems, the present invention provides a liquid ejection head having a nozzle plate on which nozzles for ejecting liquid are formed, a flow path substrate on which individual liquid chambers communicating with the nozzles are formed, and an actuator that generates a driving force for ejecting the liquid in the individual liquid chambers from the nozzles, wherein a conductive shielding layer is interposed between the flow path substrate and the nozzle plate to suppress abnormal current input to the nozzle plate from flowing to the actuator, and a conduction path that causes the abnormal current flowing into the shielding layer to flow to a conductive nozzle cover provided on the liquid ejection surface side of the nozzle plate in an outer region in the surface direction of the nozzle plate.

Advantages of the Invention

[0006] According to the present invention, it is possible to suppress problems caused by current flowing through the nozzle plate due to static electricity without complicating the manufacturing process of the liquid ejection head.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

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Figure 4

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Best Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view schematically showing a head module which is a liquid ejection head device including a liquid ejection head according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing a cross-section obtained by cutting one liquid ejection head mounted on the head module of the present embodiment along the short side direction of the head.

[0009] The head module 100 includes a plurality of liquid ejection heads 1 for ejecting liquid, a base member 102, a nozzle cover 103, a heat dissipation member 104, a manifold 105, a printed circuit board (PCB) 106, and a module case 107.

[0010] The liquid ejection head 1 includes a nozzle plate 10 in which nozzles 11 are formed, a flow path substrate 20 that forms individual flow paths such as pressure chambers 21 which are individual liquid chambers communicating with the nozzles 11, and a diaphragm 30 including a piezoelectric element 40 that is an actuator for pressurizing the liquid in the pressure chambers 21. Further, the liquid ejection head 1 includes an intermediate flow path plate 50 laminated on the diaphragm 30, a common flow path member 70 laminated on the intermediate flow path plate 50, and the like. The common flow path member 70 serves as a frame member of the liquid ejection head 1.

[0011] The flow path substrate 20 forms an individual supply flow path 22 communicating with the pressure chamber 21 and an individual recovery flow path 24 communicating with the pressure chamber 21, together with the pressure chamber 21. The intermediate flow path plate 50 forms an intermediate supply flow path 51 communicating with the individual supply flow path 22 through an opening 31 of the diaphragm 30 and an intermediate recovery flow path 52 communicating with the individual recovery flow path 24 through an opening 32 of the diaphragm 30. The common flow path member 70 forms a common supply flow path 71 communicating with the intermediate supply flow path 51 and a common recovery flow path 72 communicating with the intermediate recovery flow path 52. The common supply flow path 71 communicates with a supply port 81 through a flow path 151 of a manifold 105. The common recovery flow path 72 communicates with a recovery port 82 through a flow path 152 of the manifold 105. The printed circuit board 106 and the piezoelectric element 40 of the liquid ejection head 1 are connected via a flexible wiring member 90, and a driver IC (drive circuit) 91 which is a drive unit is mounted on the flexible wiring member 90.

[0012] A plurality of liquid ejection heads 1 are respectively inserted into openings 121 of a base member 102, and a nozzle cover 103 joined and fixed to the base member 102 is adhered (joined) to the flow path substrate 20 of the liquid ejection head 1 with an adhesive (joining agent) and fixed. The nozzle cover 103 is provided with an opening corresponding to the region of the nozzles 11 of the nozzle plate 10. The nozzle cover 103 is provided so as to cover the peripheral portion of the liquid ejection surface (ejection surface) of the nozzle plate 10 of the liquid ejection head 1.

[0013] Note that the nozzle cover 103 only needs to cover the edge of at least one side of the ejection surface of the nozzle plate 10. However, in some cases, it is required to prevent liquid or the like adhering to the ejection surface from entering between the nozzle cover 103 and the ejection surface of the nozzle plate 10. In this case, it is preferable to provide the nozzle cover 103 so as to cover the peripheral edge of the ejection surface, and configure to seal the gap between the nozzle cover 103 and the ejection surface of the nozzle plate 10 with an adhesive. In that case, generally, an epoxy-based adhesive (insulating adhesive) with high sealing performance is used as this adhesive.

[0014] The base member 102 is a member arranged with a space 150 left on the side wall surface of the flow path substrate 20, and a part of the flexible wiring member 90 is arranged in the space 150. Also, at the longitudinal end of the liquid ejection head 1 in the head longitudinal direction, a flange portion provided outside the common flow path member 70 is joined and fixed to the base member 102.

[0015] The nozzle cover 103 is a conductive member, and for example, a metal one such as SUS is used. The nozzle cover 103 is grounded via the base member 102 when the base member 102 is a conductive member, for example.

[0016] FIG. 3(a) is a plan view when the liquid ejection head in the configuration of Comparative Example 1 is viewed from the ejection surface side. FIG. 3(b) is a partial cross-sectional view showing the main part of the cross section indicated by the symbol A-A' in FIG. 3(a).

[0017] As shown in FIGS. 3(a) and (b), the outer shape of the nozzle plate 10 of the liquid ejection head 1 is smaller than the outer shape of the flow path substrate 20 in terms of the planar shape. The nozzle cover 103 has a joint surface 103b facing the surface (joint surface 20a) of the flow path substrate 20 on the nozzle plate 10 side in the outer region of the nozzle plate 10 (the region outside the nozzle plate 10 in the surface direction), and is adhered (joined) to the joint surface 20a of the flow path substrate 20 with an adhesive 300. Further, the nozzle cover 103 has a joint surface 103a facing the peripheral edge (joint surface 10b) of the ejection surface 10a of the nozzle plate 10, and is adhered (joined) to the joint surface 10b of the nozzle plate 10 that is continuous with the joint surface 20a of the flow path substrate 20 via a step, also with the adhesive 300.

[0018] Also, as shown in FIG. 3(b), a liquid contact film 25 is formed on the surface of the flow path substrate 20 on the nozzle plate 10 side. This liquid contact film 25 is for enhancing ink resistance (liquid resistance), and for example, a liquid contact film having a composition containing tantalum (Ta), silicon (Si), and oxygen (O) can be preferably used. Since the joint surface 20a of the flow path substrate 20 adhered to the joint surface 103b of the nozzle cover 103 with the adhesive 300 becomes this liquid contact film 25, it has high liquid affinity and the overflow of the adhesive 300 is suppressed.

[0019] Here, static electricity may be generated on the nozzle plate 10 of the liquid ejection head 1 in various scenarios. For example, during the use of the liquid ejection head 1, static electricity may be generated between the recording material on which liquid is ejected from the liquid ejection head 1 and an image is recorded and the nozzle plate 10. Also, in the manufacturing process of the head module 100, static electricity may be generated between the operator or manufacturing equipment and the nozzle plate 10. When such static electricity is generated, an electric current due to the static electricity may flow from the nozzle plate 10 to the piezoelectric element 40 or the driver IC 91, and there is a risk of damage or malfunction of the piezoelectric element 40 or the driver IC 91.

[0020] In the configuration of Comparative Example 1 shown in FIGS. 3(a) and (b), the grounded nozzle cover 103 and the nozzle plate 10 are adhered with an adhesive 300, but this adhesive 300 is insulating. Therefore, the current due to static electricity cannot be discharged from the nozzle plate 10 to the nozzle cover 103 through the adhesive 300. Also, the liquid contact film 25 is insulating. Therefore, the current due to static electricity cannot be discharged from the surface of the nozzle plate 10 on the side of the flow path substrate 20 to the nozzle cover 103 through the liquid contact film 25. As a result, the current due to static electricity easily flows from the nozzle plate 10 to the piezoelectric element 40 and the driver IC 91, and damage or malfunction of the piezoelectric element 40 and the driver IC 91 is likely to occur.

[0021] FIG. 4(a) is a plan view of the liquid ejection head in the present embodiment as viewed from the ejection surface side. FIG. 4(b) is a cross-sectional view of the main part showing the main part of the cross-section indicated by the reference symbol B - B' in FIG. 4(a).

[0022] As shown in FIG. 4(b), in the present embodiment, a conductive metal film 26 is interposed between the nozzle plate 10 and the flow path substrate 20. This metal film 26 is formed on the surface of the flow path substrate 20 on the side of the nozzle plate 10 (here, on the surface of the liquid contact film 25 formed on the flow path substrate 20). This metal film 26 is provided between the nozzle plate 10 and the flow path substrate 20, and the current that tries to flow from the nozzle plate 10 to the piezoelectric element 40 and the driver IC 91 can be made to flow into the metal film 26. That is, this metal film 26 functions as a shielding layer that suppresses the flow of the current due to static electricity (abnormal current) input to the nozzle plate 10 to the piezoelectric element 40 and the driver IC 91.

[0023] In this embodiment, a conduction path is formed to allow the current due to static electricity flowing into the metal film 26 to flow to the nozzle cover 103 in the outer region of the nozzle plate 10 (the region outward in the plane direction of the nozzle plate 10). As a result, the current due to static electricity flowing into the metal film 26 can escape from the metal film 26 to the nozzle cover 103 through the conduction path in the outer region of the nozzle plate 10. Consequently, it is possible to suppress the current due to static electricity from flowing from the nozzle plate 10 to the piezoelectric element 40 or the driver IC 91, and it is possible to suppress damage or malfunction of the piezoelectric element 40 or the driver IC 91.

[0024] Next, the conduction path in this embodiment will be described. In the configuration of Comparative Example 1 shown in FIG. 3(b), an insulating material (insulating layer), namely, the adhesive 300 and the liquid contact film 25, is interposed between the metal film 26 and the nozzle cover 103 in the outer region of the nozzle plate 10. Therefore, as in Comparative Example 2 shown in FIG. 5, simply providing the metal film 26 alone, the current due to static electricity flowing from the nozzle plate 10 into the metal film 26 is inhibited by the insulating liquid contact film 25 and the adhesive 300 and cannot escape from the metal film 26 to the nozzle cover 103.

[0025] Furthermore, as in Comparative Example 3 shown in FIG. 6, even if an opening 25a, which is a through hole, is provided in the portion of the liquid contact film 25 in the outer region of the nozzle plate 10 and the metal film 26 is exposed toward the nozzle cover 103 side, an insulating adhesive 300 is interposed between the metal film 26 and the nozzle cover 103. Therefore, the current due to static electricity flowing from the nozzle plate 10 into the metal film 26 is inhibited by the insulating adhesive 300 and cannot escape from the metal film 26 to the nozzle cover 103.

[0026] In this embodiment, as shown in FIG. 4(b), an opening 25a is provided in a portion of the liquid contact film 25 in the outer region of the nozzle plate 10 to expose the metal film 26 toward the nozzle cover 103 side, and a conductive adhesive 302 is used as an adhesive interposed between the metal film 26 and the nozzle cover 103. As a result, in the outer region of the nozzle plate 10, the metal film 26 and the nozzle cover 103 are electrically connected by the conductive adhesive 302 serving as a conduction path. As a result, the current due to static electricity flowing into the metal film 26 from the nozzle plate 10 can escape from the metal film 26 to the nozzle cover 103 through the conductive adhesive 302.

[0027] Also, in this embodiment, as shown in FIG. 4(b), the nozzle cover 103 and the nozzle plate 10 are also adhered to each other by the conductive adhesive 302. As a result, in this embodiment, the current due to static electricity can also be directly discharged from the nozzle plate 10 to the nozzle cover 103 through the conductive adhesive 302.

[0028] However, the current that can be directly discharged from the nozzle plate 10 to the nozzle cover 103 through the conductive adhesive 302 is the current input to the region near the peripheral edge of the nozzle plate 10 close to the nozzle cover 103 and the conductive adhesive 302. Therefore, for example, as in Comparative Example 4 shown in FIG. 7, even if the nozzle cover 103 and the nozzle plate 10 are adhered to each other by the conductive adhesive 302, a configuration in which the conductive metal film 26 is not interposed between the nozzle plate 10 and the flow path substrate 20 is insufficient. That is, in such a configuration, for example, the current input to the region of the nozzle plate 10 away from the nozzle cover 103 and the conductive adhesive 302 (for example, the region near the center in the plane direction of the nozzle plate 10) cannot be discharged to the nozzle cover 103. Therefore, damage or malfunction of the piezoelectric element 40, the driver IC 91, etc. cannot be suppressed.

[0029] In contrast, according to the present embodiment, the current input to the region of the nozzle plate 10 away from the nozzle cover 103 and the conductive adhesive 302 (for example, the region near the center in the plane direction of the nozzle plate 10, etc.) can be discharged to the nozzle cover 103 through the metal film 26. Therefore, no matter which region of the nozzle plate 10 the current due to static electricity is input to, the current can be discharged to the nozzle cover 103, and damage or malfunction of the piezoelectric element 40, the driver IC 91, etc. can be suppressed.

[0030] However, since the metal film 26 of the present embodiment is formed on the surface of the flow path substrate 20 on the nozzle plate 10 side, it cannot be provided in the region where the piezoelectric element 40 is formed (the region where the pressure chamber 21 is formed). Therefore, the metal film 26 is formed in a region deviated from the region where the piezoelectric element 40 is formed in the plane direction of the nozzle plate.

[0031] Also, the metal film 26 of the present embodiment is provided at a position that does not come into contact with the ink (liquid) inside the liquid ejection head. Therefore, there is no requirement for ink resistance (liquid resistance), and no problems occur due to the metal film 26 coming into contact with the liquid, so the degree of freedom in material selection is high.

[0032] Further, in the present embodiment, since the gap between the nozzle cover 103 and the ejection surface 10a of the nozzle plate 10 is sealed with an adhesive, the adhesive is required to have a sealing function. In terms of the sealing function, generally, the conductive adhesive 302 often has lower sealing properties than insulating adhesives such as epoxy-based adhesives. Therefore, it is not preferable to use only the conductive adhesive 302 for all of the adhesive that seals the gap between the nozzle cover 103 and the ejection surface 10a of the nozzle plate 10. Instead, it is preferable to use only a part of it as the conductive adhesive 302 and the rest as the insulating adhesive 301.

[0033] For example, only a partial circumferential portion of the peripheral edge of the ejection surface 10a of the nozzle plate 10 may be adhered with the conductive adhesive 302, and the remaining portion may be adhered with the insulating adhesive 301. Alternatively, as shown in FIG. 4(b), an outer portion (a region away from the ejection surface 10a) of the peripheral edge (joint surface 10b) of the ejection surface 10a of the nozzle plate 10 may be adhered with the conductive adhesive 302, and an inner portion (a region closer to the ejection surface 10a) may be adhered with the insulating adhesive 301. In this case, while the entire circumference of the peripheral edge of the ejection surface 10a of the nozzle plate 10 is adhered with the highly sealing insulating adhesive 301, the space between the metal film 26 and the nozzle cover 103 can be made conductive by the conductive adhesive 302.

[0034] Also, the configuration of the conduction path in the present embodiment is not limited to the above-described configuration as long as the metal film 26 and the nozzle cover 103 can be made conductive in the outer region of the nozzle plate 10 (the region outward in the plane direction of the nozzle plate 10). For example, as in the modified example shown in FIG. 8, a configuration may be adopted in which an opening 26a, which is a through-hole communicating with the opening 25a formed in the opening 25a of the liquid contact film 25, is formed in the portion of the metal film 26 in the outer region of the nozzle plate 10.

[0035] Next, another example of the apparatus for ejecting a liquid according to the present invention will be described with reference to FIGS. 9 and 10. FIG. 9 is a plan explanatory view of the main part of the apparatus, and FIG. 10 is a side explanatory view of the main part of the apparatus. This apparatus is a serial type apparatus, and the carriage 403 reciprocates in the main scanning direction by the main scanning movement mechanism 493. The main scanning movement mechanism 493 includes a guide member 401, a main scanning motor 405, a timing belt 408, and the like. The guide member 401 is bridged between the left and right side plates 491A and 491B and holds the carriage 403 movably. Then, by the main scanning motor 405, the carriage 403 is reciprocated in the main scanning direction via the timing belt 408 bridged between the drive pulley 406 and the driven pulley 407.

[0036] This carriage 403 is equipped with a liquid ejection unit 440 that integrates the head module 404 and the head tank 441 according to the present invention. The head module 404 of the liquid ejection unit 440 includes, for example, a recording unit that ejects liquids of various colors such as yellow (Y), cyan (C), magenta (M), and black (K).

[0037] A supply mechanism 494 for supplying the liquid stored outside the head module 404 to the head module 404 supplies the liquid stored in the liquid cartridge 450 to the head tank 441.

[0038] The supply mechanism 494 is composed of a cartridge holder 451 that is a filling part for mounting the liquid cartridge 450, a tube 456, a liquid feeding unit 452 including a liquid feeding pump, and the like. The liquid cartridge 450 is detachably mounted on the cartridge holder 451. The liquid in the liquid cartridge 450 is fed to the head tank 441 by the liquid feeding unit 452 via the tube 456.

[0039] This apparatus is provided with a conveyance mechanism 495 for conveying the paper 410. The conveyance mechanism 495 includes a conveyance belt 412 that is a conveyance means and a sub-scanning motor 416 for driving the conveyance belt 412.

[0040] The conveyance belt 412 adsorbs the paper 410 and conveys it to a position facing the head module 404. This conveyance belt 412 is an endless belt and is stretched between a conveyance roller 413 and a tension roller 414. The adsorption can be performed by electrostatic adsorption or air suction.

[0041] Then, the conveyance belt 412 moves circularly in the sub-scanning direction when the conveyance roller 413 is rotationally driven by the sub-scanning motor 416 via a timing belt 417 and a timing pulley 418.

[0042] Further, on one side of the carriage 403 in the main scanning direction, a maintenance and recovery mechanism 420 for maintaining and recovering the head module 404 is arranged on the side of the conveyance belt 412.

[0043] The maintenance and recovery mechanism 420 is composed of, for example, a cap member 421 that caps the ejection surface (the surface on which the nozzles are formed) of the head module 404, a wiper member 422 that wipes the ejection surface, and the like.

[0044] The main scanning movement mechanism 493, the supply mechanism 494, the maintenance and recovery mechanism 420, and the conveyance mechanism 495 are attached to a housing including side plates 491A and 491B and a back plate 491C.

[0045] In this apparatus configured as described above, the paper 410 is fed onto the conveyance belt 412 and adsorbed, and the paper 410 is conveyed in the sub-scanning direction by the circumferential movement of the conveyance belt 412.

[0046] Therefore, while moving the carriage 403 in the main scanning direction, the head module 404 is driven according to the image signal, so that liquid is ejected onto the stationary paper 410 to form an image.

[0047] In this way, since this apparatus is provided with the liquid ejection head according to the present invention, a high-quality image can be stably formed.

[0048] Next, another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 11. FIG. 11 is an explanatory plan view of the main part of the same unit.

[0049] This liquid ejection unit is composed of a housing portion formed by side plates 491A and 491B and a back plate 491C, a main scanning movement mechanism 493, a carriage 403, and a head module 404 among the members constituting the apparatus for ejecting the liquid.

[0050] In addition, a liquid ejection unit can be configured by further attaching at least one of the above-described maintenance and recovery mechanism 420 and supply mechanism 494 to, for example, the side plate 491B of this liquid ejection unit.

[0051] Next, another example of the liquid ejection unit according to the present invention will be described with reference to FIG. 12. FIG. 12 is a front explanatory view of the unit.

[0052] This liquid ejection unit is composed of a head module 404 to which a flow path component 444 is attached and a tube 456 connected to the flow path component 444.

[0053] Note that the flow path component 444 is disposed inside the cover 442. Instead of the flow path component 444, a head tank 441 can also be included. Further, a connector 443 for making an electrical connection with the head module 404 is provided above the flow path component 444.

[0054] In the present application, the "device for ejecting a liquid" is a device that includes a liquid ejection head, a liquid ejection head device (head module), or a liquid ejection unit, and drives the liquid ejection head to eject a liquid. The device for ejecting a liquid includes not only a device capable of ejecting a liquid onto an object to which the liquid can adhere, but also a device capable of ejecting a liquid into the air or into a liquid.

[0055] This "device for ejecting a liquid" can also include means related to feeding, transporting, and paper discharging of an object to which a liquid can adhere, as well as a pretreatment device, a post-treatment device, and the like.

[0056] For example, as the "device for ejecting a liquid", there are an image forming device that ejects ink to form an image on a sheet, and a three-dimensional modeling device (three-dimensional shaping device) that ejects a modeling liquid onto a powder layer formed by laminating powders in order to model a three-dimensional object (three-dimensional shaped object).

[0057] In addition, the "device for discharging liquid" is not limited to those in which significant images such as characters and figures are visualized by the discharged liquid. For example, those that form patterns or the like that have no meaning in themselves, and those that create three-dimensional images are also included.

[0058] The "object to which liquid can adhere" means an object to which liquid can adhere at least temporarily, such as an object to which liquid adheres and adheres firmly, or an object to which liquid adheres and penetrates. Specific examples include recording materials such as paper, recording paper, recording sheets, films, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and media such as test cells, and all objects to which liquid adheres are included unless otherwise specifically limited.

[0059] The material of the "object to which liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and floor materials, textile for clothing, etc., as long as liquid can adhere even temporarily.

[0060] In addition, "liquid" includes ink, treatment liquid, DNA sample, resist, pattern material, binder, shaping liquid, or solutions and dispersions containing amino acids, proteins, calcium, etc.

[0061] In addition, as the "device for discharging liquid", there is a device in which a liquid discharge head and an object to which liquid can adhere move relative to each other, but it is not limited to this. Specific examples include serial type devices that move the liquid discharge head and line type devices that do not move the liquid discharge head.

[0062] In addition, other examples of the "device for discharging liquid" include a treatment liquid coating device that discharges a treatment liquid onto paper for the purpose of modifying the surface of the paper, and an injection granulation device that injects a composition liquid in which raw materials are dispersed in a solution through a nozzle to granulate fine particles of the raw materials.

[0063] In addition, the "device for discharging a liquid" according to the present invention also includes a manufacturing device for electrodes and electrochemical elements. Hereinafter, the manufacturing device for electrodes will be described.

[0064] FIG. 13 is a schematic diagram showing an example of a manufacturing device for an electrode according to an embodiment of the present invention. The manufacturing device for an electrode is a device that manufactures an electrode including a layer having an electrode material by discharging a liquid composition using a head module 100 which is a liquid discharge head device.

[0065] The discharging means included in the manufacturing device for an electrode shown in FIG. 13 is the head module 100 according to the above-described embodiments (including modified examples). When the liquid composition is discharged from the liquid discharge head 1 included in the head module 100, the liquid composition is applied onto the object, and a liquid composition layer is formed. The object (hereinafter, may be referred to as the "discharge object") is not particularly limited as long as it is an object on which a layer containing an electrode material is formed, and can be appropriately selected according to the purpose. For example, examples of the object include an electrode substrate (current collector), an active material layer, and a layer containing a solid electrode material. Further, the object may be an electrode mixture layer containing an active material on an electrode substrate (current collector). Further, as long as the discharging means and the discharging process can form a layer having an electrode material on the discharge object, the means and the process for forming a layer having an electrode material by directly discharging the liquid composition may be used. Further, the discharging means and the discharging process may be means and a process for forming a layer having an electrode material by indirectly discharging the liquid composition.

[0066] There are no particular restrictions on other configurations included in the manufacturing device for the electrode mixture layer, and they can be appropriately selected according to the purpose. Further, there are no particular restrictions on other steps included in the manufacturing method for the electrode mixture layer, and they can be appropriately selected according to the purpose. For example, examples of the configurations and steps included in the manufacturing device and the manufacturing method for the electrode mixture layer include a heating means and a heating step.

[0067] The heating means included in the manufacturing apparatus for the electrode composite material layer is a means for heating the liquid composition discharged by the discharging means. Further, the heating step included in the method for manufacturing the electrode composite material layer is a step of heating the liquid composition discharged in the discharging step. By heating the liquid composition, the liquid composition layer can be dried.

[0068] Here, as an example of the manufacturing apparatus for an electrode, a manufacturing apparatus for an electrode that forms an electrode composite material layer containing an active material on an electrode substrate (current collector) will be described. As shown in FIG. 13, the manufacturing apparatus for an electrode includes a discharging process section 110 that includes a process of applying a liquid composition onto a printing substrate 704 having a discharge object to form a liquid composition layer, and a heating process section 130 that includes a heating process of heating the liquid composition layer to obtain an electrode composite material layer.

[0069] The manufacturing apparatus for an electrode includes a conveyance section 705 that conveys the printing substrate 704. The conveyance section 705 conveys the printing substrate 704 at a preset speed in the order of the discharging process section 110 and the heating process section 130. As a method for manufacturing the printing substrate 704 having a discharge object such as an active material layer, there are no particular limitations, and known methods can be appropriately selected. The discharging process section 110 includes a head module 100 that realizes an application process of applying a liquid composition onto the printing substrate 704. Further, the discharging process section 110 includes a storage container 111 that stores the liquid composition 707, and a supply tube 112 that supplies the liquid composition 707 stored in the storage container 111 to the head module 100.

[0070] In the discharging process section 110, the liquid composition 707 is discharged from the liquid discharge head 1 of the head module 100, the liquid composition 707 is applied onto the printing substrate 704, and a liquid composition layer is formed in a thin film shape. Note that the storage container 111 may be configured to be integrated with the manufacturing apparatus for the electrode composite material layer, or may be configured to be removable from the manufacturing apparatus for the electrode composite material layer. Further, the storage container 111 may be a storage container integrated with the manufacturing apparatus for the electrode composite material layer, or a container used for adding to a storage container that is removable from the manufacturing apparatus for the electrode composite material layer.

[0071] The storage container 111 and the supply tube 112 can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0072] In the heating engineering section 130, a solvent removal process is performed to heat and remove the solvent remaining in the liquid composition layer. Specifically, the solvent remaining in the liquid composition layer is heated and dried by the heating device 703 of the heating engineering section 130, so that the solvent is removed from the liquid composition layer. Thereby, the electrode mixture layer is formed. Further, the solvent removal process in the heating engineering section 130 may be performed under reduced pressure.

[0073] The heating device 703 is not particularly limited and can be appropriately selected according to the purpose. For example, examples of the heating device 703 include substrate heating, an IR heater, a hot air heater, etc. Further, the heating device 703 may be a combination of at least two of substrate heating, an IR heater, and a hot air heater. Also, regarding the heating temperature and heating time, they can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the formed film thickness.

[0074] By using the electrode manufacturing apparatus according to the embodiment of the present invention, the liquid composition can be discharged to the target position of the discharge object. The electrode mixture layer can be suitably used, for example, as a part of the configuration of an electrochemical element. The configuration other than the electrode mixture layer in the electrochemical element is not particularly limited, and known ones can be appropriately selected. For example, examples of the configuration other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, etc.

[0075] The "liquid discharge unit" is an integrated unit of functional parts and mechanisms in a liquid discharge head and is an aggregate of parts related to liquid discharge. For example, the "liquid discharge unit" includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism with a liquid discharge head.

[0076] Here, the term "integrated" includes, for example, cases where the liquid ejection head, functional components, and mechanisms are fixed to each other by fastening, adhesion, engagement, etc., and cases where one is held movably with respect to the other. Also, the liquid ejection head, functional components, and mechanisms may be configured to be detachable from each other.

[0077] For example, as a liquid ejection unit, there is one in which a liquid ejection head and a head tank are integrated, such as the liquid ejection unit 440 shown in FIG. 10. Also, there is one in which the liquid ejection head and the head tank are integrated by being connected to each other with a tube or the like. Here, a unit including a filter can also be added between the head tank and the liquid ejection head of these liquid ejection units.

[0078] Also, as a liquid ejection unit, there is one in which a liquid ejection head and a carriage are integrated.

[0079] Also, as a liquid ejection unit, there is one in which the liquid ejection head is movably held by a guide member that forms part of a scanning movement mechanism, and the liquid ejection head and the scanning movement mechanism are integrated. Also, as shown in FIG. 11, as a liquid ejection unit, there is one in which a liquid ejection head, a carriage, and a main scanning movement mechanism are integrated.

[0080] Also, as a liquid ejection unit, there is one in which a cap member, which is part of a maintenance and recovery mechanism, is fixed to a carriage to which a liquid ejection head is attached, and the liquid ejection head, the carriage, and the maintenance and recovery mechanism are integrated.

[0081] Also, as a liquid ejection unit, as shown in FIG. 12, there is one in which a tube is connected to a liquid ejection head to which a head tank or a flow path component is attached, and the liquid ejection head and a supply mechanism are integrated.

[0082] The main scanning movement mechanism shall also include a single guide member. Also, the supply mechanism shall include a single tube and a single loading unit.

[0083] In addition, the "liquid ejection head" is not limited to a specific actuator. For example, in addition to the piezoelectric element (which may use a stacked piezoelectric element) as described in the above embodiment, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a diaphragm and a counter electrode, etc. may be used.

[0084] Also, in the terms of this application, image formation, recording, printing, imprinting, printing, shaping, etc. are all synonymous.

[0085] Finally, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. Each of these novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Such embodiments and modifications of the embodiments are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

[0086] What has been described above is an example, and each of the following aspects has a specific effect. [Aspect 1] Aspect 1 is a liquid ejection head 1 having a nozzle plate 10 in which a nozzle 11 for ejecting a liquid (for example, ink) is formed, a flow path substrate 20 in which an individual liquid chamber (for example, pressure chamber 21) communicating with the nozzle is formed, and an actuator (for example, piezoelectric element 40) that generates a driving force for ejecting the liquid in the individual liquid chamber from the nozzle, and includes a conductive shielding layer (for example, metal film 26) interposed between the flow path substrate and the nozzle plate to suppress an abnormal current (for example, a current due to static electricity) input to the nozzle plate from flowing to the actuator, and a conduction path (for example, conductive adhesive 302) that flows the abnormal current flowing into the shielding layer to a conductive nozzle cover 103 provided on the side of the liquid ejection surface (for example, ejection surface 10a) of the nozzle plate in the outer region in the surface direction of the nozzle plate. As described above, a conventional liquid ejection head forms a conductive film over the liquid ejection surface and the back surface of the nozzle plate, as well as the inner peripheral surface of the nozzle. According to this, even if an electrostatic current flows from the nozzle plate into the liquid in the individual liquid chambers, since the conductive film portions on the back surface of the nozzle plate and the conductive film portion on the inner peripheral surface of the nozzle are in contact with the liquid, the current flowing into an actuator such as a piezoelectric element flows into these conductive film portions. Then, the current flowing into these conductive film portions flows to the conductive film portion on the liquid ejection surface of the nozzle plate and is discharged to the nozzle cover that is electrically connected to this conductive film portion. However, adding a conductive film forming process for forming a conductive film over the liquid ejection surface and the back surface of the nozzle plate, as well as the inner peripheral surface of the nozzle, causes a problem of complicating the manufacturing process of the liquid ejection head. In this aspect, a conductive shielding layer is provided between the flow path substrate and the nozzle plate, and is configured to suppress an abnormal current input to the nozzle plate from flowing into the actuator. Then, the abnormal current flowing into the shielding layer is discharged to the nozzle cover through a conduction path that leads to the nozzle cover in the outer region in the plane direction of the nozzle plate. With such a configuration, the current flowing from the nozzle plate toward the flow path substrate due to static electricity flows through the conductive shielding layer to the nozzle cover before reaching the flow path substrate, so that the current flowing into the actuator is suppressed. Therefore, even if an electrostatic current flows through the nozzle plate, it is possible to suppress damage or malfunction of the actuator, or damage or malfunction of the drive unit that drives the actuator. Moreover, in this aspect, since the current flowing through the nozzle plate due to static electricity is discharged to the nozzle cover from the conduction path in the outer region in the plane direction of the nozzle plate, it is not necessary to extend and provide the conductive shielding layer intervening between the flow path substrate and the nozzle plate up to the liquid ejection surface of the nozzle plate or the inner peripheral surface of the nozzle. Since such a formation process of the shielding layer can be realized by a general layer formation process, problems such as complication of the manufacturing process of the liquid ejection head do not occur.

[0087] [Second Aspect] The second aspect is characterized in that, in the first aspect, the shielding layer is provided at a position that does not come into contact with the liquid. According to this, since there is no requirement for liquid resistance against the liquid or occurrence of problems due to the shielding layer coming into contact with the liquid, effects such as a high degree of freedom in material selection for the shielding layer can be obtained, for example.

[0088] [Third Aspect] The third aspect is characterized in that, in the first or second aspect, the shielding layer is formed in a region deviated from the region of the individual liquid chamber in the plane direction of the nozzle plate. According to this, the shielding layer can be formed while avoiding the region of the individual liquid chamber provided to open on the surface of the nozzle plate side of the flow path substrate.

[0089] [Fourth Aspect] The fourth aspect is a liquid discharge head device (for example, head module 100) having a liquid discharge head 1 and a conductive nozzle cover 103 provided on the liquid discharge surface side of the nozzle plate 10 of the liquid discharge head, and is characterized in that any one of the liquid discharge heads of the first to third aspects is used as the liquid discharge head. According to this aspect, it is possible to provide a liquid discharge head device capable of suppressing problems caused by an electric current flowing through the nozzle plate due to static electricity without complicating the manufacturing process of the liquid discharge head.

[0090] [Fifth Aspect] The fifth aspect is characterized in that, in the fourth aspect, the space between the nozzle cover and the nozzle plate is joined by a joining agent (for example, adhesives 301, 302), at least a part of the joining agent is a conductive joining agent (for example, conductive adhesive 302), and the conduction path includes the conductive joining agent. According to this, the conduction path can be formed by the joining agent that joins the space between the nozzle cover and the nozzle plate.

[0091] [Sixth Aspect] The sixth aspect is characterized in that, in the fifth aspect, the joining agent includes the conductive joining agent and an insulating joining agent (for example, insulating adhesive 301). According to this, while ensuring the sealing property between the liquid ejection surface of the nozzle plate and the nozzle cover with an insulating adhesive, it becomes possible to form the conduction path between the shielding layer and the nozzle cover with a conductive adhesive.

[0092] [Seventh Aspect] The seventh aspect is characterized in that, in the sixth aspect, the insulating adhesive is an epoxy-based adhesive. According to this, it is possible to seal between the liquid ejection surface of the nozzle plate and the nozzle cover with high sealing property.

[0093] [Eighth Aspect] In the eighth aspect, in any one of the fifth to seventh aspects, an insulating layer (for example, the liquid contact film 25) is formed between the shielding layer and the nozzle plate, through holes (for example, the opening 25a) are formed in an outer region in the surface direction of the nozzle plate in the insulating layer, and the conductive adhesive is filled in the through holes. According to this, even if an insulating layer is provided between the shielding layer and the nozzle plate in the outer region in the surface direction of the nozzle plate, it is possible to form the conduction path between the shielding layer and the nozzle cover with a conductive adhesive.

[0094] [Ninth Aspect] The ninth aspect is characterized in that, in the eighth aspect, the insulating layer is the liquid contact film 25. According to this, the liquid wettability of the insulating layer (the bonding surface on the flow path substrate side) bonded to the nozzle cover becomes high, and the overflow of the adhesive can be suppressed.

[0095] [Tenth Aspect] The tenth aspect is characterized in that, in the ninth aspect, the liquid contact film contains tantalum (Ta), silicon (Si), and oxygen (O). According to this, it is possible to obtain liquid resistance against the ejected liquid.

[0096] [Eleventh Aspect] In the 11th aspect, in any one of the 8th to 10th aspects, the shielding layer is characterized in that a through hole (opening 26a) communicating with the through hole formed in the insulating layer is formed therein. According to this, when forming the through hole in the insulating layer, a through hole may also be formed in the shielding layer, so that the process of forming the through hole in the insulating layer becomes easier.

[0097] [12th aspect] In the 12th aspect, in any one of the 8th to 11th aspects, the through hole is characterized in that it is formed by etching. According to this, the through hole in the insulating layer can be formed by general etching.

[0098] [13th aspect] The 13th aspect is a liquid discharge unit, which is characterized by including the liquid discharge head according to any one of the 1st to 3rd aspects, or the liquid discharge head device according to any one of the 4th to 12th aspects. According to this aspect, it is possible to provide a liquid discharge unit that can suppress the problem caused by the current flowing through the nozzle plate due to static electricity without complicating the manufacturing process of the liquid discharge head.

[0099] [14th aspect] The 14th aspect is a device for discharging liquid, which is characterized by including the liquid discharge head according to any one of the 1st to 3rd aspects, the liquid discharge head device according to any one of the 4th to 12th aspects, or the liquid discharge unit according to the 13th aspect. According to this aspect, it is possible to provide a device for discharging liquid that can suppress the problem caused by the current flowing through the nozzle plate due to static electricity without complicating the manufacturing process of the liquid discharge head.

Explanation of reference numerals

[0100] 1: Liquid discharge head 10: Nozzle plate 10a: Discharge surface 10b: Bonding surface 11: Nozzle 20: Flow path substrate 20a: Bonding surface 21: Pressure chamber 22: Individual supply flow path 24: Individual recovery flow path 25: Liquid contact film 25a: Opening 26: Metal film 26a: Opening 30: Diaphragm 40: Piezoelectric element 50: Intermediate flow path plate 51: Intermediate supply flow path 52: Intermediate recovery flow path 70: Common flow path member 71: Common supply flow path 72: Common recovery flow path 81: Supply port 82: Recovery port 90: Flexible wiring member 100: Head module 102: Base member 103: Nozzle cover 103a, 103b: Bonded surface 104: Heat dissipation member 105: Manifold 106: Printed circuit board 107: Module case 110: Discharge engineering part 130: Heating engineering part 300: Adhesive 301: Insulating adhesive 302: Conductive adhesive 401: Guide member 403: Carriage 404: Head module 420: Maintenance and recovery mechanism 440: Liquid discharge unit 441: Head tank 703: Heating device 704: Printing substrate 705: Conveyor part 707: Liquid composition

Prior art documents

Patent Document

[0101]

Patent Document 1

Claims

1. A nozzle plate in which a nozzle for discharging a liquid is formed, A flow path substrate in which individual liquid chambers communicating with the nozzles are formed, An actuator that generates a driving force for discharging the liquid in the individual liquid chambers from the nozzles, and a liquid discharge head having the actuator, A conductive shielding layer that is interposed between the flow path substrate and the nozzle plate and suppresses abnormal current input to the nozzle plate from flowing to the actuator, A liquid discharge head, comprising: a conduction path that causes the abnormal current flowing into the shielding layer to flow to a conductive nozzle cover provided on the liquid discharge surface side of the nozzle plate in an outer region in the surface direction of the nozzle plate.

2. The liquid discharge head according to claim 1, wherein the shielding layer is provided at a position that does not contact the liquid.

3. The liquid discharge head according to claim 1 or 2, wherein the shielding layer is formed in a region deviated from the region of the individual liquid chamber in the surface direction of the nozzle plate.

4. A liquid discharge head device, comprising: the liquid discharge head, and a conductive nozzle cover provided on the liquid discharge surface side of the nozzle plate of the liquid discharge head, wherein the liquid discharge head according to claim 1 is used as the liquid discharge head.

5. The liquid discharge head device according to claim 4, wherein the space between the nozzle cover and the nozzle plate is joined by an adhesive, at least a part of the adhesive is a conductive adhesive, and the conduction path includes the conductive adhesive.

6. The liquid discharge head device according to claim 5, wherein the adhesive includes the conductive adhesive and an insulating adhesive.

7. The liquid discharge head device according to claim 6, wherein the insulating adhesive is an epoxy-based adhesive.

8. The liquid discharge head device according to any one of claims 5 to 7, wherein an insulating layer is formed between the shielding layer and the nozzle plate, a through hole is formed in an outer region in the surface direction of the nozzle plate in the insulating layer, and the conductive adhesive is filled in the through hole.

9. The liquid discharge head device according to claim 8, wherein the insulating layer is a liquid contact film.

10. In the liquid discharge head device according to claim 9, the liquid contact film contains tantalum (Ta), silicon (Si), and oxygen (O), and the liquid discharge head device is characterized by this.

11. In the liquid discharge head device according to claim 8, the shielding layer is formed with a through hole communicating with the through hole formed in the insulating layer, and the liquid discharge head device is characterized by this.

12. In the liquid discharge head device according to claim 8, the through hole is formed by etching, and the liquid discharge head device is characterized by this.

13. A liquid discharge unit including the liquid discharge head according to claim 1 or the liquid discharge head device according to claim 4.

14. An apparatus for discharging a liquid, comprising the liquid discharge head according to claim 1, the liquid discharge head device according to claim 4, or the liquid discharge unit according to claim 13.

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