Patent ID: 12187047

DESCRIPTION OF EXEMPLARY EMBODIMENTS

With reference to the accompanying drawings, some preferred embodiments of the present disclosure will now be described. The dimensions or scales of parts illustrated in the drawings may be different from actual dimensions or scales, and some parts may be schematically illustrated for easier understanding. The scope of the present disclosure shall not be construed to be limited to these specific examples unless and except where the description below contains an explicit mention of limiting the present disclosure.

The description below is given with reference to X, Y, and Z axes intersecting with one another. One direction along the X axis will be referred to as the X1 direction. The direction that is the opposite of the X1 direction will be referred to as the X2 direction. Similarly, directions that are the opposite of each other along the Y axis will be referred to as the Y1 direction and the Y2 direction. Directions that are the opposite of each other along the Z axis will be referred to as the Z1 direction and the Z2 direction.

Typically, the Z axis is a vertical axis, and the Z2 direction corresponds to a vertically downward direction. However, the Z axis does not necessarily have to be a vertical axis. The Z axis may be inclined with respect to the vertical axis. The X, Y, and Z axes are typically orthogonal to one another, but are not limited thereto. It is sufficient as long as the X, Y, and Z axes intersect with one another within an angular range of, for example, 80° or greater and 100° or less.

1. FIRST EMBODIMENT

1-1. Liquid Ejecting Apparatus100

FIG.1is a schematic diagram that illustrates an example of the configuration of a liquid ejecting apparatus100according to a first embodiment. The liquid ejecting apparatus100is an ink-jet-type printing apparatus that ejects droplets of ink, which is an example of “liquid”, onto a medium101. The liquid ejecting apparatus100according to the present embodiment is a so-called line-type printing apparatus in which plural nozzles configured to eject ink are provided throughout the entire width of the medium101. A typical example of the medium101is printing paper. The medium101is not limited to printing paper. The medium12may be a print target made of any material such as, for example, a resin film or a cloth.

As illustrated inFIG.1, a liquid container102that contains ink is attached to the liquid ejecting apparatus100. Some specific examples of the liquid container102are: a cartridge that can be detachably attached to the liquid ejecting apparatus100, a bag-type ink pack made of a flexible film material, an ink tank which can be refilled with ink, etc. Any type of ink may be contained in the liquid container102.

The liquid container102according to the present embodiment includes a first liquid container and a second liquid container, though not illustrated. The liquid container102contains ink that is to be supplied to a liquid ejecting head10, which will be described later. The first liquid container contains first ink. The second liquid container contains second ink, the type of which is different from the type of the first ink. For example, the color of the first ink and the color of the second ink are different from each other. The first ink and the second ink may be the same type of ink. The composition of ink is not specifically limited. For example, the composition of any of water-based ink in which a colorant such as dye or pigment is dissolved in a water-based dissolvent, ultraviolet ray curing ink, solvent-based ink may be employed.

The solvent-based ink is ink in which the main component of the solvent is an organic solvent, and is also referred to as solvent ink or non-water-based ink. The solvent-based ink is ink containing any one or more of glycol ethers, glycol ether esters, dibasic acid esters, ester-based solvents, hydrocarbon-based solvents, and alcohol-based solvents.

Examples of the glycol ether-based solvent include alkylene glycol monoether, alkylene glycol diether, and the like.

Examples of the alkylene glycol monoether include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monobenzyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monobutyl ether, pentaethylene glycol monomethyl ether, pentaethylene glycol monoethyl ether, pentaethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, and the like.

Examples of the alkylene glycol diether include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dibutyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dibutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, and the like.

Examples of glycol ether esters include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dimethylene glycol monomethyl ether acetate, dimethylene glycol monoethyl ether acetate, dimethylene glycol monopropyl ether acetate, dimethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, dipropylene glycol monopropyl ether acetate, dipropylene glycol monobutyl ether acetate, trimethylene glycol monomethyl ether acetate, trimethylene glycol monoethyl ether acetate, trimethylene glycol monopropyl ether acetate, trimethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monopropyl ether acetate, triethylene glycol monobutyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monopropyl ether acetate, tripropylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-1-butyl acetate, and the like.

Examples of dibasic acid esters include monoesters and diesters of dicarboxylic acids (for example, aliphatic dicarboxylic acids such as glutaric acid, adipic acid, and succinic acid). Specifically, dimethyl-2-methylglutarate and the like can be mentioned.

Examples of the ester-based solvent include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, isopentyl acetate, sec-butyl acetate, amyl acetate, methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate, methyl caprylate, methyl laurate, isopropyl laurate, isopropyl myristate, isopropyl palmitate, isooctyl palmitate, isostearyl palmitate, methyl oleate, ethyl oleate, isopropyl oleate, butyl oleate, methyl linoleate, isobutyl linoleate, ethyl linoleate, isopropyl isostearate, soybean oil methyl, soybean oil isobutyl, tall oil methyl, tall oil isobutyl, diisopropyl adipate, diisopropyl sebacate, diethyl sebacate, propylene glycol monocaprate, tris(2-ethylhexanoic acid) trimethylolpropane, tris(2-ethylhexanoic acid) glyceryl, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and the like.

Examples of hydrocarbon-based solvents include aliphatic hydrocarbons (for example, paraffin and isoparaffin), alicyclic hydrocarbons (for example, cyclohexane, cyclooctane, and cyclodecane), aromatic hydrocarbons (for example, benzene, toluene, xylene, naphthalene, and tetralin), and the like. As such a hydrocarbon-based solvent, a commercially available product may be used, and examples thereof include aliphatic hydrocarbons or alicyclic hydrocarbons such as IP Solvent 1016, IP Solvent 1620, IP Clean LX (all above are trade names manufactured by Idemitsu Kosan Co., Ltd.), Isopar G, Isopar L, Isopar H, Isopar M, Exxsol D40, Exxsol D80, Exxsol D100, Exxsol D130, Exxsol D140 (all above are trade names manufactured by Exxon Corporation), NS Clean 100, NS Clean 110, NS Clean 200, NS Clean 220 (all above are trade names of JXTG Energy Co., Ltd.), Naphthesol 160, Naphthesol 200, Naphthesol 220 (all above are trade names of JXTG Energy Co., Ltd.), and aromatic hydrocarbons such as Solvesso 200 (trade name manufactured by Exxon Corporation).

Examples of alcohol-based solvents include methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, isoamyl alcohol, 3-methyl-2-butanol, 3-methoxy-3-methyl-1-butanol, 4-methyl-2-pentanol, allyl alcohol, 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, isomyristyl alcohol, isopalmityl alcohol, isostearyl alcohol, oleyl alcohol, and the like.

The aforementioned ultraviolet ray curing ink is UV ink containing, for example, a monomer, an oligomer, or the like that undergoes a polymerization reaction and cures when irradiated with ultraviolet rays. Examples of the ultraviolet ray curing ink include ink whose composition includes any of (meth)acrylates, (meth)acrylamides, and N-vinyl compounds as a polymerizable compound.

Examples of monofunctional (meth)acrylates include hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, tert-octyl (meth)acrylate, isoamyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-n-butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, butoxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate, 4-bromobutyl (meth)acrylate, cyanoethyl (meth)acrylate, benzyl (meth)acrylate, butoxymethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, alkoxymethyl (meth)acrylate, alkoxyethyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-(2-butoxyethoxy)ethyl (meth)acrylate, 2,2,2-tetrafluoroethyl (meth)acrylate, 1H,1H,2H,2H-perfluorodecyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4 5-tetramethylphenyl (meth)acrylate, 4-chlorophenyl (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, glycidyloxybutyl (meth)acrylate, glycidyloxyethyl (meth)acrylate, glycidyloxypropyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hydroxyalkyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, diethylaminopropyl (meth)acrylate, trimethoxysilylpropyl (meth) acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, trimethoxysilylpropyl (meth)acrylate, trimethylsilylpropyl (meth)acrylate, polyethylene oxide monomethyl ether (meth)acrylate, oligoethylene oxide monomethyl ether (meth)acrylate, polyethylene oxide (meth)acrylate, oligoethylene oxide (meth)acrylate, oligoethylene oxide monoalkyl ether (meth)acrylate, polyethylene oxide monoalkyl ether (meth)acrylate, dipropylene glycol (meth)acrylate, polypropylene oxide monoalkyl ether (meth)acrylate, oligopropylene oxide monoalkyl ether (meth)acrylate, 2-methacryloyloxyethyl succinic acid, 2-methacryloyloxyhexahydrophthalic acid, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, butoxydiethylene glycol (meth)acrylate, trifluoroethyl (meth)acrylate, perfluorooctylethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, EO-modified phenol (meth)acrylate, EO-modified cresol (meth)acrylate, EO-modified nonylphenol (meth)acrylate, PO-modified nonylphenol (meth)acrylate, and EO-modified 2-ethylhexyl (meth)acrylate.

Examples of polyfunctional (meth)acrylates include bifunctional (meth)acrylates such as 1,6-hexanediol di(meth)acrylate and 1,10-decanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate (DPGD(M)A), tripropylene glycol di(meth)acrylate (TPGD(M)A), 2,4-dimethyl-1,5-pentanediol di(meth)acrylate, butylethylpropanediol di(meth)acrylate, ethoxylated cyclohexanemethanol di(meth)acrylate, triethylene glycol di(meth)acrylate (TEGD(M)A), polyethylene glycol di(meth)acrylate, oligoethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, 2-ethyl-2-butyl-butanediol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate, EO-modified bisphenol A di(meth)acrylate, bisphenol F polyethoxy di(meth)acrylate, polypropylene glycol di(meth)acrylate, oligopropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 2-ethyl-2-butyl-propanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, propoxy ethoxylated bisphenol A di(meth)acrylate, and tricyclodecane di(meth)acrylate.

Examples of polyfunctional (meth)acrylates further include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, alkylene oxide-modified tri(meth)acrylate of trimethylolpropane, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, trimethylolpropane tri((meth)acryloyloxypropyl) ether, isocyanuric acid alkylene oxide modified tri(meth)acrylate, dipentaerythritol propionate tri(meth)acrylate, tri((meth)acryloyloxyethyl)isocyanurate, hydroxypivalaldehyde-modified dimethylolpropane tri(meth)acrylate, sorbitol tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, ethoxylated glycerin tri(meth)acrylate: above trifunctional, pentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate propionate, ethoxylated pentaerythritol tetra(meth)acrylate: above tetrafunctional, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate: above pentafunctional, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene alkylene oxide-modified hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate: above hexafunctional, and the like.

Examples of (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-n-butyl(meth)acrylamide, N-t-butyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-methylol(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and (meth)acryloylmorpholine.

The N-vinyl compound has a structure in which a vinyl group is bonded to nitrogen (>N—CH═CH2). Specific examples of the N-vinyl compound include N-vinylformamide, N-vinylcarbazole, N-vinylindole, N-vinylpyrrole, N-vinylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, and their derivatives. Among them, N-vinylcaprolactam is particularly preferable.

The liquid ejecting apparatus100includes a control unit20, a transport mechanism30, a liquid ejecting module40, and a circulation mechanism50. The control unit20controls the operation of each component of the liquid ejecting apparatus100. The control unit20includes a processing circuit, for example, a CPU (central processing unit) or an FPGA (field programmable gate array), and a storage circuit such as a semiconductor memory. Various kinds of program and data are stored in the storage circuit. The processing circuit realizes various kinds of control by running the program and using the data.

The transport mechanism30transports the medium101in a direction DM in accordance with control by the control unit20. The direction DM according to the present embodiment is the Y2 direction. In the example illustrated inFIG.1, the transport mechanism30includes a transport roller that is elongated along the X axis and a motor that rotates the transport roller. The configuration of the transport mechanism30is not limited to the illustrated example in which the transport roller is used. For example, a drum that transports the medium101in a state in which the medium101is attracted to the circumferential surface of the drum due to an electrostatic force, etc., or an endless belt, may be used instead.

Ink is supplied from the liquid container102to the liquid ejecting module40via the circulation mechanism50. In accordance with control by the control unit20, the liquid ejecting module40ejects the supplied ink from each of a plurality of nozzles toward the medium101in the Z2 direction. The liquid ejecting module40is a line head that includes a plurality of liquid ejecting heads10arranged such that the nozzles are distributed throughout the entire width of the medium101in the direction of the X axis. That is, these liquid ejecting heads10constitute a line head that is elongated in the direction in which the X axis extends. Concurrently with the transportation of the medium101by the transport mechanism30, ink is ejected from the plurality of liquid ejecting heads10. As a result of this concurrent operation, an image is formed of ink on the surface of the medium101. The liquid ejecting module40may be a non-multi-head-type line head that is elongated in the direction in which the X axis extends. That is, the liquid ejecting module40may include only a single liquid ejecting head10arranged such that the nozzles are distributed throughout the entire width of the medium101in the direction in which the X axis extends.

In the example illustrated inFIG.1, the liquid container102is connected indirectly to the liquid ejecting module40, with the circulation mechanism50provided therebetween. The circulation mechanism50is a mechanism that supplies ink to the liquid ejecting module40and collects ink discharged from the liquid ejecting module40for the purpose of supplying the collected ink to the liquid ejecting module40again. The circulation mechanism50includes, for example, a sub tank that contains ink, a supply flow passage through which ink is supplied from the sub tank to the liquid ejecting module40, a collection flow passage through which ink is collected into the sub tank from the liquid ejecting module40, and a pump for causing ink to flow. These components are provided individually for each of the first ink and the second ink mentioned above. The above operation of the circulation mechanism50makes it possible to suppress an increase in the viscosity of ink and reduce the stay of air bubbles in ink.

The liquid ejecting apparatus100may include a maintenance mechanism that is used for maintenance operation of the liquid ejecting module40. The maintenance operation includes, for example, flushing operation and cleaning operation. The flushing operation is operation of forcibly ejecting ink that does not directly contribute to the forming of an image from a plurality of nozzles. The cleaning operation is operation of forcibly discharging ink that is present inside the liquid ejecting module40from a plurality of nozzles either by applying pressure from the upstream relative to the liquid ejecting module40or by applying a suction force from the downstream relative to the liquid ejecting module40. The maintenance mechanism includes a flushing box that receives ink ejected from each nozzle N when the flushing operation is performed and a cap for hermetically sealing the plurality of nozzles N when the cleaning operation is performed.

As described above, the liquid ejecting apparatus100includes the liquid ejecting head10, the liquid container102that contains ink to be supplied to the liquid ejecting head10, and the transport mechanism30that transports the medium101that receives ink ejected from the liquid ejecting head10.

1-2. Liquid Ejecting Module40

FIG.2is a perspective view of the liquid ejecting module40that includes the liquid ejecting heads10according to the first embodiment. As illustrated inFIG.2, the liquid ejecting module40includes a support41and the plurality of liquid ejecting heads10. The support41is a member that supports the plurality of liquid ejecting heads10. In the example illustrated inFIG.2, the support41is a plate-like member made of metal, etc. The support41has a mount hole41afor mounting the plurality of liquid ejecting heads10. The plurality of liquid ejecting heads10is mounted in the mount hole41ain a state of being arranged in a row in the direction along the X axis. Each of the plurality of liquid ejecting heads10is fastened to the support41by screws, etc. InFIG.2, two liquid ejecting heads10are illustrated as a representative example. The liquid ejecting module40may include any number of the liquid ejecting heads10. The shape, etc. of the support41is also not limited to the example illustrated inFIG.2. The support41may have any shape, etc.

1-3. Liquid Ejecting Head10

FIG.3is an exploded perspective view of the liquid ejecting head10illustrated inFIG.2. As illustrated inFIG.3, the liquid ejecting head10includes a flow passage structure body11, a wiring board12, a holder13, a plurality of head bodies14_1,14_2,14_3,14_4,14_5, and14_6, a fixing plate15, and a base16. These components are disposed in the following order as viewed toward Z2: the base16, the flow passage structure body11, the wiring board12, the holder13, the plurality of head bodies14_1,14_2,14_3,14_4,14_5, and14_6, and, finally, the fixing plate15. The components of the liquid ejecting head10will be described below sequentially. In the description below, each individual one of the plurality of head bodies14_1,14_2,14_3,14_4,14_5, and14_6is sometimes simply referred to as “head body14”.

The flow passage structure body11is a structure body inside which flow passages for flow of ink between the circulation mechanism50and the plurality of head bodies14are provided. As illustrated inFIG.3, the flow passage structure body11includes a flow passage member1and connection pipes11a,11b,11c,and11d.A supply flow passage for supplying the first ink to the plurality of head bodies14, a supply flow passage for supplying the second ink to the plurality of head bodies14, a discharge flow passage for discharging the first ink from the plurality of head bodies14, and a discharge flow passage for discharging the second ink from the plurality of head bodies14are provided inside the flow passage member1, though not illustrated inFIG.3. A filter for catching a foreign object, etc. “en route” is provided on a path of each supply flow passage. The internal structure of the flow passage member1will be described in detail later.

The flow passage member1has layers21,22, and23. They constitute a stack of layers in this order as viewed toward Z2. Flow passages such as supply flow passages and discharge flow passages are formed by providing grooves or holes, etc. in these layers. Each of the layers21,22, and23is, for example, made of a resin material and is formed by injection molding. The layers21,22, and23are bonded to each other with an adhesive, for example. The thickness of the layers21,22, and23along the Z axis may be the same as one another or different from one another.

The flow passage member1has a plate-like shape with a plane perpendicular to the Z axis. In the example illustrated inFIG.3, the flow passage member1has a hole1a,into which a connector12cdescribed later is inserted. The flow passage member1described above has a surface facing in the Z1 direction, and the connection pipes11a,11b,11c,and11dprotrude from this surface.

The connection pipe11ais a pipe that constitutes a flow passage for supplying the first ink to the flow passage member1. The connection pipe11bis a pipe that constitutes a flow passage for supplying the second ink to the flow passage member1. The connection pipe11cis a pipe that constitutes a flow passage for discharging the first ink from the flow passage member1. The connection pipe11dis a pipe that constitutes a flow passage for discharging the second ink from the flow passage member1.

The wiring board12is a mount component for electric connection between the plurality of head bodies14and a congregated board16bdescribed later. For example, the wiring board12is a rigid wiring board. The wiring board12is disposed between the flow passage structure body11and the holder13. The wiring board12has a surface facing the flow passage structure body11. On this surface, the connector12cis provided. The connector12cis a connection component coupled to the congregated board16bdescribed later. The wiring board12has a plurality of holes12aand a plurality of openings12b.Each of the plurality of holes12ais a hole that allows connection between the flow passage structure body11and the holder13. Each of the plurality of openings12bis a slit through which a wiring member14afor connection between the head body14and the wiring board12is inserted. The wiring board12has a surface facing in the Z1 direction, and the wiring member14ais connected to this surface. The wiring member14ais a member that includes wiring for electric connection to a drive element Ea or Eb described later. The wiring member14ais, for example, an FPC (Flexible Printed Circuit) or a COF (Chip On Film), etc.

The holder13is a structure component that houses and supports the plurality of head bodies14. The holder13is made of, for example, a resin material or a metal material, etc. The holder13has a plate-like shape with a plane perpendicular to the Z axis. The holder13has a plurality of ink holes13aand a plurality of wiring holes13b.Each of the plurality of ink holes13ais a flow-passage-structure-body-side opening in a flow passage through which ink flows between the head body14and the flow passage structure body11. Each of the plurality of wiring holes13bis a slit through which the wiring member14afor connection between the head body14and the wiring board12is inserted. The holder13has the following flow passages inside, though not illustrated: a supply flow passage through which the first ink is supplied to the head body14, a supply flow passage through which the second ink is supplied to the head body14, a circulation flow passage for allowing the first ink to flow from the head body14to a discharge flow passage CM of the flow passage structure body11, and a circulation flow passage for allowing the second ink to flow from the head body14to a discharge flow passage CM of the flow passage structure body11. In addition, a branch flow passage for distribution or gathering of ink between each ink hole13aand the plurality of head bodies14is provided inside the holder13, though not illustrated. The holder13has a surface facing in the Z2 direction, and, in this surface, a plurality of recesses for accommodating the plurality of head bodies14respectively is provided, though not illustrated.

Each of the plurality of head bodies14ejects ink. Specifically, though not illustrated inFIG.3, each of the plurality of head bodies14has a plurality of nozzles through which the first ink is ejected and a plurality of nozzles through which the second ink is ejected. These nozzles are provided in a nozzle face FN. The nozzle face FN is the surface, of each of the plurality of head bodies14, facing in the Z2 direction. The structure of the head body14will be described later.

The fixing plate15is a plate member for fixing the plurality of head bodies14to the holder13. Specifically, the fixing plate15is positioned such that the plurality of head bodies14is interposed between the holder13and the fixing plate15. Then, the fixing plate15is fixed to the holder13with an adhesive. The fixing plate15is made of, for example, a metal material, etc. The fixing plate15has a plurality of openings15afor exposure of the nozzles of the plurality of head bodies14. In the example illustrated inFIG.3, each of the plurality of openings15ais provided individually for the corresponding one of the plurality of head bodies14. The opening15amay be shared by two or more head bodies14.

The base16is a member for fixing the flow passage structure body11, the wiring board12, the holder13, the plurality of head bodies14, and the fixing plate15to the support41described earlier. The base16includes a base body16a,the congregated board16b,and a cover16c.

By being fastened to the holder13by screws, etc., the base body16aholds the flow passage structure body11and the wiring board12, which are disposed between the base16and the holder13. The base body16ais made of, for example, a resin material, etc. The base body16ahas a plate-like portion facing the flow passage member1described above. This plate-like portion has a plurality of holes16dinto which the connection pipes11a,11b,11c,and11ddescribed above are inserted. The base body16ahas a portion extending in the Z2 direction from this plate-like portion. A flange16efor being fixed to the support41described earlier is provided at the end of the portion extending in the Z2 direction.

The congregated board16bis a mount component for electric connection between the control unit20and the wiring board12described earlier. The congregated board16bis, for example, a rigid wiring board. The cover16cis a plate-like member for protecting the congregated board16band fixing the congregated board16bto the base body16a.The cover16cis made of, for example, a resin material, etc., and is fastened to the base body16aby screws, etc.

1-4. Head Body14

FIG.4is a plan view of the head body14of the liquid ejecting head10. InFIG.4, the internal structure of the head body14as viewed in the Z1 direction is schematically illustrated. As illustrated inFIG.4, the head body14includes a liquid ejecting section Qa and a liquid ejecting section Qb. The liquid ejecting section Qa includes a nozzle row La that is made up of a plurality of nozzles N configured to eject the first ink supplied from the circulation mechanism50described earlier. The liquid ejecting section Qb includes a nozzle row Lb that is made up of a plurality of nozzles N configured to eject the second ink supplied from the circulation mechanism50. The nozzles N belonging to the nozzle row La are arranged in a direction DN. The nozzles N belonging to the nozzle row Lb are also arranged in the direction DN.

The liquid ejecting section Qa includes a liquid reservoir Ra, a plurality of pressure compartments Ca, and a plurality of drive elements Ea. The liquid reservoir Ra is a common liquid chamber that is continuous throughout the plurality of nozzles N belonging to the nozzle row La. Each of the plurality of pressure compartments Ca is provided individually for the corresponding one of the plurality of nozzles N belonging to the nozzle row La. Each of the plurality of drive elements Ea is also provided individually for the corresponding one of the plurality of nozzles N belonging to the nozzle row La. The pressure compartment Ca is a space that is in communication with the nozzle N. To each of the plurality of pressure compartments Ca, the first ink is supplied from the liquid reservoir Ra to fill its space. The drive element Ea changes the pressure of the first ink inside the pressure compartment Ca. The drive element Ea is, for example, a piezoelectric element that changes the capacity of the pressure compartment Ca by deforming a wall surface of the pressure compartment Ca, or a heat generation element that produces air bubbles inside the pressure compartment Ca by heating the first ink inside the pressure compartment Ca. As a result of causing changes in the pressure of the first ink inside the pressure compartment Ca by the drive element Ea, the first ink contained inside the pressure compartment Ca is ejected from the nozzle N.

Similarly to the liquid ejecting section Qa, the liquid ejecting section Qb includes a liquid reservoir Rb, a plurality of pressure compartments Cb, and a plurality of drive elements Eb. The liquid reservoir Rb is a common liquid chamber that is continuous throughout the plurality of nozzles N belonging to the nozzle row Lb. Each of the plurality of pressure compartments Cb is provided individually for the corresponding one of the plurality of nozzles N belonging to the nozzle row Lb. Each of the plurality of drive elements Eb is also provided individually for the corresponding one of the plurality of nozzles N belonging to the nozzle row Lb. To each of the plurality of pressure compartments Cb, the second ink is supplied from the liquid reservoir Rb to fill its space. The drive element Eb is, for example, a piezoelectric element or a heat generation element mentioned above. As a result of causing changes in the pressure of the second ink inside the pressure compartment Cb by the drive element Eb, the second ink contained inside the pressure compartment Cb is ejected from the nozzle N.

As illustrated inFIG.4, an inlet Ra_in, an outlet Ra_out, an inlet Rb_in, and an outlet Rb_out are provided in the head body14. Each of the inlet Ra_in and the outlet Ra_out is in communication with the liquid reservoir Ra. Each of the inlet Rb_in and the outlet Rb_out is in communication with the liquid reservoir Rb.

In the head body14described above, the first ink that remains in the liquid reservoir Ra without being ejected from the nozzles N belonging to the nozzle row La circulates by flowing through the outlet Ra_out, the circulation flow passage for the first ink in the holder13, the discharge flow passage for the first ink in the flow passage structure body11, the sub tank for the first ink in the circulation mechanism50, the supply flow passage for the first ink in the flow passage structure body11, the supply flow passage for the first ink in the holder13, the inlet Ra_in, and the liquid reservoir Ra in this order. Similarly, the second ink that remains in the liquid reservoir Rb without being ejected from the nozzles N belonging to the nozzle row Lb circulates by flowing through the outlet Rb_out, the circulation flow passage for the second ink in the holder13, the discharge flow passage for the second ink in the flow passage structure body11, the sub tank for the second ink in the circulation mechanism50, the supply flow passage for the second ink in the flow passage structure body11, the supply flow passage for the second ink in the holder13, the inlet Rb_in, and the liquid reservoir Rb in this order.

FIG.5is a plan view of the holder13. As illustrated inFIG.5, the holder13holds six head bodies14_1to14_6. These head bodies are arranged in the X2 direction in the order of14_1,14_4,14_2,14_5,14_3,14_6. These head bodies are arranged in a staggered manner such that14_1to14_3are shifted in the Y1 direction from14_4to14_6. However, the head bodies14_1to14_6have portions overlapping with one another as viewed in the X1 direction or the X2 direction. In addition, the head bodies14_1to14_6are arranged such that the linear array direction DN of the nozzle row La and the linear array direction DN of the nozzle row Lb are parallel to each other. However, each of the head bodies14_1to14_6is arranged such that the direction DN is inclined with respect to the direction DM, which is the transportation direction of the medium101.

As described above, the liquid ejecting head10includes the flow passage member1and the nozzles N from which ink supplied from the supply flow passages is ejected.

1-5. Flow Passage Member1

FIG.6is a plan view of the flow passage structure body11. InFIG.6, an example of the internal structure of the flow passage member1as viewed in the Z2 direction is illustrated by broken lines. As illustrated inFIG.6, two supply flow passages CC, two discharge flow passages CM, and two filter chambers RF are provided inside the flow passage member1.

One of the two supply flow passages CC is a flow passage for supplying ink from the connection pipe11ato the liquid reservoir Ra of each of the plurality of head bodies14. The other of the two supply flow passages CC is a flow passage for supplying ink from the connection pipe11bto the liquid reservoir Rb of each of the plurality of head bodies14. For each of the two supply flow passages CC, an outlet CE, through which ink goes out toward the head bodies14, is provided in communication with the supply flow passage CC. The supply flow passage CC is in communication with the internal space of the connection pipe11aor11bvia the filter chamber RF. The filter chamber RF is a space inside which a filter25described later is provided. The filter chamber RF is in communication with the supply flow passage CC via a first flow passage C1and a second flow passage C2. Either the first flow passage C1or the second flow passage C2may be omitted. In this case, it is preferable to dispose the other of the first flow passage C1and the second flow passage C2on the central axis of the filter chamber RF.

One of the two discharge flow passages CM is a flow passage for discharging ink from the liquid reservoir Ra of each of the plurality of head bodies14to the connection pipe11c.The other of the two discharge flow passages CM is a flow passage for discharging ink from the liquid reservoir Rb of each of the plurality of head bodies14to the connection pipe11d.For each of the two discharge flow passages CM, an inlet CI, through which ink coming from the head bodies14enters, is provided in communication with the discharge flow passage CM.

FIG.7is a sectional view taken along the line VII-VII ofFIG.6. InFIG.7, regarding the flow passage member1, a structure corresponding to the connection pipe11ais illustrated. InFIG.7, the illustration of adhesives such as an adhesive B1, an adhesive B2, and an adhesive Ba illustrated inFIG.9, which will be described later, is omitted for easier view.

The structure corresponding to the connection pipe11ais described below as a representative example. A structure corresponding to the connection pipe11bis the same as the structure corresponding to the connection pipe11a.A structure corresponding to the connection pipe11cand a structure corresponding to the connection pipe11dare the same as the structure corresponding to the connection pipe11aexcept that a structure regarding the filter chamber RF is omitted and that the shape is different.

As illustrated inFIG.7, the flow passage member1includes a stack of layers21,22, and23in this order as viewed toward Z2. Each of the layers21,22, and23is made of thermosetting resin, metal, or ceramic. Therefore, as compared with a case where each of the layers21,22, and23is made of thermoplastic resin, it is possible to increase the liquid resistance and rigidity of the layers21,22, and23. The material of the layers21,22, and23may be the same as one another or different from one another. For example, one of the layers21,22, and23may be made of thermosetting resin, and the others may be made of metal or ceramic.

When the layer21,22, or23is made of thermosetting resin, the kind of the thermosetting resin is not specifically limited. Examples of the thermosetting resin used as the material include phenol resin, urea resin, melamine resin, epoxy resin, alkyd resin, unsaturated polyester resin, epoxy resin, diallyl phthalate resin, and the like. Any one of these kinds of the material may be used alone, or two or more of them may be used in combination in the form of a copolymer or a blend, etc. The thermosetting resin may contain, for example, a fiber base material such as glass fiber, or filler such as silica powder. Using such a fiber base material or filler makes it possible to improve the rigidity of the layer21,22, or23in comparison with a case where thermosetting resin only is used. The thermosetting resin may contain a coloring agent such as dye or pigment. Since using a coloring agent decreases the light transmittance of the thermosetting resin, it is possible to reduce the degradation of ink even if the ink is photo curable or even if the ink has low light resistance.

When the layer21,22, or23is made of metal, the kind of the metal is not specifically limited. Examples of the metal used as the material include aluminum, aluminum alloy, titanium, titanium alloy, iron, stainless steel, and the like. Any one of these kinds of the material may be used alone, or two or more of them may be used in combination in the form of a stack of layers, etc. When the layer21,22, or23is made of ceramic, the kind of the ceramic is not specifically limited. Examples of the ceramic used as the material include ceramic oxide such as alumina, silica, titania, zirconia, and the like, and ceramic nitride such as silicon nitride, aluminum nitride, titanium nitride, and the like. Any one of these kinds of the material may be used alone, or two or more of them may be used in combination in the form of a stack of layers, etc.

A recessed surface21a,an inlet21b,and a groove21care provided in the layer21. The recessed surface21ais provided in the surface, of the layer21, facing in the Z2 direction. The recessed surface21aconstitutes a part of the wall surface of the filter chamber RF. In the example illustrated inFIG.7, the recessed surface21ahas a sloped surface shape whose depth increases gradually toward the inlet21b.The inlet21bis a through hole that is open to the recessed surface21aand is in communication with the internal space of the connection pipe11a.In the example illustrated inFIG.7, the connection pipe11aand the layer21are configured integrally. Therefore, the connection pipe11ais made of a resin material, similarly to the layer21. The groove21cis provided in the surface, of the layer21, facing in the Z2 direction, along and outside the circumference of the recessed surface21a.The groove21cconstitutes a space that accommodates a part of a fixing member24, which will be described later. As another function, the groove21cis able to serve as a space where an adhesive can escape.

The connection pipe11amay be a separate part that is not integral with the layer21. In this case, the connection pipe11amay be made of metal, etc. The connection pipe11a,in this case, is fixed to the layer21with an adhesive, etc. The groove21cis not indispensable. If unnecessary, the groove21cmay be omitted.

A recess22a,a groove22b,a hole22c,and a hole22dare provided in the layer22. The recess22ais provided in the surface, of the layer22, facing in the Z1 direction. The recess22aconstitutes a space that accommodates a part of the fixing member24, which will be described later. The groove22bis provided in the surface, of the layer22, facing in the Z2 direction. The groove22bconstitutes a part of a flow passage C3in the supply flow passage CC. In the example illustrated inFIGS.6and7, the flow passage C3extends along the Y axis and has a shape that includes a portion whose area size on an X-Z plane becomes narrower toward Y2. Therefore, the groove22bhas a shape that extends along the Y axis. Each of the holes22cand22dis a through hole that is open to the recess22aand the groove22band goes through the layer22. In the example illustrated inFIG.7, the hole22cis connected to the Y2-directional end of the groove22b.The hole22dis connected to the groove22bat the Y1-directional position that is the opposite of the hole22c.

A groove23ais provided in the layer23. The groove23ais provided in the surface, of the layer23, facing in the Z1 direction. The groove23aconstitutes a part of the flow passage C3. In the example illustrated inFIG.7, the groove23ahas a shape that extends along the Y axis. In the example illustrated inFIG.7, the groove22bof the layer22and the groove23aof the layer23make up the supply flow passage CC. However, the flow passage C3may consist of one of the grooves22band23a.

In addition to the layers21,22, and23described above, as illustrated inFIG.7, the flow passage member1includes the fixing member24and the filter25, which are provided between the layer21and the layer22. In the description below, view in the direction in which the layer22and the fixing member24overlap with each other will be referred to as “plan view”.

FIG.8is a plan view of the fixing member24.FIG.9is an enlarged sectional view for explaining a fix state of the fixing member24and the filter25according to the first embodiment. With reference toFIGS.7,8, and9, the fixing member24and the filter25will now be explained.

As illustrated inFIG.7, the fixing member24is a substantially-plate-like member that fixes the filter25to at least one of the layers21and22and constitutes a part of the wall surface of the filter chamber RF. In the example illustrated inFIG.7, the fixing member24is provided in the recess22amentioned above.

As illustrated inFIG.9, the fixing member24is fixed to the layer22with an adhesive B1, which is an example of “a first adhesive”, and is fixed to the layer21with an adhesive B2, which is an example of “a second adhesive”. Various kinds of adhesive can be used as the adhesive B1and the adhesive B2as long as it has resistance to ink and as long as the fixing member24is able to be bonded to the layer21or the layer22with it. Though not specifically limited, for example, an epoxy adhesive, a silicone adhesive, a P-aminophenol adhesive, and the like can be used. Among them, an epoxy adhesive is used preferably because of its advantage of excellent liquid resistance. Various kinds of photo-curable adhesive such as a urethane adhesive may be used as the adhesive B1and the adhesive B2. In this case, either a visible-light-curing adhesive or an ultraviolet-ray-curing adhesive may be used. However, for the purpose of avoiding adverse effects of heat applied in the curing process, an ultraviolet-ray-curing adhesive is preferable.

The adhesive B1and the adhesive B2may be the same as each other or different from each other. The adhesive B1or the adhesive B2may be the same as an adhesive Ba, with which the layer21is bonded to the layer22, or different from the adhesive Ba. Any two or more of the adhesive B1, the adhesive B2, and the adhesive Ba may be integral. Either the adhesive B1or the adhesive B2may be omitted. However, using both the adhesive B1and the adhesive B2makes it possible to fix the fixing member24to the stack made up of the layers21,22, and23securely and makes it possible to reduce an unwanted clearance between the stack of these layers and the fixing member24.

As described above, the filter25is fixed to at least one of the layers21and22by means of the fixing member24. As compared with a structure in which the filter25is fixed to at least one of the layers21and22directly, this structure makes it possible to increase the freedom of choices in the material of the layer21and the material of the layer22, and, in addition, makes it possible to reduce a risk of unintended sticking of the adhesive B1or the adhesive B2to the filter25.

The fixing member24is made of a resin material and is formed by injection molding, for example. The material of the fixing member24may be the same as the material of the layer21or22or different therefrom.

The resin material of the fixing member24may be thermosetting resin or thermoplastic resin. However, whether the fixing member24is made of thermosetting resin or thermoplastic resin is determined depending on the shape, etc. of the fixing member24. The resin material of the fixing member24may contain, for example, a fiber base material such as glass fiber, or filler such as silica powder. Using such a fiber base material or filler makes it possible to improve the rigidity of the fixing member24in comparison with a case where resin only is used.

If the fixing member24is made of thermosetting resin, as compared with a case where the fixing member24is made of thermoplastic resin, it is possible to increase the rigidity and liquid resistance of the fixing member24.

The thermosetting resin used as the material of the fixing member24is not specifically limited. Examples include phenol resin, urea resin, melamine resin, epoxy resin, alkyd resin, unsaturated polyester resin, epoxy resin, diallyl phthalate resin, and the like, similarly to the layer21,22, or23described above. Any one of these kinds of the material may be used alone, or two or more of them may be used in combination in the form of a copolymer or a blend, etc.

If the fixing member24is made of thermoplastic resin, it is possible to fix the filter25to the fixing member24by welding. Therefore, using thermoplastic resin as the material of the fixing member24will be a good choice when it is difficult to form the fixing member24by insert molding with insertion of the filter25due to, for example, the shape of the fixing member24. In the present embodiment, it is difficult to form the fixing member24by insert molding with insertion of the filter25because the filter25is disposed on the outer surface of the fixing member24. Therefore, in the present embodiment, it is preferable to use thermoplastic resin as the material of the fixing member24.

The thermoplastic resin used as the material of the fixing member24is not specifically limited. Examples include polyphenylene ether resin (PPE), modified polyphenylene ether resin (m-PPE), polyethylene resin (PE), polystyrene resin (PS), polyamide resin (PA), polyphenylene sulfide (PPS), polypropylene (PP), liquid crystal polymer (LCP) and acrylonitrile butadiene styrene resin (ABS resin), vinyl chloride-vinyl acetate copolymer resin, polyvinyl chloride resin, and the like. Any one of these kinds of the material may be used alone, or two or more of them may be used in combination in the form of a copolymer or a blend, etc. Among them, for example, polyolefin-based thermoplastic resin such as polypropylene is preferably used as the thermoplastic resin because it can be used for injection molding and has excellent chemical resistance.

A recess24a,a frame portion24b,a first outlet24c,and a second outlet24dare provided in the fixing member24.

The recess24ais provided in the surface, of the fixing member24, facing in the Z1 direction. The recessed surface constitutes a part of the wall surface of the filter chamber RF. In the example illustrated inFIG.7, the recess24ahas a sloped shape whose depth increases gradually toward each of the first outlet24cand the second outlet24d.The frame portion24bis a loop-shaped wall portion formed along the contour of the recess24a.The frame portion24bconstitutes the sidewall of the filter chamber RF. More specifically, a part of the inner surface of the frame portion24bconstitutes the sidewall24iof a downstream chamber R2. The frame portion24bhas a placement surface24p,on which the filter25is to be placed, a convex portion24r,which protrudes from the placement surface24pin the Z1 direction, and a cutout portion24q.The placement surface24pis the surface, of the frame portion24b,facing in the Z1 direction. As illustrated inFIG.8, the placement surface24phas a loop shape that surrounds the recess24ain plan view. As illustrated inFIG.8, the convex portion24rhas a loop shape that surrounds the placement surface24pin plan view. The cutout portion24qis a loop-shaped cutout formed in a stepped manner at the most outer periphery of the frame portion24bby recessing, in the Z1 direction, the surface of the frame portion24bfacing in the Z2 direction.

In the example illustrated inFIG.7, the convex portion24rof the frame portion24bis inserted into the groove21cmentioned above. The fixing member24is positioned with respect to the layer21as a result of this insertion. In addition, by being put into contact with the bottom of the groove21c,the convex portion24rof the frame portion24bfulfills its function as a wall portion that prevents the adhesive B2and the adhesive Ba from sticking to the filter25. A clearance is formed between the outer surface of the frame portion24band the wall of the recess22a.This clearance is able to serve as a space into which the adhesive B1applied between the cutout portion24qand the bottom surface of the recess22a,the adhesive B2applied between the outer surface of the convex portion24rand the wall of the groove21c,and the adhesive Ba are allowed to escape. Each of the first outlet24cand the second outlet24dis a through hole that is open to the recess24aand goes through the fixing member24. The first outlet24cis connected to the hole22cmentioned above. The first outlet24cand the hole22cconstitute the first flow passage C1. The second outlet24dis connected to the hole22dmentioned above. The second outlet24dand the hole22dconstitute the second flow passage C2.

As illustrated inFIG.8, the fixing member24has flanges24gprotruding from the frame portion24baway from the center line LC. The flanges24ghave holes24hrespectively for positioning with respect to the layer22. On its surface facing in the Z1 direction, the layer22has protrusions that are inserted into the holes24hrespectively, though not illustrated. The center line LC is a straight line that goes through the center PC and is parallel to the Z axis. The center PC is the geometric center of the downstream chamber R2in plan view. The flanges24gare not indispensable. If unnecessary, the flanges24gmay be omitted.

The filter25is a plate-type or sheet-type member that catches a foreign object, etc. contained in ink while allowing the ink to pass through itself. The filter25is, for example, made of metal fibers having a twilled dutch weave pattern or a plain dutch weave pattern, etc. The material of the filter25is not limited to metal fibers. For example, resin fibers such as nonwoven fabric may be used.

The filter25is fixed to the frame portion24bof the fixing member24described above. As indicated by the two-dot chain line inFIG.8, the filter25is provided at an area that encompasses the entire area of the recess24a.Therefore, as illustrated inFIG.7, the filter chamber RF is partitioned by the filter25into an upstream chamber R1and a downstream chamber R2. The upstream chamber R1is a space that is located over the filter25in the Z1 direction. The recessed surface21aconstitutes a part of the wall surface of this upper space. The downstream chamber R2is a space that is located under the filter25in the Z2 direction. The sidewall24iand the recess24aconstitute a part of the wall surface of this lower space.

The filter25is fixed to the fixing member24without using an adhesive. Therefore, it is possible to prevent an adhesive from sticking to the filter25. More specifically, if the fixing member24is formed by insert molding with insertion of the filter25, the filter25is fixed to the fixing member24integrally. In this case, either thermosetting resin or thermoplastic resin may be used as the material of the fixing member24. If the fixing member24is made of thermoplastic resin, the filter25may be fixed to the fixing member24by welding. In the present embodiment, as described earlier, it is difficult to form the fixing member24by insert molding with insertion of the filter25. Therefore, it is preferable to use thermoplastic resin as the material of the fixing member24and to fix the filter25to the fixing member24by welding.

As described above, the flow passage member1includes the supply flow passage CC, the filter25, the fixing member24, and the layer22. The layer22is an example of “a first member”. As described earlier, ink, which is an example of “liquid”, flows through the supply flow passage CC. The filter25is provided on a path of the supply flow passage CC. The ink passes through the filter25. The fixing member24constitutes a part of the supply flow passage CC. The filter25is fixed to the fixing member24. The layer22constitutes a part of the supply flow passage CC. The fixing member24is fixed to the layer22.

The filter25is fixed indirectly to the layer22by means of the fixing member24disposed therebetween as described above. Therefore, as long as no adhesive is used for fixing the filter25to the fixing member24, it is possible to avoid or reduce the sticking of an adhesive to the filter25even though the adhesive B1is used for fixing the fixing member24to the layer22.

Moreover, the fixing member24is made of thermoplastic resin, whereas the layer22is made of any of thermosetting resin, metal, and ceramic.

In general, the Young's modulus of each of thermosetting resin, metal, and ceramic is higher than that of thermoplastic resin. Since the flow passage member1includes the layer22that is made of any of thermosetting resin, metal, and ceramic, therefore, as compared with a structure in which the flow passage member1is made of thermoplastic resin only, it is possible to enhance the rigidity of the flow passage member1.

Moreover, in general, the liquid resistance of each of thermosetting resin, metal, and ceramic is superior to that of thermoplastic resin. Since the flow passage member1includes the layer22that is made of any of thermosetting resin, metal, and ceramic, therefore, as compared with a structure in which the flow passage member1is made of thermoplastic resin only, it is possible to enhance the liquid resistance of the flow passage member1. Furthermore, in general, the coefficient of linear expansion of each of thermosetting resin, metal, and ceramic is less than that of thermoplastic resin. Therefore, as compared with a case where thermoplastic resin is used, it is possible to reduce deformation such as warpage of the flow passage member1due to a temperature change. Consequently, it is possible to reduce the coming off of the adhesive in the flow passage member1.

On the other hand, thermoplastic resin is able to be fixed to other member by welding. Therefore, it is possible to fix the filter25to the fixing member24by welding without using an adhesive. There are some types of thermoplastic resin that have excellent liquid resistance. Therefore, by choosing an appropriate type of thermoplastic resin as the material of the fixing member24, it is possible to impart required liquid resistance to the flow passage member1. The thermoplastic resin used as the material of the fixing member24does not necessarily have to be resistant to liquid. In this case, it is sufficient as long as surface treatment that imparts liquid resistance, for example, coating, is applied to the fixing member24.

With the structure described above, it is possible to enhance the rigidity and liquid resistance of the flow passage member1while preventing an adhesive from sticking to the filter25. Consequently, it is possible to provide the flow passage member1that offers greater reliability than that of related art.

In the present embodiment, the area size of the fixing member24in plan view is smaller than the area size of the layer22in plan view. For this reason, the influence of the rigidity of the fixing member24on the rigidity of the flow passage member1as a whole is less than the influence of the rigidity of the layer22on the rigidity of the flow passage member1as a whole. To put it the other way around, the influence of the rigidity of the layer22on the rigidity of the flow passage member1as a whole is greater than the influence of the rigidity of the fixing member24on the rigidity of the flow passage member1as a whole. For this reason, using any of thermosetting resin, metal, and ceramic as the material of the layer22makes it possible to enhance the rigidity of the flow passage member1as a whole, which is desirable. On the other hand, it can be said that the use of thermoplastic resin as the material of the fixing member24is not so much negatively influential on the rigidity of the flow passage member1as a whole.

As has already been explained, the fixing member24and the layer22are fixed to each other with the adhesive B1, which is an example of “a first adhesive”. On the other hand, the fixing member24and the filter25are fixed to each other without using an adhesive, for example, by welding. Fixing the filter25to the fixing member24without using an adhesive and fixing the filter25indirectly to the layer22by means of the fixing member24disposed therebetween as described above makes it possible to prevent the mesh of the filter25from becoming clogged with the adhesive B1.

The method of welding is not specifically limited. Any method may be used as long as it is possible to fix the fixing member24and the filter25to each other. Examples include thermal welding, laser welding, and ultrasonic welding. In the present embodiment, thermal welding is used for fixing the fixing member24and the filter25to each other. If ultrasonic welding is used, it is necessary to configure the fixing member24as two thermoplastic resin members provided in such a way as to sandwich the filter25therebetween. If laser welding is used, it is necessary to configure the fixing member24as a pair of a light-transmissive resin member and a light-absorbing resin member that are made of thermoplastic resin and are provided in such a way as to sandwich the filter25therebetween. The light-transmissive resin used for laser welding is not limited to those that allow 100% of laser light to pass therethrough. The light-absorbing resin used for laser welding is not limited to those that absorb 100% of laser light. It is sufficient as long as the light absorption factor (or the light transmission factor) of one of the light-absorbing resin and the light-transmissive resin is different from that of the other for at least one wavelength of laser light and, in addition, as long as the light-transmissive resin is more transmissive than the light-absorbing resin. Therefore, the light absorption factor of the light-absorbing resin may be less than 100%, and the light transmission factor of the light-transmissive resin may be less than 100%. In order to perform laser welding stably, the light-transmissive resin should preferably allow laser light to pass at a transmittance of, for example, 20% or greater, and more preferably, 30% or greater.

If the adhesive B1is a photo-curable adhesive, the fixing member24is preferably a member that has optical transparency. In this case, as compared with a case where the adhesive B1is other kind of adhesive such as a thermosetting adhesive, it is possible to reduce the time taken for curing or solidification during the process of bonding using the adhesive B1. Therefore, it is possible to reduce the risk of flow of the adhesive B1toward the filter25during the process of bonding. Moreover, since the fixing member24has optical transparency, it is possible to apply photo-curing light to the adhesive B1through the fixing member24. Therefore, even though the adhesive B1has a portion that is located between the fixing member24and the layer22, it is possible to photo-cure this portion. It is sufficient as long as the fixing member24has a certain degree of optical transparency that is enough for the curing of the adhesive B1when photo-curing light is applied to the adhesive B1through the fixing member24. For example, if the adhesive B1is an ultraviolet curable adhesive, it is sufficient as long as the fixing member24has a certain degree of optical transparency that is enough for the curing of the adhesive B1when ultraviolet curing light is applied to the adhesive B1through the fixing member24. The same effects as those described above, or similar effects, can be expected also in a case where the adhesive B2is a photo-curable adhesive.

Preferably, the adhesive B1does not stick to, of the filter25, a portion that contributes to fulfilling its filter function. In the present embodiment, the portion of the filter25that contributes to fulfilling its filter function is the portion where the filter25overlaps with the recess24ain plan view. The fixing member24has the surface facing in the Z1 direction and the surface facing in the Z2 direction. In the present embodiment, the surface facing in the Z2 direction and the layer22are bonded to each other with the adhesive B1, whereas the filter25is fixed to the surface facing in the Z1 direction. Therefore, the adhesive B1does not stick to the filter25. Moreover, as described earlier, the frame portion24bhas a portion that is inserted into the groove21cand, therefore, the adhesive B2and the adhesive Ba also do not stick to the filter25. Since none of the adhesives sticks to the filter25, the risk of clogging the mesh of the filter25is extremely low.

As described earlier, the flow passage member1includes the layer21, which is an example of “a second member”. The layer21constitutes a part of the supply flow passage CC. The layer21is made of any of thermosetting resin, metal, and ceramic. The layer21is stacked on the layer22, with the fixing member24disposed therebetween. Therefore, as compared with a structure in which the fixing member24is not disposed between the layer21and the layer22, it is possible to enhance the rigidity of the flow passage member1.

Similarly to the above-described comparison with the layer22, the area size of the fixing member24in plan view is smaller than the area size of the layer21in plan view. For this reason, using any of thermosetting resin, metal, and ceramic as the material of the layer21makes it possible to enhance the rigidity of the flow passage member1as a whole, which is desirable. On the other hand, it can be said that the use of thermoplastic resin as the material of the fixing member24is not so much negatively influential on the rigidity of the flow passage member1as a whole.

As has already been explained, the fixing member24and the layer21are fixed to each other with the adhesive B2, which is an example of “a second adhesive”. In the present embodiment, since the adhesive B2is used in addition to the adhesive B1, as compared with a structure in which only one of the adhesive B1and the adhesive B2is used, it is possible to fix the fixing member24to the stack including the layers21and22securely.

As has already been explained, the fixing member24has the recess24a,which is recessed from the surface to which the filter25is fixed. The bottom surface of the recess24aconstitutes a part of the supply flow passage CC and has the first outlet24cand the second outlet24d,which are through holes. Therefore, the fixing member24constitutes the floor of the downstream chamber R2. Because of this structure, as compared with a structure in which the fixing member24does not include the recess24a,it is possible to make the distance between the filter25and the first outlet24cand the distance between the filter25and the second outlet24dshorter. Consequently, it is possible to discharge air bubbles that are present inside the downstream chamber R2to the first outlet24cand the second outlet24dsuitably.

As has already been explained, the supply flow passage CC includes the flow passage C3, which extends in the direction intersecting with the stack direction of the layer22and the filter25. The flow passage C3is provided in the layer22. The layer22, in which the flow passage C3is provided, is relatively large in size in the direction intersecting with the stack direction of the layer22and the filter25. In addition, since the flow passage C3is provided, the cavity percentage of the layer22is high. Therefore, if the layer22were made of thermoplastic resin, its rigidity would tend to be insufficient. In this respect, since the layer22is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the rigidity of the layer22from being insufficient, although the flow passage C3is provided in the layer22. Moreover, there is the following advantage. When the layer22has the flow passage C3, the liquid-contact area size of the layer22in contact with ink increases. If the layer22were made of thermoplastic resin, the liquid resistance of which is lower than that of thermosetting resin, metal, and ceramic, the degradation of the layer22would be likely to occur. Therefore, there is a risk that a foreign object might be produced, or swelling might occur. In this respect, since the layer22is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the degradation of the layer22from occurring, although the flow passage C3is provided in the layer22.

In general, each of thermosetting resin, metal, and ceramic has excellent resistance not only to water-based ink but also to solvent ink and ultraviolet ray curing ink. If the ink that flows through the supply flow passage CC is ultraviolet ray curing ink or solvent ink, the ink contains a solvent. Therefore, if the flow passage member1were made of thermoplastic resin only, the flow passage member1would be susceptible to degradation caused by the solvent. In this respect, since at least a part of the flow passage member1is made of any of thermosetting resin, metal, and ceramic, even if solvent ink or ultraviolet ray curing ink is used as liquid that is to be ejected from the liquid ejecting head10, it is possible to reduce degradation caused by the solvent ink or the ultraviolet ray curing ink.

As has already been explained, the liquid ejecting head10has a circulation flow passage through ink that was not ejected from the nozzles N after passing through the supply flow passage CC flows. At least a part of the discharge flow passage CM which constitutes a part of the circulation flow passage is provided in the layer22. Therefore, the layer22constitutes a part of the circulation flow passage. The layer22, in which a part of the circulation flow passage is provided, is relatively large in size in the direction intersecting with the stack direction of the layer22and the filter25. In addition, since a part of the circulation flow passage is provided, the cavity percentage of the layer22is high. Therefore, if the layer22were made of thermoplastic resin, its rigidity would tend to be insufficient. In this respect, since the layer22is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the rigidity of the layer22from being insufficient, although a part of the circulation flow passage is provided in the layer22. Moreover, there is the following advantage. When the layer22has a part of the circulation flow passage, the liquid-contact area size of the layer22in contact with ink increases. If the layer22were made of thermoplastic resin, the degradation of the layer22would be likely to occur. In this respect, since the layer22is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the degradation of the layer22from occurring, although a part of the circulation flow passage is provided in the layer22.

The liquid resistance of each of thermoplastic resin, thermosetting resin, metal, and ceramic, etc. can be measured by experiment. Specifically, it is possible to quantitatively evaluate the liquid resistance by soaking a member such as a film having predetermined mass as a test piece in test target ink for a predetermined period of time and then by calculating a dissolution ratio based on a change in mass as a result of the soaking. By using the method described above, it is possible to measure the resistance of each material, for example, resistance to particular solvent-based ink, particular ultraviolet ray curing ink, and particular water-based ink.

1-6. Method for Manufacturing Flow Passage Member1

FIG.10is a diagram that illustrates the steps of manufacturing the flow passage member1according to the first embodiment. InFIG.10, the steps of manufacturing the flow passage member1in a case where the filter25is fixed to the fixing member24by welding are illustrated. As illustrated inFIG.10, the method for manufacturing the flow passage member1includes a preparation step S11, a welding step S12, and a bonding step S13. These steps are executed in this order.

In the preparation step S11, the fixing member24and the filter25are prepared. The fixing member24is formed by injection molding of thermoplastic resin. The fixing member24has a director24sprotruding from the placement surface24p.Though not illustrated, the director24shas a loop shape that surrounds the recess24aas viewed in the direction in which the filter25is stacked on the fixing member24. The filter25is obtained by cutting metal fibers having a twilled dutch weave pattern or a plain dutch weave pattern, etc.

In the welding step S12, the fixing member24and the filter25are fixed to each other by welding. Specifically, as illustrated inFIG.12, after the filter25is placed on the director24sof the fixing member24, energy EG is applied to the fixing member24throughout the range of contact with the peripheral portion of the filter25. In other words, the energy EG is applied to the director24s.As a result of applying the energy EG, the director24smelts, and the fixing member24and the filter25are welded to each other. The method of welding in the present embodiment is thermal welding. Therefore, the energy EG is heat.

In the bonding step S13, the fixing member24and the layer22are fixed to each other with the adhesive B1.

As explained above, in the method for manufacturing the flow passage member1, the fixing member24and the layer22are bonded to each other with the adhesive B1after welding the fixing member24and the filter25together. With the above method for manufacturing the flow passage member1, it is possible to manufacture the flow passage member1that offers great reliability as described earlier.

In the first embodiment, the layer22is an example of “a first member”, the layer21is an example of “a second member”, the adhesive B1is an example of “a first adhesive”, and the adhesive B2is an example of “a second adhesive”. However, the layer22may be an example of “a second member”, the layer21may be an example of “a first member”, the adhesive B1may be an example of “a second adhesive”, and the adhesive B2may be an example of “a first adhesive”.

2. SECOND EMBODIMENT

A second embodiment of the present disclosure will now be explained. In the exemplary embodiment described below, the same reference numerals as those used in the description of the first embodiment are assigned to elements that are the same in operation and/or function as those in the first embodiment, and a detailed explanation of them is omitted.

FIG.11is a perspective view of a liquid ejecting module40A that includes liquid ejecting heads10A according to a second embodiment. As illustrated inFIG.11, the liquid ejecting module40A includes a support41A and the plurality of liquid ejecting heads10A. The support41A is a member that supports the plurality of liquid ejecting heads10A. In the example illustrated inFIG.11, the support41A is a plate-like member made of metal, etc. The support41A has a plurality of mount holes41bfor mounting the plurality of liquid ejecting heads10A. The liquid ejecting head10A is inserted in each of the plurality of mount holes41b.Each of the plurality of liquid ejecting heads10A is fastened to the support41A by screws, etc. InFIG.11, the plural liquid ejecting heads10A are arranged in a matrix along the X axis and the Y axis. The number of the liquid ejecting heads10A included in the liquid ejecting module40A is not limited to the example illustrated inFIG.11. The liquid ejecting module40A may include any number of the liquid ejecting heads10A. The shape, etc. of the support41A is also not limited to the example illustrated inFIG.11. The support41A may have any shape, etc.

FIG.12is an exploded perspective view of the liquid ejecting head10A illustrated inFIG.11. As illustrated inFIG.12, the liquid ejecting head10A includes a flow passage structure body11A, a wiring board12A, a holder13A, head bodies14_1,14_2,14_3, and14_4, a fixing plate15A, a reinforcing plate17, and a cover18. These components are disposed in the following order as viewed toward Z2: the cover18, the wiring board12A, the flow passage structure body11A, the holder13A, the head bodies14_1,14_2,14_3, and14_4, the reinforcing plate17, and, finally, the fixing plate15A. The components of the liquid ejecting head10A will be described below sequentially.

The flow passage structure body11A has the same structure as that of the flow passage structure body11according to the foregoing first embodiment except that, firstly, its stack is composed of layers Su1to Su5, and, secondly, it has a different shape. Therefore, the flow passage structure body11A has a structure regarding a filter, similarly to the flow passage structure body11. This structure will be described in detail later. The layers Su1to Su5are made of any of thermosetting resin, metal, and ceramic. The layers Su1to Su5are fixed to each other with an adhesive. The layer Su3is an example of “a first member”. The layer Su2is an example of “a second member”.

The wiring board12A is a mount component for electrically connecting the head bodies14_1,14_2,14_3, and14_4to the control unit20. For example, the wiring board12A is a flexible wiring board or a rigid wiring board, etc. The wiring board12A is disposed between the flow passage structure body11A and the cover18. The wiring board12A has a surface facing the flow passage structure body11A. On the surface that is the opposite of this surface, the connector12cis provided. The connector12cis a connection component for electric connection to the control unit20. The wiring board12A is electrically connected to the plurality of head bodies14via wiring that is not illustrated. The wiring is, for example, configured as a combination of a flexible wiring board and a rigid wiring board. The wiring may be configured as a part of the wiring board12A integrally.

Except for a difference in shape, the holder13A is the same as the holder13according to the foregoing first embodiment. The head bodies14_1,14_2,14_3, and14_4are held by the holder13A such that the direction in which the nozzles N belonging to the nozzle row La and the nozzles N belonging to the nozzle row Lb are arranged are parallel to the Y axis. Except for a difference in shape, the fixing plate15A is the same as the fixing plate15according to the foregoing first embodiment. However, the reinforcing plate17is disposed between the holder13A and the fixing plate15A. InFIG.12, a structure in which the holder13A does not include any branch flow passage is illustrated.

The reinforcing plate17is a plate-like member for reinforcement of the fixing plate15A. The reinforcing plate17is stacked on the fixing plate15A and is fixed to the fixing plate15A with an adhesive. The reinforcing plate17has a plurality of openings inside which the plurality of head bodies14is disposed. The reinforcing plate17is made of, for example, a metal material, etc.

The cover18is a box-type member that houses the flow passage member1A of the flow passage structure body11A and the wiring board12A. The cover18is made of, for example, a resin material, etc. The cover18has four through holes18aand an opening18b.These four through holes18acorrespond to four connection pipes of the flow passage structure body11A. The corresponding connection pipe11a,11b,11c,or11dis inserted through each of these four through holes18a.The connector12cis inserted through the opening18bfrom the inside to the outside of the cover18.

FIG.13is a diagram that illustrates the flow passages of the flow passage member1A according to the second embodiment. As illustrated inFIG.13, a supply flow passage Sa, a discharge flow passage Da, a supply flow passage Sb, and a discharge flow passage Db are provided inside the flow passage member1A. The supply flow passage Sa is a flow passage leading from the connection pipe11ato the liquid reservoir Ra of each of the plurality of head bodies14. The discharge flow passage Da is a flow passage leading from the liquid reservoir Ra of each of the plurality of head bodies14to the connection pipe11b.The supply flow passage Sb is a flow passage leading from the connection pipe11cto the liquid reservoir Rb of each of the plurality of head bodies14. The discharge flow passage Db is a flow passage leading from the liquid reservoir Rb of each of the plurality of head bodies14to the connection pipe11d.These flow passages are formed by providing grooves and through holes in the layers Su1to Su5described above.

As illustrated inFIG.13, four filter portions Fa_1to Fa_4are provided for the supply flow passage Sa. Similarly, four filter portions Fb_1to Fb_4are provided for the supply flow passage Sb. The filter portion Fa_1is described below as a representative example. The structure of the filter portions Fa_2, Fa_3, and Fa_4is the same as that of the filter portion Fa_1.

FIG.14is a sectional view of the flow passage member1A according to the second embodiment. In the structure illustrated inFIG.14, the filter portion Fa_1is provided between the layer Su2and the layer Su3. As illustrated inFIG.14, the filter portion Fa_1includes the filter chamber RF, a fixing member24A, and a filter25A.

In the present embodiment, the filter chamber RF is made up of a recess26a,a recess27a,and a recess27b.The recess26ais provided in the surface, of the layer Su2, facing in the Z2 direction. The recesses27aand27bare provided in the surface, of the layer Su3, facing in the Z1 direction. In the example illustrated inFIG.14, the recess27ais provided in the same area as the recess26ain plan view. The recess27bis provided in the bottom surface of the recess27a.The recess27bis provided in a narrower area inside the area of the recess26ain plan view.

The fixing member24A and the filter25A are disposed inside the filter chamber RF and partition the filter chamber RF into the upstream chamber R1and the downstream chamber R2. The upstream chamber R1is in communication with the connection pipe11adescribed above through a flow passage Pa1. The flow passage Pa1is made up of a groove provided in the surface, of the layer Su2, facing in the Z2 direction, and a groove provided in the surface, of the layer Su3, facing in the Z1 direction, though not illustrated. The downstream chamber R2is in communication with the head bodies14through a flow passage Pa2. The flow passage Pa2is the internal space of a through hole27cthat is open to the bottom surface of the recess27aand goes through the layer Su3.

Except for a difference in shape, the fixing member24A is the same as the fixing member24according to the foregoing first embodiment. Except for a difference in shape, the filter25A is also the same as the filter25according to the foregoing first embodiment. The fixing member24A and the filter25A will now be explained with a focus on the points of difference from the fixing member24and the filter25.

FIG.15is a plan view of the fixing member24A according to the second embodiment.FIG.16is an enlarged sectional view for explaining a fix state of the fixing member24A and the filter25A according to the second embodiment.

As illustrated inFIG.15, the fixing member24A has a frame shape in plan view. In the example illustrated inFIG.15, each of the internal edge and the external edge of the fixing member24A has a substantially quadrangular shape. The filter25A has a quadrangular shape in plan view. The peripheral portion of the filter25A is fixed to one surface of the fixing member24A by welding, etc. without using an adhesive.

As illustrated inFIG.16, a structure that is made up of the fixing member24A and the filter25A is disposed inside the recess27a.Of the two surfaces of the fixing member24A, the one surface to which the filter25A is fixed is fixed to the layer Su3with the adhesive B1. Therefore, an inner surface24jof the fixing member24A constitutes a part of the wall surface of the upstream chamber R1. It is possible to make the distance between the filter25A and the flow passage Pa2shorter because, of the two surfaces of the fixing member24A, the one surface to which the filter25A is fixed is fixed to the layer Su3with the adhesive B1. Consequently, it is possible to discharge air bubbles that are present inside the downstream chamber R2to the flow passage Pa2suitably.

The adhesive B1is applied not only to the fixing member24A and the layer Su3but also to an outer peripheral portion of the filter25A that is a welded portion that does not have a filter function. The filter25A has an area T, which is a painted-in-black area in the illustration ofFIG.16. The area T of the filter25A depicts a portion where the mesh of the filter25A is clogged due to the melting of the director of the fixing member24A by welding. That is, no resin of the fixing member24A that melted during the welding process is present in an inner portion that is more inside than the area T of the filter25A and has a filter function and an outer peripheral portion that is more outside than the area T of the filter25A. Therefore, by applying the adhesive B1between the recess27aand the outer peripheral portion that is more outside than the area T of the filter25A, it is possible to strengthen the force of bonding with the adhesive B1by anchoring effects taking advantage of the surface irregularities of the filter25A. Moreover, the adhesive B1is not applied to a region closer to the center of the filter25A than the area T is, in plan view. Therefore, it is possible to reduce the risk of clogging the mesh of the filter25A as a result of the flow of the adhesive B1to the portion that has the filter function of the filter25A due to capillary action. InFIG.16, the adhesive B1is applied between the area T of the filter25A and the bottom surface of the recess27aand is applied also to the outer peripheral portion that is more outside than the area T of the filter25A. However, the adhesive B1may be applied to the outer peripheral portion that is more outside than the area T of the filter25A without being applied between the area T of the filter25A and the bottom surface of the recess27a.

The second embodiment described above makes it possible to provide the flow passage member1A that offers great reliability, similarly to the foregoing first embodiment. Moreover, in the present embodiment, as described above, the fixing member24A is a frame member that has a shape along the contour of the filter25A. Therefore, as compared with the fixing member24according to the foregoing first embodiment, the fixing member24A makes it possible to make the size of an area in contact with ink smaller. Therefore, even if thermoplastic resin is used as the material of the fixing member24A so as to fix the filter25A to the fixing member24A by welding, it is possible to prevent the degradation or swelling of the fixing member24A due to contact with solvent-based ink or ultraviolet ray curing ink, etc.

The fixing member24A has one opening surrounded by the inner surface24j.However, the fixing member24A may have a plurality of openings. In other words, the fixing member24A may have not only a frame portion that is along the contour of the filter25A but also beams bridging therebetween. The fixing member24A can be said as a frame member also in this case. In this case, a plurality of individual filters may be provided for the plurality of openings respectively.

Each of the supply flow passages Sa and Sb described above has a branch flow passage branching off therefrom as illustrated inFIG.13. If the branch flow passages are formed in the layer Su3, the size of the layer Su3will increase, and the cavity percentage of the layer Su3will be high. Therefore, if the layer Su were made of thermoplastic resin, its rigidity would tend to be insufficient. In this respect, since the layer Su3is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the rigidity of the layer Su3from being insufficient, even if the branch flow passages are provided in the layer Su3. Moreover, there is the following advantage. If the layer Su3has the branch flow passages, the liquid-contact area size of the layer Su3in contact with ink increases. If the layer Su3were made of thermoplastic resin, the degradation of the layer Su3would be likely to occur. In this respect, since the layer Su3is made of any of thermosetting resin, metal, and ceramic, it is possible to prevent the degradation of the layer Su3from occurring, even if the branch flow passages are provided in the layer Su3.

Even when configured as in the second embodiment described above, it is possible to enhance the reliability of the flow passage member1A, similarly to the foregoing first embodiment.

3. THIRD EMBODIMENT

A third embodiment of the present disclosure will now be explained. In the exemplary embodiment described below, the same reference numerals as those used in the description of the first embodiment are assigned to elements that are the same in operation and/or function as those in the first embodiment, and a detailed explanation of them is omitted.

FIG.17is a sectional view of a flow passage member1B according to the third embodiment. The flow passage member1B is the same as the flow passage member1A according to the foregoing second embodiment except that the installation orientation of the structure made up of the fixing member24A and the filter25A is inverted upside down. That is, in the flow passage member1B, of the two surfaces of the fixing member24A, the opposite one, which is the opposite of the one surface to which the filter25A is fixed, is fixed to the layer Su3with the adhesive B1.

Even when configured as in the third embodiment described above, it is possible to enhance the reliability of the flow passage member1B, similarly to the foregoing first embodiment. Moreover, the present embodiment has an additional advantage that it is less likely that the adhesive B1will stick to the filter25A as compared with the second embodiment because, of the two surfaces of the fixing member24A, the opposite one, which is the opposite of the one surface to which the filter25A is fixed, is fixed to the layer Su3with the adhesive B1.

InFIG.17, for the purpose of increasing bonding strength, the adhesive B1is applied between the opposite surface, which is the opposite of the one surface of the fixing member24A to which the filter25A is fixed, and the bottom surface of the recess27a,and is applied also between the outer peripheral surface of the fixing member24A and the inner wall surface of the recess27a.However, the concept of the present embodiment is not limited to this example. The adhesive B1may be applied only between the opposite surface, which is the opposite of the one surface of the fixing member24A to which the filter25A is fixed, and the bottom surface of the recess27a.This structure has an advantage that it is less likely that the adhesive B1will stick to the filter25A as compared with the third embodiment.

4. FOURTH EMBODIMENT

A fourth embodiment of the present disclosure will now be explained. In the exemplary embodiment described below, the same reference numerals as those used in the description of the first embodiment are assigned to elements that are the same in operation and/or function as those in the first embodiment, and a detailed explanation of them is omitted.

FIG.18is a sectional view of a flow passage member1C according to the fourth embodiment. The flow passage member1C is the same as the flow passage member1B according to the foregoing third embodiment except that a recess27dis provided in the layer Su3. The recess27dis provided in the bottom surface of the recess27aaround the recess27b.The recess27dhas a loop shape in plan view. The recess27dhas a bottom surface27d-1, a first inner surface27d-2, and a second inner surface27d-3. The first inner surface27d-2is an inner surface of the recess27dthat is located closer to the center of the recess27athan the second inner surface27d-3is. The Z2-directional end of the fixing member24A is accommodated in the recess27d.The fixing member24A is fixed to the wall surfaces of the recess27dwith the adhesive B1. Specifically, the adhesive B1is provided continuously between the opposite surface, which is the opposite of the one surface of the fixing member24A to which the filter25A is fixed, and the bottom surface27d-1, and between the outer peripheral surface of the fixing member24A and the second inner surface27d-3, and between the inner peripheral surface of the fixing member24A and the first inner surface27d-2.

Even when configured as in the fourth embodiment described above, it is possible to enhance the reliability of the flow passage member1C, similarly to the foregoing first embodiment. Moreover, in the present embodiment, it is possible to make the distance between the filter25A and the flow passage Pa2shorter because the fixing member24A is disposed such that its end is accommodated in the recess27d.Consequently, it is possible to discharge air bubbles that are present inside the downstream chamber R2to the flow passage Pa2suitably. Moreover, in the present embodiment, it is possible to increase the bonding strength of the fixing member24A and the layer Su3because the size of the area where the adhesive B1is provided increases.

5. FIFTH EMBODIMENT

A fifth embodiment of the present disclosure will now be explained. In the exemplary embodiment described below, the same reference numerals as those used in the description of the first embodiment are assigned to elements that are the same in operation and/or function as those in the first embodiment, and a detailed explanation of them is omitted.

FIG.19is a sectional view of a flow passage member1D according to the fifth embodiment. The flow passage member1D is the same as the flow passage member1B according to the foregoing third embodiment except that the flow passage member1D includes a fixing member24D in place of the fixing member24A.

The fixing member24D is the same as the fixing member24A according to the foregoing third embodiment except that the fixing member24D has a recess24kinside which the filter25A is disposed. The recess24kis provided in the surface, of the fixing member24D, facing in the Z1 direction. The recess24kaccommodates the filter25A.

Even when configured as in the fifth embodiment described above, it is possible to enhance the reliability of the flow passage member1D, similarly to the foregoing first embodiment. Moreover, in the present embodiment, it is possible to make the distance between the filter25A and the flow passage Pa2shorter because the filter25A is disposed inside the recess24k.Consequently, it is possible to discharge air bubbles that are present inside the downstream chamber R2to the flow passage Pa2suitably.

6. SIXTH EMBODIMENT

A sixth embodiment of the present disclosure will now be explained. In the exemplary embodiment described below, the same reference numerals as those used in the description of the first embodiment are assigned to elements that are the same in operation and/or function as those in the first embodiment, and a detailed explanation of them is omitted.

FIG.20is a sectional view of a flow passage member1E according to the sixth embodiment. The flow passage member1E is the same as the flow passage member1A according to the foregoing second embodiment except that the flow passage member1E includes a fixing member24E in place of the fixing member24A.

The fixing member24E is the same as the fixing member24A according to the foregoing second embodiment except that the filter25A is fixed inside at a certain internal position in the thickness direction of the fixing member24E. The fixing member24E is molded integrally with the filter25A by being formed by insert molding with insertion of the filter25A.

As described above, in the flow passage member1E, the fixing member24E is formed by insert molding with insertion of the filter25A. That is, the fixing member24E and the filter25A are molded integrally by insert molding. Therefore, it is possible to fix the fixing member24E and the filter25A to each other without using an adhesive. The layer Su3, which is an example of “a first member”, and the fixing member24E are fixed to each other with the adhesive B1.

FIG.21is a diagram that illustrates the steps of manufacturing the flow passage member1E according to the sixth embodiment. InFIG.21, the steps of manufacturing the flow passage member1E in a case where the fixing member24E and the filter25A are fixed to each other by insert molding are illustrated. As illustrated inFIG.21, the method for manufacturing the flow passage member1E includes an insert step S21, a molding step S22, a release step S23, and a bonding step S24. These steps are executed in this order.

In the insert step S21, in a state in which molding dies301and302are opened, the filter25A is inserted as an inserted article at a desired position between these dies.

In the molding step S22, in a state in which molding dies301and302are closed, the cavity inside the dies is filled with resin. The resin may be thermoplastic resin, thermosetting resin. The thermosetting resin will be advantageous from the viewpoint of liquid resistance and rigidity. If the resin is thermoplastic resin, the fixing member24E inside which the filter25A is fixed can be obtained by filling the cavity inside the dies with thermoplastic resin softened by heating and thereafter by cooling the molten thermoplastic resin for solidification. If the resin is thermosetting resin, the fixing member24E inside which the filter25A is fixed can be obtained by filling the cavity inside the dies with thermosetting resin that has fluidity before curing and thereafter by curing the thermosetting resin by curing action.

In the release step S23, the fixing member24E obtained through the steps described above is released from the molding dies301and302.

In the bonding step S24, the fixing member24E and the layer Su3are fixed to each other with the adhesive B1as done in the bonding step S13of the foregoing first embodiment.

As explained above, in the method for manufacturing the flow passage member1E, the fixing member24E and the layer Su3are bonded to each other with the adhesive B1after forming the fixing member24E by insert molding with insertion of the filter25A. With the above method for manufacturing the flow passage member1E, it is possible to manufacture the flow passage member1E that offers great reliability as described earlier. Moreover, if the fixing member24E is made of thermosetting resin, as compared with a case where the fixing member24E is made of thermoplastic resin, it is possible to increase the rigidity and liquid resistance of the fixing member24E.

Even when configured as in the sixth embodiment described above, it is possible to enhance the reliability of the flow passage member1E, similarly to the foregoing first embodiment. Moreover, in the present embodiment, it is possible to make the distance between the filter25A and the flow passage Pa2shorter because the filter25A is fixed inside at a certain internal position in the thickness direction of the fixing member24E. Consequently, it is possible to discharge air bubbles that are present inside the downstream chamber R2to the flow passage Pa2suitably.

7. VARIATION EXAMPLES

The embodiments described as examples above can be modified in various ways. Some specific examples of modification that can be applied to the embodiments described above are described below. Two or more variation examples selected arbitrarily from the description below may be combined as long as they are not contradictory to each other or one another.

7-1. First Variation Example

FIG.22is a sectional view of a flow passage member1F according to a first variation example. The flow passage member1F includes a layer21F, which is an example of “a fixing member”, a layer22F, which is an example of “a first member”, and a filter25F. The layers21F and22F constitute a stack of layers in this order as viewed toward Z2 and are fixed to each other with an adhesive. In plan view, the area size of the layer21F is smaller than the area size of the layer22F. The layer21F is made of thermoplastic resin. The layer22F is made of thermosetting resin, metal, or ceramic.

The filter25F is disposed inside a space formed between the layer21F and the layer22F. The layer21F has a recess21dthat is provided in its surface facing in the Z2 direction. The layer22F has a recess22ethat is provided in its surface facing in the Z1 direction. The recess21dand the recess22econstitute the filter chamber RF. The filter25F is disposed inside the recess21d.The filter25F is fixed to the layer21F by welding, etc., without using an adhesive.

The filter25F partitions the filter chamber RF into the upstream chamber R1and the downstream chamber R2. The connection pipe11ais provided on the layer21F. The connection pipe11ais in communication with the upstream chamber R1. An outlet22fthat is open to the downstream chamber R2is provided in the layer22F. Even when configured as in the first variation example described above, the same effects as those of the foregoing exemplary embodiments, or similar effects, can be obtained. The outlet22fonly, instead of forming both of the outlet22fand the recess22e,may be formed in the layer22F.

As described above, in plan view, the area size of the layer21F is smaller than the area size of the layer22F. Therefore, even if the layer21F is made of thermoplastic resin, it is possible to suppress a decrease in the rigidity of the flow passage member1F as a whole. Not only the layer21F on which the connection pipe11ais formed but also a plurality of layers21F on which the connection pipes11b,11c,and11dare formed respectively may be stacked on the layer22F with an adhesive. Even if the structure is modified in this way, it is possible to suppress a decrease in the rigidity of the flow passage member1F as long as the layer22F, the area size of which is larger than that of each of the layers21F in plan view, is made of thermosetting resin. In plan view, the area size of the layer21F may be approximately the same as the area size of the layer22F. The meaning of “the area size of the layer21F is approximately the same as the area size of the layer22F” encompasses cases where the area size of the layer21F is 90% or more but less than 110% of the area size of the layer22F.

7-2. Second Variation Example

FIG.23is a sectional view of a flow passage member1G according to a second variation example. The flow passage member1G is the same as the flow passage member1F according to the first variation example described above except that, firstly, the flow passage member1G includes a layer22G and a layer23G in place of the layer22F and, secondly, the position where the filter25F is disposed is different from that of the first variation example described above. That is, the flow passage member1G includes the layer21F, which is an example of “a first member”, the layer22G, which is an example of “a fixing member”, the layer23G, which is an example of “a second member”, and the filter25F. The layer21F can be an example of “a second member”, too. If the layer21F is an example of “a second member”, the layer23G becomes an example of “a first member”. The layers21F,22G, and23G constitute a stack of layers in this order as viewed toward Z2 and are fixed to each other with an adhesive. Each of the layers21F and23G is made of thermosetting resin, metal, or ceramic. The layer22G is made of thermoplastic resin.

The filter25F is disposed inside a space formed between the layer21F and the layer22G. The layer21F has the recess21dthat is provided in its surface facing in the Z2 direction. The layer22G has a through-hole opening22g.The recess21d,the opening22g,and the surface of the layer23G facing in the Z1 direction constitute the filter chamber RF. The filter25F is disposed inside the opening22g.The filter25F is fixed to the layer22G by welding, etc., without using an adhesive.

The filter25F partitions the filter chamber RF into the upstream chamber R1and the downstream chamber R2. The connection pipe11ais provided on the layer21F. The connection pipe11ais in communication with the upstream chamber R1. An outlet23bthat is open to the downstream chamber R2is provided in the layer23G. Even when configured as in the second variation example described above, the same effects as those of the foregoing exemplary embodiments, or similar effects, can be obtained.

7-3. Third Variation Example

FIG.24is a sectional view of a flow passage member1H according to a third variation example. The flow passage member1H is the same as the flow passage member1F according to the first variation example described earlier except that the filter25F is fixed indirectly to the layer21F by means of a fixing member24H disposed therebetween. That is, the flow passage member1H includes the layer21F, which is an example of “a first member”, the layer22F, which is an example of “a second member”, the fixing member24H, and the filter25F.

The fixing member24H is made of thermoplastic resin and has a frame shape. The fixing member24H is fixed to the layer21F with an adhesive that is not illustrated. The filter25F is fixed to the fixing member24H by welding, etc., without using an adhesive. Even when configured as in the third variation example described above, the same effects as those of the foregoing exemplary embodiments, or similar effects, can be obtained. The fixing member24H may be made of thermosetting resin if the fixing member24H is molded integrally with the filter25F by insert molding such that the peripheral portion of the filter25A is embedded in the fixing member24H as in the foregoing sixth embodiment.

7-4. Fourth Variation Example

FIG.25is a sectional view of a flow passage member1I according to a fourth variation example. The flow passage member1I includes a layer21H, which is an example of “a second member”, the layer22F, which is an example of “a first member”, the fixing member24H, and the filter25F. The layers21H and22F constitute a stack of layers in this order as viewed toward Z2 and are fixed to each other with an adhesive. Each of the layers21H and22F is made of thermosetting resin, metal, or ceramic.

The filter25F is disposed inside a space formed between the layer21H and the layer22F. The layer21H has the recess21dthat is provided in its surface facing in the Z2 direction. The layer22F has the recess22ethat is provided in its surface facing in the Z1 direction. The recess21dand the recess22econstitute the filter chamber RF. The fixing member24H and the filter25F are disposed inside the recess22e.The filter25F is fixed indirectly to the layer22F by means of the fixing member24H.

In this variation example, the fixing member24H has a stack structure made up of two members24mand24n.Both of the members24mand24nare made of thermoplastic resin. The members24mand24nare bonded to each other, and to the filter25F, by laser welding or ultrasonic welding, etc. When laser welding is used, one of the members24mand24nis made of light-transmissive resin, and the other is made of light-absorbing resin. Even when configured as in the fourth variation example described above, the same effects as those of the foregoing exemplary embodiments, or similar effects, can be obtained.

7-5. Fifth Variation Example

In the foregoing exemplary embodiments, cases where the liquid ejecting head10is configured as a line head have been described for the purpose of presenting examples. However, the scope of the present disclosure is not limited to the foregoing examples. The concept of the present disclosure may be applied to a serial-type configuration in which the liquid ejecting head10is reciprocated along the X axis.

7-6. Sixth Variation Example

The liquid ejecting apparatus100disclosed as examples in the foregoing exemplary embodiments can be applied to not only print-only machines but also various kinds of equipment such as facsimiles and copiers, etc. The scope of application of a liquid ejecting apparatus according to the present disclosure is not limited to printing. For example, a liquid ejecting apparatus that ejects a colorant solution can be used as an apparatus for manufacturing a color filter of a liquid crystal display device. A liquid ejecting apparatus that ejects a solution of a conductive material can be used as a manufacturing apparatus for forming wiring lines and electrodes of a wiring substrate.