Liquid jet head and liquid jet recording apparatus

Abstract

To suppress contamination of a jet plate near an injection nozzle by splash scattering from a welding part when welding a guard member to the jet plate in a liquid jet head.SOLUTION: An ink jet head 5 includes: a nozzle plate 51 where a nozzle hole 71 jetting ink is formed; and a nozzle guard 100 which covers the nozzle plate 51 and forms an opening 103 exposing the nozzle hole 71. The nozzle guard 100 has: a facing surface 101b facing the nozzle plate 51 with a gap; and a welding part 120 which extends to the nozzle plate 51 side from the facing surface 101b and is bonded to the nozzle plate 51. There is provided a rib 104 which is arranged so as to shield a route combining the welding part 120 and the opening 103 in a plane direction along the facing surface 101b.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a liquid jet head and a liquid jet recording apparatus. [Background technology]

[0002] Patent Document 1 listed below discloses a method for manufacturing a droplet ejection head in which at least the joining portion between a nozzle plate (ejection plate) having nozzles (ejection holes) for ejecting droplets and the nozzle plate of a joined member to be joined, and at least the joining portion between the nozzle plate and the joined member, are made of a molten material that melts with laser light, and a laser is irradiated onto the molten material from the nozzle plate side or the joined member side to melt the molten material and weld the nozzle plate to the joined member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-144390 Summary of the Invention [Problem to be solved by the invention]

[0004] In the liquid jet head described above, if the jet plate becomes charged by static electricity from a recording medium such as paper or from an external source, the pressure conversion element that ejects the liquid and the driver IC that drives the pressure conversion element may be affected. To address this issue, the jet plate is welded to a guard member that covers the jet plate and electrically grounded, thereby eliminating static electricity from the jet plate. However, when welding the guard member to the jet plate, splashes from the welded portion can contaminate the jet plate near the jet holes, potentially causing a decrease in print quality.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to prevent splashes from flying off from the welded portion from contaminating the injection plate near the injection hole when welding a guard member to an injection plate in a liquid injection head. [Means for solving the problem]

[0006] (1) A liquid injection head according to one aspect of the present disclosure includes an injection plate having an injection hole formed therein for injecting liquid, and a guard member covering the injection plate and having an opening for exposing the injection hole, wherein the guard member has an opposing surface facing the injection plate with a gap therebetween, and a welded portion extending toward the injection plate beyond the opposing surface and joined to the injection plate, and includes a rib arranged to block a path connecting the welded portion and the opening in a planar direction along the opposing surface.

[0007] In the liquid jet head according to this aspect, the rib disposed between the welded portion and the opening of the guard member blocks splashes generated at the welded portion, making it difficult for the splashes to reach the vicinity of the jet nozzle. Furthermore, since the welded portion is disposed outside the rib as viewed from the opening of the guard member, the distance between the jet nozzle and the welded portion can be increased. This prevents splashes from the welded portion from contaminating the jet plate near the jet nozzle.

[0008] (2) In the liquid injection head of aspect (1), the injection holes may form an injection row in a first direction, the opening may be formed as a long hole that exposes the injection row, and the welding portion may be positioned on an extension line of the opening.

[0009] In this case, by arranging the welds on the extension of the openings, the ejection plate can be electrically grounded for each row of ejection holes at a position that has minimal impact on the ejection of the liquid or the transport of the media. This makes it possible to prevent malfunctions of the ejection plate for each row of ejection holes due to charging, without reducing the quality of the characters and images recorded on the recording medium.

[0010] (3) In the liquid injection head of aspect (1), the injection holes may form an injection row in a first direction, the opening may be formed as a long hole that exposes the injection row, and the welding portion may be arranged in an oblique direction that intersects with an extension line of the opening.

[0011] In this case, by arranging the weld diagonally across the extension of the opening, the distance between the weld and the opening can be increased without having to secure space on the extension of the opening, which prevents splashes from the weld from contaminating the injection plate near the injection hole.

[0012] (4) In the liquid jet head of aspect (3), the jet row may have a first jet row and a second jet row extending parallel to each other, the opening may have a first opening exposing the first jet row and a second opening exposing the second jet row, and the welded portion may be located at the intersection of a first intersection line extending diagonally toward the second opening from an extension line of the first opening, and a second intersection line extending diagonally toward the first opening from an extension line of the second opening.

[0013] In this case, two adjacent jet rows can be electrically grounded by one welded portion, thereby reducing the number of welding steps.

[0014] (5) In the liquid jet head of aspect (4), the rib may be extended so as to block a first path connecting the welded portion and the first opening and a second path connecting the welded portion and the second opening.

[0015] In this case, one rib can block splashes from reaching two adjacent openings, which reduces the number of ribs required.

[0016] (6) In the liquid jet head according to any one of the aspects (1) to (5), the guard member may have a peripheral wall portion surrounding the opposing surface, and the welded portion may be formed in an island shape spaced apart from the peripheral wall portion.

[0017] In this case, the amount of heat input to the welded portion is small, so the welding work can be carried out quickly.

[0018] (7) In the liquid ejection head according to any one of the aspects (1) to (5), the guard member may have a peripheral wall portion surrounding the opposing surface, and the welded portion may be formed in a peninsula shape extending from the peripheral wall portion.

[0019] In this case, by forming the weld in a peninsula shape extending from the peripheral wall, the weld and the peripheral wall are integrated, and the precision of forming the weld by etching or the like can be improved compared to an island shape, thereby improving the reliability of the electrical grounding of the injection plate.

[0020] (8) In the liquid jet head according to any one of the aspects (1) to (5), the welded portion may be formed in a peninsula shape extending from the rib.

[0021] In this case, forming the weld in a peninsula shape extending from the rib integrates the weld and the rib, allowing for higher accuracy in forming the weld by etching or other methods than with an island shape. This improves the reliability of electrical grounding of the jet plate. Furthermore, forming the weld in a peninsula shape extending from the rib increases the rigidity of the rib and reduces the stress on the jet plate bonded to the guard member. This reduces deformation of the jet plate and reduces degradation of print quality.

[0022] (9) In the liquid jet head according to any one of aspects (1) to (8), the rib may include a first rib provided on the periphery of the opening and a second rib provided on the welded portion side with a gap from the first rib.

[0023] In this case, the splash that has climbed over the second rib can be captured in the gap between the second rib and the first rib, making it difficult for the splash that flies off from the welded portion to reach the vicinity of the ejection hole.

[0024] (10) In the liquid jet head according to the aspect (9), a first distance between the second rib and the welded portion may be shorter than a first distance between the first rib and the second rib.

[0025] In this case, by arranging the second rib near the weld, the spread of splash is suppressed and the space between the second rib and the first rib is relatively widened, making it easier to capture splash that goes over the second rib. Therefore, splash flying from the weld is less likely to reach the vicinity of the injection hole.

[0026] (11) In the liquid jet head according to any one of the aspects (1) to (10), the rib may be formed on the guard member.

[0027] In this case, the rib and the welded portion can be formed simultaneously by etching, etc. Furthermore, by integrating the rib and the guard member, the number of parts of the liquid ejection head can be reduced compared to when the rib is a separate part.

[0028] (12) A liquid jet recording apparatus according to one aspect of the present disclosure includes the liquid jet head according to any one of the aspects (1) to (11).

[0029] According to the liquid jet recording apparatus of this aspect, a highly reliable product can be provided. [Effects of the Invention]

[0030] According to the above aspect of the present disclosure, when welding the guard member to the ejection plate in the liquid ejection head, splashes from the welded portion can be prevented from contaminating the ejection plate near the ejection holes. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic configuration diagram of a printer according to a first embodiment. [Figure 2]FIG. 2 is a schematic diagram illustrating the configuration of an inkjet head and an ink circulation mechanism according to the first embodiment. [Figure 3] FIG. 1 is an exploded perspective view of an inkjet head according to a first embodiment. [Figure 4] FIG. 4 is an explanatory diagram of the inkjet head according to the first embodiment, and corresponds to a cross section taken along line IV-IV in FIG. 3 in an assembled state of the inkjet head. [Figure 5] FIG. 2 is a plan view showing the configuration of the main part of the nozzle guard according to the first embodiment. [Figure 6] 4 is a cross-sectional view showing a state in which the nozzle guard according to the first embodiment is welded to the nozzle plate. FIG. [Figure 7] FIG. 10 is a plan view showing the configuration of a main part of a nozzle guard according to a second embodiment. [Figure 8] FIG. 10 is a plan view showing the configuration of a main part of a nozzle guard according to a third embodiment. [Figure 9] FIG. 10 is a plan view showing the configuration of a main part of a nozzle guard according to a fourth embodiment. [Figure 10] FIG. 10 is a plan view showing the configuration of a main part of a nozzle guard according to a fifth embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing the configuration of a main part of a nozzle guard according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0033] In the embodiments and modifications described below, corresponding components may be assigned the same reference numerals and their description may be omitted. Furthermore, in the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," not only strictly indicate such arrangements, but also indicate a state in which there is a relative displacement with a tolerance or an angle or distance that provides the same function.

[0034] In the following embodiments, an inkjet printer (hereinafter simply referred to as a printer) that uses ink (liquid) to record on a recording medium will be described as an example. Note that in the drawings used in the following description, the scale of each component has been appropriately changed so that each component can be recognized.

[0035] (First embodiment) [Printer 1] FIG. 1 is a schematic diagram of a printer 1 according to the first embodiment. As shown in FIG. 1, a printer 1 (liquid jet recording apparatus) of this embodiment includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head 5 (liquid jet head), an ink circulation mechanism 6, and a scanning mechanism 7.

[0036] In the following explanation, an X, Y, Z Cartesian coordinate system will be used as necessary. The Y direction is the transport direction (sub-scanning direction) of the recording medium P (e.g., paper, etc.). The X direction is the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction is the height direction (gravity direction) perpendicular to the X and Y directions.

[0037] In the following description, the arrows in the X, Y, and Z directions are referred to as the plus (+) side and the opposite side as the minus (-) side. In this embodiment, the +Z side corresponds to the upward direction of gravity, and the -Z side corresponds to the downward direction of gravity.

[0038] The transport mechanism 2 includes a grit roller 11 extending in the X direction, a pinch roller 12 extending parallel to the grit roller 11, and a drive mechanism (not shown) such as a motor that rotates the grit roller 11 about its axis. Similarly, the transport mechanism 3 includes a grit roller 13 extending in the X direction, a pinch roller 14 extending parallel to the grit roller 13, and a drive mechanism (not shown) for rotating the grit roller 13 about its axis.

[0039] The ink tanks 4 are, for example, ink tanks 4Y, 4M, 4C, and 4K containing four colors of ink, yellow, magenta, cyan, and black, arranged side by side in the Y direction. Note that the ink tanks 4 are not limited to ink tanks 4Y, 4M, 4C, and 4K containing four types of ink, yellow, magenta, cyan, and black, and may also include ink tanks containing ink of more than one color.

[0040] FIG. 2 is a schematic diagram of the inkjet head 5 and the ink circulation mechanism 6 according to the first embodiment. 2, the ink circulation mechanism 6 includes a circulation flow path 23 having an ink supply pipe 21 that supplies ink to the inkjet head 5 and an ink discharge pipe 22 that discharges ink from the inkjet head 5, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22. The ink supply pipe 21 and the ink discharge pipe 22 are made of flexible hoses that are flexible enough to accommodate the operation of the scanning mechanism 7 that supports the inkjet head 5.

[0041] The pressure pump 24 applies pressure to the ink supply pipe 21, and sends ink to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side relative to the inkjet head 5 is under positive pressure. The suction pump 25 reduces the pressure inside the ink discharge pipe 22 and sucks ink from the inkjet head 5. As a result, the ink discharge pipe 22 side relative to the inkjet head 5 is under negative pressure. The ink can be circulated between the inkjet head 5 and the ink tank 4 via a circulation flow path 23 by driving a pressure pump 24 and a suction pump 25 .

[0042] 1, the scanning mechanism 7 includes a pair of guide rails 31, 32 extending in the X direction, a carriage 33 movably supported on the pair of guide rails 31, 32, and a drive mechanism 34 that moves the carriage 33 in the X direction. The drive mechanism 34 includes a pair of pulleys 35, 36 disposed between the pair of guide rails 31, 32, an endless belt 37 wound between the pair of pulleys 35, 36, and a drive motor 38 that rotationally drives one of the pulleys 35.

[0043] A pair of pulleys 35, 36 are disposed between both ends of the pair of guide rails 31, 32, respectively. An endless belt 37 is disposed between the pair of guide rails 31, 32. A carriage 33 is connected to this endless belt 37. The carriage 33 is mounted with a plurality of inkjet heads 5, namely inkjet heads 5Y, 5M, 5C, and 5K for inks of four colors, yellow, magenta, cyan, and black, lined up in the X direction. The transport mechanisms 2, 3 and scanning mechanism 7 constitute a movement mechanism that moves the inkjet heads 5 and the recording medium P relatively.

[0044] <Inkjet head 5> Next, a detailed description will be given of the inkjet head 5. Note that the inkjet heads 5Y, 5M, 5C, and 5K all have the same configuration except for the color of ink they supply, and therefore will be collectively referred to as the inkjet head 5 in the following description.

[0045] Fig. 3 is an exploded perspective view of the inkjet head 5 of the first embodiment. Fig. 4 is an explanatory diagram of the inkjet head 5 of the first embodiment, and is a cross-sectional view taken along line IV-IV in Fig. 3 when the inkjet head 5 is assembled. 3 and 4, the inkjet head 5 is a so-called side shoot type that ejects ink from the center of the ejection channel 61 (described later) in the channel extension direction (X direction). This type of side shoot type inkjet head 5 is equipped with the ink circulation mechanism 6 described above, and is a circulation type that circulates ink between the inkjet head 5 and the ink tank 4.

[0046] The inkjet head 5 mainly comprises a head chip 50 including a nozzle plate 51 (ejection plate), an actuator plate 52, a cover plate 53 and a flow path plate 54, a circuit board 80 connected to the head chip 50, and a nozzle guard 100 (guard member) that covers the nozzle plate 51 and has an opening 103 that exposes the nozzle hole 71 formed in the nozzle plate 51. The head chip 50 is configured such that a nozzle plate 51, an actuator plate 52, a cover plate 53, and a flow path plate 54 are laminated in this order in the Z direction with an adhesive or the like.

[0047] <Actuator plate 52> As shown in FIG. 3, the actuator plate 52 is a plate formed of a piezoelectric material such as PZT (lead zirconate titanate) into a rectangular plate shape elongated in the Y direction. The actuator plate 52 is a so-called monopole substrate, the polarization direction of which is set in one direction along the thickness direction (Z direction). However, the actuator plate 52 may also be a so-called chevron substrate, the polarization direction of which is different between the positive and negative sides of the Z direction. In this embodiment, an example will be described in which the actuator plate 52 is formed of a single substrate, but the configuration is not limited to this. The actuator plate 52 may also be formed by joining multiple (e.g., two) piezoelectric plates.

[0048] The actuator plate 52 is provided with four channel rows in the X direction (first channel row 63, second channel row 64, third channel row 65 and fourth channel row 66 indicated by arrows in Figure 3) consisting of multiple channels 61, 62 formed side by side in the Y direction. A first opening H1 is formed between the second channel row 64 and the third channel row 65, penetrating from the upper surface US to the lower surface LS of the actuator plate 52. Since the channel rows 63 to 66 have the same basic configuration, the following description will mainly focus on the first channel row 63, and the same reference numerals will be used to designate parts of the second to fourth channel rows 64 to 66 that correspond to those of the first channel row 63, and descriptions thereof will be omitted.

[0049] The multiple channels 61, 62 are composed of ejection channels 61 that are filled with ink and non-ejection channels 62 that are not filled with ink. The ejection channels 61 and the non-ejection channels 62 are arranged alternately in the Y direction. The ejection channels 61 penetrate from the upper surface US to the lower surface LS of the actuator plate 52. The ejection channels 61 are formed in arc shapes that protrude from the upper surface US toward the lower surface LS. On the other hand, the non-ejection channels 62 are formed in arc shapes that protrude from the lower surface LS toward the upper surface US.

[0050] Here, the ejection channels 61 and non-ejection channels 62 included in the first channel row 63 are referred to as first ejection channels 61a and first non-ejection channels 62a. The ejection channels 61 and non-ejection channels 62 included in the second channel row 64 are referred to as second ejection channels 61b and second non-ejection channels 62b. The ejection channels 61 and non-ejection channels 62 included in the third channel row 65 are referred to as third ejection channels 61c and third non-ejection channels 62c. The ejection channels 61 and non-ejection channels 62 included in the fourth channel row 66 are referred to as fourth ejection channels 61d and fourth non-ejection channels 62d.

[0051] The ejection channels 61a to 61d included in each of the first to fourth channel rows 63 to 66 are formed at a predetermined pitch in the Y direction. Furthermore, the ejection channels 61a to 61d are shifted by 1 / 4 of the predetermined pitch in the Y direction for each of the first to fourth channel rows 63 to 66. As a result, the ejection channels 61a to 61d are arranged at a 1 / 4 pitch in the Y direction, and the recording density can be four times higher than when a single channel row is used.

[0052] 4, on the lower surface LS of the actuator plate 52, ejection channels 61a to 61d that are short in the X direction and non-ejection channels 62a to 62d that are long in the X direction are alternately arranged in the Y direction to form channel rows 63 to 66. A first opening H1 formed in the actuator plate 52 is positioned at the center of the actuator plate 52 in the X direction. Driving electrodes 68 are formed on both side surfaces in the Y direction of the ejection channels 61a to 61d and the non-ejection channels 62a to 62d.

[0053] Terminal electrodes 69 are formed on the lower surface LS of the actuator plate 52 in correspondence with the channel rows 63-66, respectively. With respect to the first channel row 63, the terminal electrodes 69 are formed near the side surfaces in the X direction of the actuator plate 52. The terminal electrodes 69 include a common terminal electrode electrically connected to the drive electrodes 68 on both side surfaces of the first ejection channel 61a, and individual terminal electrodes (neither of which is shown) electrically connected to the drive electrodes 68 on the side surfaces of the two first non-ejection channels 62a that sandwich the first ejection channel 61a. The individual terminal electrodes are formed along the side surfaces in the X direction of the actuator plate 52. On the other hand, the common terminal electrode is formed closer to the first ejection channel 61a than the individual terminal electrodes.

[0054] With respect to the second channel row 64, the terminal electrode 69 is formed near the side surface of the first opening H1. The terminal electrode 69 includes a common terminal electrode electrically connected to the driving electrodes 68 (see FIG. 4) on both side surfaces of the second ejection channel 61b, and individual terminal electrodes (neither of which is shown) electrically connected to the driving electrodes 68 on the side surfaces of the two second non-ejection channels 62b that sandwich the second ejection channel 61b. The individual terminal electrodes here are formed along the first opening H1. On the other hand, the common terminal electrode is formed closer to the second ejection channel 61b than the individual terminal electrodes. The terminal electrodes 69 for the third channel row 65 and the fourth channel row 66 also have a similar configuration.

[0055] The lower surface LS of the actuator plate 52 has four exposed regions 52a that are exposed from the nozzle plate 51. The four exposed regions 52a are regions on the lower surface LS of the actuator plate 52 that correspond to the channel rows 63 to 66 on which the terminal electrodes 69 are formed. Specifically, the exposed regions 52a are provided on both ends of the lower surface LS of the actuator plate 52 in the X direction and on both ends of the lower surface LS of the actuator plate 52 in the X direction that sandwich the first opening H1.

[0056] <Cover plate 53> 3 and 4, the cover plate 53 is in the form of a plate and is adhered to the upper surface US of the actuator plate 52 so as to close each of the channel rows 63 to 66. The cover plate 53 is formed with a second opening H2 formed in the center in the X direction, first and second inlet-side common ink chambers 90a and 90b, and first to fourth outlet-side common ink chambers 91a to 91d. The second opening H2 and each of the inlet-side common ink chambers 90a, 90b, 91a to 91d are formed as slits extending through the cover plate 53 in the Y direction.

[0057] The first inlet-side common ink chamber 90a communicates with the end of the first ejection channel 61a included in the first channel row 63 on the second channel row 64 side, and the end of the second ejection channel 61b included in the second channel row 64 on the first channel row 63 side. The first outlet-side common ink chamber 91a communicates with the other end of the first ejection channel 61a. The second outlet-side common ink chamber 91b communicates with the other end of the second ejection channel 61b.

[0058] On the other hand, the second inlet side common ink chamber 90b communicates with the end of the third ejection channel 61c included in the third channel row 65 on the fourth channel row 66 side, and the end of the fourth ejection channel 61d included in the fourth channel row 66 on the third channel row 65 side. The third outlet side common ink chamber 91c communicates with the other end of the third ejection channel 61c. Furthermore, the fourth outlet side common ink chamber 91d communicates with the other end of the fourth ejection channel 61d.

[0059] <Flow path plate 54> As shown in FIG. 4, the flow path plate 54 is joined to the main surface of the cover plate 53 opposite to the actuator plate 52. The flow path plate 54 includes a supply flow path 95, a discharge flow path 96, and a third opening H3. The third opening H3 is a slit extending through the flow path plate 54 in the Y direction. The supply flow path 95 communicates with the ink supply pipe 21 (see FIG. 2) of the ink circulation mechanism 6 and also communicates with the inlet-side common ink chambers 90a, 90b of the cover plate 53. The discharge flow path 96 communicates with the ink discharge pipe 22 (see FIG. 2) of the ink circulation mechanism 6 and also communicates with the first to fourth outlet-side common ink chambers 91a to 91d. In other words, ink is supplied to the actuator plate 52 from the supply flow path 95, and ink is discharged from the discharge flow path 96.

[0060] <Nozzle plate 51> As shown in FIGS. 3 and 4, the nozzle plate 51 is a plate made of a metal such as stainless steel and formed into a rectangular shape elongated in the Y direction to correspond to the shape of the actuator plate 52. The nozzle plate 51 is attached to the lower surface LS of the actuator plate 52 by adhesive or the like. The nozzle plate 51 has nozzle rows (ejection rows: first to fourth nozzle rows 72 to 75 indicated by arrows in FIG. 3) in which a plurality of nozzle holes 71 (ejection holes) communicating with the ejection channels 61 are arranged in the Y direction. Note that the nozzle holes 71 in the first to fourth nozzle rows 72 to 75 do not need to be arranged in a straight line as long as they are arranged in the Y direction. For example, the nozzle holes 71 may be arranged in a staggered pattern in which odd-numbered nozzle holes 71 and even-numbered nozzle holes 71 are shifted in the direction (X direction) perpendicular to the row direction (Y direction). In other words, the nozzle holes 71 in the first to fourth nozzle rows 72 to 75 may be shifted to an extent that does not significantly change the overall shape.

[0061] The width of the nozzle plate 51 in the X direction is narrower than the width of the actuator plate 52 in the X direction. As a result, the nozzle plate 51 exposes, as the above-mentioned exposed regions 52a, four terminal formation regions on the lower surface LS of the actuator plate 52, which correspond to the channel rows 63 to 66 on which the terminal electrodes 69 are formed.

[0062] <Circuit board 80> The upper surface of each circuit board 80 is attached to the exposed region 52a of the lower surface LS of the actuator plate 52. Each circuit board 80 is a flexible printed circuit board, and is joined to the actuator plate 52 by thermocompression bonding via an ACF (Anisotropic Conductive Film), not shown. Of the four circuit boards 80, two circuit boards 80 attached to the exposed region 52a along the side surface of the first opening H1 are drawn upward through the first to third openings H1 to H3. The actuator plate 52 and the circuit boards 80 may be joined together using a conductive adhesive or the like.

[0063] <Nozzle Guard 100> 3, nozzle guard 100 is made of a metal such as stainless steel. Nozzle guard 100 is formed so as to cover head chip 50 from below nozzle plate 51. Specifically, nozzle guard 100 includes bottom wall portion 101 provided so as to cover nozzle plate 51 and actuator plate 52 from the lower surface side of nozzle plate 51, and side wall portion 102 rising from the outer periphery of bottom wall portion 101.

[0064] The bottom wall 101 is formed in the shape of a rectangular plate that is long in the Y direction so as to correspond to the shape of the actuator plate 52. The bottom wall 101 is bonded to the underside of the head chip 50 via an adhesive layer 55 (see FIG. 4) made of adhesive. An opposing surface 101b (recess) that faces the nozzle plate 51 across a gap in the Z direction is formed on the upper surface (the surface on the nozzle plate 51 side) of the bottom wall 101. A peripheral wall 101a (step) on which the bolt seats 107, 108 are erected is formed around the opposing surface 101b so as to surround the opposing surface 101b.

[0065] The opposing surface 101b has openings 103 formed in positions corresponding to the first to fourth nozzle rows 72 to 75 of the nozzle plate 51, respectively, that expose the nozzle holes 71 of the first to fourth nozzle rows 72 to 75 downward. Each opening 103 is formed in the shape of an elongated hole extending in the Y direction. A rib 104 stands upright on the periphery of each opening 103. Furthermore, a welded portion 120 that is joined to the nozzle plate 51 stands upright on the outer side of the rib 104 (the side opposite the opening 103).

[0066] Square bolt seats 107 are provided at the four corners of the peripheral wall 101a. A central bolt seat 108 is provided at the center of the peripheral wall 101a in the X direction. These bolt seats 107, 108 are formed in a substantially rectangular prism shape. Each bolt seat 107, 108 has a through hole 107a, 108a that penetrates in the Z direction. A female thread is formed in the through hole 108a, and a base plate (not shown) is fastened to the upper surface of the nozzle guard 100 via a bolt. The base plate is attached to the carriage 33 (see FIG. 1). The through hole 107a serves as a thread relief when the base plate is screwed together with a joint member (not shown).

[0067] Furthermore, Y-direction positioning dowels 109 that protrude in the Y direction from the opposing surfaces are integrally formed with the pair of central bolt seats 108. Furthermore, X-direction positioning dowels 110 are integrally formed with the inner surfaces on both sides of the side wall portion 102 in the X direction, near the corner bolt seats 107 at each of the four corners. Therefore, the actuator plate 52 housed in the nozzle guard 100 is positioned in the X and Y directions relative to the bottom wall portion 101 by the X-direction positioning dowels 110 and Y-direction positioning dowels 109.

[0068] Fig. 5 is a plan view showing the configuration of the main parts of the nozzle guard 100 according to the first embodiment. Note that Fig. 5 shows the configuration near the -Y side end of the openings 103 corresponding to the third nozzle row 74 and the fourth nozzle row 75, but the configuration near the +Y side end of the openings 103 is similar. Furthermore, the configuration near the +Y and -Y side ends of the openings 103 corresponding to the first nozzle row 72 and the second nozzle row 73 (not shown) is also similar to the configuration shown in Fig. 5.

[0069] 5, the nozzle guard 100 includes an opposing surface 101b that faces the nozzle plate 51 with a gap therebetween, and a welded portion 120 that extends toward the nozzle plate 51 (+Z side) beyond the opposing surface 101b and is joined to the nozzle plate 51. The welded portion 120 is formed in an island shape spaced apart from the peripheral wall portion 101a that surrounds the opposing surface 101b. The welded portion 120 of this embodiment is formed in a cylindrical shape that stands upright from the opposing surface 101b toward the nozzle plate 51 (+Z side).

[0070] The welded portion 120 is disposed on an extension line 200 of the opening 103 formed in the opposing surface 101b. The nozzle holes 71 form nozzle rows 74 and 75 in the Y direction (first direction). The openings 103 include a first opening 103A formed in the shape of an elongated hole whose major axis extends along the nozzle row 74 (first ejection row), and a second opening 103B formed in the shape of an elongated hole whose major axis extends along the nozzle row 75 (second ejection row). The welded portion 120 passes through the center position of each opening 103 in the X direction (width direction) and is disposed on an extension line 200 (center axis) extending in the Y direction.

[0071] Nozzle guard 100 includes rib 104 arranged so as to block path 121 connecting welded portion 120 and opening 103 in a planar direction (XY plane direction) along opposing surface 101b. Note that path 121 connecting welded portion 120 and opening 103 refers to the area sandwiched between two common circumferential lines connecting welded portion 120 and opening 103. Rib 104 extends between welded portion 120 and opening 103 so as to cross path 121 connecting welded portion 120 and opening 103.

[0072] The rib 104 stands from the opposing surface 101b toward the nozzle plate 51 (+Z) and is formed in a ring shape around the opening 103. The rib 104 includes a first rib 104a provided on the periphery of the opening 103 and a second rib 104b provided on the welded portion 120 side with a gap from the first rib 104a. In other words, the rib 104 is provided in a double ring shape around the opening 103.

[0073] The first rib 104a is formed at a height that allows it to abut against the nozzle plate 51. The first rib 104a positions the nozzle guard 100 by abutting against the nozzle plate 51. The second rib 104b is formed lower than the first rib 104a. A gap 105 formed between the first rib 104a and the second rib 104b functions as a trap that captures splashes 130 (see FIG. 6, which will be described later) that fly from the welded portion 120. The gap 105 formed between the first rib 104a and the second rib 104b also functions as a reservoir for excess adhesive of the adhesive layer 55. Note that the second rib 104b may also be formed at a height that allows it to abut against the nozzle plate 51, similar to the first rib 104a.

[0074] FIG. 6 is a cross-sectional view showing how the nozzle guard 100 according to the first embodiment is welded to the nozzle plate 51. As shown in FIG. 6, the nozzle guard 100 is laser welded (spot welded) to, for example, the nozzle plate 51. For example, a laser torch 210 is positioned directly above the welded portion 120 of the nozzle guard 100, and the welded portion 120 and the nozzle plate 51 are joined by deep penetration welding. At this time, splashes 130 fly from the welded portion 120.

[0075] Splash 130 scattered from welded portion 120 collides with second rib 104b arranged between welded portion 120 and opening 103. Splash 130 that passes over second rib 104b is captured in gap 105 between second rib 104b and first rib 104a. Furthermore, splash 130 that is not captured in gap 105 collides with first rib 104a. As a result, splash 130 scattered from welded portion 120 is blocked just before reaching opening 103, and contamination of nozzle plate 51 near nozzle hole 71 can be suppressed.

[0076] <Printer 1 operation> Next, a case where characters, figures, etc. are recorded on the recording medium P using the printer 1 will be described. 1 are each fully filled with ink of a different color. Also, the ink in the ink tanks 4 is filled into the inkjet head 5 via the ink circulation mechanism 6.

[0077] When the printer 1 is operated in this initial state, the grit rollers 11 and 13 of the conveyance mechanisms 2 and 3 rotate, conveying the recording medium P in the conveyance direction (Y direction) between the grit rollers 11 and 13 and the pinch rollers 12 and 14. At the same time, the drive motor 38 rotates the pulleys 35 and 36 to move the endless belt 37. As a result, the carriage 33 moves back and forth in the X direction while being guided by the guide rails 31 and 32. During this time, four color inks are ejected from the inkjet heads 5 onto the recording medium P as appropriate, thereby recording characters, images, and the like.

[0078] The operation of each inkjet head 5 will now be described in detail. In the circulation type inkjet head 5 of the side chute type as in this embodiment, first, the pressure pump 24 and the suction pump 25 shown in Fig. 2 are operated to circulate ink in the circulation flow path 23. In this case, the ink circulating in the ink supply pipe 21 passes through the inlet side common ink chambers 90a and 90b via the supply flow path 95 and is supplied to the ejection channels 61 of each of the channel rows 63 to 66.

[0079] Furthermore, the ink in each ejection channel 61 flows into each of the outlet-side common ink chambers 91a to 91d, and is then discharged to the ink discharge pipe 22. The ink discharged to the ink discharge pipe 22 is returned to the ink tank 4, and then supplied again to the ink supply pipe 21. In this way, the ink is circulated between the inkjet head 5 and the ink tank 4.

[0080] Then, when the carriage 33 (see FIG. 1) starts to move back and forth, a control device (not shown) applies a drive voltage to the drive electrode 68 via the circuit board 80. This causes thickness slip deformation in the drive wall (actuator plate 52) that defines the ejection channel 61, changing the volume within the ejection channel 61. This increases the pressure within the ejection channel 61, pressurizing the ink. As a result, droplets of ink are ejected to the outside through the nozzle holes 71, recording characters, images, and the like on the recording medium P.

[0081] Here, the nozzle plate 51 is welded to the nozzle guard 100, and the nozzle guard 100 is electrically grounded via the carriage 33. This prevents the nozzle plate 51 from becoming charged, and prevents breakdowns in the actuator plate 52, the driver IC on the circuit board 80, etc.

[0082] 5 and 6, in the inkjet head 5 of this embodiment, the rib 104 disposed between the welded portion 120 and the opening 103 of the nozzle guard 100 blocks the splash 130 generated at the welded portion 120, making it difficult for the splash 130 to reach the vicinity of the nozzle hole 71. Furthermore, because the welded portion 120 is disposed outside the rib 104 when viewed from the opening 103 of the nozzle guard 100, the distance between the nozzle hole 71 and the welded portion 120 can be increased. Therefore, it is possible to prevent the splash 130 flying off from the welded portion 120 from contaminating the nozzle plate 51 near the nozzle hole 71.

[0083] As described above, the inkjet head 5 described above includes a nozzle plate 51 in which nozzle holes 71 for ejecting ink are formed, and a nozzle guard 100 in which openings 103 that cover the nozzle plate 51 and expose the nozzle holes 71 are formed, wherein the nozzle guard 100 has an opposing surface 101b that faces the nozzle plate 51 with a gap therebetween, and a welded portion 120 that extends toward the nozzle plate 51 beyond the opposing surface 101b and is joined to the nozzle plate 51, and includes a rib 104 that is arranged so as to block a path 121 that connects the welded portion 120 and the opening 103 in a planar direction along the opposing surface 101b. With this configuration, when the nozzle guard 100 is welded to the nozzle plate 51 in the inkjet head 5, splashes 130 flying from the welded portion 120 can be prevented from contaminating the nozzle plate 51 near the nozzle holes 71.

[0084] 5, in the inkjet head 5 of this embodiment, the nozzle holes 71 form nozzle rows 74 and 75 in the Y direction (first direction), the opening 103 is formed as an elongated hole that exposes the nozzle rows 74 and 75, and the welded portion 120 is located on an extension line 200 of the opening 103. According to this configuration, by locating the welded portion 120 on the extension line 200 of the opening 103, it is possible to electrically ground the nozzle plate 51 for each row of the nozzle holes 71 at a position that has minimal impact on ink ejection and media transport. Therefore, it is possible to prevent malfunctions and the like caused by charging of the nozzle plate 51 for each row of the nozzle holes 71 without degrading the quality of characters and images recorded on the recording medium P.

[0085] In the inkjet head 5 of this embodiment, the nozzle guard 100 has a peripheral wall 101a that surrounds the opposing surface 101b, and the welding portion 120 is formed in an island shape spaced apart from the peripheral wall 101a. With this configuration, the amount of heat input to the welding portion 120 is small, allowing the welding work to be performed quickly.

[0086] Furthermore, in the inkjet head 5 of this embodiment, the rib 104 includes a first rib 104a provided on the periphery of the opening 103 and a second rib 104b provided on the welded portion 120 side with a gap between the first rib 104a and the first rib 104a. With this configuration, splashes 130 that pass over the second rib 104b can be captured in the gap 105 between the second rib 104b and the first rib 104a. Therefore, splashes 130 that fly off from the welded portion 120 are less likely to reach the vicinity of the nozzle hole 71. Note that if the second rib 104b is not provided, there is no problem as long as the first rib 104a is in close contact with the nozzle plate 51 around the entire periphery. However, if the nozzle guard 100 is distorted or if the adhesive layer 55 has uneven thickness, a gap may be formed between the first rib 104a and the nozzle plate 51. Therefore, providing the second rib 104b increases the reliability of preventing contamination by splash 130.

[0087] Furthermore, in the inkjet head 5 of this embodiment, the rib 104 is formed on the nozzle guard 100. With this configuration, the rib 104 and the welded portion 120 can be formed simultaneously by etching or the like. Furthermore, by integrating the rib 104 and the nozzle guard 100, the number of parts in the inkjet head 5 can be reduced compared to when the rib 104 is a separate part.

[0088] The printer 1 according to this embodiment is equipped with the above-described inkjet head 5. This printer 1 can provide a highly reliable product.

[0089] (Second embodiment) Next, a second embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. FIG. 7 is a plan view showing the configuration of the main parts of the nozzle guard 100 according to the second embodiment. The second embodiment differs from the above-described embodiments in that the welded portion 120 is disposed in a diagonal direction intersecting with an extension line 200 of the opening 103, as shown in FIG.

[0090] Nozzle guard 100 has first opening 103A exposing nozzle row 74 (first ejection row) and first opening 103A exposing nozzle row 75 (second ejection row). Welded portion 120 is located at intersection 122 of first intersection line 201A extending diagonally toward second opening 103B with respect to extension line 200 of first opening 103A, and second intersection line 201B extending diagonally toward first opening 103A with respect to extension line 200 of second opening 103B.

[0091] First intersection line 201A is, for example, a bisector of a corner of first opening 103A on the side of second opening 103B. Second intersection line 201B is, for example, a bisector of a corner of second opening 103B on the side of first opening 103A. Intersection 122 of first intersection line 201A and second intersection line 201B is located outside first opening 103A and second opening 103B in the Y direction, and is located between first opening 103A and second opening 103B in the X direction.

[0092] The second rib 104b of the rib 104 provided on the first opening 103A side is formed in half of the area of ​​the first opening 103A on the second opening 103B side. This allows the second rib 104b to block the first path 121A connecting the welded portion 120 and the first opening 103A. The first rib 104a provided on the first opening 103A side is formed around the entire periphery of the first opening 103A to position the nozzle plate 51 and the nozzle guard 100.

[0093] Furthermore, the second rib 104b of the rib 104 provided on the second opening 103B side is formed in half of the area of ​​the second opening 103B on the first opening 103A side. This allows the second rib 104b to block the second path 121B connecting the welded portion 120 and the second opening 103B. The first rib 104a provided on the second opening 103B side is formed around the entire periphery of the second opening 103B to position the nozzle plate 51 and the nozzle guard 100.

[0094] In the second embodiment having the above configuration, the nozzle holes 71 form nozzle rows 74, 75 in the Y direction (first direction), the opening 103 is formed as an elongated hole that exposes the nozzle rows 74, 75, and the welded portion 120 is disposed in an oblique direction intersecting with an extension line 200 of the opening 103. According to this configuration, by disposing the welded portion 120 in an oblique direction intersecting with the extension line 200 of the opening 103, it is possible to increase the distance between the welded portion 120 and the opening 103 without having to secure space on the extension line 200 of the opening 103. Therefore, it is possible to prevent splashes 130 flying from the welded portion 120 from contaminating the nozzle plate 51 near the nozzle holes 71.

[0095] Furthermore, in the inkjet head 5 of this embodiment, the nozzle rows 74, 75 extend parallel to each other, the opening 103 includes a first opening 103A exposing the nozzle row 74 and a second opening 103B exposing the nozzle row 75, and the weld 120 is disposed at an intersection 122 between a first intersection line 201A extending diagonally toward the second opening 103B with respect to an extension line 200 of the first opening 103A, and a second intersection line 201B extending diagonally toward the first opening 103A with respect to the extension line 200 of the second opening 103B. With this configuration, the two adjacent nozzle rows 74, 75 can be electrically grounded by a single weld 120. This reduces the number of steps required for welding.

[0096] (Third embodiment) Next, a third embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. FIG. 8 is a plan view showing the configuration of the main parts of the nozzle guard 100 according to the third embodiment. As shown in FIG. 8, the third embodiment differs from the above-described embodiments in that the welded portion 120 is formed in the shape of a peninsula extending from the peripheral wall portion 101a.

[0097] The arrangement of the welded portion 120 in the third embodiment is the same as that in the second embodiment. The welded portion 120 in the third embodiment is integrated with an extension portion 123 that extends from the nearest peripheral wall portion 101a. As described above, the nozzle guard 100 of the third embodiment has a peripheral wall 101a that surrounds the opposing surface 101b, and the welded portion 120 is formed in a peninsula shape extending from the peripheral wall 101a. With this configuration, the welded portion 120 is integrated with the peripheral wall 101a, and therefore the accuracy of forming the welded portion 120 by etching or the like can be improved compared to an island shape. This improves the reliability of electrical grounding of the nozzle plate 51.

[0098] (Fourth embodiment) Next, a fourth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. FIG. 9 is a plan view showing the configuration of the main parts of the nozzle guard 100 according to the fourth embodiment. The fourth embodiment differs from the above-described embodiments in that the welded portion 120 is formed in the shape of a peninsula extending from the rib 104, as shown in FIG.

[0099] The arrangement of the welded portion 120 in the fourth embodiment is the same as in the second and third embodiments. The welded portion 120 in the fourth embodiment is integrated with an extending portion 124 that extends obliquely from the nearest second rib 104b. As described above, the welded portion 120 in the fourth embodiment is formed in a peninsula shape extending from the rib 104. According to this configuration, by forming the welded portion 120 in a peninsula shape extending from the rib 104, the formation precision of the welded portion 120 can be improved, as in the third embodiment. This can improve the reliability of electrical grounding of the nozzle plate 51. Furthermore, by forming the welded portion 120 in a peninsula shape extending from the rib 104, the rigidity of the rib 104 can be increased. This can restrict warping of the nozzle guard 100 and reduce stress applied to the nozzle plate 51 via the rib 104. This can suppress degradation of print quality due to deformation of the nozzle plate 51, etc.

[0100] (Fifth embodiment) Next, a fifth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. FIG. 10 is a plan view showing the configuration of the main part of the nozzle guard 100 according to the fifth embodiment. The fifth embodiment differs from the above-described embodiments in that, as shown in FIG. 10, the rib 104 extends so as to block a first path 121A connecting the welded portion 120 and the first opening 103A and a second path 121B connecting the welded portion 120 and the second opening 103B.

[0101] The arrangement of the welded portion 120 in the fifth embodiment is the same as in the second to fourth embodiments. The rib 104 in the fifth embodiment includes a first rib 104a provided on the periphery of each of the first opening 103A and the second opening 103B, and a second rib 104b arranged closer to the welded portion 120 than the first rib 104a and surrounding the welded portion 120. The second rib 104b is formed in a U-shape in a plan view and extends so as to block a first path 121A connecting the welded portion 120 and the first opening 103A and a second path 121B connecting the welded portion 120 and the second opening 103B.

[0102] That is, the second rib 104b in the fifth embodiment is shared by both the first opening 103A and the second opening 103B. The nozzle guard 100 in the fifth embodiment further includes a third rib 104c disposed in the gap between the first opening 103A and the second opening 103B. The third rib 104c extends in the Y direction parallel to the first opening 103A and the second opening 103B and is connected to the second rib 104b. This increases the rigidity of the second rib 104b.

[0103] In this way, the rib 104 (second rib 104b) of the fifth embodiment extends so as to block the first path 121A connecting the welded portion 120 and the first opening 103A and the second path 121B connecting the welded portion 120 and the second opening 103B. With this configuration, one rib 104 can block splash 130 into two adjacent first openings 103A and second openings 103B. This allows the number of ribs 104 to be reduced.

[0104] (Sixth embodiment) Next, a sixth embodiment will be described. In the following description, the same or equivalent components as those in the above-described embodiments will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. FIG. 11 is a cross-sectional view showing the configuration of the main part of the nozzle guard 100 according to the sixth embodiment. The sixth embodiment differs from the above-described embodiments in that, as shown in FIG. 11, the first distance D1 between the second rib 104b and the welded portion 120 is shorter than the second distance D2 between the first rib 104a and the second rib 104b.

[0105] According to the sixth embodiment, by arranging the second rib 104b near the welded portion 120, the spread of the splash 130 is suppressed, and the gap 105 between the second rib 104b and the first rib 104a is relatively widened, making it easier to capture the splash 130 that has gone over the second rib 104b. Therefore, the splash 130 that is scattered from the welded portion 120 is less likely to reach the vicinity of the nozzle hole 71.

[0106] While preferred embodiments of the present disclosure have been described and illustrated above, it should be understood that these are illustrative of the present disclosure and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present disclosure. Accordingly, the present disclosure should not be deemed limited by the foregoing description, but rather by the scope of the claims.

[0107] For example, in the above-described embodiment, an inkjet printer has been described as an example of a liquid jet recording apparatus, but the liquid jet recording apparatus is not limited to a printer. For example, a fax machine, an on-demand printer, or the like may also be used. In the above-described embodiment, a configuration in which the inkjet head moves relative to the recording medium during printing (a so-called shuttle machine) has been described as an example, but the present disclosure is not limited to this configuration. The configuration according to the present disclosure may also be employed in a configuration in which the inkjet head is fixed and the recording medium moves relative to the inkjet head (a so-called fixed head machine). In the above-described embodiment, the recording medium P is paper, but this is not limiting. The recording medium P is not limited to paper, and may be a metal material, a resin material, or a food product. In the above-described embodiment, a configuration in which the liquid jet head is mounted on a liquid jet recording apparatus has been described, but the present invention is not limited to this configuration. That is, the liquid jetted from the liquid jet head is not limited to the liquid that lands on a recording medium, but may be, for example, a medicinal liquid to be mixed into a medicine, a food additive such as a seasoning or flavoring to be added to food, or an aromatic to be sprayed into the air. In the above-described embodiment, the Z direction coincides with the direction of gravity, but the invention is not limited to this configuration, and the Z direction may be aligned with the horizontal direction. In the above-described embodiment, the first direction coincides with the Y direction, but the present invention is not limited to this configuration. The first direction may be determined separately from the Y direction. [Explanation of symbols]

[0108] 1...Printer (liquid jet recording device) 5...Inkjet head (liquid jet head) 50...Head tip 51...Nozzle plate (injection plate) 71...Nozzle hole (injection hole) 74...Nozzle row (first injection row) 75...Nozzle row (second injection row) 100...Nozzle guard (guard member) 101a...peripheral wall part 101b...Opposing surface 103…Aperture 103A…1st opening 103B…Second opening 104...Rib 104a...First Rib 104b...Second rib 105...Gap 120...Welded section 121...Route 121A... Route 1 121B...Second Route 122...intersection 130...Splash 200...Extension line 201A...First Intersection Line 201B...Second Intersection Line D1: First distance D2…Second distance

Claims

1. an injection plate having injection holes formed therein for injecting the liquid; a guard member that covers the ejection plate and has an opening that exposes the ejection hole, The guard member is an opposing surface that faces the injection plate with a gap therebetween; a peripheral wall portion surrounding the opposing surface; a welded portion formed in an island shape spaced apart from the peripheral wall portion, extending toward the injection plate beyond the opposing surface, and joined to the injection plate, a rib disposed so as to interrupt a path connecting the welded portion and the opening in a planar direction along the opposing surface;

2. An injection plate having injection holes for injecting liquid; a guard member that covers the ejection plate and has an opening that exposes the ejection hole, The guard member is an opposing surface that faces the injection plate with a gap therebetween; a peripheral wall portion surrounding the opposing surface; a welded portion formed in a peninsula shape extending from the peripheral wall portion, extending toward the injection plate beyond the opposing surface, and joined to the injection plate, a rib disposed so as to interrupt a path connecting the welded portion and the opening in a planar direction along the opposing surface;

3. An injection plate having injection holes for injecting liquid; a guard member that covers the ejection plate and has an opening that exposes the ejection hole, The guard member is an opposing surface that faces the injection plate with a gap therebetween; a welded portion extending toward the injection plate from the opposing surface and joined to the injection plate, a rib disposed so as to interrupt a path connecting the welding portion and the opening in a planar direction along the opposing surface, The liquid jet head, wherein the welded portion is formed in a peninsula shape extending from the rib.

4. The injection holes form an injection row in a first direction, The opening is formed in a long hole shape that exposes the injection row, 4. The liquid jet head according to claim 1, wherein the welded portion is disposed on an extension line of the opening.

5. The injection holes form an injection row in a first direction, The opening is formed in a long hole shape that exposes the injection row, 4. The liquid jet head according to claim 1, wherein the welded portion is disposed in an oblique direction intersecting with an extension line of the opening.

6. The jet rows include a first jet row and a second jet row extending parallel to each other, the openings include a first opening exposing the first jet row and a second opening exposing the second jet row; 6. The liquid jet head according to claim 5, wherein the welded portion is disposed at the intersection of a first intersection line extending diagonally toward the second opening with respect to an extension line of the first opening, and a second intersection line extending diagonally toward the first opening with respect to the extension line of the second opening.

7. 7. The liquid jet head according to claim 6, wherein the rib extends so as to block a first path connecting the welded portion and the first opening and a second path connecting the welded portion and the second opening.

8. The rib is a first rib provided on a peripheral edge of the opening; 8. The liquid jet head according to claim 1, further comprising: a second rib provided on the welded portion side with a gap from the first rib.

9. An injection plate having injection holes for injecting liquid; a guard member that covers the ejection plate and has an opening that exposes the ejection hole, The guard member is an opposing surface that faces the injection plate with a gap therebetween; a welded portion extending toward the injection plate from the opposing surface and joined to the injection plate, a rib disposed so as to interrupt a path connecting the welding portion and the opening in a planar direction along the opposing surface, The rib is a first rib provided on a peripheral edge of the opening; a second rib provided on the welded portion side with a gap from the first rib.

10. 10. The liquid jet head according to claim 8, wherein a first distance between the second rib and the welded portion is shorter than a first distance between the first rib and the second rib.

11. 11. The liquid jet head according to claim 1, wherein the rib is formed on the guard member.

12. A liquid jet recording apparatus comprising the liquid jet head according to any one of claims 1 to 11.

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