Liquid jet head, and liquid jet device

Abstract

To provide a liquid jet head and a liquid jet device which suppress deterioration of print quality.SOLUTION: A liquid jet head includes four or more head chips arranged in a zigzag manner along a first direction, and a support member which supports the plurality of head chips. The plurality of head chips are arranged so as to have an overlapping area in which a part of a nozzle forming area of the one head chip out of adjacent head chips and a part of a nozzle forming area of the other head chip overlap when viewed from a second direction orthogonal to the first direction. The plurality of overlapping areas include a first overlapping area, and a second overlapping area which is farther than the first overlapping area from a center position regarding the first direction of all nozzle forming areas consisting of all of the nozzle forming areas of the plurality of head chips. The first overlapping area is larger than the second overlapping area in regard to the first direction.SELECTED DRAWING: Figure 7

Description

[Technical field]

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

[0002] 2. Description of the Related Art Liquid ejection apparatuses equipped with liquid ejection heads that eject liquid such as ink onto a medium such as printing paper have been proposed.

[0003] The liquid jet head described in Patent Document 1 includes a plurality of head chips arranged in a staggered pattern, a fixing plate, and a case member. The plurality of head chips are accommodated and supported in a space formed by the fixing plate and the case member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-489 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the liquid jet head described in Patent Document 1, adjacent head chips among the multiple head chips have overlapping regions where they overlap with each other. In this document, the multiple head chips are arranged in a staggered pattern, and multiple overlapping regions exist. In such liquid jet heads with multiple overlapping regions, the size of each overlapping region has not been sufficiently considered in the past. [Means for solving the problem]

[0006] A liquid ejection head according to one embodiment of the present disclosure comprises a plurality of four or more head chips arranged in a staggered pattern along a first direction, and a support member supporting the plurality of head chips, wherein the plurality of head chips are arranged such that a portion of a nozzle forming region of one of adjacent head chips overlaps a portion of a nozzle forming region of the other head chip when viewed in a second direction perpendicular to the first direction, the plurality of overlapping regions including a first overlapping region and a second overlapping region that is farther away from a center position in the first direction of a total nozzle forming region formed by all the nozzle forming regions of the plurality of head chips than the first overlapping region, and wherein the first overlapping region is larger than the second overlapping region in the first direction.

[0007] A liquid ejecting apparatus according to an aspect of the present disclosure includes a liquid ejecting head that ejects liquid onto a medium, and a transport unit that transports the medium.

[0008] In one embodiment of the liquid ejection device of the present disclosure, the multiple overlapping areas include a third overlapping area having a size smaller than the first overlapping area in the first direction, the second overlapping area is disposed between the first overlapping area and the third overlapping area in the first direction, the support member has a notch between the second overlapping area and the third overlapping area, and the liquid ejection device comprises a liquid ejection head that ejects liquid onto a medium and a suppression portion that suppresses the medium from floating, the suppression portion being disposed in the notch. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating an example of the configuration of a liquid ejecting apparatus according to a first embodiment. [Diagram 2] 2 is an exploded perspective view of the liquid jet head shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line aa in FIG. [Figure 4] FIG. 2 is a top view of the liquid jet head according to the first embodiment. [Diagram 5] 5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 6]2 is a schematic diagram of a bottom surface of the liquid jet head according to the first embodiment. FIG. [Figure 7] FIG. 2 is a bottom view of the liquid jet head according to the first embodiment. [Figure 8] 11 is a diagram illustrating an example of air current flow in a plurality of head chips. [Figure 9] FIG. 4 is a bottom view of a liquid jet head of a comparative example. [Figure 10] 13 is a diagram for explaining the landing of ink droplets in a second overlapping region. FIG. [Figure 11] 11 is a diagram for explaining the landing of ink droplets in a first overlapping region. FIG. [Figure 12] 6 is a perspective view of a portion of the support member shown in FIG. 5. [Figure 13] 13 is a view of the support member shown in FIG. 12 with a fixing plate removed. [Figure 14] FIG. 14 is a bottom view of the support member shown in FIG. [Figure 15] FIG. 13 is a bottom view of a frame portion of another example. [Figure 16] 13 is a diagram showing the overlapping number of nozzles from which ink droplets are ejected in the second overlapping region. FIG. [Figure 17] 13 is a diagram showing the overlapping number of nozzles from which ink droplets are ejected in a first overlapping region. FIG. [Figure 18] 11 is a bottom view of a liquid jet head according to a first modified example. FIG. [Figure 19] 13 is a bottom view of a liquid jet head according to a second modified example. FIG. [Figure 20] 13 is a bottom view of a liquid jet head according to a third modified example. FIG. [Figure 21] 11A and 11B are diagrams for explaining the landing of ink droplets when not affected by air currents; [Figure 22] 11A and 11B are diagrams for explaining the impact of ink droplets when affected by air currents; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the dimensions and scale of each part in the drawings may differ from the actual dimensions, and some parts are shown diagrammatically to facilitate understanding. In addition, the scope of the present disclosure is not limited to these forms unless otherwise specified in the following description to the effect that the present disclosure is limited.

[0011] In the following description, the mutually intersecting X-axis, Y-axis, and Z-axis are used as appropriate. Moreover, one direction along the X-axis is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. Similarly, the opposite directions along the Y-axis are referred to as the Y1 direction and the Y2 direction. Moreover, the opposite directions along the Z-axis are referred to as the Z1 direction and the Z2 direction. The Y1 direction or the Y2 direction is an example of the "first direction." The X1 direction or the X2 direction is an example of the "second direction." Below, viewing from the Z1 direction or the Z2 direction is referred to as "planar view."

[0012] Typically, the Z axis is a vertical axis, and the Z1 direction corresponds to the downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. Also, the X axis, the Y axis, and the Z axis are typically perpendicular to each other, but are not limited to this, and may intersect at an angle within a range of 80° to 100°, for example.

[0013] 1. First embodiment 1-1. Schematic configuration of the liquid ejection device 100 1 is a schematic diagram showing an example of the configuration of a liquid ejection device 100 according to a first embodiment. The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a liquid, as droplets onto a medium M. The medium M is typically printing paper. Note that the medium M is not limited to printing paper, and may be a printing target made of any material, such as a resin film or fabric.

[0014] As shown in FIG. 1, the liquid ejection device 100 includes a liquid container 10, a control unit 20, a conveying section 50, a liquid ejection head 30, a plurality of holding sections 60 and a plurality of holding sections 61. The liquid ejection device 100 includes a liquid container 10, a control unit 20, a conveying section 50, a liquid ejection head 30, a plurality of holding sections 60 and 61.

[0015] The liquid container 10 is a container that stores ink. Specific examples of the liquid container 10 include a cartridge that is detachable from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink. The type of ink stored in the liquid container 10 is not particularly limited and may be any type.

[0016] The control unit 20 controls the operation of each element of the liquid ejection device 100. The control unit 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls the operation of each element of the liquid ejection device 100.

[0017] The transport unit 50 transports the medium M in a direction DM under the control of the control unit 20. The direction DM in this embodiment is the X1 direction. In the example shown in FIG. 1, the transport unit 50 includes a long transport roller along the Y axis and a motor that rotates the transport roller. Note that the transport unit 50 is not limited to a configuration using a transport roller, and may be configured to use, for example, a drum or an endless belt that transports the medium M while adsorbing it to its outer circumferential surface by electrostatic force or the like.

[0018] The suppressing portions 60, 61 are provided on a head support member (not shown) that supports the liquid ejection head 30. The suppressing portions 60, 61 suppress floating of the medium M relative to the liquid ejection head 30. The suppressing portions 60, 61 include, for example, a knurled roller that comes into contact with the medium M being transported and rotates in response. The knurled roller is rotatable about a rotation axis along the Y axis, and a plurality of protrusions are provided on the outer periphery of the rotation axis.

[0019] The liquid jet head 30 jets ink supplied from the liquid container 10 from each of the multiple nozzles N onto the medium M in the Z2 direction under the control of the control unit 20. The liquid jet head 30 is a line head that is long in the direction in which the Y axis extends. The liquid jet head 30 has multiple head chips 3 that are arranged so that the multiple nozzles N are distributed over the entire range of the medium M in the direction along the Y axis. An ink image is formed on the surface of the medium M by jetting ink from the liquid jet head 30 in parallel with the transport of the medium M by the transport unit 50.

[0020] The number and arrangement of the head chips 3 of the liquid jet head 30 are not limited to the example shown in Fig. 1 and may be arbitrary. In addition, when the liquid jet head 30 is configured to be capable of circulating ink, the liquid jet head 30 may be connected to the liquid container 10 via a circulation mechanism for circulating the ink in the liquid jet head 30.

[0021] As described above, the above liquid ejection device 100 has the liquid ejection head 30 that ejects ink onto the medium M, and the transport unit 50 that transports the medium M. As will be described later, the liquid ejection head 30 reduces the difference in landing deviation between the multiple head chips 3. Therefore, the liquid ejection device 100 including the liquid ejection head 30 can suppress the deterioration of print quality.

[0022] The liquid ejection device 100 also includes a liquid ejection head 30 and a suppression unit 60 that suppresses floating of the medium M. As will be described in detail later, the liquid ejection head 30 can be made compact in the direction along the Y axis, while the suppression unit 60 can effectively suppress floating of the medium M. Therefore, the liquid ejection device 100 including such a liquid ejection head 30 can be made compact and suppress deterioration in print quality.

[0023] 1-2. Overall configuration of head chip 3 Fig. 2 is an exploded perspective view of the head chip 3 shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line aa in Fig. 2. The cross section shown in Fig. 3 is a cross section parallel to the XZ plane. The Z axis is an axis along the direction in which ink is ejected by the liquid ejection head 30.

[0024] As illustrated in FIG. 2, the head chip 3 has a plurality of nozzles N arranged along the Y axis. The plurality of nozzles N are divided into nozzle rows La and nozzle rows Lb arranged side by side at intervals along the X axis. Each of the nozzle rows La and nozzle rows Lb is a collection of a plurality of nozzles N arranged linearly along the Y axis. The liquid ejecting head 30 has a structure in which elements related to each nozzle N of the nozzle row La and elements related to each nozzle N of the nozzle row Lb are arranged in a substantially plane-symmetrical manner. In the following description, the elements corresponding to the nozzle row La will be described primarily, and descriptions of elements corresponding to the nozzle row Lb will be omitted as appropriate. In the following description, when there is no need to distinguish between the nozzle rows La and the nozzle rows Lb, they will be referred to as the nozzle row L.

[0025] As illustrated in FIGS. 2 and 3, the head chip 3 includes a communication plate 31, a pressure chamber substrate 32, a vibration plate 33, a nozzle plate 37, a vibration absorber , a plurality of drive elements , a sealing substrate 35, a housing portion and a wiring substrate .

[0026] The communicating plate 31, the pressure chamber substrate 32, the vibration plate 33, the nozzle plate 37, and the vibration absorber 38 are each a long plate-like member extending along the Y axis. The pressure chamber substrate 32 and the housing part 36 are disposed on the surface of the communicating plate 31 facing in the Z2 direction. The nozzle plate 37 and the vibration absorber 38 are disposed on the surface of the communicating plate 31 facing in the Z1 direction. For example, the respective members are fixed together by an adhesive.

[0027] The nozzle plate 37 is a plate-like member in which a plurality of nozzles N are formed. Each of the plurality of nozzles N is a circular through-hole for ejecting ink. For example, the nozzle plate 37 is manufactured by processing a single crystal substrate of silicon (Si) using semiconductor manufacturing techniques such as photolithography and etching.

[0028] The communication plate 31 is formed with a plurality of throttle portions 312, a plurality of communication channels 314, a communication space Ra, and a common channel Rb. Each of the throttle portions 312 and the communication channels 314 extends in the Z1 direction and is a through hole formed for each nozzle N. The communication channel 314 overlaps the nozzle N in a plan view. The communication space Ra is an opening formed in an elongated shape along the Y axis. The communication space Ra extends along the Y axis. The common channel Rb communicates with the communication space Ra and overlaps with the communication space Ra in a plan view. The common channel Rb extends along the Y axis. The common channel Rb communicates with the plurality of throttle portions 312. In addition, the communication space Ra communicates the common channel Rb with an external channel of the head chip 3 via a space Rc and a supply port 361 described later.

[0029] A plurality of pressure chambers C1 are formed in the pressure chamber substrate 32. The pressure chamber C1 is a space located between the communication plate 31 and the vibration plate 33 and formed by the wall surface 320 of the pressure chamber substrate 32. A pressure chamber C1 is formed for each nozzle N. The pressure chamber C1 is an elongated space extending in the X1 direction. The plurality of pressure chambers C1 are arranged along the Y axis. One end of the pressure chamber C1 in the X1 direction is connected to the nozzle N via a communication flow path 314. The other end of the pressure chamber C1 in the X1 direction is connected to a throttle portion 312. The throttle portion 312 has a smaller cross-sectional area than the pressure chamber C1. An individual flow path for each nozzle N is formed by the pressure chamber C1, the nozzle N, the communication flow path 314, and the throttle portion 312.

[0030] The communication plate 31 and the pressure chamber substrate 32 are manufactured by processing a semiconductor substrate such as a silicon single crystal substrate.

[0031] An elastically deformable vibration plate 33 is disposed above the pressure chamber C1. The vibration plate 33 is laminated on the pressure chamber substrate 32 and contacts the surface of the pressure chamber substrate 32 opposite to the communicating plate 31. The vibration plate 33 is a plate-like member formed in a long rectangular shape along the Y axis in a plan view. The thickness direction of the vibration plate 33 is parallel to the Z1 direction. The pressure chamber C1 communicates with the communicating flow path 314 and the throttle portion 312. Therefore, the pressure chamber C1 communicates with the nozzle N via the communicating flow path 314, and communicates with the communicating space Ra via the throttle portion 312. Note that, for ease of explanation, the pressure chamber substrate 32 and the vibration plate 33 are illustrated in FIG. 2 as separate substrates, but in reality, they are laminated on a single silicon substrate.

[0032] A driving element 34 is formed for each pressure chamber C1 on the surface of the vibration plate 33 opposite to the pressure chamber C1. The driving element 34 is an elongated piezoelectric element extending along the X-axis in a plan view. The driving element 34 includes, for example, a pair of electrodes and a piezoelectric body sandwiched between the pair of electrodes. The driving element 34 may be an electrothermal conversion element that generates thermal energy.

[0033] The housing 36 is a case for storing ink to be supplied to the multiple pressure chambers C1, and is formed by, for example, injection molding of a resin material. A space Rc and a supply port 361 are formed in the housing 36. The supply port 361 is a conduit through which ink is supplied from the liquid container 10, and communicates with the space Rc. The space Rc of the housing 36 and the communication space Ra of the communication plate 31 communicate with each other. The communication space Ra, the common flow path Rb, and the space Rc described above form a common space R that is common to the multiple nozzles N. The common space R functions as a liquid storage chamber that stores ink to be supplied to the multiple pressure chambers C1. The ink stored in the common space R branches off to each throttle section 312 and is supplied to and filled in parallel with the multiple pressure chambers C1.

[0034] The vibration absorber 38 is a flexible film that constitutes the wall surface of the communication space Ra, and absorbs pressure fluctuations of the ink in the common space R. The vibration absorber 38 is, for example, a laminate of an ink-resistant resin film, a SUS (stainless steel) member that holds the resin film and has spring properties, and a fixed plate that protects the resin film and the SUS member. By providing the vibration absorber 38, the natural frequency of the flow path from the nozzle N through the pressure chamber C1 to the throttle section 312 is stabilized regardless of the nozzle N that is driven.

[0035] A frame 56 is bonded to the surface of the vibration absorber 38 facing the Z1 direction with an adhesive or the like. The frame 56 is a frame-shaped member that fits along the outer periphery of the vibration absorber 38. The frame 56 is made of, for example, a metal material. A fixing plate 532 (described later) is bonded to the surface of the frame 56 facing the Z1 direction with an adhesive or the like, as indicated by the two-dot chain line in the drawing.

[0036] The sealing substrate 35 is a structure that protects the multiple driving elements 34 and reinforces the mechanical strength of the pressure chamber substrate 32 and the vibration plate 33, and is fixed to the surface of the vibration plate 33 with, for example, an adhesive. The multiple driving elements 34 are housed inside a recess formed on the surface of the sealing substrate 35 facing the vibration plate 33. The wiring board 40 is inserted into a through hole 362 of the housing part 36 and a through hole 353 of the sealing substrate 35. The wiring board 40 is bonded to the surface of the vibration plate 33. The wiring board 40 is a mounting component on which multiple wirings for electrically connecting the control unit 20 and the head chip 3 are formed. The wiring board 40 includes a driving IC. The driving IC is a circuit including a switching element that selects whether or not to supply the driving signal Com to the driving element 34. For example, a TCP (Tape Carrier Package) or an FPC (Flexible Printed Circuit) is used as the wiring board 40. A drive signal for driving the drive elements 34 and a reference voltage are supplied to each drive element 34 from the wiring board 40 .

[0037] In this head chip 3, when the driving element 34 contracts due to energization, the vibration plate 33 is bent and deflected in a direction that reduces the volume of the pressure chamber C1, and the pressure inside the pressure chamber C1 rises, causing an ink droplet to be ejected from the nozzle N. At this time, pressure also propagates from the pressure chamber C1 toward the throttle portion 312, and ink also flows into the common flow path Rb through the throttle portion 312. After the ink is ejected, the driving element 34 returns to its original position. At this time, the ink in the common flow path Rb from the nozzle N also vibrates. Then, at the same time that the meniscus of the nozzle N returns to its original state, ink is supplied from the throttle portion 312. Through the above series of operations, ink is ejected from the nozzle N.

[0038] 1-3. Liquid ejection head 30 Fig. 4 is a top view of liquid jet head 30 of the first embodiment. Fig. 5 is a cross-sectional view taken along line AA in Fig. 4. Fig. 6 is a schematic view of the bottom surface of liquid jet head 30 of the first embodiment. Figs. 4, 5, and 6 diagrammatically show liquid jet head 30 having head chips 3-1 to 3-7. Each of head chips 3-1 to 3-7 is the head chip 3 described above. Hereinafter, each of head chips 3-1 to 3-7 may be referred to as head chip 3.

[0039] The liquid jet head 30 includes head chips 3-1 to 3-7, a flow path structure 52, and a support member 53.

[0040] Head chips 3-1 to 3-7 are arranged in a staggered pattern along the Y2 direction when viewed along the Z axis. Head chips 3-1, 3-3, 3-5, and 3-7 are arranged in a line in the Y2 direction in this order. Head chips 3-1, 3-3, 3-5, and 3-7 are arranged so that their positions are aligned with each other in the direction along the X axis. Head chips 3-2, 3-4, and 3-6 are arranged in a line in the Y2 direction in this order. Head chips 3-2, 3-4, and 3-6 are arranged at positions in the X2 direction lower than head chips 3-1, 3-3, 3-5, and 3-7, so that their positions are aligned with each other in the direction along the X axis.

[0041] The flow path structure 52 is a structure in which a flow path Pa is provided for supplying ink from the liquid container 10 to the plurality of head chips 3. The flow path structure 52 is made of, for example, a resin material or a metal material. The flow path structure 52 is provided with a plurality of pipe sections 52d. Each of the plurality of pipe sections 52d protrudes from the flow path structure 52 in the Z1 direction.

[0042] The flow path Pa has a common flow path Pa1, a plurality of branch flow paths Pa2, and a plurality of openings HL. The common flow path Pa1 and the plurality of branch flow paths Pa2 are formed in the flow path structure 52. The plurality of openings HL are formed in a one-to-one correspondence with the plurality of pipe portions 52d.

[0043] The common flow path Pa1 is a flow path provided in common to multiple head chips 3. Specifically, the common flow path Pa1 is composed of a flow path provided in common to head chips 3-1, 3-3, 3-5, and 3-7, and a flow path provided in common to head chips 3-2, 3-4, and 3-6. Each of these flow paths extends in the direction along the Y axis, and both ends of each flow path communicate with an opening HL facing in the Z2 direction. Ink is introduced from the liquid container 10 into the opening HL.

[0044] The branch flow paths Pa2 are provided for each of the supply ports 361 of the head chips 3-1 to 3-7. Each of the branch flow paths Pa2 communicates with the corresponding supply port 361.

[0045] Support member 53 is a member that directly and commonly supports a plurality of head chips 3. Support member 53 is disposed on a surface of flow path structure 52 facing the Z1 direction, and is connected to flow path structure 52. Support member 53 includes a frame portion 531 and a fixing plate 532.

[0046] Frame portion 531 has a plurality of recesses 53a that accommodate a plurality of head chips 3. The plurality of recesses 53a are depressions provided on a surface of frame portion 531 facing the Z1 direction. Note that the plurality of recesses 53a may be provided for each head chip 3, or may be provided for each group of two or more head chips 3. For example, the plurality of recesses 53a are formed by dividing one recess into a plurality of sections.

[0047] Fixing plate 532 is disposed on a surface of frame portion 531 facing direction Z1, and is connected to frame portion 531. Fixing plate 532 is a plate-like member for fixing a plurality of head chips 3. Head chips 3 are accommodated in an accommodating space defined by fixing plate 532 and recesses 53a of frame portion 531.

[0048] The fixed plate 532 is provided with a plurality of exposure openings 53b that expose the nozzle plate 37 of each head chip 3 to the outside of the liquid ejection head 30. Each exposure opening 53b is a hole formed in the fixed plate 532. The plurality of exposure openings 53b are individually provided for each head chip 3. Each exposure opening 53b exposes a plurality of nozzles of the nozzle plate 37 of each head chip 3. The surface of the fixed plate 532 of the liquid ejection head 30 facing the Z1 direction constitutes an ejection surface FN together with the nozzle plate 37 exposed from the exposure openings 53b. As shown in FIG. 3, in this embodiment, the exposure openings 53b are formed so as to overlap with the plurality of nozzles N of the nozzle plate 37. A part of the fixed plate 532 overlaps with the outer peripheral portion of the nozzle plate 37 when viewed in the Z1 direction. The exposure openings 53b may overlap with the entire area of ​​the nozzle plate 37 in a plan view. That is, the entire nozzle plate 37 may be exposed from the exposure openings 53b.

[0049] The support member 53 is made of, for example, a metal material such as stainless steel, titanium, or magnesium alloy, or a resin material. The fixed plate 532 and the frame 531 are made of separate members, but may be integrally formed. A part of the support member 53 may be integrally formed with the flow path structure 52. For example, the frame 531 may be integrally formed with the flow path structure 52.

[0050] 1-4. Overlapping area of ​​head chip 3 FIG. 7 is a bottom view of the liquid jet head 30 according to the first embodiment.

[0051] As shown in FIG. 7, the ejection surface FN of the liquid ejection head 30 includes a total nozzle forming region S30 consisting of all the nozzle forming regions S3 of the multiple head chips 3. The nozzle forming region S3 is a region from the nozzle N arranged at one end in the Y1 direction to the nozzle N arranged at the other end among the multiple nozzles N formed in one head chip 3. Note that in FIG. 7, the nozzles N are omitted from illustration, and only the nozzle forming region S3 is illustrated. Also, the total nozzle forming region S30 is a region in the Y1 direction from the end of the nozzle forming region S3 of the head chip 3-1 in the Y1 direction to the end of the nozzle forming region S3 of the head chip 3-7 in the Y2 direction. Also, in this embodiment, the sizes of the nozzle forming regions S3 of the multiple head chips 3, that is, the lengths in the direction along the Y axis, are approximately the same as each other. Note that approximately the same means that the difference between the two is 1% or less when the size of the nozzle forming region S3 of one head chip 3 is 100%.

[0052] As described above, the multiple head chips 3 are arranged in a staggered manner along the Y1 direction, and four or more head chips are provided. In the illustrated example, seven head chips 3 are provided. The multiple head chips 3 are arranged such that a part of the nozzle forming region S3 of one head chip 3 of adjacent head chips 3 overlaps with a part of the nozzle forming region S3 of the other head chip 3 when viewed in the X1 direction, forming an overlapping region A. Therefore, the overlapping region A exists between the adjacent head chips 3. Thus, the multiple head chips 3 include multiple overlapping regions A. The Y1 direction and the X1 direction are parallel to the nozzle forming region S3 and perpendicular to the Z1 direction, which is the ink ejection direction.

[0053] The multiple overlapping regions A include a first overlapping region A1, a second overlapping region A2, a third overlapping region A3, a fourth overlapping region A4, a fifth overlapping region A5, and a sixth overlapping region A6.

[0054] The first overlap region A1 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-4 and a part of the nozzle forming region S3 of the head chip 3-5 overlap when viewed in the X1 direction. The first overlap region A1 is closest to the center position O1 among the multiple overlap regions A. The center position O1 is the center position in the Y1 direction of all the nozzle forming regions S30.

[0055] The second overlap region A2 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-5 and a part of the nozzle forming region S3 of the head chip 3-6 overlap when viewed in the X1 direction. The second overlap region A2 is farther away from the center position O1 than the first overlap region A1. In this embodiment, the second overlap region A2 is provided in the Y2 direction with respect to the first overlap region A1. Also, the second overlap region A2 is disposed between the first overlap region A1 and a third overlap region A3 (described later) with respect to the Y1 direction. Also, the size of the second overlap region A2, i.e., the length along the Y axis, is smaller than the size of the first overlap region A1, i.e., the length along the Y axis.

[0056] The third overlap region A3 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-6 and a part of the nozzle forming region S3 of the head chip 3-7 overlap when viewed in the X1 direction. The third overlap region A3 is farther away from the center position O1 than the first overlap region A1 and the second overlap region A2. The third overlap region A3 is disposed so as to sandwich the second overlap region A2 between the first overlap region A1 and the third overlap region A3 in the Y1 direction. In this embodiment, the third overlap region A3 is located furthest in the Y2 direction among the multiple overlap regions A. The size of the third overlap region A3, that is, the length in the direction along the Y axis, is smaller than the size of the first overlap region A1 in the Y1 direction. In addition, in this embodiment, the size of the third overlap region A3 is approximately the same as the length of the second overlap region A2 in the direction along the Y axis. Note that "approximately the same" refers to a difference between the two being 1% or less when the size of the nozzle forming region S3 of one head chip 3 is 100%.

[0057] The fourth overlap region A4 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-3 and a part of the nozzle forming region S3 of the head chip 3-3 overlap when viewed in the X1 direction. The fourth overlap region A4 is disposed with the center position O1 between it and the first overlap region A1. In this embodiment, the distance between the fourth overlap region A4 and the center position O1 is approximately the same as the distance between the first overlap region A1 and the center position O1. Therefore, the fourth overlap region A4 is the closest to the center position O1 among the multiple overlap regions A, similar to the first overlap region A1. In addition, the size of the fourth overlap region A4, that is, the length in the direction along the Y axis, is approximately the same as the size of the first overlap region A1.

[0058] The fifth overlap region A5 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-3 and a part of the nozzle forming region S3 of the head chip 3-2 overlap when viewed in the X1 direction. The fifth overlap region A5 is farther away from the center position O1 than the first overlap region A1 and the fourth overlap region A4. In this embodiment, the fifth overlap region A5 is provided in the Y1 direction with respect to the fourth overlap region A4. Also, the fifth overlap region A5 is disposed between the fourth overlap region A4 and a sixth overlap region A6 described below with respect to the Y1 direction. Also, the size of the fifth overlap region A5, i.e., the length in the direction along the Y axis, is smaller than the size of the fourth overlap region A4.

[0059] The sixth overlap region A6 is an overlap region A where a part of the nozzle forming region S3 of the head chip 3-2 and a part of the nozzle forming region S3 of the head chip 3-1 overlap when viewed in the X1 direction. The sixth overlap region A6 is farther away from the center position O1 than the fourth overlap region A4 and the fifth overlap region A5. The sixth overlap region A6 is disposed so as to sandwich the fifth overlap region A5 between the fourth overlap region A4 and the sixth overlap region A6 in the Y1 direction. In this embodiment, the sixth overlap region A6 is located furthest in the Y1 direction among the multiple overlap regions A. The size of the sixth overlap region A6, that is, the length along the Y axis, is smaller than the size of the fourth overlap region A4 in the Y1 direction. Also, in this embodiment, the size of the sixth overlap region A6 is approximately the same as the length along the Y axis of the fifth overlap region A5.

[0060] The fourth overlap region A4, the fifth overlap region A5, and the sixth overlap region A6 may be regarded as the first overlap region A1, the second overlap region A2, and the third overlap region A3. The number of head chips 3 may be four or more, and may be five, six, eight, or more.

[0061] In addition, in each overlap region A, several nozzles N belonging to the nozzle forming region S3 of one of two adjacent head chips 3 overlap with several nozzles N belonging to the nozzle forming region S3 of the other head chip 3 for each nozzle row L when viewed in the X1 direction.

[0062] Furthermore, each head chip 3 includes, among its nozzle forming region S3, a non-overlapping region B that does not overlap, when viewed in the X1 direction, with the nozzle forming region S3 of an adjacent head chip 3. The non-overlapping region B is a region different from the overlapping region A. The non-overlapping region B includes multiple non-overlapping regions B1, B2, B3, B4, B5, B6, and B7.

[0063] The non-overlapping region B1 is a region of the nozzle forming region S3 of the head chip 3-4 that is different from the first overlapping region A1 and the fourth overlapping region A4. The non-overlapping region B1 is a remaining region of the nozzle forming region S3 of the head chip 3-4 excluding the first overlapping region A1 and the fourth overlapping region A4. In this embodiment, the size of the non-overlapping region B1, that is, the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-4. The size of the non-overlapping region B1 is larger than the size of each of the first overlapping region A1 and the fourth overlapping region A4.

[0064] The non-overlapping region B2 is a region of the nozzle forming region S3 of the head chip 3-5 that is different from the first overlapping region A1 and the second overlapping region A2. The non-overlapping region B2 is a remaining region of the nozzle forming region S3 of the head chip 3-5 excluding the first overlapping region A1 and the second overlapping region A2. In this embodiment, the size of the non-overlapping region B2, that is, the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-5. The size of the non-overlapping region B2 is larger than the size of each of the first overlapping region A1 and the second overlapping region A2.

[0065] The non-overlapping region B3 is a region of the nozzle forming region S3 of the head chip 3-6 that is different from the second overlapping region A2 and the third overlapping region A3. The non-overlapping region B3 is a remaining region of the nozzle forming region S3 of the head chip 3-6 excluding the second overlapping region A2 and the third overlapping region A3. In this embodiment, the size of the non-overlapping region B3, that is, the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-6. The size of the non-overlapping region B3 is larger than the size of each of the second overlapping region A2 and the third overlapping region A3.

[0066] The non-overlapping region B4 is a region of the nozzle forming region S3 of the head chip 3-7 that is different from the third overlapping region A3. The non-overlapping region B4 is the remaining region of the nozzle forming region S3 of the head chip 3-7 excluding the third overlapping region A3. In this embodiment, the size of the non-overlapping region B4, i.e., the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-7. The size of the non-overlapping region B4 is larger than the size of the third overlapping region A3.

[0067] The non-overlapping region B5 is a region of the nozzle forming region S3 of the head chip 3-3 that is different from the fourth overlapping region A4 and the fifth overlapping region A5. The non-overlapping region B5 is a remaining region of the nozzle forming region S3 of the head chip 3-3 excluding the fourth overlapping region A4 and the fifth overlapping region A5. In this embodiment, the size of the non-overlapping region B5, that is, the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-3. The size of the non-overlapping region B5 is larger than the size of each of the fourth overlapping region A4 and the fifth overlapping region A5.

[0068] The non-overlapping region B6 is a region of the nozzle forming region S3 of the head chip 3-2 that is different from the fifth overlapping region A5 and the sixth overlapping region A6. The non-overlapping region B6 is a remaining region of the nozzle forming region S3 of the head chip 3-2 excluding the fifth overlapping region A5 and the sixth overlapping region A6. In this embodiment, the size of the non-overlapping region B6, that is, the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-2. The size of the non-overlapping region B6 is larger than the size of each of the fifth overlapping region A5 and the sixth overlapping region A6.

[0069] The non-overlapping region B7 is a region of the nozzle forming region S3 of the head chip 3-1 that is different from the sixth overlapping region A6. The non-overlapping region B7 is the remaining region of the nozzle forming region S3 of the head chip 3-1 excluding the sixth overlapping region A6. In this embodiment, the size of the non-overlapping region B7, i.e., the length in the direction along the Y axis, is more than half the size of the nozzle forming region S3 of the head chip 3-1. The size of the non-overlapping region B7 is larger than the size of the sixth overlapping region A6.

[0070] 8 is a diagram illustrating an example of the flow of air currents generated around a plurality of head chips 3. In the liquid ejecting head 30, there is a risk that ink droplets will not land on the intended location on the medium M due to the air currents.

[0071] As shown in Fig. 8, there are multiple gaps between the multiple head chips 3. For this reason, air currents escape through the multiple gaps. As shown by solid arrow a0 in Fig. 8, air currents escape through the multiple gaps between the multiple head chips 3. As the air currents escape, there is a risk that landing deviations will occur between the multiple head chips 3. The air currents are generated, for example, by the transportation of the medium M.

[0072] For example, when all nozzles N are in a solid state, the ink droplets ejected from the seven head chips 3 form a curtain in accordance with the shape of the nozzle rows L aligned in the Y1 direction, obstructing the flow of the air current. For example, the liquid ejection head 30 of this embodiment is a line head. In this case, the air current generated in the X1 direction by the transport of the medium M is obstructed by the ink droplets.

[0073] However, in the Y1 direction, for head chips 3-1 and 3-7 located on both sides of total nozzle formation region S30, the airflow escapes from a location where there are no adjacent chips. In other words, the airflow escapes as shown by dashed arrow a9 in Fig. 8. For this reason, the vicinity of head chips 3-1 and 3-7 is less affected by landing deviation than head chip 3-4, which is closest to center position O1.

[0074] Moreover, the airflow speed is faster toward the center of the entire nozzle formation region S30 in the Y1 direction and slower toward both ends. Therefore, the center is more susceptible to the influence of the airflow, which causes a larger landing deviation, and the both ends are less susceptible to the influence of the airflow, which causes a smaller landing deviation. In this way, due to the influence of the multiple gaps between the multiple head chips 3, a difference in landing deviation occurs in the Y1 direction. In this embodiment, in order to reduce this difference, the overlap amount of the overlap area A near the center position O1 is made larger than the overlap amount at both ends, taking into consideration that the landing deviation near the center position O1 is larger than the landing deviation at both ends.

[0075] Specifically, as described above, in the Y1 direction, the size of the first overlapping area A1 is larger than the second overlapping area A2. Therefore, compared to a case where the sizes of the multiple overlapping areas A are the same, it is possible to suppress deterioration of print quality due to differences in landing deviations between the multiple head chips 3.

[0076] The same problem exists when the liquid jet head 30 is a serial head instead of a line head. For example, when the liquid jet head 30 is a serial head, the airflow generated by the movement of the carriage that supports and reciprocates the liquid jet head 30 in the direction perpendicular to the extension direction of all the nozzle formation regions S30, i.e., the direction in which the head chips 3 are arranged in a staggered pattern, is obstructed by ink droplets. Even in such a case, the size of the first overlap region A1 is larger than the second overlap region A2, so that it is possible to suppress the deterioration of print quality due to the difference in landing deviation between the head chips 3, compared to the case in which the sizes of the overlap regions A are the same.

[0077] Fig. 9 is a bottom view of a liquid jet head 30x of a comparative example. As shown in Fig. 9, in the conventional liquid jet head 30x, the sizes of the multiple overlapping regions A are substantially the same. In such a liquid jet head 30x, a difference occurs in the landing deviation in the Y1 direction within all nozzle forming regions S30. As a result, there is a risk of a decrease in print quality.

[0078] Fig. 21 is a diagram for explaining the landing of ink droplets M0 when not affected by air current. Fig. 22 is a diagram for explaining the landing of ink droplets M0 when affected by air current. Note that Figs. 21 and 22 show the nozzle row La of each head chip 3 as a representative.

[0079] 21, when there is no influence of air currents, ideally, ink droplets M0 are ejected directly below nozzle N. Since adjacent head chips 3 have overlapping area A, no white streaks are generated on medium M corresponding to the area between adjacent head chips 3.

[0080] 22, when the ink droplet M0 is affected by the airflow, the ink droplet M0 is not ejected directly below the nozzle N, and instead moves toward the center of the nozzle row La. As a result, an area A0 where no ink droplets are ejected is generated on the medium M. This area A0 appears as a white streak on the medium M.

[0081] Fig. 10 is a diagram for explaining the landing of ink droplets M0 in the second overlap region A2. Fig. 11 is a diagram for explaining the landing of ink droplets M0 in the first overlap region A1. Note that in Figs. 10 and 11, the nozzle row La of each head chip 3 is shown as a representative.

[0082] As shown in FIGS. 10 and 11, there is a risk that ink droplets M0 ejected from some nozzles N located near the ends of one nozzle row La may move toward the center of the nozzle row La due to the influence of the air current described above.

[0083] The space between the head chip 3-5 and the head chip 3-6 is located closer to the end of the liquid ejection head 30 than the space between the head chip 3-4 and the head chip 3-5. Therefore, the space between the head chip 3-5 and the head chip 3-6 is less susceptible to the influence of airflow than the space between the head chip 3-4 and the head chip 3-5. Therefore, even if the size of the second overlapping region A2 is smaller than the size of the first overlapping region A1, white streaks are less likely to occur. On the other hand, airflow is easily allowed to escape between the head chip 3-4 and the head chip 3-5. Therefore, the size of the first overlapping region A1 is made larger than the size of the second overlapping region A2. This makes it possible to suppress the risk of white streaks occurring on the medium M even if a large landing deviation of the ink droplets M0 occurs between the head chip 3-4 and the head chip 3-5 due to the influence of airflow.

[0084] It should be noted that, like the nozzle rows La, the nozzle rows Lb of adjacent head chips 3 also have overlapping portions when viewed in the X1 direction.

[0085] 7, the first overlapping region A1 is the overlapping region A that is closest to the center position O1 in the Y1 direction among the multiple overlapping regions A. In this case, since the first overlapping region A1 is larger than the second overlapping region A2, it is possible to effectively suppress deterioration of print quality due to differences in landing deviations between the multiple head chips 3.

[0086] Furthermore, with respect to the Y1 direction, the size of the first overlap region A1 is preferably at least twice the average size of the multiple overlap regions A. When the size of the first overlap region A1 is at least twice the average size of the multiple overlap regions A, white streaks are less likely to occur even if ink droplets are affected by a relatively large air current in the first overlap region A1, compared to when the size is less than twice the average size of the multiple overlap regions A.

[0087] From another perspective, it is preferable that the number of nozzles belonging to the first overlap region A1 is at least twice the average number of nozzles belonging to the multiple overlap regions A. For example, consider a case where the number of nozzles in each of the first overlap region A1 and the fourth overlap region A4 is 64, and the number of nozzles in each of the second overlap region A2, the third overlap region A3, the fifth overlap region A5, and the sixth overlap region A6 is 9. In this case, the average number of nozzles belonging to the multiple overlap regions A is about 27. Therefore, twice the average is about 54. When the number of nozzles belonging to the first overlap region A1 is at least twice the average number of nozzles belonging to the multiple overlap regions A, the effect of the first overlap region A1 being larger than the second overlap region A2 is more pronounced than when the number of nozzles is less than twice the average number of nozzles belonging to the multiple overlap regions A.

[0088] The size of the first overlap region A1 may be less than twice the average size of the multiple overlap regions A. Furthermore, the number of nozzles belonging to the first overlap region A1 may be less than twice the average number of nozzles belonging to the multiple overlap regions A.

[0089] Furthermore, in the Y1 direction, the size of the second overlap region A2 is preferably equal to or less than 1 / 2 the average size of the multiple overlap regions A. If the size of the second overlap region A2 exceeds 1 / 2 the average size of the multiple overlap regions A, the effect of the first overlap region A1 being larger than the second overlap region A2 is weakened compared to when the size is 1 / 2 or less.

[0090] From another perspective, it is preferable that the number of nozzles belonging to the second overlap region A2 is at least 1 / 2 the average number of nozzles belonging to the multiple overlap regions A. For example, consider a case where the number of nozzles in each of the first overlap region A1 and the fourth overlap region A4 is 64, and the number of nozzles in each of the second overlap region A2, the third overlap region A3, the fifth overlap region A5, and the sixth overlap region A6 is 9. In this case, the average number of nozzles belonging to the multiple overlap regions A is about 27. Therefore, 1 / 2 the average is about 14. When the number of nozzles belonging to the second overlap region A2 is 1 / 2 or less the average number of nozzles belonging to the multiple overlap regions A, the effect of the first overlap region A1 being larger than the second overlap region A2 is more pronounced than when the number of nozzles exceeds 1 / 2.

[0091] In particular, it is preferable that the size of the first overlap region A1 in the Y1 direction is at least twice the average size of the multiple overlap regions A, and that the size of the second overlap region A2 in the Y1 direction is at most 1 / 2 the average size of the multiple overlap regions A. By satisfying these relationships, degradation of print quality due to differences in landing deviations between the multiple head chips 3 can be particularly effectively suppressed compared to cases where these relationships are not satisfied.

[0092] The size of the second overlap region A2 may exceed 1 / 2 the average size of the multiple overlap regions A. Furthermore, the number of nozzles belonging to the second overlap region A2 may exceed 1 / 2 the average number of nozzles belonging to the multiple overlap regions A.

[0093] The size of the first overlap region A1 in the Y1 direction is preferably at least five times the size of the second overlap region A2, and may be at least seven times the size of the second overlap region A2 in the Y1 direction.

[0094] In the Y1 direction, the total size of the multiple overlapping regions A is smaller than the size of the nozzle forming region S3 of one head chip 3. Since the total size is smaller than the size of the nozzle forming region S3, it is possible to avoid an excessively large number of nozzles included in the overlapping region A, and the liquid ejecting head 30 can be suitably used as a line head. Note that the total size may be larger than the size of one nozzle forming region S3.

[0095] 1-5. Support member 53 Fig. 12 is a perspective view of a portion of the support member 53 shown in Fig. 5. Fig. 13 is a view of the support member 53 shown in Fig. 12 with the fixing plate 532 removed. Fig. 14 is a bottom view of the support member 53 shown in Fig. 13. Fig. 14 illustrates a state in which the fixing plate 532 has been removed.

[0096] 12, the support member 53 has a frame portion 531 and a fixed plate 532. As described above, the fixed plate 532 is provided with a plurality of exposure openings 53b.

[0097] As shown in FIG. 13 and FIG. 14, the frame 531 includes a base 5311 and a frame body 5312. The base 5311 is a portion connected to the flow path structure 52. The frame body 5312 is provided on a surface of the base 5311 facing the Z1 direction. A through hole is provided in the frame body 5312. The inner wall surface of the through hole and the surface of the base 5311 in the Z1 direction form the above-mentioned multiple recesses 53a. In the illustrated example, the multiple recesses 53a are partially connected to form one recess. Furthermore, the frame body 5312 is provided with multiple cutouts 55, 57.

[0098] Fig. 15 is a bottom view of a support member 53 of a modified example. A frame body 5312y of a frame portion 531y of a support member 53y shown in Fig. 15 does not have a plurality of notches 55, 57. On the other hand, a frame body 5312 of the present embodiment shown in Fig. 14 is provided with a plurality of notches 55, 57. Each of the notches 55, 57 is formed by cutting out a part of the frame body 5312y shown in Fig. 15.

[0099] As described above, in this embodiment, the first overlap region A1 is larger than the second overlap region A2 in the Y1 direction. Therefore, in the Y1 direction, the gap between adjacent head chips 3 closer to the edge than the central position O1 can be made larger. Therefore, the notch 55 can be provided closer to the edge than the central position O1. Any component can be placed in the notch 55. For example, a temperature sensor, a heater, or the like can be provided in the notch 55. Therefore, the liquid ejection head 30 can be made smaller in size.

[0100] As shown in FIG. 14, in this embodiment, one notch 55 is provided between the second overlapping region A2 and the third overlapping region A3 in the Y1 direction. The other notch 55 is provided between the fifth overlapping region A5 and the sixth overlapping region A6 in the Y1 direction. Therefore, the support member 53 has a notch 55 between the second overlapping region A2 and the third overlapping region A3 and between the fifth overlapping region A5 and the sixth overlapping region A6. By providing the notch 55 in the frame body 5312, it is possible to arrange the suppressing portion 60 that suppresses the floating of the medium M in the notch 55. Therefore, it is possible to provide the suppressing portion 60 in the liquid ejection head 30. Therefore, it is not necessary to separately provide a member other than the liquid ejection head 30 for arranging the suppressing portion 60. Therefore, it is possible to reduce the size of the liquid ejection device 100. In addition, by providing the notch 57, it is possible to arrange the suppressing portion 61.

[0101] For example, the suppressing portion 60 is movable in the X1 direction and the X2 direction as indicated by the double-headed arrow a5. Similarly, the suppressing portion 61 is movable in the X1 direction and the X2 direction as indicated by the double-headed arrow a6. Therefore, when the liquid ejecting device 100 is in use, the suppressing portions 60, 61 can be disposed at the positions shown in FIG. 14 to suppress floating of the medium M. Furthermore, when cleaning the ejection surface FN of the liquid ejecting head 30, the suppressing portions 60, 61 are moved in the X1 direction from the positions shown in FIG. 14. This allows the ejection surface FN to be cleaned efficiently.

[0102] 14, the frame 5312 of the support member 53 does not have a notch between the first overlap region A1 and the second overlap region A2. Since no notch is formed in this location, the rigidity of the support member 53 can be increased compared to when a notch is formed.

[0103] As described above, the fourth overlap region A4 is disposed with the center position O1 sandwiched between it and the first overlap region A1. In the Y1 direction, the size of the first overlap region A1 is approximately the same as that of the fourth overlap region A4. Note that "approximately the same size" refers to a difference between the two being 1% or less when the size of the nozzle formation region S3 of one head chip in the first direction is 100%. For example, "approximately the same size" refers to a difference of 4 nozzles or less, which is 1% of the size of the nozzle formation region S3 of one head chip in the first direction, when the number of nozzles included in the nozzle formation region S3 of one head chip in the first direction is 400 nozzles.

[0104] Since the size of the first overlapping region A1 is approximately the same as the size of the fourth overlapping region A4, the central portion of the entire nozzle forming region S30 has a configuration that is line-symmetrical with respect to the central position O1. In the case of this line-symmetrical configuration, the holding portion 60 is disposed in the aforementioned cutout 55, so that the medium M can be easily stably fixed by the holding portion 60. In particular, when the medium M is set so that the center line of the medium M in the transport direction coincides with the central position O1, even if the width of the medium M is smaller than the entire nozzle forming region S30, the holding portion 60 can support the medium M so that both ends in the direction along the Y axis do not float.

[0105] 14, in this embodiment, two notches 57 are formed at the Y1-direction end and the Y2-direction end of the frame 5312. Then, a pressing portion 61 is disposed in the notch 57. This allows the pressing portion 61 to support both ends of the medium M in the direction along the Y axis so that they do not float.

[0106] Fig. 16 is a diagram showing the overlapping number of nozzles that eject ink droplets in the second overlapping region A2. Fig. 17 is a diagram showing the overlapping number of nozzles that eject ink droplets in the first overlapping region A1. Note that Figs. 16 and 17 show the nozzle row La of each head chip 3 as a representative.

[0107] The number of nozzles in the first overlap region A1 is different from that in the second overlap region A2, but the overlapping number of nozzles used to eject ink droplets may be set to be equal.

[0108] 16, seven nozzles in the nozzle row La of the head chip 3-6 belong to the second overlapping region A2, and seven nozzles in the nozzle row La of the head chip 3-5 belong to the second overlapping region A2. Of the seven nozzles N, three nozzles N9 and two nozzles N8 are nozzles N used to eject ink droplets. In the second overlapping region A2, the three nozzles N9 of the head chip 3-6 and the three nozzles N9 of the head chip 3-5 overlap in the X1 direction.

[0109] Therefore, the number of nozzles belonging to the second overlap region A2 is 7 in one nozzle row La. In contrast, in the second overlap region A2, the number of overlapping nozzles used to eject ink droplets in one nozzle row La is 3.

[0110] 17, 17 nozzles in the nozzle row La of the head chip 3-5 belong to the first overlapping region A1, and 17 nozzles in the nozzle row La of the head chip 3-4 belong to the first overlapping region A1. Of the 17 nozzles N, three nozzles N9 and seven nozzles N8 are nozzles N used to eject ink droplets. In the first overlapping region A1, the three nozzles N9 of the head chip 3-5 and the three nozzles N9 of the head chip 3-4 overlap in the X1 direction.

[0111] Therefore, the number of nozzles belonging to the first overlap region A1 in one nozzle row La is 17. In contrast, in the first overlap region A1, the number of overlapping nozzles used to eject ink droplets in one nozzle row La is three.

[0112] The first overlap region A1 and the second overlap region A2 have the same overlapping number of nozzles used to eject ink droplets. By making the overlapping number equal in each overlap region A, it is possible to reduce the difference in the degree of overlap of the ink droplets that land between the head chips 3 even if the first overlap region A1 is made larger than the second overlap region A2 in the Y1 direction in order to provide the suppression unit 60 in the liquid ejection head 30. The overlapping amount may be set according to the transport speed of the medium M caused by the air flow speed or the movement speed of the carriage.

[0113] 2. Variations Each of the above-mentioned exemplary embodiments may be modified in various ways. Specific modified embodiments that may be applied to each of the above-mentioned embodiments are illustrated below. Two or more embodiments selected from the following examples may be appropriately combined as long as they are not mutually contradictory.

[0114] 2-1. First modified example 18 is a bottom view of a liquid jet head 30A of a first modified example. The liquid jet head 30A of the first modified example shown in FIG. 18 includes a head chip 3-1 including a first overlapping region A1 and a non-overlapping region B1. The non-overlapping region B1 of the head chip 3-1 is a non-overlapping region B that does not overlap with the nozzle forming region S3 of another head chip 3-5 when viewed in the X1 direction and is less than half the size of the nozzle forming region S3. Even when a head chip 3-1 having such a non-overlapping region B1 is provided, since the first overlapping region A1 is larger than the second overlapping region A2, it is possible to effectively suppress deterioration in print quality due to differences in landing deviations between multiple head chips 3.

[0115] In the head chip 3-4 including the nozzle formation region S3 that constitutes the first overlap region A1, the size of the non-overlapping region B, which is different from the overlap region A, is equal to or smaller than the first overlap region A1. By having the size of the non-overlapping region B1 equal to or smaller than the size of the first overlap region A1, it is possible to reduce the size of the liquid ejecting head 30 in the Y1 direction compared to the case where the size of the non-overlapping region B1 exceeds the size of the first overlap region A1.

[0116] Incidentally, as in the embodiment described above, by making the size of the non-overlapping region B1 larger than the size of the first overlapping region A1, it is possible to provide a liquid ejecting head 30 suitable for a line head.

[0117] 2-2. Second modified example FIG. 19 is a bottom view of the liquid jet head 30A of the second modified example. The liquid jet head 30B of the second modified example shown in FIG. 19 has six head chips 3. The number of head chips 3 of the liquid jet head 30B is an even number. In the example of FIG. 19, the center position O1 is located within the first overlap region A1 in the Y1 direction. The fourth overlap region A4 is disposed on either side of the center position O1 with respect to the second overlap region A2. With respect to the Y1 direction, the size of the second overlap region A2 is approximately the same as the size of the fourth overlap region A4. Even if the number of head chips 6 is an even number, the deterioration of print quality can be effectively suppressed as in the above-described embodiment.

[0118] Note that "substantially the same size" refers to a difference between the two being 1% or less when the size of the nozzle formation region S3 of one head chip in the first direction is 100%. For example, when the number of nozzles included in the nozzle formation region S3 of one head chip in the first direction is 400 nozzles, "substantially the same size" refers to 1% of that, or 4 nozzles or less.

[0119] 2-3. Third modified example FIG. 20 is a bottom view of the liquid jet head 30C of the third modified example. In the liquid jet head 30C of the third modified example shown in FIG. 20, the second overlap region A2 is smaller than the first overlap region A1 and larger than the third overlap region A3 in the Y1 direction. That is, the sizes of the third overlap region A3, the second overlap region A2, and the first overlap region A1 increase in this order. Therefore, the size of the overlap region A increases stepwise toward the center position O1. From another perspective, the size of the overlap region A is changed according to the airflow speed distribution in the Y1 direction. According to this modified example, it is possible to effectively suppress the deterioration of print quality due to the difference in landing deviation between the multiple head chips 3 compared to the above-mentioned embodiment. Note that, with respect to the fourth overlap region A4, the fifth overlap region A5, and the sixth overlap region A6, the fifth overlap region A5 is smaller than the fourth overlap region A4 and larger than the sixth overlap region A6 in the Y1 direction.

[0120] 2-4. Other Modifications Although head chip 3 does not have a structure for circulating ink, head chip 3 may be a circulation type head having a so-called circulation flow path.

[0121] A "liquid ejection apparatus" may be employed in various devices such as facsimile machines and copy machines, in addition to devices dedicated to printing. The uses of a liquid ejection apparatus are not limited to printing. For example, a liquid ejection apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus for forming color filters for display devices such as liquid crystal display panels. A liquid ejection apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus for forming wiring and electrodes for a wiring board. A liquid ejection apparatus that ejects a solution of an organic substance related to a living organism is used as a manufacturing apparatus for manufacturing biochips, for example.

[0122] Although the present invention has been described based on the preferred embodiment, the present invention is not limited to the above embodiment. Furthermore, the configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above embodiment, and any configuration can be added. [Explanation of symbols]

[0123] 3...head chip, 30...liquid ejection head, 34...driving element, 37...nozzle plate, 53...support member, 55...notch, 56...frame, 60...retaining portion, 100...liquid ejection device, A...overlapping area, A1...first overlapping area, A2...second overlapping area, A3...third overlapping area, A4...fourth overlapping area, A5...fifth overlapping area, B...non-overlapping area, B1...non-overlapping area, L...nozzle row, M...medium, N...nozzle, O1...center position, S3...nozzle forming area, S30...total nozzle forming area.

Claims

1. Four or more head tips arranged in a staggered pattern along the first direction, A support member that supports the plurality of head chips, Equipped with, The plurality of head chips are arranged such that a portion of the nozzle forming region of one adjacent head chip and a portion of the nozzle forming region of the other head chip overlap when viewed in a second direction perpendicular to the first direction. The plurality of overlapping regions include a first overlapping region and a second overlapping region which is further away from the first overlapping region than the first overlapping region with respect to the center position in the first direction of the entire nozzle formation region composed of all nozzle formation regions of the plurality of head tips. With respect to the first direction, the first overlapping region is larger than the second overlapping region. The plurality of overlapping regions include a third overlapping region that is smaller in size than the first overlapping region with respect to the first direction. The second overlapping region is located between the first overlapping region and the third overlapping region with respect to the first direction. The support member has a notch between the second overlapping region and the third overlapping region. A liquid spray head characterized by the following features.

2. The first overlapping region is the overlapping region that is closest to the center position among the plurality of overlapping regions with respect to the first direction. The liquid spray head according to feature 1.

3. With respect to the first direction, the size of the first overlapping region is at least twice the average size of the plurality of overlapping regions. The liquid spray head according to feature 1.

4. With respect to the first direction, the size of the second overlapping region is less than or equal to half the average size of the plurality of overlapping regions. The liquid spray head according to feature 1.

5. With respect to the first direction, the size of the first overlapping region is at least twice the average size of the plurality of overlapping regions. With respect to the first direction, the size of the second overlapping region is less than or equal to half the average size of the plurality of overlapping regions. The liquid spray head according to feature 1.

6. With respect to the first direction, the size of the first overlapping region is five times or more the size of the second overlapping region. The liquid spray head according to feature 1.

7. The plurality of head chips include a head chip that includes a first overlapping region and a non-overlapping region that does not overlap with the nozzle forming region of another head chip when viewed in the second direction and is less than half the size of the nozzle forming region. The liquid spray head according to feature 1.

8. In the head tip including the nozzle formation region that constitutes the first overlapping region, the size of the non-overlapping region, which is different from the overlapping region, is less than or equal to the size of the first overlapping region. The liquid spray head according to feature 1.

9. The support member is provided such that no notch is formed between the first overlapping region and the second overlapping region. The liquid spray head according to feature 1.

10. The plurality of overlapping regions include a fourth overlapping region that is positioned between the first overlapping region and the center position, With respect to the first direction, the size of the first overlapping region is approximately the same as the size of the fourth overlapping region. The liquid spray head according to feature 1.

11. The aforementioned center position is located within the first overlapping region in the first direction, The plurality of overlapping regions include a fourth overlapping region that is positioned between the second overlapping region and the center position, With respect to the first direction, the size of the second overlapping region is approximately the same as the size of the fourth overlapping region. The liquid spray head according to feature 1.

12. The plurality of overlapping regions include a third overlapping region arranged in the first direction such that it sandwiches the second overlapping region between the first overlapping region and the third overlapping region. With respect to the first direction, the size of the second overlapping region is smaller than the size of the first overlapping region and larger than the size of the third overlapping region. The liquid spray head according to feature 1.

13. With respect to the first direction, the total size of the multiple overlapping regions is smaller than the size of the nozzle forming region of the head tip. The liquid spray head according to feature 1.

14. A liquid spray head according to any one of claims 1 to 13 for spraying liquid onto a medium, A transport unit for transporting the aforementioned medium, A liquid injection device characterized by being equipped with the following features.

15. A liquid spray head according to claim 1 for spraying liquid onto a medium, A retaining part that suppresses the floating of the aforementioned medium, Equipped with, The aforementioned retaining portion is positioned in the notch. A liquid injection device characterized by the following features.

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