Liquid ejection head

Abstract

To continue to supply a liquid to each opening even when air bubbles clogs a flow channel.SOLUTION: A liquid discharge head includes: a direction changing flow channel 34 which communicates with a common supply flow channel and extends in a direction intersecting with the common supply flow channel; a liquid supply passage 18 which communicates with the direction changing flow channel 34 and extends in a direction intersecting with the direction changing flow channel 34; a plurality of liquid chambers which communicate with the liquid supply passage 18; a plurality of discharge ports which respectively communicate with the plurality of liquid chambers; and energy generation elements which are arranged in the plurality of liquid chambers respectively and provide energy to a liquid for discharging. The direction changing flow channel 34 includes a main body part 340 and at least one groove-shaped flow channel 32. The main body part 340 has a first wall surface 34a with an opening 21 for supplying the liquid to the liquid supply passage 18 arranged. The groove-shaped flow channel 32 extends along a direction in which the main body part 340 extends on the first wall surface 34a. The groove-shaped flow channel 32 is narrower than the main body part 340.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a liquid ejection head that ejects liquid such as ink. [Background technology]

[0002] As an example of a liquid ejection head, Patent Document 1 describes an inkjet recording head. This inkjet recording head includes an ejection circuit section that ejects ink, and a flow path that guides the ink to the ejection circuit section. The flow path has a vertical section that extends vertically, and a horizontal section that extends horizontally from the lower end of the vertical section and is connected to a supply port. A groove-shaped flow path narrower than the flow path is continuously formed from the side wall of the vertical section to the ceiling section of the horizontal section. The ceiling section of the horizontal section is inclined so that the vertical section side is higher. Even if air bubbles accumulate in the horizontal section and block the flow path, ink flows through the groove-shaped flow path. The flow of ink through the groove-shaped flow path acts to move the air bubbles accumulated in the horizontal section.

[0003] Incidentally, some liquid ejection heads have a direction change flow channel. This type of liquid ejection head is equipped with a direction change flow channel that communicates with a common supply flow channel and extends in a direction intersecting the common supply flow channel, and a liquid supply channel that communicates with the direction change flow channel and extends in a direction intersecting the direction change flow channel. A plurality of liquid chambers communicate with the liquid supply channel, and an ejection port is provided for each liquid chamber. The direction change flow channel is provided with an opening for supplying liquid to the liquid supply channel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4018577 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned liquid ejection head, air bubbles may accumulate in the direction change flow passage, and the accumulated air bubbles may block the direction change flow passage. However, the inkjet recording head described in Patent Document 1 is not configured to supply liquid to the supply port (opening) in a state where air bubbles block the flow passage. According to the study by the present inventors, a measure was needed to continue supplying liquid to the opening even in a state where air bubbles block the direction change flow passage.

[0006] It is therefore an object of the present invention to continue to supply liquid to an opening even when an air bubble blocks the flow path. [Means for solving the problem]

[0007] In order to achieve the above object, a liquid ejection head according to one aspect of the present invention comprises: a plurality of ejection ports for ejecting liquid; a plurality of liquid chambers each communicating with the plurality of ejection ports; an energy generating element provided in each of the plurality of liquid chambers for generating energy for ejecting liquid from the ejection ports; a common supply flow path that supplies a liquid; a direction change flow path that is in communication with the common supply flow path and extends in a direction intersecting the common supply flow path; and a liquid supply path that is in communication with the direction change flow path and extends in a direction intersecting the direction change flow path; have The direction change flow passage is a main body and , narrower than the main body The main body portion has a groove-shaped flow path. The first wall of for supplying liquid to the liquid supply passage The opening At least one Setting Knocked down And, The groove-shaped flow path is The above main body Above first wall To It extends along the extending direction of the main body portion. A liquid ejection head according to another aspect of the present invention ejects liquid. Ru Exit A plurality of liquid chambers having and a flow path having an opening on a wall surface thereof for supplying the liquid to the liquid supply path, the flow path extending in a direction intersecting the liquid supply path. teeth The liquid supply device further includes a groove-like flow passage communicating with the opening, the groove-like flow passage supplying the liquid to the opening by capillary action. Effect of the Invention

[0008] According to the present invention, even when air bubbles block the flow path, liquid can continue to be supplied to the opening. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram for explaining a schematic configuration of a recording apparatus. [Diagram 2] 1 is a perspective view showing a liquid ejection head according to an embodiment of the present invention. [Diagram 3] 3 is an exploded perspective view of the liquid ejection head shown in FIG. 2. [Figure 4] FIG. 2 is a schematic diagram for explaining a configuration of a flow path member. [Diagram 5] 4 is a perspective view showing a fluid connection structure between a recording element substrate and a flow path member. FIG. [Figure 6] 6 is a diagram showing a cross section of the connection structure shown in FIG. 5. [Figure 7] FIG. 2 is a diagram for explaining a configuration of a discharge module. [Figure 8] FIG. 2 is a diagram illustrating a configuration of a recording element substrate. [Figure 9] 5A and 5B are diagrams for explaining the structure of a flow path portion that communicates with the ejection ports of the recording element substrate. [Figure 10] FIG. 10 is a perspective view showing a schematic cross section taken along line BB in FIG. [Figure 11] 10 is a schematic diagram showing air bubbles generated in a direction change flow channel. FIG. [Figure 12] 11 is a diagram for explaining the positional relationship between bubbles in a direction changing flow channel and a groove-shaped flow channel. FIG. [Figure 13] FIG. 13 is a diagram for explaining the flow of liquid through an opening. [Figure 14] 10A and 10B are schematic diagrams showing an example of a configuration in which a groove-shaped flow path fluidly connects adjacent openings to each other. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention.

[0011] A liquid ejection head according to an embodiment of the present invention will be described.

[0012] (Description of recording device) First, a recording apparatus incorporating the liquid ejection head of this embodiment will be described. 1 is a schematic diagram for explaining the general configuration of a recording device. The recording device 1000 has a transport unit 1 that transports a recording medium 2, and a liquid ejection head 3 that ejects liquid such as ink toward the recording medium 2. Here, the recording device 1000 performs full-color recording by ejecting liquid of four colors, CMYK (cyan, magenta, yellow, and black). Four single-color liquid ejection heads 3 corresponding to the four colors, CMYK, are arranged in parallel in the transport direction of the recording medium 2.

[0013] The liquid ejection head 3 has a plurality of ejection port arrays. The number of the ejection port arrays is, for example, 20 (see the explanation of FIG. 8(a) described later). By appropriately allocating the recording data to the plurality of ejection port arrays and performing recording, extremely high-speed recording is possible. Furthermore, for an ejection port that has failed to eject liquid, it is possible to eject liquid from an ejection port in another array at a corresponding position in the conveying direction of the recording medium 2 in a supplementary manner, thereby improving reliability. Liquid is supplied to each liquid ejection head 3 from a liquid supply system via a liquid connection part. An electric control unit is electrically connected to each liquid ejection head 3. The electric control unit transmits power and an ejection control signal to the liquid ejection head 3. The liquid path and the electric signal path in the ejection head 3 will be described later.

[0014] (Description of Liquid Ejection Head Configuration) Fig. 2 is a perspective view of the liquid ejection head 3 of this embodiment. Fig. 2(a) is a view of the liquid ejection head 3 seen from diagonally below the side from which the liquid is ejected. Fig. 2(b) is a view of the liquid ejection head 3 seen from diagonally above the side opposite to the side from which the liquid is ejected.

[0015] As shown in FIGS. 2(a) and 2(b), the liquid ejection head 3 is an inkjet line-type recording head capable of recording with one color liquid, and includes a plurality of recording element substrates 10. For example, 16 recording element substrates 10 are linearly arranged in the longitudinal direction of the liquid ejection head 3. The liquid ejection head 3 includes a liquid connection section 111, a signal input terminal 91, and a power supply terminal 92. Since there are many ejection port rows in this embodiment, the signal input terminal 91 and the power supply terminal 92 are disposed on both sides of the liquid ejection head 3. This makes it possible to reduce voltage drops and signal transmission delays that occur in the wiring sections provided on the recording element substrate 10.

[0016] Fig. 3 is an exploded perspective view of the liquid ejection head 3. Fig. 3 shows a state in which each part or unit constituting the liquid ejection head 3 is disassembled according to its function. The liquid ejection head 3 has a liquid ejection unit 300, a support part 81 that supports the liquid ejection unit 300, an electric wiring board 90, and a liquid supply unit 220.

[0017] The liquid ejection unit 300 has a flow path member 210 and an ejection module 200. The flow path member 210 is composed of a first flow path member 50 and a second flow path member 60. The ejection surface of the ejection module 200 is covered with a cover member 130 having an opening 131. The opening 131 is formed so that each recording element substrate 10 is exposed.

[0018] Two of each of the support parts 81, electric wiring boards 90, and liquid supply units 220 are provided. The support parts 81 are connected to both ends of the second flow path member 60. The liquid supply units 220 and the electric wiring boards 90 are attached to each of the support parts 81. Each liquid supply unit 220 includes a negative pressure control unit 230 and has a built-in filter (not shown). The negative pressure control unit 230 provided in one liquid supply unit 220 and the negative pressure control unit 230 provided in the other liquid supply unit 220 are set to control pressure at different negative pressures (relatively high and low negative pressures).

[0019] 3, the high-pressure side negative pressure control unit 230 is provided at one end of the liquid ejection head 3, and the low-pressure side negative pressure control unit 230 is provided at the other end of the liquid ejection head 3. In this case, the liquid flows in opposite directions in the common supply flow path 211 and the common recovery flow path 212 (see FIGS. 5 and 6 described below) that extend in the longitudinal direction of the liquid ejection head 3. This structure promotes heat exchange between the common supply flow path 211 and the common recovery flow path 212, so that the temperature difference in these common supply flow paths can be reduced. This makes it difficult for a temperature difference to occur between the multiple recording element substrates 10 provided along the common supply flow path, and as a result, there is an advantage in that recording unevenness due to the temperature difference is less likely to occur.

[0020] Next, the flow path member 210 of the liquid discharge unit 300 will be described in detail. As shown in Fig. 3, the flow path member 210 is formed by laminating a first flow path member 50 and a second flow path member 60, and distributes the liquid supplied from the liquid supply unit 220 to each discharge module 200. The flow path member 210 also functions to return the liquid circulating from the discharge module 200 to the liquid supply unit 220. A common supply flow path 211 and a common recovery flow path 212 are formed inside the second flow path member 60 of the flow path member 210. The second flow path member 60 also plays a role in ensuring the rigidity of the liquid ejection head 3. For this reason, the material of the second flow path member 60 is preferably one that has sufficient corrosion resistance against liquid and high mechanical strength. Specifically, SUS, Ti, alumina, etc. can be preferably used.

[0021] FIG. 4 is a schematic diagram for explaining the configuration of the flow path member 210. FIG. 4(a) shows the surface of the first flow path member 50 on which the ejection module 200 is mounted. FIG. 4(b) shows the surface of the first flow path member 50 on which the second flow path member 60 comes into contact. FIG. 4(c) shows the surface of the second flow path member 60 on which the first flow path member 50 comes into contact. FIG. 4(d) shows a cross section of the center in the thickness direction of the second flow path member 60. FIG. 4(e) shows the surface of the second flow path member 60 on which the liquid supply unit 220 comes into contact.

[0022] As shown in FIG. 4(a), the first flow path member 50 includes a plurality of members 50a corresponding to the plurality of ejection modules 200, respectively. These members 50a are arranged adjacent to each other. With this division structure, the length of the liquid ejection head 3 is determined according to the number of members 50a arranged. Therefore, it is particularly suitable for use in a relatively long-scale liquid ejection head corresponding to, for example, B2 size or a length larger than that. The communication port 51 of the first flow path member 50 communicates with the ejection module 200.

[0023] As shown in FIG. 4(b), the first flow path member 50 has a plurality of individual communication ports 53. As shown in FIG. 4(c), the second flow path member 60 has a plurality of communication ports 61. The individual communication ports 53 are arranged in a row in the longitudinal direction of the first flow path member 50. The communication ports 61 are arranged in a row in the longitudinal direction of the second flow path member 60. Here, the individual communication ports 53 and the communication ports 61 are both arranged in two rows, and two or three individual communication ports 53 are arranged for one communication port 61. The communication ports 61 communicate with the corresponding individual communication ports 53.

[0024] 4(d), the second flow path member 60 has two common flow path grooves 71. The common flow path grooves 71 are arranged in parallel and all extend in the longitudinal direction of the second flow path member 60. One common flow path groove 71 is arranged to correspond to one row of the individual communication ports 53 and the communication ports 61. The other common flow path groove 71 is arranged to correspond to the other row of the individual communication ports 53 and the communication ports 61.

[0025] As shown in Fig. 4(e), the second flow path member 60 has a plurality of communication ports 72 at both ends. Both ends of each common flow path groove 71 are connected to communication ports 72 provided at corresponding positions. Each common flow path groove 71 is configured so that liquid flows from one end to the other end. One common flow path groove 71 constitutes a common supply flow path 211, and the other common flow path groove 71 constitutes a common recovery flow path 212 (see Figs. 5 and 6 described below).

[0026] FIG. 5 is a perspective view showing a fluid connection structure between the recording element substrate 10 and the flow path member 210. As shown in FIG. 5, a set of a common supply flow path 211 and a common recovery flow path 212 is provided in the flow path member 210. The common supply flow path 211 and the common recovery flow path 212 are arranged in parallel, and both extend in the longitudinal direction of the liquid ejection head 3. A liquid supply path is formed that communicates from the communication port 72 of the second flow path member 60 to the communication port 51 of the first flow path member 50 via the common supply flow path 211. Similarly, a liquid recovery path is formed that communicates from the communication port 72 of the second flow path member 60 to the communication port 51 of the first flow path member 50 via the common recovery flow path 212. The liquid supply path communicates with each opening 21 of the recording element substrate 10 via the liquid supply port 31.

[0027] Figure 6 is a diagram showing a cross section of the connection structure shown in Figure 5. Figure 6(a) is a diagram showing a cross section taken along line FF in Figure 5. Figure 6(b) is a partially enlarged view of Figure 6(a). 6(a), a first flow path member 60 and a second flow path member 60 are laminated, and a support member 30 having a liquid supply port 31 is provided on the upper surface of the first flow path member 60. The support member 30 supports the recording element substrate 10. The common supply flow path 211 is fluidly connected to the ejection module 200 via the communication port 61, the individual communication port 53, and the communication port 51.

[0028] The recording element substrate 10 has an ejection port array in which a plurality of ejection ports 13 are arranged in a row. The recording element substrate 10 has flow paths formed therein that communicate with the respective ejection ports 13, and is configured to be capable of supplying and discharging (recovering) liquid. The common supply flow path 211 is fluidically connected to the negative pressure control unit 230 on the high pressure side, and the common recovery flow path 212 is fluidically connected to the negative pressure control unit 230 on the low pressure side. The liquid flows from the common supply flow path 211 through the ejection ports 13 of the recording element substrate 10 to the common recovery flow path 212. In this embodiment, the common supply flow path 211 commonly supplies liquid to a plurality of ejection port arrays of the recording element substrate 10.

[0029] As shown in FIG. 6(b), the support member 30 is joined to the surface (second surface 10b) of the recording element substrate 10 on which the opening 21 is formed, and forms a direction change flow channel 34 together with the recording element substrate 10. The direction change flow channel 34 intersects with the common supply flow channel 211 and extends along the second surface 10b of the recording element substrate 10. The direction change flow channel 34 has a main body 340 and a groove-shaped flow channel 32. The main body 340 has a first wall surface 34a and a second wall surface 34b facing the first wall surface 34a. The first wall surface 34a is disposed on the ejection port side, and the second wall surface 34b is disposed on the liquid supply port side. The first wall surface 34a is a part of the second surface 10b of the recording element substrate 10. An opening 21 for supplying liquid to the liquid supply channel 18 is formed in the first wall surface 34a. The groove 32 extends along the first wall surface 34a in the direction in which the direction-changing flow passage 34 (or the main body portion 340) extends. The groove 32 will be described in detail later.

[0030] (Explanation of the discharge module) Fig. 7 is a diagram for explaining the configuration of the discharge module 200. Fig. 7(a) is a perspective view of the discharge module 200, and Fig. 7(b) is an exploded view thereof. The discharge module 200 is composed of a recording element substrate 10, a support member 30, and two flexible wiring substrates 40. Terminals 16 are formed on both ends of the recording element substrate 10. A terminal 41 is formed on one end of the flexible wiring substrate 40, and a terminal 42 is formed on the other end.

[0031] A manufacturing method of the discharge module 200 will be briefly described. First, the recording element substrate 10 and the flexible wiring substrate 40 are adhered onto a support member 30 on which a liquid supply port 31 is previously provided. Next, the terminals 16 at both ends of the recording element substrate 10 and the terminals 41 of each flexible wiring substrate 40 are electrically connected by wire bonding. Finally, the wire bonding portion (electrical connection portion) is covered and sealed with a sealant 110.

[0032] The other terminal 42 of the flexible wiring board 40 is electrically connected to the connection terminal of the electric wiring board 90 shown in Fig. 3. The support member 30 is a support body that supports the recording element substrate 10, and is also a flow path member that fluidly connects the recording element substrate 10 to the flow path member 210 shown in Fig. 3. For this reason, the material of the support member 30 is preferably one that has a high degree of flatness and can be bonded to the recording element substrate 10 with sufficiently high reliability. For example, alumina or a resin material is preferable.

[0033] (Explanation of the structure of the recording element substrate) Fig. 8 is a diagram for explaining the configuration of the recording element substrate 10. Fig. 8(a) is a schematic diagram of the ejection port forming member 12 that forms the ejection port 13. Fig. 8(b) is a schematic diagram of the substrate 11 that forms the liquid supply path 18 and the liquid recovery path 19. Fig. 8(c) is a schematic diagram of the cover plate 20. Fig. 8(b) shows the surface of the substrate 11 that is joined to the cover plate 20. In Fig. 8, the x direction, y direction, and z direction are perpendicular to one another. The recording element substrate 10 is made up of an ejection port forming member 12, a substrate 11, and a cover plate 20. The ejection port forming member 12 constitutes a first surface 10a of the recording element substrate 10. The cover plate 20 constitutes a second surface 10b of the recording element substrate 10. The second surface 10b is the surface opposite to the first surface 10a.

[0034] 8(a), a plurality of ejection port arrays are formed in the ejection port formation member 12, in which a plurality of ejection ports 13 are arranged in a row along the x direction. Here, the number of ejection port arrays is 20. In the following description, the direction in which the ejection port arrays extend (the ejection port array direction) is referred to as the "ejection port array direction". As shown in Fig. 8(b), grooves 18a constituting the liquid supply path 18 and grooves 19a constituting the liquid recovery path 19 are alternately provided in the substrate 11 along the ejection port array direction. As shown in Fig. 8(c), a plurality of openings 21 are formed in a row in the cover plate 20 along the ejection port array direction (x direction). The liquid supply path 18 and the liquid recovery path 19 are formed by joining the substrate 11 and the cover plate 20. The plurality of openings 21 communicate with the liquid supply path 18.

[0035] 9A and 9B are diagrams for explaining the structure of a flow path portion communicating with the ejection port 13 of the recording element substrate 10. FIG. 9A is a schematic diagram of the surface of the ejection port forming member 12 on which the ejection port 13 is formed. FIG. 9B is an enlarged view of a portion indicated by A in FIG. 9A. FIG. 9C is a schematic diagram of the surface of the cover plate 20 on which the opening 21 is formed. In FIG. 9A and FIG. 9B, the opening 21 is indicated by a square (broken line) so that the relative positional relationship of the opening 21 of the cover plate 20 to the ejection port forming member 12 can be seen.

[0036] As shown in FIG. 9(a) and FIG. 9(b), the inkjet head has a plurality of liquid chambers 23 that communicate with the liquid supply path 18. The liquid chambers 23 are also called pressure chambers. The liquid chambers 23 are isolated from one another by partitions 22. The ejection ports 13 are provided corresponding to the liquid chambers 23 and communicate with the corresponding liquid chambers 23. The inkjet head has a recording element 15, which is an energy generating element that provides the liquid with energy for ejection, provided within each liquid chamber 23. The recording element 15 is, for example, a heat generating element that causes the liquid to bubble with thermal energy. The recording element 15 is electrically connected to a terminal 16 by an electrical wiring (not shown).

[0037] The control circuit of the recording device 1000 supplies a pulse signal to the recording elements 15 via the electric wiring board 90 (FIG. 3) and the flexible wiring board 40 (FIG. 7). The recording elements 15 generate heat based on the pulse signal, causing the liquid to boil. The liquid is discharged from the discharge port 13 by utilizing the force of bubbles generated by this boiling. A liquid supply path 18 extends in the direction of the ejection port array on one side, and a liquid recovery path 19 extends in the direction of the ejection port array on the other side. The liquid supply path 18 communicates with the ejection port 13 via a supply port 17a (see FIG. 10, described later). The liquid recovery path 19 communicates with the ejection port 13 via a recovery port 17b (see FIG. 10, described later).

[0038] As shown in Fig. 9(c), the cover plate 20 is provided with a plurality of openings 21 that communicate with the liquid supply path 18 and the liquid recovery path 19. In the example of Fig. 9(c), two openings 21 correspond to one liquid supply path 18, and one opening 21 corresponds to one liquid recovery path 19. As shown in Fig. 9(b), each opening 21 of the cover plate 20 communicates with the plurality of communication ports 51 shown in Fig. 5(a).

[0039] The cover plate 20 forms a part of the walls of the liquid supply passage 18 and the liquid recovery passage 19. For this reason, the material of the cover plate 20 is preferably one that has sufficient corrosion resistance against the liquid. In addition, from the viewpoint of preventing color mixing, high accuracy is required for the shape and position of the opening 21. For this reason, it is preferable to use a photosensitive resin material or Si (silicon) as the material of the cover plate 20, and to provide the opening 21 by a photolithography process. The cover plate 20 is configured so that the pitch of the flow path is changed by the opening 21. In consideration of pressure loss, it is preferable that the thickness of the cover plate 20 is thin. In this case, it is preferable to configure the cover plate 20 with, for example, a film-like member.

[0040] Next, the flow of liquid within the recording element substrate 10 will be described. Fig. 10 is a perspective view that shows a schematic cross section along line BB in Fig. 9(a). A substrate 11 and an ejection port forming member 12 are laminated, and a cover plate 20 is bonded to the rear surface of the substrate 11. A recording element 15 is formed on one surface of the substrate 11. Grooves 18a and 19a are formed on the other surface of the substrate 11. By bonding the cover plate 20 to the other surface of the substrate 11, a liquid supply path 18 and a liquid recovery path 19 are formed.

[0041] The liquid supply path 18 is fluidly connected to a common supply flow path 211, and the liquid recovery path 19 is fluidly connected to a common recovery flow path 212. A pressure difference occurs between the liquid supply path 18 and the liquid recovery path 19. Due to this pressure difference, when the liquid ejection head 3 ejects liquid to perform recording, a flow (circulation) of liquid indicated by an arrow C occurs in the ejection port 13 that is not performing an ejection operation. Specifically, the liquid in the liquid supply path 18 flows to the liquid recovery path 19 via the supply port 17a, the pressure chamber 23, and the recovery port 17b. Due to this flow, liquid that has become thickened due to evaporation from the ejection port 13, bubbles, foreign matter, and the like can be recovered to the liquid recovery path 19. In addition, the thickening of the liquid that occurs in the ejection port 13 and the liquid chamber 23 can also be suppressed. The liquid recovered to the liquid recovery path 19 flows through the opening 21 of the cover plate 20 and the liquid supply port 31 (see FIG. 7(b)) of the support member 30 toward the communication port 51 in the flow path member 210. The liquid then passes through the communication port 51, the individual recovery path 214, and the common recovery path 212 in that order, and is finally recovered into the supply path of the recording device 1000.

[0042] (Explanation of the relationship between groove-shaped channels and bubbles) Fig. 11 is a schematic diagram showing air bubbles generated in a direction change flow channel 34. In Fig. 11, the x direction, y direction, and z direction are perpendicular to one another. The x direction is the direction in which the ejection port row extends. Although not shown in Fig. 11, the liquid supply channel 18 and the liquid recovery channel 19 both extend in the x direction. The direction toward the back of the drawing (z direction) is the liquid ejection direction. The direction change flow channel 34 extends in a direction intersecting the liquid supply channel 18 (here, the y direction). Each liquid supply channel 18 communicates with the direction change flow channel 34 via a corresponding opening 21. The direction change flow channel 34 communicates with an individual communication port 53 via a communication port 51 (see FIG. 6(a)). When the direction change flow channel 34 is viewed from the first flow channel member 50 side, the opening size of the communication port 51 is larger than that of the direction change flow channel 34, and the opening size of the individual communication port 53 is smaller than that of the communication port 51.

[0043] The direction change flow channel 34 is a dead end. The individual communication port 53 is arranged on the end side opposite to the tip of the direction change flow channel 34. The individual communication port 53 is provided on a second wall surface 34b (see FIG. 6(b)) of the direction change flow channel 34. On a first wall surface 34a of the direction change flow channel 34, a plurality of openings 21 are arranged in a row in the longitudinal direction (y direction) of the direction change flow channel 34. The liquid is supplied from the individual communication port 53 to the direction change flow channel 34 and flows toward each opening 21.

[0044] The groove-like flow channel 32 extends along the direction in which the direction change flow channel 34 extends (the direction of the row of the openings 21). Here, the groove-like flow channel 32 extends in the direction in which the direction change flow channel 34 extends from a region R1 facing the individual communication port 53 of the first wall surface 34a. The region R1 may be, for example, a region in which the individual communication port 53 is projected onto the first wall surface 34a when viewed from a direction perpendicular to the first wall surface 34a. The groove-like flow channel 32 fluidly connects the respective openings 21, and extends to the end of the row of the openings 21 (a region on the tip side of the direction change flow channel 34). The tip of the direction change flow channel 34 is the part located most downstream in the direction in which the liquid flows, and here, is the part where it becomes a dead end. The width w2 of the groove-like flow channel 32 (dimension in the x direction) is narrower than the width w1 (dimension in the x direction) of the direction change flow channel 34. The groove-like flow channel 34 may be formed by machining, or may be formed by etching using photolithography. When the groove-like flow channel 34 is formed by using photolithography, for example, the cover plate 20 is formed from Si or the like. In this case, the relative position of the groove-like flow channel 34 with respect to the opening 21 can be formed with high precision.

[0045] When filling with liquid, air bubbles 33 tend to accumulate on the tip side of the direction change flow channel 34. Figure 12 is a diagram for explaining the positional relationship between the air bubbles 33 in the direction change flow channel 34 and the groove-like flow channel 32. Figure 12(a) is a schematic diagram showing a cross section taken along line FF in Figure 11, and Figure 12(b) is a schematic diagram showing a cross section taken along line GG in Figure 11. If the height of the groove-shaped flow channel 32 is h2, the height of the opening 21 is h1, and the thickness of the cover plate 20 is h, then h2

[0046] Fig. 13 is a diagram for explaining the flow of liquid through the opening 21. Fig. 13(a) is a schematic diagram showing the flow of liquid on the tip end side of the direction change flow channel 34, and Fig. 13(b) is a schematic diagram showing the flow of liquid on the individual communication port 53 side of the direction change flow channel 34. Both Fig. 13(a) and Fig. 13(b) show the state of the direction change flow channel 34 viewed from the first flow channel member 50 side. In the direction change flow channel 34, the liquid supplied from the individual communication ports 53 is supplied in sequence from the opening 21 closest to the opposing region R1 of the individual communication ports 53 toward the opening 21 farthest from the opposing region R1 in the horizontal direction (y direction) (see the open arrows). The liquid is supplied to each liquid supply path 18 through each opening 21. The liquid is then supplied from the liquid supply path 18 to the discharge port 13 through the supply port 17a.

[0047] ​According to the liquid ejection head 3 of this embodiment, even when the air bubbles 33 block the direction change flow passage 34, the liquid flows in the groove-shaped flow passage 32 by the action of capillary action. The groove-shaped flow passage 32 can supply the liquid to each opening 21. Therefore, the liquid can be continuously supplied to each opening 21. For example, as shown in FIG. 11, even if the air bubbles 33 accumulate on the tip side of the direction change flow passage 34 and the opening 21 is blocked by the air bubbles 33, the liquid can be supplied to the opening 21 through the groove-shaped flow passage 32. Also, even if the air bubbles 33 are generated near the center of the direction change flow passage 34, the liquid can be supplied to the space beyond the air bubbles 33 through the groove-shaped flow passage 32. In this way, since the liquid can be continuously supplied to each opening 21, for example, non-ejection of the ejection port 13 due to the air bubbles 33 can be suppressed.

[0048] In this embodiment, one groove-like flow path 32 is provided for one direction change flow path 34, but this is not limited thereto. A plurality of groove-like flow paths 32 may be provided for one direction change flow path 34. For example, a plurality of groove-like flow paths 32 may be provided in parallel. Furthermore, the groove-like flow passage 32 fluidly connects each of the openings 21, but is not limited thereto. For example, the groove-like flow passage 32 may be connected to at least one of the multiple openings 21. In this case, for example, the groove-like flow passage 32 may be connected to the opening 21 that is farthest from the individual communication port 53.

[0049] Fig. 14 is a schematic diagram for explaining modified examples of the configuration in which the groove-like flow path 32 fluidly connects adjacent openings 21 to each other. Fig. 14(a) shows a first modified example, Fig. 14(b) shows a second modified example, and Fig. 14(c) shows a third modified example. In a first modified example shown in FIG. 14(a), a first groove-shaped flow path 32a fluidly connects a first opening 21a farthest from an individual communication port 53 and a second opening 21b adjacent to the first opening 21a. Openings other than the first and second openings are not connected to the groove-shaped flow path 32. In this case, a plurality of first groove-shaped flow paths 32a may be provided as shown by the dashed block. According to this first modified example, the groove-shaped flow path can be efficiently arranged in the region (region on the tip side) of the direction change flow path 34 where bubbles 33 are likely to accumulate.

[0050] In the second modified example shown in FIG. 14(b), in addition to the configuration of the first modified example, there is a second groove-shaped flow path 32b that fluidically connects an opening different from the first opening 21a and an opening adjacent to the opening (an opening different from the first opening 21) to each other. Here, all openings other than the first opening 21a are fluidically connected to each other by the second groove-shaped flow path 32b. The number of the first groove-shaped flow paths 32a and the second groove-shaped flow paths 32b provided between adjacent openings is one or more. For example, if the number of the first groove-shaped flow paths 32a and the second groove-shaped flow paths 32b is two or more, liquid can be reliably supplied to each opening 21 throughout the entire direction change flow path 34.

[0051] The number of first groove-like channels 32a provided between the first opening 21a and the second opening 21b may be greater than the number of second groove-like channels 32b provided between an opening other than the first opening 21a and an opening adjacent to the first opening 21a (an opening other than the first opening 21). For example, in a third modified example shown in Fig. 14(c), the number of first groove-like channels 32a is three, and the number of second groove-like channels 32b is one. This allows the groove-like channels to be efficiently arranged in the region (region on the tip side) of the direction change channel 34 where bubbles 33 are likely to accumulate. Furthermore, the openings 21 may be arranged at equal intervals. In this case, the total flow path area of ​​the first groove-shaped flow path 32a provided between the first opening 21a and the second opening 21b may be larger than the total flow path area of ​​the second groove-shaped flow path 32b provided between an opening other than the first opening 21a and an opening adjacent to the first opening 21a. The larger the total flow path area is within the range where capillary phenomenon occurs, the greater the amount of liquid supplied to the openings. Therefore, it is possible to supply a sufficient amount of liquid to the openings in the area (the area on the tip side) where bubbles 33 are likely to accumulate.

[0052] In this embodiment, a degassing mechanism for degassing air bubbles may be provided in the liquid supply path. By providing the degassing mechanism, air bubbles remaining in the flow path can be further reduced in size when the liquid is circulated. As the degassing mechanism, for example, a tank for temporarily holding the liquid to be supplied to the liquid ejection head and a mechanism for reducing the pressure inside the tank using a vacuum pump or the like may be used.

[0053] A liquid ejection head according to another modified example of the present invention has a liquid supply path that communicates with a plurality of ejection ports that eject liquid, and a flow path that has an opening in a wall surface for supplying liquid to the liquid supply path and extends in a direction intersecting the liquid supply path. The flow path is a dead end, and has a groove-like flow path in the wall surface that communicates with the opening. The groove-like flow path supplies liquid to the opening by capillary action. The liquid supply path, the flow path, and the groove-like flow path respectively correspond to the liquid supply path 18, the direction change flow path 34, and the groove-like flow path 32 described in the first embodiment. According to the liquid ejection head of this modified example, even when air bubbles block the flow path, liquid can be continuously supplied to the opening. [Explanation of symbols]

[0054] 18 Liquid supply path 21 Aperture 32 Groove channel 34 Direction change channel

Claims

1. A liquid ejection device comprising: a plurality of ejection ports for ejecting liquid; a plurality of liquid chambers each in communication with the plurality of ejection ports; an energy generating element provided in each of the plurality of liquid chambers, the energy generating element generating energy for ejecting liquid from the ejection port; a common supply flow passage that is in communication with the plurality of liquid chambers and supplies liquid to the liquid chambers; a direction change flow passage communicating with the common supply flow passage and extending in a direction intersecting the common supply flow passage; a liquid supply passage communicating with the direction change passage and extending in a direction intersecting the direction change passage; having The direction change flow passage has a main body portion and a groove-shaped flow passage having a width narrower than that of the main body portion, the first wall surface of the main body is provided with at least one opening for supplying liquid to the liquid supply path; The liquid ejection head, wherein the groove-shaped flow path extends on the first wall surface of the main body along a direction in which the main body extends.

2. The liquid ejection head according to claim 1 , wherein a plurality of the openings are provided along a direction in which the main body portion extends.

3. The liquid ejection head according to claim 2 , wherein the groove-shaped flow path is in communication with at least one of the plurality of openings.

4. The liquid ejection head according to claim 2 , wherein the groove-shaped flow path fluidly connects the plurality of openings.

5. The liquid ejection head according to claim 1 , wherein a plurality of the groove-like flow paths are provided in parallel.

6. The liquid ejection head according to claim 1 , wherein the main body portion includes a second wall surface facing the first wall surface, and the second wall surface is provided with a communication port communicating with the common supply flow path.

7. The liquid ejection head according to claim 6 , wherein the groove-shaped flow path extends from a region of the first wall surface facing the communication port in a direction in which the main body portion extends.

8. The openings are provided in a plurality of locations along an extension direction of the main body portion, The liquid ejection head according to claim 6 , wherein the groove-shaped flow path communicates with an opening that is farthest from the communication port.

9. The openings are provided in a plurality of locations along an extension direction of the main body portion, The liquid ejection head according to claim 6 , wherein the groove-shaped flow path has a first groove-shaped flow path fluidly connecting a first opening farthest from the communication port and a second opening adjacent to the first opening.

10. The liquid ejection head according to claim 9 , wherein a plurality of the first groove-like flow paths are provided.

11. 11. The liquid ejection head according to claim 9, wherein openings other than the first and second openings do not communicate with the groove-shaped flow path.

12. The liquid ejection head according to claim 9 or 10, wherein the groove-like flow path has a second groove-like flow path fluidically connecting a third opening different from the first opening and a fourth opening adjacent to the third opening and different from the first opening.

13. The liquid ejection head according to claim 12 , wherein a plurality of the second groove-like flow paths are provided.

14. 14. A liquid ejection head according to claim 12 or 13, wherein the number of the first groove-shaped flow paths provided between the first opening and the second opening is greater than the number of the second groove-shaped flow paths provided between the third opening and the fourth opening.

15. The plurality of openings are equally spaced apart, A liquid ejection head as described in claim 12 or 13, wherein a total flow path area of ​​the first groove-shaped flow path provided between the first opening and the second opening is larger than a total flow path area of ​​the second groove-shaped flow path provided between the third opening and the fourth opening.

16. The liquid ejection head according to claim 1 , wherein the direction-changing flow passage is a dead end.

17. The liquid ejection head according to claim 1 , wherein the first wall surface is disposed on the ejection port side.

18. The liquid ejection head according to claim 1 , wherein the groove-shaped flow path is configured to be capable of supplying the liquid to the opening by capillary action.

19. A liquid ejection head according to any one of claims 1 to 18, further comprising a liquid recovery path communicating with each of the plurality of liquid chambers, and liquid supplied from the liquid supply path to the plurality of ejection ports that is not ejected is recovered via the liquid recovery path.

20. A recording element substrate including the plurality of liquid chambers and the liquid supply path, and a support member forming the direction changing flow path together with the recording element substrate, the recording element substrate has a first surface and a second surface opposite to the first surface, the ejection ports of the plurality of liquid chambers are provided on the first surface, and the openings for supplying liquid to the liquid supply paths are provided on the second surface; The liquid ejection head according to claim 1 , wherein the support member is bonded to the second surface of the recording element substrate.

21. a liquid supply passage communicating with a plurality of liquid chambers having ejection ports for ejecting liquid; a flow path having an opening in a wall surface for supplying the liquid to the liquid supply path and extending in a direction intersecting the liquid supply path; The flow path is a dead end, and the wall surface is provided with a groove-shaped flow path communicating with the opening, The liquid ejection head is configured so that the groove-shaped flow path supplies the liquid to the opening by capillary action.

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