Liquid ejection head

Abstract

To provide a technique that is able to stabilize the flow of a liquid in a flow passage.SOLUTION: A liquid ejection head includes 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 flow passages 205, 206, 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 ribs 209, 210 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. In the liquid ejection head, the ribs 209, 210 have grooves 220, 221 extending in a direction intersecting a direction in which the flow paths 205, 206 extend at a distal end of the ribs 209, 210.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 The rib has a groove at a tip thereof, the groove extending in a direction intersecting with the direction in which the flow path extends. 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 The rib has a protruding portion protruding from a tip of the rib. 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. 11 is a schematic configuration diagram of a liquid ejection head according to a second comparative embodiment. [Figure 9] FIG. 11 is a schematic configuration diagram of a support member according to a second embodiment. [Figure 10] FIG. 11 is a schematic configuration diagram of a support member according to a first modified example of the second embodiment. [Figure 11] FIG. 13 is a schematic configuration diagram of a second modified example of the second embodiment. [Figure 12] FIG. 11 is a schematic configuration diagram of a third modified example of the second embodiment. [Figure 13] FIG. 13 is a schematic configuration diagram of a support member according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, 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. The general configuration is the same as that of a liquid ejection head 100d according to a first comparative configuration shown in Fig. 5, which will be described later, except for some components.

[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] 1 and subsequent drawings, the direction of arrow D coincides with the ejection direction of ink from the ejection port 109. The direction of arrow D also 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 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. A film formation technique is used to form a plurality of electric heat exchange bodies 107 for generating energy, and electric wiring (not shown) for supplying power to each of the electric heat exchange bodies 107. A recording element substrate 110 is formed with a plurality of ink flow paths corresponding to the plurality of electric heat exchange bodies 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, which are formed by photolithography.

[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 on the board support member 112 using an adhesive. At this time, the electric wiring board 111 is positioned within a range in which the connection terminals of the recording element board 110 and the lead terminals of the electric wiring board 111 can be connected, and they are electrically connected by TAB mounting technology. After the electrical connection is completed, 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, the adhesive and sealant are To harden the coating, the coating was heat cured at a temperature of about 100 to 150 degrees for 2 to 3 hours.

[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 passage 205 and the recovery flow passage 206 are formed by integrally joining the tank member 200 and the flow passage forming member 201. The tank member 200 has flow passage forming holes 250 and 260 which form a part of the supply flow passage 205 and the recovery flow passage 206. The above-mentioned openings 225 and 235 are formed as a part of the flow passage forming hole 250, and the above-mentioned openings 226 and 236 are formed as a part of the flow passage forming hole 260. In addition, the flow passage forming holes 250 and 260 have openings 251 and 261 which open to the flow passage joining surface 204 (204a, 204b) which is the side surface (first side surface, second side surface) of the tank member 200. The openings 251 and 261 open to the flow passage 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.

[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 forming member 201a joined thereto. The tank member 200 has a first flow path joining surface 204a to which the second flow path forming member 201b 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 opposite sides of the side surface of the tank member 200 in the direction of arrow E perpendicular to the direction of arrow D. The flow path forming holes 250 and 260 respectively 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.

[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] The flow channel joint surface 204 and the adhesive surface 208 come into contact with each other, and thus flow channel grooves 215 are formed between the flow channel walls 207 and the supply flow channel ribs 209, and between the flow channel walls 207 and the recovery flow channel ribs 210 along the ribs. The flow channel grooves 215 are gaps of a predetermined width formed between the ribs 209, 210 and the flow channel forming holes 250, 260 in a width direction intersecting both the insertion direction (arrow E direction) of the ribs 209, 210 into the opening 251 and the extension direction of the flow channels 205, 206. When the flow channel width of the supply flow channel 205 and the recovery flow channel 206 in the width direction is 1, the flow channel width of the flow channel groove 215 relative to the flow channel width of the supply flow channel 205 and the recovery flow channel 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, the flow path width of the flow path groove 215 should not be set to 0.125 or less. If the flow path width of the flow path groove 215 is 0.125 or less, the capillary force becomes strong, which may cause ink stagnation and slow down the ink supply speed.

[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 0.2 mm or more and 0.8 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 generated during ink ejection. If bubbles generated during ink ejection enter the flow path groove 215, they will remain in the flow path groove 215 and will 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 three colors (three types) of ink are arranged on one recording element substrate 110. That is, 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 are formed independently and integrally on one recording element substrate 110. By arranging flow paths capable of ejecting three colors of ink on one recording element substrate 110 in this manner, there are cost benefits such as a shorter tact time when joining the recording element substrate 110 and a reduction in the number of parts.

[0043] As shown in FIG. 5, since 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, a portion of the supply flow path 205 and the recovery flow path 206 of the tank member 200a are inclined flow paths.

[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 disposed 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 flow path portion 205i is inclined with respect to the extending direction of the straight flow path portions 205s1 and 205s2. The straight flow path portion 205s1 extends in the direction of the straight flow path portion 205s2 and serves as a flow path connecting the straight flow path portion 205s1 and the straight flow path 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] In accordance with the inclination of the flow paths 205 and 206 described above, the ribs 209 and 210 also have inclined portions. Therefore, the flow channel 215 formed between the flow channel wall 207 and the ribs 209, 210 also has an inclined portion in accordance with the inclination of the flow channels 205, 206.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] Here, as described above, the flow paths 205, 206 of the support member 102a (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.

[0060] To remove bubbles that have accumulated in the flow path groove 215 in this way, the recording device body that is equipped with the liquid ejection head has a recovery operation that forcibly sucks the ink out of the ejection port 109 and discharges the ink. Because this is a suction operation that forcibly removes the ink, the ink flow in the flow path during the suction operation is several times faster than the flow speed during ink ejection. The suction force that causes such a fast flow speed discharges the bubbles from the flow path groove 215 at the same time as the ink. However, if the bubbles cannot be removed with a single suction operation, it will be necessary to perform the suction operation multiple times. If the bubbles are still not removed, it will be necessary to further increase the suction pressure. As a result, ink consumption increases and the number of pages printed per ink tank may decrease.

[0061] 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.

[0062] The liquid ejection head 100 according to the first embodiment of the present invention is provided with a liquid flow path structure capable of suppressing the above-mentioned residual ink bubbles, as a countermeasure against ejection defects that may occur when bubbles remain in the flow path groove 215 and ink cannot be supplied stably. This will be described below with reference to Figs. 6 and 7.

[0063] Fig. 6 is a schematic plan view of the flow path forming member 201 (201a, 201b) in the first embodiment. Fig. 7 is a schematic cross-sectional view of the support member 102 in the first embodiment in which the flow path forming member 201 is fitted into the tank member 200.

[0064] 6, in the flow path forming member 201 of this embodiment, grooves 220, 221 are formed in the supply flow path ribs 209 and the recovery flow path ribs 210, which extend in a direction intersecting with the direction corresponding to the extension direction of the supply flow paths 205 and the recovery flow paths 206. Alternatively, the supply flow path ribs 209 and the recovery flow path ribs 210 of the flow path forming member 201 in this embodiment can also be seen as being configured to be separated into multiple parts in the direction in which the supply flow paths 205 and the recovery flow paths 206 extend, respectively.

[0065] As shown in FIG. 7, the grooves 220 and 221 are shaped to cross the supply flow path 205 and the recovery flow path 206. The upper flow path groove 215a and the lower flow path groove 215b formed in each of the flow paths 205 and 206 by fitting the flow path forming member 201 to the tank member 200 are connected to each other by the grooves 220 and 221. With the presence of such grooves 220 and 221, even if bubbles obstruct the flow of ink in one of the upper flow path groove 215a and the lower flow path groove 215b, a flow can be formed that bypasses the other groove via the grooves 220 and 221. This reduces the effect of bubbles on the flow of ink, enabling a stable supply of ink. Furthermore, when ink is sucked by the recovery operation of the device main body, the presence of the grooves 220 and 221 makes it easier to generate turbulence, improving bubble removal, and making it possible to sufficiently suck ink even with a low suction pressure, which also leads to a reduction in waste ink.

[0066] The grooves 220, 221 include those that extend in the horizontal direction (direction perpendicular to the direction of arrow D) and those that extend in the vertical direction (direction of arrow D). The number, position, size (width), direction, etc. of the grooves 220, 221 are appropriately set from the viewpoint of balancing the pressure loss in each flow path, similar to the adjustment of the opposing distance between the ribs 209, 210 shown in FIG. 4(c).

[0067] As shown in Fig. 5, of the three pairs of supply flow passage 205 and recovery flow passage 206 that form one ink circulation path, the supply flow passage 205 and recovery flow passage 206 that constitute the pair in the middle in the figure have a mutually symmetrical structure. As shown in Fig. 6, the pair RB of ribs 209, 210 corresponding to this pair of supply flow passage 205 and recovery flow passage 206 are also configured to have mutually symmetrical shapes.

[0068] The supply flow passage rib 209 of the pair RB is an upstream straight rib 209s1 and a downstream straight rib The straight rib 209s1 includes a straight rib 209s2 and an inclined rib 209i disposed therebetween. The straight rib 209s1, the inclined rib 209i, and the straight rib 209s2 are disposed at intervals along a direction corresponding to the upstream-to-downstream direction of the supply flow passage 205. That is, a groove 220 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the straight rib 209s1 and the upstream end of the inclined rib 209i. In addition, a groove 220 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the inclined rib 209i and the upstream end of the straight rib 209s2.

[0069] Similarly, the recovery passage rib 210 of the pair RB includes an upstream straight rib 210s1, a downstream straight rib 210s2, and an inclined rib 210i disposed therebetween. The straight rib 210s1, the inclined rib 210i, and the straight rib 210s2 are disposed at intervals along a direction corresponding to the upstream-to-downstream direction of the recovery passage 206. That is, a groove 221 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the straight rib 210s1 and the upstream end of the inclined rib 210i. In addition, a groove 221 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the inclined rib 210i and the upstream end of the straight rib 210s2.

[0070] On the other hand, of the three pairs shown in Fig. 5, the supply channel 205 and the recovery channel 206 constituting the pair on the right side in the figure have an asymmetric structure. As shown in Fig. 6, the pair RC of ribs 209, 210 corresponding to this pair of supply channel 205 and recovery channel 206 is also configured to have an asymmetric shape.

[0071] The supply flow passage rib 209 of the pair RC includes an upstream straight rib 209s1, a downstream straight rib 209s2, and an inclined rib 209i disposed therebetween. The inclined rib 209i includes a first inclined rib 209i1, a second inclined rib 209i2, and a third inclined rib 209i3. The straight rib 209s1, the first inclined rib 209i1, the second inclined rib 209i2, the third inclined rib 209i3, and the straight rib 209s2 are arranged at intervals along a direction corresponding to the upstream-to-downstream direction of the supply flow passage 205. That is, a groove 220 extending in the horizontal direction (a direction perpendicular to the direction of the arrow D) is formed between the downstream end of the straight rib 209s1 and the upstream end of the first inclined rib 209i1. Moreover, a groove 220 extending in the vertical direction (direction of arrow D) is formed between the downstream end of the first inclined rib 209i1 and the upstream end of the second inclined rib 209i2. Moreover, a groove 220 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the second inclined rib 209i2 and the upstream end of the third inclined rib 209i3. Moreover, a groove 220 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the third inclined rib 209i3 and the upstream end of the straight rib 209s2.

[0072] On the other hand, the recovery channel rib 210 of pair RC includes an inclined rib 210i and a straight rib 210s2 disposed downstream thereof. The inclined rib 210i and the straight rib 210s2 are disposed spaced apart in the same direction corresponding to the upstream-to-downstream direction of the recovery channel 206. That is, a groove 221 extending horizontally (in a direction perpendicular to the direction of arrow D) is formed between the downstream end of the inclined rib 210i and the upstream end of the straight rib 210s1.

[0073] 5, the supply channel 205 and the recovery channel 206 constituting the pair on the left side in the figure are also asymmetrical to each other. As shown in FIG 6, the pair RA of ribs 209, 210 corresponding to this pair of supply channel 205 and recovery channel 206 are also configured to have asymmetrical shapes.

[0074] The supply flow path rib 209 of the pair RA is a straight rib 209s1 on the upstream side and a straight rib 209s2 on the downstream side. The straight rib 209s1 and the inclined rib 209i are arranged at intervals along a direction corresponding to the upstream-to-downstream direction of the supply flow passage 205. That is, a groove 220 extending in the horizontal direction (a direction perpendicular to the direction of arrow D) is formed between the downstream end of the straight rib 209s1 and the upstream end of the inclined rib 209i.

[0075] On the other hand, the recovery passage rib 210 of the pair RA includes an upstream straight rib 210s1, a downstream straight rib 210s2, and an inclined rib 210i disposed therebetween. The inclined rib 210i includes a first inclined rib 210i1, a second inclined rib 210i2, and a third inclined rib 210i3. The straight rib 210s1, the first inclined rib 210i1, the second inclined rib 210i2, the third inclined rib 210i3, and the straight rib 210s2 are disposed at intervals along a direction corresponding to the direction from upstream to downstream of the recovery passage 206. That is, a groove 221 extending in the horizontal direction (a direction perpendicular to the direction of the arrow D) is formed between the downstream end of the straight rib 210s1 and the upstream end of the first inclined rib 210i1. Moreover, a groove 221 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the first inclined rib 210i1 and the upstream end of the second inclined rib 210i2. Moreover, a groove 221 extending in the vertical direction (direction of arrow D) is formed between the downstream end of the second inclined rib 210i2 and the upstream end of the third inclined rib 210i3. Moreover, a groove 221 extending in the horizontal direction (direction perpendicular to the direction of arrow D) is formed between the downstream end of the third inclined rib 210i3 and the upstream end of the straight rib 210s2.

[0076] It is desirable that the grooves 220 and 221 have a width equal to or greater than that of the flow path groove 215 and up to 1.5 times that of the flow path groove 215. If the groove 221 is large, the bubble removal property improves, but the ink supply by capillary force weakens.

[0077] According to the above configuration, the grooves crossing the flow path grooves make it possible to change the direction of ink flow, reduce the impact of bubbles on the ink flow, and enable a stable ink supply. Furthermore, since turbulence can be created in the ink flow during the recovery operation, bubble removal is also improved. This makes it possible to reduce the number of times the recovery operation is performed, reduces ink consumption, and suppresses the occurrence of printing defects. Furthermore, turbulence can be easily generated even during cleaning with pure water during shipping inspection, improving cleaning efficiency and reducing the impact of residual inspection ink.

[0078] The configuration of the ribs 209, 210 and the arrangement of the grooves 220, 221 (the number, positions, size (width), direction, etc. of the grooves 220, 221) in the present embodiment described above are merely examples and may be set appropriately depending on the device configuration.

[0079] For example, the positions of the grooves 220, 221 formed in the ribs 209a, 210a of one flow path forming member 201a in the direction in which the flow paths extend may be different from the positions of the grooves 220, 221 formed in the ribs 209b, 210b of the other flow path forming member 201b.

[0080] In addition, in this embodiment, the ribs 209, 210 are configured to be divided into multiple parts in the direction in which the flow path extends, but the present invention is not limited to such a configuration. For example, the ribs 209, 210 may be configured such that straight ribs and inclined ribs are connected in the flow path direction, and the height of the ribs 209, 210 may be locally lowered to form the grooves 220, 221.

[0081] As for the flow channel 215, in addition to the flow channel utilizing the gap between the rib and the hole as in this embodiment, for example, a flow channel extending along the flow direction on the tip surface of the rib may be additionally provided. By having grooves 220 and 221 intersect with the flow channel formed in this way and connect it to other flow channel, a stable ink supply can be realized.

[0082] [Second embodiment] A second embodiment of the present invention will be described with reference to Figures 8 to 12. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and detailed description thereof will be omitted. Items in the second embodiment that are not particularly described here are the same as those in the first embodiment.

[0083] 8 is a schematic cross-sectional view showing a schematic configuration of a support member 102e of a liquid ejection head according to a second comparative embodiment. In the liquid ejection head according to the second comparative embodiment, the configuration of the support member 102e is different from that of the support member 102b of the liquid ejection head according to the second embodiment. As shown in FIG. 8, recesses 217, 218, and 219 that form a bent portion are provided in a part of a flow path wall 207 (flow path side surface) of a tank member 200. These recesses 217, 218, and 219 are provided to distribute stress caused by cooling after molding of the tank member 200, which is an injection molded product, and to suppress deformation due to occurrence of sink marks, etc. There is a concern that the occurrence of such deformation may cause the following problems.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] In the tank member 200, convex portions are also formed on the ribs 209 and 210 in correspondence with the concave portions 217 and 219 of the flow passage forming holes on the side closer to the head portion 101. Groove 215 includes a flow channel portion extending horizontally (in a direction perpendicular to the direction of arrow D) in the portion corresponding to recesses 217 and 219. In this horizontal flow channel portion, bubbles generated by ejection are difficult to escape and tend to accumulate, which may result in unstable ink supply and cause printing defects.

[0089] Furthermore, the test ink used in the test of the ejection performance of the liquid ejection head before shipping is often different from the printing ink used as the recording liquid of the liquid ejection device, due to the effect of ink volatilization during storage of the head and to reduce ink costs. Therefore, liquid ejection heads that are determined to have no problem with the ejection accuracy are shipped in a dry state after the test ink inside is removed. Since the test ink and the 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.

[0090] 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.

[0091] Here, in the liquid ejection head of the second 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 with pure water in the flow channel 215 (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.

[0092] Furthermore, in the recess 217 provided at the midpoint of the inclined portions of the flow paths 205 and 206, 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), or vice versa. In particular, the capillary force is high at the right angle portion, which tends to cause stagnation in the ink flow, and this 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 with these concentrated test ink components remaining, impurities may be generated.

[0093] 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 a second 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 FIG.

[0094] FIG. 9 is a schematic cross-sectional view of a support member 102b of the second embodiment in which a flow path forming member 201 is fitted into a tank member 200. As shown in FIG.

[0095] As shown in Fig. 9, grooves 220 and 221 are formed in the ribs 209 and 210 at the portions corresponding to the recessed portion 217, and extend in a direction intersecting the direction corresponding to the extension direction of the flow paths 205 and 206. The grooves 220 and 221 include grooves 220V and 221V extending in a vertical direction (direction of arrow D) and grooves 220H and 221H extending in a horizontal direction (direction perpendicular to the direction of arrow D). The grooves 220V and 221V extending in the vertical direction are disposed on the extension lines of the flow path groove portions extending in the vertical direction and formed at right angles by the recessed portion 217 in the flow path groove 215, and the flow path groove portions extending in the horizontal direction. The grooves 220H and 221H extending in the horizontal direction are disposed on the extension lines of the flow path groove portions extending in the vertical direction and formed at right angles by the recessed portion 217 in the flow path groove 215, and the flow path groove portions extending in the horizontal direction.

[0096] The bubbles that have flowed into the lower-stage flow channel 215b move to the flow channel portion extending in the horizontal direction of the flow channel 215, pass through the grooves 220 and 221, and flow into the upper-stage flow channel 215a and the large liquid chamber 216. Even if bubbles are retained in the flow channel portion extending in the horizontal direction of the flow channel 215, ink can be supplied from the upper-stage flow channel 215a to the grooves 220 and 221 and the lower-stage flow channel 215b. This makes it possible to suppress a decrease in ink supply due to the influence of bubbles, and reduces the number of times the recovery operation is performed. Furthermore, this makes it easier to generate turbulence in the recovery operation, thereby improving bubble removal, and allows sufficient ink suction even with a low suction pressure in the recovery operation, thereby reducing the amount of waste ink.

[0097] In the ejection performance test before the product is shipped, the grooves 220, 221 are provided to generate turbulence by a flow speed during the suction operation that is faster than that during ink ejection, thereby making it possible to change the direction of the ink flow and improving the cleaning effect. In other words, according to the second embodiment of the present invention, it is not necessary to fill the ink for printing with test ink components remaining, and the quality of the liquid ejection head can be improved.

[0098] 10 is a schematic cross-sectional view of a support member 102b1 of Modification 1 of the second embodiment. In the support member 102b1 of Modification 1, vertically extending grooves 220V, 221V are arranged at a portion where a flow channel groove portion extending in the horizontal direction in the recess 217 of the flow channel 215 joins with an inclined flow channel groove portion of the flow channel 215 along the inclined portions of the ribs 209, 210. By arranging the grooves 220, 221 in this manner, it is possible to facilitate the flow of bubbles from the lower-stage flow channel 215b to the upper-stage flow channel 215a.

[0099] 11 is a schematic cross-sectional view of a support member 102b2 of Modification 2 of the second embodiment. In the support member 102b2 of Modification 2, a protrusion 207a that partially projects toward the recess 217 is provided in a portion of the opposing flow path walls 207 of the flow paths 205 and 206 that faces the recess 217. The arrangement of the grooves 220 and 221 is similar to that of the second embodiment (FIG. 9). By providing such a protrusion 207a, it is possible to further increase the change in the flow of the fluid around the recess 217 of the flow paths 205 and 206. Therefore, it becomes easier to generate a turbulent flow during the recovery operation.

[0100] 12 is a schematic cross-sectional view of a support member 102b3 of Modification 3 of the second embodiment. In the support member 102b3 of Modification 3, grooves 220 and 221 are also provided in the ribs 209 and 210 at portions corresponding to the recesses 218 and 219, in contrast to the configuration of the second embodiment (FIG. 9). In this manner, the grooves 220 and 221 may be provided corresponding to the recesses 218 and 219. In addition, in Modification 3, horizontally extending grooves 220H and 221H are provided at portions corresponding to the recesses 218 of the ribs 209 and 210, and vertically extending grooves 220V and 221V are provided at portions corresponding to the recesses 219 of the ribs 209 and 210.

[0101] The liquid ejection head of this embodiment having the above-described grooves 220, 221 and a circulation function can prevent the ink supply path from being blocked by bubbles and reduce the effects of residual ink for inspection during shipping inspection.

[0102] The configurations of the ribs 209, 210 and the arrangements of the grooves 220, 221 (the number, positions, size (width), direction, etc. of the grooves 220, 221) in the second embodiment and modified examples 1 to 3 described above are merely examples and may be set appropriately depending on the device configuration.

[0103] [Third embodiment] A third embodiment of the present invention will be described with reference to Fig. 13. In the third embodiment, the same components as those in the first and second embodiments are designated by the same reference numerals as those in the first and second embodiments, and detailed description thereof will be omitted. In the third embodiment, matters that are not particularly described here are the same as those in the first embodiment. This is the same as the first embodiment and the second embodiment.

[0104] 13, in the present embodiment as well, a flow path groove 215 is formed in a supply flow path 205 and a recovery flow path 206 in a tank member 200 by a supply flow path rib 209 and a recovery flow path rib 210 of a flow path forming member 201. Unlike the grooves in the other embodiments, in this embodiment, convex portions 222, 223 that protrude towards the large liquid chamber 216 are provided at part of the tip of each of the supply flow path rib 209 and the recovery flow path rib 210.

[0105] The convex portions 222 and 223 protrude from the rib tip surfaces so as to locally narrow the opposing interval (flow path cross section) between the opposing ribs 209a, 209b, 210a, and 210b in the pair of flow path forming members 201a and 201b. The convex portions 222 and 223 are formed so as to extend in a direction intersecting the flow paths 205 and 206. The convex portions 222 and 223 include those that extend in the horizontal direction (direction perpendicular to the direction of arrow D) and those that extend in the vertical direction (direction of arrow D). The number, position, size (width), direction, and the like of the convex portions 222 and 223 may be appropriately set from the viewpoint of balancing the pressure loss in each flow path, similar to the adjustment of the opposing interval between the ribs 209 and 210 shown in FIG. 4(c). Furthermore, in the direction in which the flow paths extend, the positions of the convex portions 222, 223 of the ribs 209a, 210a of one flow path forming member 201a and the positions of the convex portions 222, 223 of the ribs 209b, 210b of the other flow path forming member 201b may be different from each other.

[0106] By providing such convex portions 222, 223, the heights of the supply flow path rib 209 and the recovery flow path rib 210 can be lowered while the volumes of the supply flow path 205 and the recovery flow path 206 remain the same, compared to the first comparative embodiment in which the convex portions 222, 223 are not provided. For example, the heights of the supply flow path rib 209 and the recovery flow path rib 210 on the side closer to the discharge port 109 can be lowered by the volume of the convex portions 222, 223. As a result, even if bubbles generated during discharge enter the flow path groove 215, the bubbles will move quickly to the large liquid chamber 216 because the height of the ribs 209, 209 is lower on the side closer to the discharge port 109. Therefore, discharge defects due to bubbles are less likely to occur.

[0107] In addition, the provision of the convex portions 222 and 223 is effective in removing bubbles from the flow channel 215 during the recovery operation. If the convex portions 222 and 223 are not provided, an ink flow may be formed in which half of the ink flowing in the recovery operation passes through the large liquid chamber 216 and exits from the ejection port 109, and the remaining half flows into the flow channel 215 to remove bubbles from the flow channel 215. According to this embodiment, a part of the ink flowing in the large liquid chamber 216 hits the convex portion 222 protruding toward the large liquid chamber 216 side and is diffused, and flows from the large liquid chamber 216 to the flow channel 215. This makes it possible to increase the amount of ink flowing into the flow channel 215. Furthermore, the diffused ink flows into the flow channel 215, generating turbulence, which improves bubble removal. Therefore, it becomes easier to generate diffusion and turbulence during cleaning after inspection, and it becomes possible to improve the cleaning efficiency.

[0108] According to a liquid ejection head having a circulation function and including the convex portions 222, 223 as described above, it is possible to prevent the ink supply path from being blocked by bubbles and reduce the influence of residual ink for inspection during shipping inspection.

[0109] The configurations of each of the above embodiments can be combined with each other.

[0110] 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 The liquid ejection head according to claim 1, wherein the rib has a groove at a tip thereof, the groove extending in a direction intersecting with a direction in which the flow path extends. (Configuration 2) the side surface being a first side surface, the opening being a first opening, the rib being a first rib, the flow path forming member being a first flow path forming member, and the groove being a first groove; the support member body has a second side surface opposite to the first side surface, the second side surface having the flow passage forming hole opened therein; the support member has a second rib that is inserted into a second opening of the flow path forming hole that opens to the second side surface, and a second flow path forming member that is joined to the second side surface so as to close the second opening and forms another part of the flow path, The liquid ejection head according to configuration 1, wherein the second rib has a second groove at a tip of the second rib, the second groove extending in a direction intersecting with the direction in which the flow path extends. (Configuration 3) 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 The liquid ejection head according to the present invention is characterized in that the rib has a convex portion protruding from a tip of the rib. (Configuration 4) the side surface being a first side surface, the opening being a first opening, the rib being a first rib, the flow path forming member being a first flow path forming member, and the convex shaped portion being a first convex shaped portion; the support member body has a second side surface opposite to the first side surface, the second side surface having the flow passage forming hole opened therein; the support member has a second rib that is inserted into a second opening of the flow path forming hole that opens to the second side surface, and a second flow path forming member that is joined to the second side surface so as to close the second opening and forms another part of the flow path, The liquid ejection head according to configuration 3, wherein the second rib has a second convex portion protruding from a tip of the second rib. (Configuration 5) The rib extends along the direction in which the flow passage extends inside the flow passage forming hole. the law of nature, A liquid ejection head described in any one of configurations 1 to 4, characterized in that a gap of a predetermined width is formed between the rib and the flow path forming hole in a width direction intersecting both the insertion direction of the rib into the opening and the extension direction of the flow path. (Configuration 6) A liquid ejection head according to any one of configurations 1 to 5, wherein the predetermined width is a size that 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 7) 7. The liquid ejection head according to any one of configurations 1 to 6, wherein the predetermined width is within a range of 0.2 mm or more and 0.8 mm or less. (Configuration 8) the support member has a bonding surface to which the liquid ejection unit is bonded, The liquid ejection head according to any one of configurations 1 to 7, wherein the flow path includes an inclined flow path portion extending in a direction inclined with respect to a direction perpendicular to the joining surface. (Configuration 9) A liquid ejection head described in any one of configurations 1 to 8, characterized in that the inclined flow path portion has a recess in a part of the flow path side surface opposing in a width direction intersecting both the insertion direction of the rib relative to the opening and the extension direction of the flow path. (Configuration 10) A liquid ejection head described in any one of configurations 1 to 9, characterized in that the recess includes a first flow path side extending parallel to the bonding surface and a second flow path side extending perpendicular to the bonding surface. (Configuration 11) 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 10, 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 12) 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; 12. The liquid ejection head according to any one of configurations 1 to 11, comprising: [Explanation of symbols]

[0111] 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, 220, 221...groove

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 The liquid ejection head according to claim 1, wherein the rib has a groove at a tip thereof, the groove extending in a direction intersecting with a direction in which the flow path extends.

2. the side surface being a first side surface, the opening being a first opening, the rib being a first rib, the flow path forming member being a first flow path forming member, and the groove being a first groove; the support member body has a second side surface opposite to the first side surface, the second side surface having the flow passage forming hole opened therein; the support member has a second rib that is inserted into a second opening of the flow path forming hole that opens to the second side surface, and a second flow path forming member that is joined to the second side surface so as to close the second opening and forms another part of the flow path, The liquid ejection head according to claim 1 , wherein the second rib has a second groove at a tip thereof, the second groove extending in a direction intersecting with a direction in which the flow path extends.

3. 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 The liquid ejection head according to the present invention is characterized in that the rib has a convex portion protruding from a tip of the rib.

4. the side surface being a first side surface, the opening being a first opening, the rib being a first rib, the flow path forming member being a first flow path forming member, and the convex portion being a first convex portion; the support member body has a second side surface opposite to the first side surface, the second side surface having the flow passage forming hole opened therein; The support member has a second rib that is inserted into a second opening of the flow passage forming hole that opens on the second side surface, and is joined to the second side surface so as to close the second opening, and a second flow path forming member forming a part of the The liquid ejection head according to claim 3 , wherein the second rib has a second convex portion protruding from a tip of the second rib.

5. The rib extends along a direction in which the flow passage extends inside the flow passage forming hole, A liquid ejection head as described in claim 1 or 3, characterized in that a gap of a predetermined width is formed between the rib and the flow path forming hole in a width direction intersecting both the insertion direction of the rib into the opening and the extension direction of the flow path.

6. 6. The liquid ejection head according to claim 5, wherein the predetermined width is equal to or greater than 0.125 and equal to or less than 0.25 when the width of the flow path in the width direction is taken as 1.

7. 6. The liquid ejection head according to claim 5, wherein the predetermined width is in the range of 0.2 mm to 0.8 mm.

8. the support member has a bonding surface to which the liquid ejection unit is bonded, 4. The liquid ejection head according to claim 1, wherein the flow path includes an inclined flow path portion extending in a direction inclined with respect to a direction perpendicular to the joining surface.

9. The liquid ejection head according to claim 8 , wherein the inclined flow passage portion has recesses in parts of the flow passage side surfaces that face each other in a width direction that intersects both the insertion direction of the rib with respect to the opening and the extension direction of the flow passage.

10. The liquid ejection head according to claim 9 , wherein the recess includes a first flow path side extending parallel to the joining surface, and a second flow path side extending perpendicular to the joining surface.

11. 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 10, 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.

12. 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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