Liquid ejection head

Abstract

To provide a technique that is able to stabilize flow of a liquid in a flow passage.SOLUTION: A liquid ejection head including a support member 102 having a flow passage through which a liquid flows between a pressure chamber of a liquid ejection unit and a liquid supply unit. The support member 102 includes: a support member main body 200 having a flow-passage formation hole forming a part of the flow passage 205, and a side surface in which the flow-passage formation hole is opened; and a flow-passage formation member 201 forming another part of the flow passage by having a rib 209 inserted into an opening of the flow-passage formation hole opened in the side surface and by its being bonded to the side surface so as to close the opening. The liquid ejection head has a flow passage groove 215 formed between the rib 209 and the flow-passage formation hole 250. The width of the flow passage groove 215 is partially increased in a facing portion between a recessed part 217 formed in a part of the flow-passage formation hole 250 forming the flow passage groove 215 and a projecting part 223 formed on a side surface of the rib 209 corresponding to the recessed part 217.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head having an ejection port for ejecting liquid. [Background technology]

[0002] In the field of liquid ejection devices (e.g., inkjet printers) that perform recording by ejecting liquid such as ink, the recording applications have become more diverse in recent years, and the demand for high-definition and high-quality recording has further increased. To achieve high-definition recording, a method is known in which a liquid ejection head provided in the liquid ejection device has a plurality of ejection ports arranged at high density to increase the recording resolution. In addition, in order to achieve even higher quality recording, it is necessary to suppress the increase in ink viscosity due to evaporation of water from the ejection ports, which causes a decrease in the ejection speed of droplets and a modulation in the coloring material concentration. As a method for suppressing the increase in ink viscosity due to evaporation of water from the ejection ports, a method is known in which ink is forced to flow in a pressure chamber that imparts energy to the ink to eject it from the ejection port, and ink remaining in the pressure chamber is caused to flow out (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-024254 A [Patent Document 2] JP 2019-014172 A Summary of the Invention [Problem to be solved by the invention]

[0004] A path along which ink supplied from an ink tank reaches an ejection port in a liquid ejection head includes a plurality of flow paths. The plurality of flow paths formed by an assembly having a multi-layer structure may include flow paths with different distances and extending directions. If a difference in pressure loss of the liquid occurs between flow paths having different configurations, the flow of the liquid may become unstable, and the ejection of the liquid from the ejection port may become unstable. For example, a method for balancing the pressure loss may be to adjust the cross-sectional area (volume) of the flow path. However, bubbles in the liquid generated during ejection may destabilize the flow of the liquid, and ejection defects may not be sufficiently suppressed by adjusting the cross-sectional area of ​​the flow path alone.

[0005] An object of the present invention is to provide a technique capable of stabilizing the flow of liquid in a flow channel. [Means for solving the problem]

[0006] In order to achieve the above object, the liquid ejection head of the present invention comprises: a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; A rib is inserted into the opening of the flow passage forming hole that opens on the side surface, and the opening a flow path forming member that is joined to the side surface so as to close the flow path and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the support member body has a recess recessed in the width direction on at least one of a pair of flow path side surfaces facing each other in the width direction in the flow path forming hole, the rib has a protrusion protruding in the width direction at a portion of a rib side surface facing the flow channel side surface, the protrusion protruding in the width direction at a portion of the rib side surface facing the flow channel side surface, the protrusion The opposing distance between the flow channel side surface and the rib side surface is partially enlarged at the opposing portion between the recessed portion and the protruding portion. In order to achieve the above object, the liquid ejection head of the present invention comprises: a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; a flow path forming member that has a rib that is inserted into an opening of the flow path forming hole that opens on the side surface, and is joined to the side surface so as to close the opening, and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the flow path groove includes a deflection path portion that temporarily changes a direction of the flow path of the flow path groove extending from the upstream side to the downstream side of the flow path so as to temporarily bulge the path to one side in the width direction, The width of the flow passage groove is partially expanded in the deflection path portion. Effect of the Invention

[0007] According to the present invention, the flow of liquid in the flow path can be stabilized. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an exploded perspective view of the liquid ejection head. [Diagram 2] FIG. 2 is a schematic diagram of a liquid ejection head. [Diagram 3] FIG. 2 is a schematic diagram of a support member according to the first embodiment. [Figure 4] 5 is a cross-sectional view taken along line AA in a joining step of the support member according to the first embodiment. FIG. [Diagram 5] FIG. 2 is a schematic configuration diagram of a liquid ejection head according to a first comparative embodiment. [Figure 6] FIG. 2 is a plan view of a flow passage forming member according to the first embodiment. [Figure 7] FIG. 2 is a schematic configuration diagram of a support member according to the first embodiment. [Figure 8] FIG. 8 is an enlarged view of the periphery of a recess in FIG. [Figure 9] FIG. 8 is a cross-sectional view of FIG. 7 shown in FIG. [Figure 10] 6 is a schematic configuration diagram of a support member according to a first modified example of the first embodiment. FIG. [Figure 11] 10 is a schematic configuration diagram of a support member according to a second modified example of the first embodiment. FIG. [Figure 12] 13 is a schematic configuration diagram of a support member according to a third modified example of the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. The present invention does not limit the scope of the present invention. Although the embodiment describes a plurality of features, not all of these features are essential to the invention, and the plurality of features may be combined in any manner. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and duplicated descriptions are omitted.

[0010] [First embodiment] FIG. 1 is an exploded perspective view of a liquid ejection head 100 according to an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view showing a general configuration of the liquid ejection head 100. As shown in FIG.

[0011] 2 is a schematic diagram of the basic configuration of the liquid ejection head 100, and the specific configuration is common to a liquid ejection head 100d according to a first comparative configuration shown in FIG 5, with the exception of some components. Details will be described later.

[0012] The liquid ejection head 100 described below is configured as an inkjet recording head used to record a desired image on a recording material by ejecting ink as a recording liquid onto the recording material in an inkjet printer or the like as a recording device. Note that "recording" does not only include forming meaningful information such as characters and figures, but also includes forming images, patterns, and the like on a recording medium, whether meaningful or unmeaning, or processing the medium, regardless of whether it is manifested in a way that can be visually perceived by humans. In addition, although a sheet of paper is assumed as the "recording medium" in this embodiment, it may also be cloth, plastic film, and the like.

[0013] The present invention can also be suitably applied to applications other than inkjet recording heads. That is, the recording device to which the present invention can be applied is not limited to an inkjet recording device, and can also be applied to, for example, a thermal transfer type recording device such as a melting type or a dye-sublimation type. The recording device may also be a manufacturing device for manufacturing, for example, a color filter, an electronic device, an optical device, a microstructure, or the like using a predetermined recording method. The recording device may also be a device for forming a three-dimensional image from 3D data.

[0014] As the recording method of the recording device according to this embodiment, a thermal method or a piezoelectric method is preferably adopted. The thermal method is a method in which ink is heated by a heater (a heating element that generates heat when electricity is applied) as an energy generating element to generate bubbles, and the energy generated at this time is used to eject ink. The piezoelectric method is a method in which a voltage is applied to a piezoelectric element (piezo element) as an energy generating element to change its volume, and the energy generated at this time is used to eject ink. Note that methods other than these may also be used.

[0015] As shown in FIG. 1 and FIG. 2, the liquid ejection head 100 is mainly composed of a head section 101, a support member 102, and a circulation pump unit 103. The head section 101 constitutes a liquid ejection section that ejects ink in the liquid ejection head 100. The head section 101 includes a pressure chamber 108, an ejection port 109 for ejecting ink from the pressure chamber 108, and an electric heat exchanger 107 as an energy generating element that generates energy for ejecting the ink in the pressure chamber 108 from the ejection port 109. The support member 102 is a member that connects the head section 101 and the circulation pump unit 103. The support member 102 includes a flow path that distributes liquid between the pressure chamber of the head section 101 and the circulation pump unit 103, and has a function of storing ink. The circulation pump unit 103 constitutes a liquid supply section that forms an ink flow that circulates and supplies ink to the head section 101 through the flow path of the support member 102 in the liquid ejection head 100.

[0016] Here, the direction of the arrow D shown in FIG. 1 and subsequent drawings coincides with the ejection direction of ink from the ejection port 109. The direction of the arrow D coincides with the arrangement direction (stacking direction, joining direction) of the head portion 101, the support member 102, and the circulation pump unit 103 in the liquid ejection head 100. Furthermore, the direction of the arrow D also coincides with the stacking direction in the stacked structure of the recording element substrate 110, which will be described later.

[0017] The head unit 101 is made up of a recording element substrate 110, an electric wiring substrate 111, a recording element substrate support member 112 (hereinafter, substrate support member 112), and an electric substrate 113.

[0018] The recording element substrate 110 is a laminated structure in which a plurality of layers are laminated on a silicon substrate having a thickness of 0.6 to 0.8 mm. On one side of the silicon substrate, a plurality of electric heat exchangers 107 for generating energy for ejecting ink and electric wiring (not shown) for supplying power to each electric heat exchanger 107 are formed by film formation technology. In the recording element substrate 110, a plurality of ink flow paths corresponding to the plurality of electric heat exchangers 107, a plurality of ejection ports 109, and a plurality of communication ports 105, 106 communicating with the flow paths of the support member 102 are formed by photolithography technology.

[0019] The multiple ejection ports 109 open to one surface (downstream side of arrow D) in the stacking direction of the stacked structure of the recording element substrate 110. The multiple communication ports 105, 106 open to the other surface (upstream side of arrow D) in the stacking direction of the recording element substrate 110. The multiple ejection ports 109 are provided corresponding to the multiple electric heat exchange bodies 107. That is, one ejection port 109 opens for one electric heat exchange body 107 at a position facing the electric heat exchange body 107. The multiple communication ports 105, 106 are provided in a silicon substrate on which the electric heat exchange body 107 is formed so as to penetrate the silicon substrate at a position different from that of the electric heat exchange body 107.

[0020] Inside the recording element substrate 110, an ink circulation flow path 114 is spread around the multiple electric heat exchangers 107 as a common flow path that communicates between the multiple communication ports 105, 106 and the multiple ejection ports 109. In the ink circulation flow path 114, a space between the electric heat exchanger 107 and the corresponding ejection port 109 functions as a pressure chamber 108 as an area where the electric heat exchanger 107 generates ink ejection energy. The ink circulation flow path 114 is configured to supply ink supplied from the circulation pump unit 103 via the communication port 105 to the pressure chamber 108, and to recover ink not ejected from the ejection port 109 to the circulation pump unit 103 via the communication port 106.

[0021] The electrical wiring board 111 is used to apply electrical signals to the recording element board 110 to eject ink, and has lead terminals corresponding to the connection terminals of the recording element board 110 and terminal portions corresponding to the wiring of the electrical board 113.

[0022] The substrate support member 112 is integrally formed with a portion for supporting and fixing the recording element substrate 110, a plurality of supply channels 115 for supplying ink to the recording element substrate 110, and a plurality of ink recovery channels 116 for recovering ink to the circulation pump unit 103. One end of the supply channel 115 is connected to the communication port 105 of the recording element substrate 110, and the other end is connected to a supply channel 205 of the support member 102, which will be described later. One end of the ink recovery channel 116 is connected to the communication port 106 of the recording element substrate 110, and the other end is connected to a recovery channel 206 of the support member 102, which will be described later. The supply channel 115 and the ink recovery channel 116 are formed to extend in the stacking direction of the recording element substrate 110 and the substrate support member 112 (a direction perpendicular to the bonding surface of the recording element substrate 110 and the substrate support member 112, the direction of the arrow D).

[0023] A wide variety of materials can be used as the material for forming the substrate support member 112, such as a resin material or a ceramic material such as alumina, etc. In this embodiment, alumina is used.

[0024] The recording element substrate 110 is bonded to a predetermined position of the substrate support member 112 via an adhesive 117, and the supply flow path 115 and recovery flow path 116 of the substrate support member 112 are communicated with the circulation flow path 114 of the recording element substrate 110.

[0025] Next, the electric wiring board 111 is also bonded to a predetermined position of the board support member 112 using an adhesive. At this time, the electric wiring board 111 is positioned within a range where the connection terminals of the recording element board 110 and the lead terminals of the electric wiring board 111 can be connected, and are electrically connected by TAB mounting technology. After the electrical connection, the lead terminals are covered with a sealant 118. The adhesive and sealant used are preferably ones with good ink resistance, and in this embodiment, both are thermosetting materials whose main component is epoxy resin. Therefore, in this embodiment, after the sealant is applied, heat curing is performed at a temperature of about 100 to 150 degrees for 2 to 3 hours to harden the adhesive and sealant.

[0026] After the adhesive and sealant are cured, the electric substrate 113 and the electric wiring substrate 111 are bonded. Specifically, the wiring portion protruding from the electric wiring substrate 111 and the terminal portion of the electric substrate 113 are bonded by heat welding. In this embodiment, the bonding is performed by applying heat at a temperature of 300 to 320 degrees with a load of 200 to 300 N. This bonding between the electric substrate 113 and the electric wiring substrate 111 makes it possible to send an electric signal to the recording element substrate 110 from the liquid ejection device to which the liquid ejection head 100 is attached.

[0027] The support member 102 will be described with reference to Fig. 3 and Fig. 4. Fig. 3(a) is a schematic perspective view showing a general configuration of the support member 102, and Fig. 3(b) is a side view of the support member 102 (view taken along arrow C in Fig. 3(a)). Fig. 4 is a cross-sectional view taken along line AA in Fig. 3, showing a fitting process of the tank member 200 and the flow path forming member 201 (201a, 201b) constituting the support member 102.

[0028] The support member 102 is mainly composed of a tank member 200 as a support member main body, and a flow path forming member 201. The support member 102 has a plurality of supply flow paths 205 and a plurality of recovery flow paths 206 as a plurality of flow paths for circulating liquid between the pressure chamber 108 of the head portion 101 and the circulation pump unit 103.

[0029] The tank member 200 is formed with a joint surface 202 that is joined to the head portion 101, a coupling surface 203 that is joined to the circulation pump unit 103, and a flow path coupling surface 204 (204a, 204b) that is joined to the flow path forming member 201 (201a, 201b). The joint surface 202 and the coupling surface 203 are surfaces that are opposite to each other in the arrangement direction (arrow D direction) of the head portion 101, the support member 102, and the circulation pump unit 103. That is, the joint surface 202 is one end surface (first end surface) of the tank member 200 in the above arrangement direction, and the coupling surface 203 is the other end surface (second end surface) of the tank member 200 in the above arrangement direction. The tank portion flow path coupling surface 204 (204a, 204b) is a side surface of the tank member 200 along a direction perpendicular to the joint surface 202 and the coupling surface 203 (the above arrangement direction).

[0030] The supply flow channel 205 and the recovery flow channel 206 open to the joint surface 202 and the combined surface 203, respectively. That is, the supply flow channel 205 has an opening (outlet opening) 225 that opens to the joint surface 202, and an opening (inlet opening) 235 that opens to the combined surface 203. Similarly, the recovery flow channel 206 has an opening (inlet opening) 226 that opens to the joint surface 202, and an opening (outlet opening) 236 that opens to the combined surface 203. The supply flow channel 205 is used to supply ink to the head unit 101, and the recovery flow channel 206 is used to recover ink from the head unit 101 to the circulation pump unit 103.

[0031] The supply flow path 205 and the recovery flow path 206 are formed by integrally joining the tank member 200 and the flow path forming member 201. The tank member 200 has flow path forming holes 250 and 260 which form a part of the channel 206. The above-mentioned openings 225 and 235 are formed as a part of the flow path forming hole 250, and the above-mentioned openings 226 and 236 are formed as a part of the flow path forming hole 260. In addition, the flow path forming holes 250 and 260 have openings 251 and 261 which open to a flow path joining surface 204 (204a, 204b) which is a side surface (first side surface, second side surface) of the tank member 200. The openings 251 and 261 open to the flow path joining surface 204 (204a, 204b) in a direction perpendicular to the arrangement direction of the head portion 101, the support member 102, and the circulation pump unit 103 in the flow path joining surface 204 (204a, 204b).

[0032] In this embodiment, the flow path forming member 201 is configured as a pair of flow path forming members 201a and 201b. That is, the tank member 200 has a first flow path joining surface 204a to which the first flow path forming member 201a is joined, and a second flow path joining surface 204b to which the second flow path forming member 201b is joined. The first flow path joining surface 204a and the second flow path joining surface 204b are surfaces on the side surface of the tank member 200 that are opposite to each other in the direction of arrow E perpendicular to the direction of arrow D. The flow path forming holes 250 and 260 have openings 251a and 261a as first openings that open into the first flow path joining surface 204a, and openings 251b and 261b as second openings that open into the second flow path joining surface 204b, respectively.

[0033] The supply flow passage 205 and the recovery flow passage 206 are formed by blocking the openings 251a and 261a of the flow passage forming holes 250 and 260 with a flow passage forming member 201a, and blocking the openings 251b and 261b of the flow passage forming holes 250 and 260 with a second flow passage forming member 201b. These two types of flow passages are separated by a flow passage wall 207. The number of the supply flow passages 205 and the recovery flow passages 206 is the same and is determined by the number of inks to be used. In this embodiment, it is assumed that three colors are used, and there are three supply flow passages 205 and three recovery flow passages 206. Furthermore, in order to simplify the structure, it is assumed that adjacent supply flow passages 205 and recovery flow passages 206 circulate ink of the same color.

[0034] As shown in FIG. 4(a), the flow path forming member 201 (201a, 201b) has an adhesive surface 208 (208a, 208b) that abuts against the flow path joining surface 204 (204a, 204b) of the tank member 200. The adhesive surface 208 (208a, 208b) is formed with a supply flow path rib 209 (209a, 209b) and a recovery flow path rib 210 (210a, 210b) that are inserted into the openings 251 (251a, 251b). The supply flow path rib 209 and the recovery flow path rib 210 are formed to adjust the volume and ink flow of the supply flow path 205 and the recovery flow path 206. The volume adjustment is necessary to adjust the internal pressure balance of the supply flow path 205 and the recovery flow path 206 when the flow path lengths of the three colors cannot be made the same due to the structure.

[0035] As shown in FIG. 4(b), adhesive 211 is applied to the bonding surface 208 (208a, 208b). Thereafter, as shown in FIG. 4(c), the tank member 200 and the flow path forming member 201 (201a, 201b) are bonded together so that the flow path joining surface 204 (204a, 204b) and the bonding surface 208 (208a, 208b) come into contact with each other. At this time, the tank member 200 and the flow path forming member 201 are formed so that the width of the flow path wall 207 is narrower than the width of the bonding surface 208, and the supply flow path rib 209 is narrower than the supply flow path 205 and the recovery flow path rib 210 is narrower than the recovery flow path 206. As a result, the flow path wall 207 fits between the supply flow path rib 209 and the recovery flow path rib 210, and the supply flow path rib 209 fits into the opposing supply flow path 205 and the recovery flow path rib 210 fits into the opposing recovery flow path 206, respectively. By fitting together in this manner, the flow path joining surface 204 of the tank member 200 and the adhesive surface 208 of the flow path forming member 201 come into contact with each other, and the tank member 200 and the flow path forming member 201 can be attached together without any gaps.

[0036] When the flow path joint surface 204 and the adhesive surface 208 come into contact with each other, flow path grooves 215 are formed along the ribs between the flow path wall 207 and the supply flow path rib 209, and between the flow path wall 207 and the recovery flow path rib 210. The flow path grooves 215 are formed in the direction of insertion of the ribs 209, 210 into the opening 251 (indicated by arrow E The gap is a gap of a predetermined width formed between the ribs 209, 210 and the flow passage forming holes 250, 260 in a width direction intersecting both the ink flow direction (the ink flow direction) and the direction in which the flow passages 205, 206 extend. The width of the flow passage groove 215 is required to be 0.05 mm to 1.2 mm, although the capillary force varies depending on the ink density, the wettability of the material, and the surface tension. When the flow passage width of the supply flow passage 205 and the recovery flow passage 206 in the width direction is 1, the flow passage width of the flow passage groove 215 relative to the flow passage width of the supply flow passage 205 and the recovery flow passage 206 is preferably 0.125 or more and 0.25 or less. With such a dimensional ratio, the amount of ink consumed by ejection can be stably supplied, and the print quality can be stabilized.

[0037] However, no matter how small the flow path width is designed to be, it is preferable that the flow path width of the flow path groove 215 is not set to 0.125 mm or less. If the flow path width of the flow path groove 215 is 0.125 mm or less, the capillary force becomes strong, which may cause ink stagnation and slow the ink supply speed. Conversely, no matter how large the flow path width is designed to be, it is preferable that the flow path width of the flow path groove 215 is not set to 1.0 mm or more. If the flow path width of the flow path groove 215 is 1.0 mm or more, the capillary force becomes weak, the ink supply becomes fast, and the position of the meniscus at the ejection port 109 changes due to the weight of the ink, which may prevent stable ejection.

[0038] In this embodiment, the width of the flow channel groove 215 is designed to be 0.2 mm larger than the fit tolerance of the ribs 209, 210 relative to the width of the flow channel forming holes 250, 260. In this embodiment, the preferred range of the width of the flow channel groove 215 is 0.5 mm or more and 1.0 mm or less for the flow channels 205, 206 of 2.0 mm. Note that these specific values ​​are merely examples and are set appropriately depending on the device configuration.

[0039] As shown in FIG. 4(c), the flow path forming members 201a and 201b are fitted and joined to the tank member 200, so that the opposing space between the tip surface of the supply flow path rib 209a and the tip surface of the supply flow path rib 209b forms the large liquid chamber 216. This large liquid chamber 216 becomes the supply flow path 205. Similarly, the flow path forming members 201a and 201b are fitted and joined to the tank member 200, so that the opposing space between the tip surface of the recovery flow path rib 210a and the tip surface of the recovery flow path rib 210b forms the large liquid chamber 216. This large liquid chamber 216 becomes the recovery flow path 206. These large liquid chambers 216 are structured to collect bubbles 280 generated during ink ejection. If bubbles 280 generated during ink ejection enter the flow path groove 215, they may accumulate in the flow path groove 215 and not be used for ink supply, which may result in stable ink ejection.

[0040] Fig. 5 is a schematic cross-sectional view showing a schematic configuration of a liquid ejection head 100d according to a first comparative embodiment. In the liquid ejection head 100d according to the first comparative embodiment, the configuration of a support member 102d is different from the configuration of the support member 102 of the liquid ejection head 100 according to the first embodiment. As described above, Fig. 2 is a diagram showing a schematic basic configuration of the liquid ejection head 100 according to the first embodiment, whereas Fig. 5 is a diagram showing a more specific configuration of the liquid ejection head 100 according to the first embodiment.

[0041] Here, the configuration of the liquid ejection head 100d according to the first comparative embodiment will be described, including the configuration common to the liquid ejection head 100 according to the first embodiment. The configuration common to the liquid ejection head 100d according to the first comparative embodiment and the liquid ejection head 100 according to the first embodiment will be described with the same reference numerals.

[0042] 5, flow paths capable of independently ejecting ink of three colors (three types) are arranged on one recording element substrate 110. That is, one recording element substrate 110 has three sets of supply flow paths 115 for supplying ink and ink recovery flow paths 116 for recovering ink to the circulation pump unit 103, which are formed independently and integrally. In this way, a configuration in which flow paths capable of ejecting ink of three colors are arranged on one recording element substrate 110 This has cost advantages such as shortening the tact time required to join the recording element substrate 110 and reducing the number of parts.

[0043] 5, the size of the recording element substrate 110 and the size of the circulation pump unit 103 are different, and the positions of the inlets and outlets of the flow paths are different in the direction perpendicular to the joining direction, so that the supply flow path 205 and the recovery flow path 206 of the tank member 200a are partially inclined. Furthermore, the inclined flow paths include flow paths with long inclinations and flow paths with short inclinations.

[0044] That is, the supply flow path 205 includes a straight flow path portion 205s1 on the upstream side, a straight flow path portion 205s2 on the downstream side, and an inclined flow path portion 205i connecting them. The straight flow path portions 205s1 and 205s2 are portions that extend along a direction perpendicular to the joining surface 202 and the bonding surface 203, or along the arrangement direction of the head portion 101, the support member 102, and the circulation pump unit 103. This direction (the direction of the arrow D) coincides with the stacking direction of the recording element substrate 110 and the substrate support member 112, or with a direction perpendicular to the joining surface of the recording element substrate 110 and the substrate support member 112. The straight flow path portion 205s1 and the straight flow path portion 205s2 are arranged at positions shifted from each other in a direction along the joining surface 202 and the bonding surface 203, or in a direction perpendicular to the arrangement direction. The inclined channel portion 205i extends in a direction inclined with respect to the extending direction of the straight channel portions 205s1 and 205s2, and serves as a channel connecting the straight channel portion 205s1 and the straight channel portion 205s2.

[0045] In the supply flow path 205, the straight flow path portion 205s1 on the upstream side communicates with the supply port 301 of the circulation pump unit 103, and the straight flow path portion 205s2 on the downstream side communicates with the supplied port 125 of the head portion 101.

[0046] Similarly, the recovery channel 206 includes an upstream straight channel portion 206s1, a downstream straight channel portion 206s2, and an inclined channel portion 206i connecting them. The straight channel portions 206s1 and 206s2 are portions that extend along a direction perpendicular to the joining surface 202 and the joining surface 203, or along the above-mentioned arrangement direction. The straight channel portion 206s1 and the straight channel portion 206s2 are arranged at positions offset from each other in a direction along the joining surface 202 and the joining surface 203, or in a direction perpendicular to the above-mentioned arrangement direction. The inclined channel portion 206i extends in a direction inclined with respect to the extension direction of the straight channel portions 206s1 and 206s2, and serves as a channel that connects the straight channel portion 206s1 and the straight channel portion 206s2.

[0047] In the recovery channel 206, the upstream straight channel section 206s1 communicates with the recovery port 126 of the head section 101, and the downstream straight channel section 206s2 communicates with the recovery port 302 of the circulation pump unit 103.

[0048] The inclined supply flow passage 205 and recovery flow passage 206 have different distances and inclinations for each of the three types of ejection systems. Therefore, as shown in Fig. 4(c), the cross section of the flow passage is made different for each system, so that the pressure loss balance during ink supply does not differ for each flow passage. Specifically, the opposing distance between the tip surface of the supply flow passage rib 209a and the tip surface of the supply flow passage rib 209b, and the opposing distance between the tip surface of the recovery flow passage rib 210a and the tip surface of the recovery flow passage rib 210b are each made different for each ejection system (D1 to D3 in Fig. 4(c), etc.).

[0049] 4(c) and 5 show three pairs of a supply flow path 205 and a recovery flow path 206 that form one ink circulation path. Of these, the supply flow path 205 and the recovery flow path 206 that form the pair in the middle of the figure have a symmetrical structure, but the supply flow path 205 and the recovery flow path 206 that form the pairs on both sides of the figure have an asymmetrical structure.

[0050] That is, the supply channel 205 and recovery channel 206 constituting the pair at the center in the figure are symmetrical in plan view as shown in Fig. 5, and the distance between the opposing rib tip faces is D3 in both cases as shown in Fig. 4(c), so that the channel cross sections are the same. On the other hand, for example, the supply channel 205 and recovery channel 206 constituting the pair at the right in the figure are formed such that the inclined channel section 205i is longer than the inclined channel section 206i, and the distance between the opposing rib tip faces is D1 for the former and D2 for the latter as shown in Fig. 4(c), so that the channel cross sections are different from each other.

[0051] In this way, by adjusting the distance between the opposing rib tips and adjusting the cross-sectional area of ​​the flow passages, the volumes of the flow passages are made the same, thereby achieving a balance in pressure loss between the flow passages.

[0052] In the first comparative embodiment and this embodiment, for example, the narrowest facing distance D1 is set to 22 mm, the widest facing distance D3 is set to 44 mm, and the facing distance D2 therebetween is set to 33 mm. Note that these specific numerical values ​​are merely examples and are set appropriately depending on the device configuration.

[0053] The ribs 209 and 210 also have inclined portions in accordance with the inclination of the above-mentioned flow channels 205 and 206. Therefore, the flow channel grooves 215 formed between the flow channel wall 207 and the ribs 209 and 210 also have inclined portions in accordance with the inclination of the flow channels 205 and 206.

[0054] Furthermore, recesses 217, 218, and 219 are provided to form a curved portion in a part of the flow path wall 207 (flow path side surface) of the tank member 200. These recesses 217, 218, and 219 are provided, for example, to distribute stress caused by cooling after molding of the tank member 200, which is an injection molded product, and to suppress deformation caused by the occurrence of sink marks, etc. There is a concern that the occurrence of such deformation may cause the following problems.

[0055] For example, if the bonding surface 203 that is bonded to the circulation pump unit 103 is significantly deformed, it may cause ink leakage. Also, if the bonding surface 202 that is bonded to the head unit 101 is significantly deformed, there is a possibility that the thickness of the adhesive used to bond to the head unit 101 may differ, which may cause a difference in stress when curing, resulting in a precision defect.

[0056] If the recesses 217-219 are not provided, the thickness shape of the tank member 200 between the outside of the tank member 200 and the inclined portions of the flow paths 205, 206 close to the outside of the tank member 200 will be triangular. The presence of such thick portions is considered to be the cause of deformation. The thickness of the tank member 200 between the inclined flow path portion and the joining surface 202 or the connecting surface 203 becomes thinner the closer it is to the head portion 101 or the circulation pump unit 103, and becomes thicker the further it is from the head portion 101 or the circulation pump unit 103 (closer to the center). It is considered that heat is accumulated in these thick portions, making them more susceptible to deformation.

[0057] As a countermeasure, a recess 217 is provided at the middle position of the inclined flow path portion in the flow paths 205, 206 to form a portion where the thickness of the tank member 200 is uniform between the joint surface 202 and the flow paths 205, 206 (portion having thicknesses T1h, T1v). The recess 217 includes a horizontal flow path side 207h (first flow path side) extending parallel to the joint surface 202 and a vertical flow path side 207v (second flow path side) extending perpendicularly to the joint surface 202. The horizontal flow path side 207h is a portion for making the thickness of the tank member 200 between the joint surface 202 and the flow path side forming the inclined flow path portion in the direction perpendicular to the joint surface 202 (direction of arrow D) partially constant (thickness T1h). Moreover, the vertical flow path side surface 207v is a portion for making the thickness of the tank member 200 between the flow path side surface forming the inclined flow path portion and the outer surface of the tank member 200 partially constant (thickness T1v) in the direction along the joint surface 202. This makes it difficult for the above-mentioned heat accumulation to occur, and suppresses deformation of the tank member 200.

[0058] In addition, the flow path wall 207 between the supply flow path 205 and the recovery flow path 206 also deforms due to heat accumulation. As a countermeasure, a recess 218 for suppressing deformation on the joining surface 203 side of the tank member 200 and a recess 219 for suppressing deformation on the joining surface 202 side of the tank member 200 are provided. That is, in the tank member 200, a portion having a thickness T2 is formed within a predetermined range by the recess 218, and a portion having a thickness T3 is formed within a predetermined range by the recess 219.

[0059] In such a tank member 200, a convex portion is also formed in the rib 209 corresponding to the recesses 217, 219 of the flow path forming hole on the side closer to the head portion 101. Therefore, the flow path groove 215 includes a flow path groove portion extending horizontally (a direction perpendicular to the direction of arrow D) in the portion corresponding to the recesses 217, 219. In this horizontal flow path groove portion, bubbles generated by ejection are difficult to escape and tend to accumulate, which may result in unstable ink supply and cause printing defects.

[0060] Among the recesses 217 to 219, the recess 217 in particular may be provided from a viewpoint other than the viewpoint of the moldability of the tank member described above.

[0061] When the inclined flow passage portion of the flow passages 205, 206 is longer, the flow passage groove 215 is also longer, and the amount of ink held is greater than that of the flow passage groove 215 in a flow passage with a shorter inclination. When the amount of ink is greater, the ink flows faster due to the weight of the ink. By narrowing or widening the width of the flow passage groove 215 according to the length of the inclination, it is possible to control the speed of the ink due to its own weight by capillary force and to control the ink supply speed. However, such a measure requires high accuracy in the fitting accuracy of the tank member 200 and the flow passage forming member 201, the dimensional accuracy of each member, etc.

[0062] As a measure that does not require such high accuracy, a method of providing a recess 217 at the middle position of a region with a long inclination in the flow channel 2056 can be mentioned. A convex portion 223d corresponding to the recess 217 is formed in the rib 209, and the width of the flow channel 215 is kept constant even in the recess 217. That is, a vertical flow channel groove portion 215v extending vertically and a horizontal flow channel groove portion 215h extending horizontally are formed in the portion of the flow channel 215 corresponding to the recess 217. The vertical flow channel groove portion 215v and the horizontal flow channel groove portion 215h form a deflection path portion 215c that temporarily changes the direction of the flow channel 215 so as to temporarily bulge the path to one side in the flow channel width direction in the middle of the path of the flow channel 215 from the upstream to the downstream of the flow channel 205. This can slow down the ink self-weight speed in the flow channel 215. The ink that falls from the vertical flow groove portion 215v of the flow channel 215 moves faster due to its own weight, but the surface area with which the ink comes into contact increases in the recess 217 including the vertical flow groove portion 215v and the horizontal flow groove portion 215h of the flow channel 215, resulting in increased pressure loss. At the corner between the vertical flow groove portion 215v and the horizontal flow groove portion 215h of the flow channel 215 (the connection portion between the vertical flow groove portion 215v and the horizontal flow groove portion 215h), the contact area increases, causing the ink fluidity to deteriorate and the ink flow to stagnate. In this way, the ink flow resistance increases in the recess 217, and pressure is also required to push out the ink in the horizontal portion of the flow channel 215, so that the ink supply speed in the recess 217 can be slowed overall. That is, the ink supply speed can be adjusted by adjusting the size of the recess 217.

[0063] However, in the inclined flow channel 215, bubbles generated by ejection enter the flow channel 215, rise, and escape to the large liquid chamber 216, but the bubbles have difficulty escaping and tend to accumulate in the horizontal flow channel portion 215h in the recess 217. This can cause the ink supply to become unstable, potentially resulting in poor printing.

[0064] In this embodiment, the tank member 200 and the flow path forming member 201 are both formed by molding using modified PPE, fitted together, and joined with the adhesive 211, but other joining methods may be used.

[0065] The circulation pump unit 103 will now be described. The circulation pump unit 103 has a box body 300 made of modified PPE. The box body 300 has, at its joint surface with the support member 102, a supply port 301 that communicates with the supply flow path 205 of the support member 102, and a recovery port 302 that communicates with the recovery flow path 206. Inside the box body 300, a circulation flow path is formed so that ink flows from the recovery port 302 to the supply port 301. An electrically driven drive pump 304 is provided between the recovery port 302 and the supply port 301, and the operation of the drive pump 304 causes ink to flow in the circulation flow path.

[0066] Between the recovery port 302 and the drive pump 304, a filter chamber 305 made of a SUS filter is formed, and has the function of removing impurities mixed in during circulation. Negative pressure valves 306 are provided between the filter chamber 305 and the drive pump 304, and between the drive pump 304 and the supply port 301. The negative pressure valves 306 have the role of generating and controlling negative pressure in the liquid ejection heads 100d and 100, and in this embodiment, a valve that opens and closes with a spring is used.

[0067] The circulation pump units 103 are connected to the support member 102 in the same number as the types of ink used in the liquid ejection heads 100d and 100.

[0068] In this embodiment, the circulation pump unit 103 is connected to the support member 102 by fastening with screws, and a rubber seal is sandwiched between the support member 102 and the circulation pump unit 103 to prevent liquid leakage. This rubber seal is preferably one with good ink resistance, and is made of EPDM in this embodiment. By connecting the circulation pump unit 103, an ink flow path is formed that circulates ink inside the liquid ejection heads 100d, 100, and the pressure inside the liquid ejection heads 100d, 100 can be kept within a certain range. Ink is supplied to the liquid ejection heads 100d, 100 by providing an ink supply path that sends ink from an ink storage unit (liquid supply source) called a main tank 400 to a recovery port 302 of the circulation pump unit 103.

[0069] Here, as described above, the flow paths 205, 206 of the support member 102d (102) include the inclined flow path portions 205i, 206i in part, and the ribs 209, 210 and the flow path groove 215 also include inclined portions corresponding to the inclination. Bubbles generated during ink ejection that enter the flow path groove 215 rise while hitting the flow path wall 207, the supply flow path rib 209, and the recovery flow path rib 210, and escape to the large liquid chamber 216. At this time, particularly in the inclined portion of the flow path groove 215, the bubbles are likely to get caught by the flow path wall 207, the supply flow path rib 209, and the recovery flow path rib 210 and remain there. If bubbles generated during ink ejection remain in the flow path groove 215, the ink supply becomes unstable, which may cause printing defects.

[0070] As an operation for removing the bubbles remaining in the flow channel 215, there is a function of forcibly sucking the ink from the discharge port 109 by a recovery operation of the main body of the recording device equipped with the liquid discharge head, and discharging the ink. Since this is a suction operation that forcibly removes the ink, the ink flow in the flow channel during the suction operation is several times faster than the flow speed during ink discharge. The suction force that causes such a fast flow speed discharges the bubbles from the flow channel 215 at the same time as the ink. However, if the bubbles cannot be removed by one suction operation, it may be necessary to perform the suction operation multiple times. If the bubbles are still not removed, it may be necessary to further increase the suction pressure. As a result, the amount of ink consumed may increase, and the number of printed sheets per ink tank may decrease.

[0071] In addition, before the device is shipped, the liquid ejection head is inspected for ejection performance. In the ejection performance inspection, the liquid ejection head is mounted on an ejection performance inspection machine, and an ejection operation is performed in which ink is actually ejected from all the ejection ports. The ink is ejected onto high-quality dedicated paper, and the landing position of the ink droplets is evaluated and inspected to see if it is within a predetermined accuracy. The ink ejected at this time is an inspection ink, and it is necessary to remove the inspection ink from the liquid ejection head and wash the inside of the head with pure water before shipping. Ink residue is likely to occur in the flow channel including the inclination as described above, and there is a concern that the residual components of the inspection ink may affect the ejection performance when the product is actually used.

[0072] The test ink used in the ejection performance test of liquid ejection heads before shipping is often different from the printing ink used as the recording liquid for the liquid ejection device, due to the effect of ink volatilization during head storage and to reduce ink costs. Therefore, liquid ejection heads that are determined to have no problem with ejection accuracy are shipped in a dry state after the test ink inside is removed. Since the test ink and printing ink are different, any remaining components of the test ink may react with the printing ink, causing foreign matter to be generated from the printing ink.

[0073] In this embodiment, the inside of the liquid ejection head 100 is washed with pure water after the ejection performance test in order to reduce the residual rate of the test ink. A main tank 400 containing pure water is prepared and filled into the liquid ejection head 100. The main tank 400 is then removed, the ejection ports 109 are blocked, and the liquid ejection head 100 is agitated so that the pure water spreads throughout the liquid ejection head 100. After agitation is complete, a suction pad is attached to the recording element substrate 110 side, and the cleaning water is sucked at a reduced pressure of about -80 kPa.

[0074] Here, in the liquid ejection head of the first comparative embodiment, even if the cycle of filling with pure water, stirring, and suction is performed about five times, the replacement of the test ink in the flow channel 215 with pure water (hereinafter referred to as the pure water replacement rate or replacement rate) may not progress sufficiently. In particular, the replacement with pure water may become poor in the above-mentioned horizontal flow channel portion of the flow channel 215.

[0075] Furthermore, in the recess 217 provided at the middle of the inclined portion of the flow path 205, the flow path groove 215 is configured to change direction at a substantially right angle from the vertical direction (the direction of the arrow D) to the horizontal direction (the direction perpendicular to the direction of the arrow D). In particular, the capillary force is high at the right angle portion, which tends to cause stagnation in the ink flow, and this portion becomes a portion that deteriorates the replacement rate of the test ink components with pure water. If drying is performed in a state where the replacement rate is poor, the test ink components will become concentrated and thick. If printing ink is filled while these concentrated test ink components remain, impurities may be generated.

[0076] In this way, in a liquid ejection head in which recesses 217, 218, and 219 are provided in flow path groove 215, ejection defects and insufficient replacement may occur. As a countermeasure, liquid ejection head 100 according to the first embodiment of the present invention is provided with a liquid flow path structure that can improve the above-mentioned ejection defects and insufficient replacement. This will be described below with reference to Figures 6, 7, 8, and 9.

[0077] Fig. 6 is a schematic plan view of a flow path forming member 201 (201a, 201b) in the first embodiment. Fig. 7 is a schematic cross-sectional view of a support member 102 in the first embodiment in which the flow path forming member 201 is fitted into a tank member 200. Fig. 8 is an enlarged view of the periphery of a recess 217 in Fig. 7. Fig. 9 is a schematic cross-sectional view of the FF cross section of Fig. 7, showing the generation of bubbles 280.

[0078] As shown in Fig. 9, small bubbles 280 generated during ejection flow through the flow channel 215 into the large liquid chamber 216, and at that time, large bubbles 280 may form in the large liquid chamber 216. Such large bubbles 280 may be formed when bubbles 280 that have entered the recesses 217 of the flow channel 215 remain in the recesses 217 and the small bubbles join together. Such a large bubble 280 can cause the ink supply to become unstable, resulting in printing defects.

[0079] As described above, the tank member 200 has a recess 217 formed in one of the pair of flow path side surfaces 207a, 207b that form the flow path forming hole 250. The pair of flow path side surfaces 207a, 207b face each other in a width direction W (FIG. 8) that intersects with both the insertion direction of the rib 209 into the opening 251 and the direction G in which the flow path 205 extends, and the recess 217 has a shape that is generally recessed in the width direction W. In this embodiment, the recess 217 includes a horizontal flow path side surface 207h (first flow path side surface) that extends parallel to the joint surface 202 and a vertical flow path side surface 207v (second flow path side surface) that extends perpendicularly. For such a recess 217, the rib 209 has a protrusion 223 that protrudes in the width direction W at a portion corresponding to the recess 217 on the rib side surface 222a that faces the flow path side surface 207a.

[0080] The flow channel 215 forms a deflection path portion 215c at a portion between the recessed portion 217 and the protruding portion 223, which is located midway along the path of the flow channel 215 extending from the upstream to the downstream of the flow channel 205. The deflection path portion 215c is a portion that extends so as to temporarily change the direction of the path of the flow channel 215 so as to temporarily bulge the path of the flow channel 215 to one side in the width direction W.

[0081] As described above, in this embodiment, the deflection path portion 215c is composed of the vertical flow path groove portion 215v and the horizontal flow path groove portion 215h. The path of the flow path groove 215 includes an upstream path portion extending along the direction G of the flow path 205 on the upstream side of the deflection path portion 215c, and a downstream path portion extending along the direction G of the flow path 205 on the downstream side of the deflection path portion 215c. The vertical flow path groove portion 215v is connected to the upstream path portion described above to form a first path portion extending in a first direction that is a direction intersecting the direction in which the flow path 205 extends and is a direction away from the upstream path portion in the width direction W. Further, the horizontal flow channel groove portion 215h forms a second path portion extending in a second direction between the first path portion and the downstream path portion, the second direction being a direction intersecting both the extending direction G of the flow channel 205 and the first direction and approaching the upstream path portion in the width direction W. In this embodiment, the first direction corresponds to the vertical direction and the second direction corresponds to the horizontal direction, but this configuration is merely an example.

[0082] The convex portion 223 of this embodiment is configured to expand the width of the flow channel 215 in the deflection path portion 215c of the flow channel 215, particularly at the corner between the vertical flow channel portion 215v and the horizontal flow channel portion 215h. This makes it easier for bubbles 280 that have entered the deflection path portion 215c to return to the large liquid chamber 216 without remaining in the deflection path portion 215c, particularly the horizontal flow channel portion 215h.

[0083] The protruding portion 223 in this embodiment is configured to have an arc-shaped cross section along the width direction W. In this embodiment, the radius of curvature R of the arc-shaped cross section is set to be in the range of 1.5 mm or more and 3.0 mm or less. By making the protruding portion 223 have an arc-shaped cross section, a convex curved surface is formed on a part of the rib side surface 222a that forms the flow channel groove 215.

[0084] Here, the vertical flow path side surface 207v and the horizontal flow path side surface 207h of the recessed portion 217, which the convex portion 223 faces, may have a difference in length because the inclination angle of the inclined portion (inclined flow path portion 205i) of the flow path 205 changes depending on the configuration of the support member 102. For example, as the inclination angle of the inclined flow path portion 205i of the flow path 205 approaches horizontal, the length of the vertical flow path side surface 207v (vertical flow path groove portion 215v) becomes shorter than the length of the horizontal flow path side surface 207h (horizontal flow path groove portion 215h). In order to ensure the above-mentioned dimensional range of the curvature radius R of the arc-shaped portion of the convex portion 223, it is desirable that the length of the shorter one of the vertical flow path side surface 207v and the horizontal flow path side surface 207h is twice or more the curvature radius R of the arc-shaped portion of the convex portion 223.

[0085] The larger the radius of curvature R of the arc shape, the better the bubble removal property, but the length of the vertical flow groove portion 215v or the horizontal flow groove portion 215h may become too short, which may weaken the capillary force. Also, if the corner between the vertical flow groove portion 215v and the horizontal flow groove portion 215h is too far away from the convex portion 223 and the width W215 of the flow groove 215 becomes too wide, the ink flow resistance may become too weak, which may make it difficult to control the ink supply speed due to the ink's own weight.

[0086] By setting the radius of curvature R of the arc shape of the convex portion 223 within the above dimensional range, a shape is formed that allows small bubbles 280 to easily escape without getting caught in the deflection path portion 215c, and small bubbles 280 that have entered the deflection path portion 215c can be effectively and efficiently discharged into the large liquid chamber 216.

[0087] The shape of the convex portion 223 may be such that an arc-shaped portion is formed at least at the tip of the convex portion 223. The shape of the convex portion 223 is not limited to an arc with a constant radius of curvature, and may be, for example, an arc shape with a gradually changing radius of curvature.

[0088] As described above, by locally and partially widening the gap of the deflection path portion 215c in the flow path groove 215, the bubble 280 in the flow path groove 215 can be easily moved to the large liquid chamber 216. In particular, by forming the convex portion 223 into a circular arc shape in cross section and forming the rib side surface forming the flow path groove 215 into a convex curved surface, the bubble 280 that has entered the flow path groove 215 can be easily moved along the arc (curved surface) to the large liquid chamber 216. This makes it possible to prevent the bubble 280 from blocking the flow path groove 215 and causing printing defects as a result. Even if the bubble 280 that has entered gets caught on the wall of the flow path groove 215, the wide gap of the deflection path portion 215c ensures a flow path through which the ink flows. This makes the flow of ink turbulent due to the recovery operation, improving the bubble removal property. Therefore, it becomes possible to avoid performing the recovery operation multiple times, reducing the amount of ink consumption, and preventing printing defects from occurring. Furthermore, even when cleaning with pure water, turbulence is more likely to occur, which improves cleaning efficiency and reduces the effects of test ink.

[0089] Fig. 10 is a schematic cross-sectional view of a support member 102a according to Modification 1 of the first embodiment. As shown in Fig. 10, in the case of a flow channel 215 with a long inclination, the number of recesses 217 may be increased. Even with this configuration, the same effects as those of the first embodiment can be achieved.

[0090] Fig. 11 is a schematic enlarged cross-sectional view of the periphery of the recess 217 of the support member 102b of the second modified example of the first embodiment. The shape of the protrusion 223 is not limited to the above-mentioned cross-sectional arc shape, and may be configured to have a cross-sectional shape with a contour (polygonal contour) in which straight lines whose angles are gradually changed are connected, as in the case of the protrusion 223b shown in Fig. 11. That is, the protrusion 223b of the second modified example is configured such that the vertical rib side surface 223v as the first rib side surface, the inclined rib side surface 223i as the third rib side surface, and the horizontal rib side surface 223h as the second rib side surface are connected from the upstream to the downstream of the flow path 205.

[0091] The vertical rib side surface 223v, in a cross-sectional shape along the width direction W, extends in a vertical direction as a first direction intersecting with the direction G in which the flow channels 205 extend. The horizontal rib side surface 223h extends in a horizontal direction as a second direction intersecting with both the direction G in which the flow channels 205 extend and the first direction. The inclined rib side surface 223i extends between the vertical rib side surface 223v and the horizontal rib side surface 223h in a direction substantially along the direction G in which the flow channels 205 extend as a third direction intersecting with both the first direction and the second direction.

[0092] Even with this configuration, the same effects as those of the first embodiment can be achieved. Note that the configuration of the polygonal contour of the convex portion 223b is not limited to the above-mentioned configuration, and it is also possible to provide a plurality of The side surfaces may be connected (multiple inclined surfaces are connected with gradually changing inclination angles).

[0093] 12 is a schematic enlarged cross-sectional view of the periphery of a recess 217 of a support member 102c of Modification 3 of the first embodiment. In the first embodiment, the recess 217 is formed on one of the pair of flow path side surfaces 207a, 207b that form the flow path forming hole 250, but in Modification 3, the recess 217b is formed on the other flow path side surface 207b. In correspondence with the recess 217b, a protrusion 223c is formed on a rib side surface 222a that faces the flow path side surface 207b and forms the flow path groove 215.

[0094] With this configuration as well, it is possible to achieve the same effects as in the first embodiment. Note that the convex portion 223b may be provided as an additional configuration to the first embodiment or the first and second modifications.

[0095] The configuration of the rib 209 and the configuration of the recessed portion 217 and the protruding portion 223 (the number, position, size (width), shape, etc. of the recessed portion 217 and the protruding portion 223) in the present embodiment described above are merely examples, and may be appropriately set according to the configuration of the device. Also, in the present embodiment, the recessed portion 217 and the protruding portion 223 are provided in the supply flow path 205, but the recessed portion 217 and the protruding portion 223 may be provided in the recovery flow path 206.

[0096] In the present embodiment, the recess 217 is configured with a horizontal flow path side surface 207h (first flow path side surface) extending parallel to the joint surface 202 and a vertical flow path side surface 207v (second flow path side surface) extending perpendicularly to the joint surface 202, but the configuration of the recess 217 is not limited thereto. For example, the recess 217 may be configured with a first flow path side surface and a second flow path side surface extending in a direction having an angle with respect to the horizontal direction or the vertical direction.

[0097] For example, the positions of the recesses 217 and protrusions 223 formed in the rib 209a of one flow path forming member 201a in the direction in which the flow path extends may be different from the positions of the recesses 217 and protrusions 223 formed in the rib 209b of the other flow path forming member 201b.

[0098] The above-described embodiment and each of the modified examples can be combined with each other.

[0099] The disclosure of the embodiments of the present invention includes the following configurations. (Configuration 1) a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; a flow path forming member that has a rib that is inserted into an opening of the flow path forming hole that opens on the side surface, and is joined to the side surface so as to close the opening, and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the support member body has a recess recessed in the width direction on at least one of a pair of flow path side surfaces facing each other in the width direction in the flow path forming hole, The rib has a front end provided at a portion of the rib side surface facing the flow passage side surface, the portion corresponding to the recess. The tape has a protrusion protruding in the width direction, The opposing distance between the flow channel side surface and the rib side surface is partially enlarged at the opposing portion between the recessed portion and the protruding portion. A liquid ejection head comprising: (Configuration 2) 2. The liquid ejection head according to configuration 1, wherein the protrusion includes an arc-shaped portion at least at a tip in a cross-sectional shape along the width direction. (Configuration 3) 3. The liquid ejection head according to configuration 1 or 2, wherein the radius of curvature of the arc-shaped portion is 1.5 mm or more and 3.0 mm or less. (Configuration 4) A liquid ejection head described in any one of configurations 1 to 3, characterized in that the convex portion, in its cross-sectional shape along the width direction, includes a first rib side extending in a first direction intersecting the direction in which the flow path extends, a second rib side extending in a second direction intersecting both the direction in which the flow path extends and the first direction, and a third rib side extending in a third direction intersecting both the first direction and the second direction between the first rib side and the second rib side. (Configuration 5) A liquid ejection head described in any one of configurations 1 to 4, characterized in that the recess, in the cross-sectional shape, includes, in a portion facing the arc-shaped portion, a first flow path side surface extending in a first direction intersecting the direction in which the flow path extends, and a second flow path side surface extending in a second direction intersecting both the direction in which the flow path extends and the first direction. (Configuration 6) the support member has a bonding surface to which the liquid ejection unit is bonded, The flow path includes an inclined flow path portion extending in a direction inclined with respect to a direction perpendicular to the joint surface, 6. The liquid ejection head according to any one of configurations 1 to 5, wherein the recessed portion and the protruding portion are formed in the inclined flow path portion. (Configuration 7) The first flow path side surface extends parallel to the joint surface, The liquid ejection head according to any one of configurations 1 to 6, wherein the second flow path side surface extends perpendicular to the joining surface. (Configuration 8) the first flow path side surface is a portion for making a thickness of the support member between the inclined flow path portion and the joint surface partially constant in a direction perpendicular to the joint surface, A liquid ejection head described in any one of configurations 1 to 7, characterized in that the second flow path side is a portion for making the thickness of the support member between the inclined flow path portion and the outer surface of the support member partially constant in the direction along the joint surface. (Configuration 9) a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; a flow path forming member that has a rib that is inserted into an opening of the flow path forming hole that opens on the side surface, and is joined to the side surface so as to close the opening, and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the flow path groove includes a deflection path portion that temporarily changes a direction of the flow path of the flow path groove extending from the upstream side to the downstream side of the flow path so as to temporarily bulge the path to one side in the width direction, A liquid ejection head, wherein a width of the flow path groove is partially expanded in the deflection path portion. (Configuration 10) The route is an upstream path portion extending along a direction in which the flow channel extends, on an upstream side of the deflection path portion; a downstream path portion extending along a direction in which the flow channel extends on a downstream side of the deflection path portion; Including, The deflection path portion is a first path portion that is connected to the upstream path portion and extends in a first direction that intersects with the extension direction of the flow channel and is a direction away from the upstream path portion in the width direction; a second path portion extending in a second direction between the first path portion and the downstream path portion, the second path portion being a direction intersecting both the extension direction of the flow channel and the first direction and approaching the upstream path portion in the width direction; Including, A liquid ejection head according to any one of configurations 1 to 9, characterized in that the width of the flow path groove in the width direction partially widens at a connection portion between the first path portion and the second path portion. (Configuration 11) A liquid ejection head described in any one of configurations 1 to 10, characterized in that the width of the flow path groove in the width direction is 0.125 or more and 0.25 or less, assuming that the width of the flow path in the width direction is 1. (Configuration 12) 12. The liquid ejection head according to any one of configurations 1 to 11, wherein the width of the flow path groove in the width direction is within a range of 0.5 mm or more and 1.0 mm or less. (Configuration 13) The flow path is a supply flow path for supplying liquid from the liquid supply unit to the pressure chamber; a recovery flow path for recovering liquid from the pressure chamber to a liquid supply unit; Including, The liquid supply unit includes: a circulation flow path that connects the supply flow path and the recovery flow path and is supplied with liquid from a liquid supply source; a pump that generates a flow of liquid flowing from the recovery flow path through the circulation flow path to the supply flow path; 13. The liquid ejection head according to any one of configurations 1 to 12, comprising: [Explanation of symbols]

[0100] 102...support member, 200...tank member, 201...flow path forming member, 204...flow path joining surface, 205...supply flow path, 206...recovery flow path, 207...flow path wall, 208...adhesive surface, 209...supply flow path rib, 210...recovery flow path rib, 215...flow path groove, 217...recess, 223...projection

Claims

1. a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; a flow path forming member that has a rib that is inserted into an opening of the flow path forming hole that opens on the side surface, and is joined to the side surface so as to close the opening, and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the support member body has a recess recessed in the width direction on at least one of a pair of flow path side surfaces facing each other in the width direction in the flow path forming hole, the rib has a protrusion protruding in the width direction at a portion of a rib side surface facing the flow channel side surface, the protrusion protruding in the width direction at a portion of the rib side surface facing the flow channel side surface, the protrusion The opposing distance between the flow channel side surface and the rib side surface is partially enlarged at the opposing portion between the recessed portion and the protruding portion. A liquid ejection head comprising:

2. The liquid ejection head according to claim 1 , wherein the protrusion includes an arc-shaped portion at least at a tip in a cross section along the width direction.

3. 3. The liquid ejection head according to claim 2, wherein the radius of curvature of the arc-shaped portion is 1.5 mm or more and 3.0 mm or less.

4. The liquid ejection head described in claim 1, characterized in that the convex portion, in its cross-sectional shape along the width direction, includes a first rib side surface extending in a first direction intersecting the direction in which the flow path extends, a second rib side surface extending in a second direction intersecting both the direction in which the flow path extends and the first direction, and a third rib side surface extending in a third direction intersecting both the first direction and the second direction between the first rib side surface and the second rib side surface.

5. A liquid ejection head as described in claim 2, characterized in that the recess, in its cross-sectional shape, includes, in a portion facing the arc-shaped portion, a first flow path side extending in a first direction intersecting the direction in which the flow path extends, and a second flow path side extending in a second direction intersecting both the direction in which the flow path extends and the first direction.

6. the support member has a bonding surface to which the liquid ejection unit is bonded, The flow path includes an inclined flow path portion extending in a direction inclined with respect to a direction perpendicular to the joint surface, 6. The liquid ejection head according to claim 5, wherein the recessed portion and the protruding portion are formed in the inclined flow path portion.

7. The first flow path side extends parallel to the joint surface, The liquid crystal display device according to claim 6 , wherein the second flow path side surface extends perpendicular to the joining surface. Body ejection head.

8. the first flow path side surface is a portion for making a thickness of the support member between the inclined flow path portion and the joint surface in a direction perpendicular to the joint surface partially constant, A liquid ejection head as described in claim 7, characterized in that the second flow path side is a portion for making the thickness of the support member between the inclined flow path portion and the outer surface of the support member partially constant in a direction along the joint surface.

9. a liquid ejection unit including a pressure chamber, an ejection port for ejecting liquid from the pressure chamber, and an energy generating element for generating energy for ejecting the liquid in the pressure chamber from the ejection port; A liquid supply unit; a support member connecting the liquid ejection unit and the liquid supply unit, the support member having a flow path for distributing liquid between the pressure chamber and the liquid supply unit; Equipped with The support member is a support member body having a flow passage forming hole that forms a part of the flow passage and a side surface on which the flow passage forming hole opens; a flow path forming member that has a rib that is inserted into an opening of the flow path forming hole that opens on the side surface, and is joined to the side surface so as to close the opening, and forms another part of the flow path; In a liquid ejection head having a flow passage groove formed by a gap between the rib and the flow passage forming hole in a width direction intersecting both an insertion direction of the rib with respect to the opening and an extension direction of the flow passage, the flow path groove includes a deflection path portion that temporarily changes a direction of the flow path of the flow path groove extending from the upstream side to the downstream side of the flow path so as to temporarily bulge the path to one side in the width direction, A liquid ejection head, wherein a width of the flow path groove is partially expanded in the deflection path portion.

10. The route is an upstream path portion extending along a direction in which the flow channel extends, on an upstream side of the deflection path portion; a downstream path portion extending along a direction in which the flow channel extends on a downstream side of the deflection path portion; Including, The deflection path portion is a first path portion that is connected to the upstream path portion and extends in a first direction that intersects with a direction in which the flow path extends and is a direction away from the upstream path portion in the width direction; a second path portion extending in a second direction between the first path portion and the downstream path portion, the second path portion being a direction intersecting both the extension direction of the flow path and the first direction and approaching the upstream path portion in the width direction; Including, 10. The liquid ejection head according to claim 9, wherein the width of the flow path groove in the width direction is partially increased at a connection portion between the first path portion and the second path portion.

11. 10. The liquid ejection head according to claim 1, wherein a width of the flow passage groove in the width direction is 0.125 or more and 0.25 or less, assuming that a width of the flow passage in the width direction is 1.

12. 12. The liquid ejection head according to claim 11, wherein the width of the flow passage groove in the width direction is in the range of 0.5 mm or more and 1.0 mm or less.

13. The flow path is a supply flow path for supplying liquid from the liquid supply unit to the pressure chamber; a recovery flow path for recovering liquid from the pressure chamber to a liquid supply unit; Including, The liquid supply unit includes: a circulation flow path that connects the supply flow path and the recovery flow path and is supplied with liquid from a liquid supply source; a pump that generates a flow of liquid flowing from the recovery flow path through the circulation flow path to the supply flow path; The liquid ejection head according to claim 1 , further comprising:

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