Liquid ejection device

Abstract

Even in a case where a nozzle row direction is inclined with respect to a conveyance direction, deviation at a position where a liquid drops to a medium is suppressed. A liquid ejecting apparatus is provided with: a liquid ejecting head having a plurality of nozzle rows in which a plurality of nozzles are arranged side by side in a nozzle row direction; a conveyance mechanism that conveys a medium in a first direction; and a blast mechanism that generates an air current in a third direction that intersects any one of the first direction, a second direction, and the nozzle row direction, the second direction being orthogonal to both the first direction and a liquid ejecting direction.

Description

Technical Field

[0001] This invention relates to a liquid injection device. Background Technology

[0002] In the past, techniques for jetting liquids such as ink from multiple nozzles into a medium such as printing paper have been proposed. For example, Patent Document 1 discloses a liquid jetting device in which multiple nozzles are arranged in a straight line and the direction of the nozzle line is inclined relative to the transport direction of the medium.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-55476

[0004] However, in the aforementioned existing liquid injection device, since the direction of the nozzle array is tilted relative to the conveying direction, deviations may occur at the location where the liquid drips onto the medium. Summary of the Invention

[0005] The liquid injection device disclosed herein comprises: a liquid injection head having an injection surface having a plurality of nozzles arranged side-by-side in a nozzle array direction for injecting liquid in an injection direction; a conveying mechanism for conveying a medium in a first direction at a position opposite to the injection surface; and an air supply mechanism wherein the nozzle array direction intersects both the first direction and a second direction, the second direction being orthogonal to both the first direction and the injection direction, and the air supply mechanism generating an airflow in a third direction that intersects any one of the first direction, the second direction, and the nozzle array direction, such that it runs along the injection surface.

[0006] Furthermore, the liquid jetting apparatus of the suitable solution disclosed herein comprises: a liquid jetting head having a plurality of head chips, each of the plurality of head chips having a nozzle group consisting of a plurality of nozzles that jet liquid in a jetting direction; a conveying mechanism for conveying a medium in a first direction at a position opposite to the jetting surface of the liquid jetting head; and an air supply mechanism, wherein the plurality of nozzles includes a plurality of application nozzles used in a printing operation of jetting liquid toward the medium, wherein when a region in each of the plurality of nozzle groups is defined as a nozzle region by a minimum convex polygon surrounding the plurality of application nozzles, each of the plurality of nozzle regions corresponding to each of the plurality of nozzle groups is elongated in a fourth direction intersecting both the first direction and the second direction, the second direction being orthogonal to both the first direction and the jetting direction, and the air supply mechanism generates an airflow in a third direction intersecting any one of the first direction, the second direction, and the fourth direction, such that the airflow is along the jetting surface. Attached Figure Description

[0007] Figure 1This is an explanatory diagram showing an example of the liquid injection device 100 according to the first embodiment.

[0008] Figure 2 This is a 3D view of head module 3.

[0009] Figure 3 This is a diagram showing multiple liquid jet heads 30 viewed in the Z1 direction.

[0010] Figure 4 This is an exploded perspective view of the liquid injection head 30.

[0011] Figure 5 This is an exploded 3D view of the head chip 38_1.

[0012] Figure 6 yes Figure 5 A cross-sectional view of the VI-VI line.

[0013] Figure 7 This is a diagram of head module 3 viewed in the X1 direction.

[0014] Figure 8 yes Figure 7 A cross-sectional view of line VIII-VIII in the diagram.

[0015] Figure 9 yes Figure 2 A cross-sectional view of the IX-IX line.

[0016] Figure 10 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96.

[0017] Figure 11 This is a diagram illustrating the air supply direction of the air supply mechanism 96 in the second embodiment.

[0018] Figure 12 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the first modified example.

[0019] Figure 13 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the second variation.

[0020] Figure 14 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the third variation.

[0021] Figure 15 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the fourth variation.

[0022] Figure 16 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the fourth variation.

[0023] Figure 17This is an explanatory diagram showing an example of a liquid injection device 100D of the fifth modified example.

[0024] Figure 18 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96D in the fifth modification.

[0025] Figure 19 This is a diagram used to illustrate the air supply direction of the air supply mechanism 96 in the seventh variation.

[0026] Explanation of reference numerals in the attached figures

[0027] 3. 3D…head module, 13. 13D…head fixing substrate, 15…assembly hole, 30…liquid jet head, 31…casing, 32…cover substrate, 33…assembly substrate, 34…flow path structure, 35…wiring substrate, 37…bracket, 38…head chip, 39…fixing plate, 39N…surface, 90…control device, 91…moving mechanism, 92…conveying mechanism, 93…liquid container, 94…circulation mechanism, 96. 96D…air supply mechanism, 100…liquid jet device. 387… Nozzle plate, 388… Wiring component, 391… Exposed opening, 911… Carriage, 912… Annular belt, 962… Fan housing, 962A… Space, 962F… Fan, 962K, 962M… Opening, 964… Convergence section, 964A… Space, 964K, 964M… Opening, 966… Rectifier section, 966A… Through hole, 966A1… First space, 966A2… Second space, 966M, 3850… Opening, 385… 1…Inlet, 3852…Outlet, Du1, Du2…Flow path components, FN…Spray surface, GN…Nozzle assembly, IR1~IR4…Unused area, Img…Printing data, LW, LWA~LWG…Imaginary straight line, LZ1, LZB1, LZC1, LZD1, LZE1, LZF1…First straight line, LZA2, LZF2, LZG2…Second straight line, LZA3, LZF3, LZG3…Third straight line, Lk…Nozzle segment, Ln …Nozzle array, N…Nozzle, NRA, NRC, NRE, NRF, NRG…Nozzle area, Ni…Nozzle not in use, Ns…Nozzle in use, PP…Media, SN…Nozzle face, d12, d34…Distance, θ1, θB1, θC1, θD1, θE1, θF1…First angle, θ2, θB2, θC2, θD2, θE2, θF2…Second angle, θA3, θF3, θG3…Third angle, θA4, θF4, θG4…Fourth angle. Detailed Implementation

[0028] Hereinafter, the methods for implementing this disclosure will be described with reference to the accompanying drawings. However, in each drawing, the dimensions and scale of each part are appropriately different from the actual dimensions and scale. Furthermore, the embodiments described below are suitable specific examples of this disclosure and are therefore given various technically preferred limitations, but the scope of this disclosure is not limited to these methods unless otherwise specifically limited in the description below.

[0029] 1. First Implementation Method

[0030] 1-1. Overview of the liquid injection device 100

[0031] Figure 1 This is an explanatory diagram showing an example of the liquid jetting apparatus 100 according to the first embodiment. The liquid jetting apparatus 100 according to this embodiment is an inkjet printing apparatus that jets ink, an example of a liquid, as droplets onto a medium PP. The liquid jetting apparatus 100 of this embodiment is a so-called line printing apparatus in which multiple nozzles N for jetting ink are distributed throughout the entire width direction of the medium PP. The medium PP is, for example, printing paper, but any printing object such as resin film or fabric can be used as the medium PP.

[0032] like Figure 1 As illustrated, the liquid ejection device 100 includes a liquid container 93 for storing ink. The liquid container 93 can be, for example, an ink cartridge that can be attached to and detached from the liquid ejection device 100, a bag-shaped ink pouch formed of a flexible membrane, or an ink canister for refilling ink. One or more types of ink are stored in the liquid container 93.

[0033] like Figure 1 As illustrated, the liquid injection device 100 includes: a head module 3 having multiple liquid injection heads 30; a control device 90; a delivery mechanism 92; and a circulation mechanism 94. The control device 90 includes processing circuitry such as a CPU or FPGA and storage circuitry such as semiconductor memory, controlling the various elements of the liquid injection device 100. Here, CPU stands for Central Processing Unit, and FPGA stands for Field Programmable Gate Array.

[0034] The conveying mechanism 92 conveys the medium PP in the Y1 direction under the control of the control device 90. Furthermore, hereinafter, the Y1 direction and the Y2 direction, which is the opposite direction to the Y1 direction, are sometimes collectively referred to as the direction along the Y-axis.

[0035] Under the control of the control device 90, the head module 3 ejects ink supplied from the liquid container 93 in the Z2 direction. The Z2 direction is orthogonal to the Y1 direction. Hereinafter, the Z2 direction and the Z1 direction, which is opposite to the Z2 direction, are sometimes collectively referred to as the direction along the Z-axis. Figure 2 Let's explain header module 3.

[0036] 1-2. Header Module 3

[0037] Figure 2 This is a perspective view of head module 3. Head module 3 includes multiple liquid injection heads 30, a head fixing base plate 13 for holding the multiple liquid injection heads 30, and an air supply mechanism 96. Figure 2 In order to avoid complicating the accompanying drawings, an example is shown where the head module 3 has two liquid injection heads 30.

[0038] Multiple liquid ejection heads 30 are arranged side-by-side and fixed to the head fixing base plate 13 in directions orthogonal to the Y1 direction, which is the conveying direction, namely the X1 and X2 directions. The X2 direction is the opposite direction to the X1 direction. Hereinafter, the X1 and X2 directions are sometimes collectively referred to as the direction along the X-axis. The head module 3 is a row head having multiple liquid ejection heads 30 arranged in such a way that multiple nozzles N are distributed throughout the entire range of the medium PP in the direction along the X-axis. That is, the multiple liquid ejection heads 30 constitute a row head with the direction along the X-axis as its long side. The ejection of ink from the multiple liquid ejection heads 30 is performed in parallel with the conveying of the medium PP by the conveying mechanism 92, thereby forming an ink-based image on the surface of the medium PP. In addition, the head module 3 may also be a row head that is long in the X-axis extension direction and is composed of only a single liquid ejection head 30 arranged in such a way that multiple nozzles N are distributed throughout the entire range of the medium PP in the direction along the X-axis. The head fixing base plate 13 has multiple mounting holes 15 for mounting the liquid ejection heads 30. The liquid injection head 30 is supported on the head fixing base plate 13 with its insertion through the mounting hole 15. Figure 2 In the figure, the head fixing base plate 13 is shown as a plate-shaped member, but it can also be a shape other than a plate.

[0039] The air supply mechanism 96, under the control of the control device 90, supplies air between the medium PP and the liquid injection head 30. Figure 2 In this example, the air supply mechanism 96 is positioned in the Y2 direction relative to the liquid injection head 30. Furthermore, regarding the air supply mechanism 96, using... Figures 7 to 9 To be discussed later.

[0040] Return to the instructions Figure 1 The conveying mechanism 92 conveys the medium PP relative to the head module 3 in the direction along the Y-axis. Figure 1In the example shown, the liquid container 93 is connected to the head module 3 via a circulation mechanism 94. The circulation mechanism 94 is a mechanism for supplying ink to each of the plurality of liquid nozzles 30 and for recovering ink discharged from each of the plurality of liquid nozzles 30 back to the liquid nozzles 30. The circulation mechanism 94 includes, for example: a secondary tank for storing ink; a flow path for supplying ink from the secondary tank to the liquid nozzles 30; a flow path for recovering ink from the liquid nozzles 30 back to the secondary tank; and a pump for properly flowing the ink. Through the operation of the circulation mechanism 94, the increase in ink viscosity can be suppressed or the retention of air bubbles within the ink can be reduced.

[0041] The control device 90 receives printing data Img, which shows the image to be formed by the liquid jetting device 100, from a host computer such as a PC or digital camera. Upon receiving the printing data Img, the liquid jetting head 30 is supplied with a drive signal Com for driving the liquid jetting head 30 and a control signal SI for controlling the liquid jetting head 30 from the control device 90. Then, under the control of the control signal SI, the liquid jetting head 30 is driven by the drive signal Com, causing ink to be ejected from some or all of the plurality of nozzles N provided on the liquid jetting head 30 in the Z2 direction, thereby performing the printing operation to form the image shown in the printing data Img on the medium PP. Furthermore, regarding the nozzles N, Figure 5 and Figure 6 This will be discussed later.

[0042] Figure 3 This is a view of the plurality of liquid injection heads 30 viewed in the Z1 direction. Each of the plurality of liquid injection heads 30 has a plurality of head chips 38 and a fixing plate 39. In the first embodiment, one liquid injection head 30 has six head chips 38_1, 38_2, 38_3, 38_4, 38_5 and 38_6. Hereinafter, they will be referred to as head chips 38 without distinction.

[0043] The fixing plate 39 is used to fix each of the multiple head chips 38 to the fixing plate 39. Figure 4 The plate component of the bracket 37 shown.

[0044] Each of the multiple head chips 38 is arranged to extend in the V2 direction. The V2 direction is a direction perpendicular to the direction along the Z-axis and intersecting the directions along the X-axis and Y-axis; it is the direction between the X1 and Y2 directions. The opposite direction of the V2 direction is called the V1 direction. Furthermore, the V1 and V2 directions are sometimes collectively referred to as the direction along the V-axis. Additionally, directions perpendicular to the directions along the Z-axis and V-axis are called the W1 and W2 directions. The W1 direction is the direction between the X1 and Y1 directions, and the W2 direction is the direction between the X2 and Y2 directions. Sometimes the W1 and W2 directions are collectively referred to as the direction along the W-axis.

[0045] Each of the multiple head chips 38 has a nozzle array Ln. The nozzle array Ln is composed of M nozzles N arranged side by side in the V2 direction. M is two or more integers.

[0046] like Figure 3 As shown, in the first embodiment, the surface of one liquid injection head 30 facing the Z2 direction, i.e., the injection surface FN, has six nozzle rows Ln. Figure 3 As shown, the six nozzle rows Ln are arranged side-by-side along the X-axis. Figure 3 As shown, when viewed in the Y1 direction, at least two adjacent nozzle rows Ln of the six nozzle rows Ln overlap. For example, when viewed in the Y1 direction, the nozzle rows Ln of head chip 38_1 and head chip 38_2 completely overlap. Furthermore, when viewed in the Y1 direction, the nozzle rows Ln of head chip 38_1 and head chip 38_2 can also approximately completely overlap by half the distance along the X-axis between the nozzles N of the nozzle rows Ln, which are offset from each other in the X-axis direction. Therefore, by supplying the same type of ink to head chips 38_1 and 38_2, the resolution along the X-axis direction can be improved. When viewed in the Y1 direction, the overlap methods of head chips 38_3 and 38_4 and head chips 38_5 and 38_6 can be set to be the same as the overlap method of head chips 38_1 and 38_2.

[0047] Furthermore, when viewed in the Y1 direction, the nozzle array Ln of head chip 38_2 partially overlaps with the nozzle array Ln of head chip 38_3, and the nozzle array Ln of head chip 38_4 partially overlaps with the nozzle array Ln of head chip 38_5.

[0048] Furthermore, when viewed in the Y1 direction, the nozzle array Ln of head chip 38_1 partially overlaps with the nozzle array Ln of head chip 38_3, and the nozzle array Ln of head chip 38_3 partially overlaps with the nozzle array Ln of head chip 38_5. Therefore, when the same type of ink is ejected from head chips 38_1, 38_3, and 38_5, the nozzle array Ln of head chips 38_1, 38_3, and 38_5 is considered to be a single nozzle array actually arranged side-by-side along the X-axis. The same applies to head chips 38_2, 38_4, and 38_6.

[0049] In the first embodiment, the W-axis spacing dw1 of two adjacent nozzle rows Ln within a single liquid injection head 30 is approximately the same. "Approximately the same" means that, in addition to being completely identical, it also includes cases where manufacturing errors would allow for their consideration. Furthermore, the W-axis spacing dw2 of the nozzle rows Ln of two adjacent liquid injection heads 30 on the X-axis is approximately the same as spacing dw1. However, by reducing the spacing between two adjacent liquid injection heads 30 on the X-axis, spacing dw2 can also be smaller than spacing dw1.

[0050] Here, "the spacing between two adjacent nozzle rows Ln on the W axis" refers to, if it can be determined according to... Figure 3 As understood, when one nozzle array Ln is configured relative to the other nozzle array Ln in the W2 direction, the distance between the end in the W1 direction of the inner edge of the opening of the nozzle N of one nozzle array Ln and the end in the W2 direction of the inner edge of the opening of the nozzle N of the other nozzle array Ln in the direction along the W axis.

[0051] 1-3. Liquid injection head 30

[0052] Figure 4 This is an exploded perspective view of the liquid injection head 30. The liquid injection head 30 includes a housing 31, a cover substrate 32, a collection substrate 33, a flow path structure 34, a wiring substrate 35, a support 37, multiple head chips 38, and a fixing plate 39.

[0053] The flow path structure 34 has flow path plates Su1 to Su3, connecting pipes 341i1, 341i2, 341o1, 341o2, and connector hole 343.

[0054] The support 37 has flow path components Du1 and Du2, and connecting pipes 373i1, 373i2, and 373o_1 to 373o_6. Hereinafter, they will be collectively referred to as connecting pipes 373. Furthermore, the support 37 has six openings 371 extending in the direction along the Z-axis.

[0055] The housing 31 supports the flow path structure 34, the wiring substrate 35, the bracket 37, and the fixing plate 39. Furthermore, the housing 31 has supply holes 311i1 and 311i2, discharge holes 312o1 and 312o2, and a collection substrate hole 313. A connecting pipe 341i1 is inserted into the supply hole 311i1. A connecting pipe 341i2 is inserted into the supply hole 311i2. A connecting pipe 341o1 is inserted into the discharge hole 312o1. A connecting pipe 341o2 is inserted into the discharge hole 312o2. A collection substrate 33 is inserted into the collection substrate hole 313.

[0056] The cover substrate 32 clamps the assembly substrate 33 between itself and the portion of the housing 31 extending in the Z1 direction. The assembly substrate 33 is a substrate on which wiring is formed for transmitting the drive signal Com and control signal SI supplied from the control device 90 to each of the plurality of head chips 38. The assembly substrate 33 is a plate-shaped member extending parallel to the XZ plane. Here, "parallel" means, in addition to the case of complete parallelism, also includes the concept of parallelism that, although designed to be parallel, can be considered parallel if, for example, errors caused by manufacturing errors of the liquid injection head 30 are taken into account.

[0057] The flow path structure 34 is a structure internally configured to allow ink to flow between the circulation mechanism 94 and the individual head chips 38 of the plurality of head chips 38. The flow path structure 34 is disposed between the housing 31 and the wiring substrate 35. The flow path boards Su1 to Su3 included in the flow path structure 34 are stacked in the Z1 direction in this order. The connector 355 of the wiring substrate 35 is inserted into the connector hole 343.

[0058] Connecting pipes 341i1 and 341i2 introduce ink supplied from liquid container 93 into bracket 37. Connecting pipes 341o1 and 341o2 discharge ink discharged from bracket 37 out of liquid injection head 30.

[0059] The wiring substrate 35 is a mounting component for electrically connecting the liquid injection head 30 to the control device 90. The wiring substrate 35 is a substrate on which wiring for transmitting various control signals and power supply voltages to the head chip 38 is formed. The wiring substrate 35 is a plate-like member extending parallel to the XY plane and disposed between the flow path structure 34 and the support 37. The wiring substrate 35 is, for example, a rigid substrate. The wiring substrate 35 has a connector 355, four openings 351, two cutouts 352, four openings 357, and two cutouts 358. Figure 4 As illustrated, the four openings 351 and two cutouts 352 are arranged in an alternating pattern. The connector 355 is inserted into the connector hole 343 and electrically connected to the assembly substrate 33.

[0060] Any one of the connecting tubes 373o_1, 373o_3, 373o_4, and 373o_6 is inserted into each of the four openings 357. Any one of the connecting tubes 373o_2 and 373o_5 is inserted into the two cuts 358.

[0061] A support 37 is disposed between the wiring substrate 35 and the fixing plate 39 and is fixed to the fixing plate 39 by an adhesive. Therefore, the support 37 reinforces the fixing plate 39. The support 37 also internally provides a flow path for ink between the circulation mechanism 94 and the individual head chips 38. The flow path components Du1 and Du2 included in the support 37 are stacked in the Z1 direction in this order. The support 37 is made of, for example, resin or metal. The surface of the support 37 on the Z2 direction side has a recess (not shown) for accommodating the multiple head chips 38, and the multiple head chips 38 are disposed between this recess and the fixing plate 39 to hold them in place.

[0062] Connecting pipe 373i1 is connected to any one of the plurality of outlets (not shown) formed on the Z2 direction surface of flow path structure 34, introducing ink from flow path structure 34 into support 37. The ink introduced into support 37 is distributed within support 37 and supplied to head chips 38_1, 38_3, and 38_5. Ink discharged from head chips 38_1, 38_3, and 38_5 is introduced into support 37. Connecting pipes 373o_1, 373o_3, and 373o_5 are connected to any one of the plurality of inlet ports (not shown) formed on the Z2 direction surface of flow path structure 34, introducing ink from support 37 into flow path structure 34.

[0063] The connecting pipe 373i2 is connected to any one of the plurality of outlets (not shown) formed on the Z2 direction surface of the flow path structure 34, introducing ink from the flow path structure 34 into the support 37. The ink introduced into the support 37 is distributed within the support 37 and supplied to the head chips 38_2, 38_4, and 38_6. Ink discharged from the head chips 38_2, 38_4, and 38_6 is introduced into the support 37. The connecting pipes 373o_2, 373o_4, and 373o_6 are connected to any one of the plurality of inlet ports (not shown) formed on the Z2 direction surface of the flow path structure 34, introducing ink from the support 37 into the flow path structure 34.

[0064] The wiring components 388 of each of the plurality of head chips 38 are inserted into six openings 371. The six openings 371 are each arranged in an interleaved manner.

[0065] Each head chip 38 has one nozzle plate 387 and piezoelectric elements PZq corresponding to the M nozzles N of the head chip 38. The arrangement of the six head chips 38 is also staggered, similar to the openings 351 and cutouts 352 of the wiring substrate 35. Figure 5 and Figure 6 A more detailed explanation of head chip 38.

[0066] 1-4. Head chip 38

[0067] Figure 5 This is an exploded 3D view of the head chip 38_1. Figure 6 yes Figure 5 The cross-sectional view of the VI-VI line. The VI-VI line is an imaginary straight line passing through the inlet 3851 and outlet 3852, and through nozzle N. Furthermore, in Figure 6 In the figure shown, in addition to the cross-section of the head chip 38_1, the cross-section of the fixing plate 39 is also shown.

[0068] The head chip 38_1 includes a nozzle plate 387, a malleable substrate 3861, a connecting plate 382, ​​a pressure chamber substrate 383, a vibrating plate 384, a housing 385, and a wiring component 388.

[0069] The nozzle plate 387 is a plate-shaped member that extends parallel to the VW plane along the V-axis and forms M nozzles N. Furthermore, each nozzle N is a through hole through the nozzle plate 387 along the Z-axis. In this embodiment, as an example, it is envisioned that the M nozzles N in the nozzle plate 387 are arranged as a nozzle array Ln extending along the V-axis. However, the nozzle plate 387 can also be configured as a nozzle array Ln having a portion of multiple M nozzles N arranged in the V-axis direction.

[0070] A connecting plate 382 is provided in the Z1 direction of the nozzle plate 387. The connecting plate 382 is a plate-shaped member that extends along the V-axis and is approximately parallel to the VW plane, forming an ink flow path. Specifically, a supply liquid chamber RA1, a discharge liquid chamber RA2, a connecting flow path RX1, and a connecting flow path RX2 are formed in the connecting plate 382. The supply liquid chamber RA1 is configured to communicate with the supply liquid chamber RB1 (described later) and extends in the V-axis direction. The connecting flow path RX1 is configured to communicate with the supply liquid chamber RA1 and is located in the W2 direction when viewed from the supply liquid chamber RA1, extending in the W-axis direction. The discharge liquid chamber RA2 is configured to communicate with the discharge liquid chamber RB2 (described later) and extends in the V-axis direction. The connecting flow path RX2 is configured to communicate with the discharge liquid chamber RA2 and is located in the W1 direction when viewed from the discharge liquid chamber RA2, extending in the W-axis direction. Hereinafter, the common liquid chamber formed by the supply liquid chamber RA1, the supply liquid chamber RB1 and the connecting flow path RX1 will be referred to as the "supply-side common liquid chamber MN1". Similarly, the common liquid chamber formed by the discharge liquid chamber RA2, the discharge liquid chamber RB2 and the connecting flow path RX2 will be referred to as the "discharge-side common liquid chamber MN2".

[0071] Additionally, the following are formed in the connecting plate 382: M nozzle flow paths RN, each corresponding to one of the M nozzles N; M connecting flow paths RR1, each corresponding to one of the M nozzles N; M connecting flow paths RR2, each corresponding to one of the M nozzles N; M connecting flow paths RK1, each corresponding to one of the M nozzles N; and M connecting flow paths RK2, each corresponding to one of the M nozzles N.

[0072] In the first embodiment, the connecting flow path RK1 is configured to be connected to the connecting flow path RX1, and when viewed from the connecting flow path RX1, it is located in the W2 direction and extends in the Z-axis direction. Furthermore, the connecting flow path RR1 is configured to be located in the W2 direction and extend in the Z-axis direction when viewed from the connecting flow path RK1. Additionally, the connecting flow path RK2 is configured to be connected to the connecting flow path RX2, and when viewed from the connecting flow path RX2, it is located in the W1 direction and extends in the Z-axis direction. Furthermore, the connecting flow path RR2 is located in the W1 direction when viewed from the connecting flow path RK2, and in the W2 direction when viewed from the connecting flow path RR1.

[0073] Additionally, the nozzle flow path RN is configured to connect the connecting flow paths RR1 and RR2, located in the W2 direction when viewed from the connecting flow path RR1, and in the W1 direction when viewed from the connecting flow path RR2, extending along the W-axis. The nozzle flow path RN is connected to the nozzle N corresponding to this nozzle flow path RN.

[0074] A pressure chamber substrate 383 is provided in the Z1 direction of the connecting plate 382. The pressure chamber substrate 383 is a plate-shaped member that extends approximately parallel to the VW plane along the V-axis and forms the ink flow path. Specifically, M pressure chambers CB1 and M pressure chambers CB2, each corresponding to one of the M nozzles N, are formed in the pressure chamber substrate 383. Hereinafter, pressure chambers CB1 and CB2 are collectively referred to as pressure chambers CB. Pressure chamber CB1 connects the connecting flow path RK1 and the connecting flow path RR1. When viewed along the Z-axis, it is configured to connect the end of the connecting flow path RK1 in the W1 direction and the end of the connecting flow path RR1 in the W2 direction and extend along the W-axis. Similarly, pressure chamber CB2 connects the connecting flow path RK2 and the connecting flow path RR2. When viewed along the Z-axis, it is configured to connect the end of the connecting flow path RK2 in the W2 direction and the end of the connecting flow path RR2 in the W1 direction and extend along the W-axis. Furthermore, the number of pressure chambers CB provided corresponding to one nozzle N can be one; in other words, it can be a configuration in which either pressure chamber CB1 or pressure chamber CB2 is provided relative to one nozzle N.

[0075] A vibrating plate 384 is provided in the Z1 direction of the pressure chamber substrate 383. The vibrating plate 384 is a plate-shaped member that is elongated in the direction along the V-axis and extends substantially parallel to the VW plane, and is a member capable of elastic vibration. Alternatively, the vibrating plate 384 may be formed of the same member as the pressure chamber substrate 383.

[0076] In the Z1 direction plane of the vibrating plate 384, M piezoelectric elements PZ1, corresponding one-to-one with the M pressure chambers CB1, and M piezoelectric elements PZ2, corresponding one-to-one with the M pressure chambers CB2, are provided. Hereinafter, piezoelectric elements PZ1 and PZ2 are collectively referred to as piezoelectric elements PZq.

[0077] The piezoelectric element PZq is a passive element that deforms according to the potential change of the driving signal Com.

[0078] The fixing plate 39 is bonded to the Z2 direction surface of the malleable substrate 3861 and the Z2 direction surface of the support 37. That is, the nozzle surface SN of the nozzle plate 387 is exposed in the six exposed openings 391 provided in the fixing plate 39. The nozzle surface SN is the surface in which multiple nozzles N are formed and faces the nozzle plate 387 in the Z2 direction, and is perpendicular to the Z2 direction. Figure 3 The spray surface FN shown is divided into a nozzle surface SN and a surface 39N facing the fixing plate 39 in the Z2 direction. The arrangement of the six exposed openings 391 is also staggered, just like the openings 351 and cutouts 352 of the wiring substrate 35.

[0079] The flexible substrate 3861 has a flexible membrane 3861a and a support plate 3861b. The flexible membrane 3861a is a flexible component such as a membrane, and the support plate 3861b is a rigid component. The flexible membrane 3861a is a component that covers the openings of the supply liquid chamber RA1, the connecting flow paths RX1, RK1, RK2, RX2, and the discharge liquid chamber RA2 of the connecting plate 382 from the Z2 direction side by fixing it to the Z2 direction surface. The support plate 3861b is fixed to the Z2 direction surface of the flexible membrane 3861a, and when viewed along the Z-axis, it has openings at positions overlapping with the supply liquid chamber RA1, the connecting flow paths RX1, RK1, RK2, RX2, and the discharge liquid chamber RA2. The fixing plate 39 is bonded to the support plate 3861b in a manner that seals the openings of the support plate 3861b from the Z2 direction. The space defined by the Z2 direction surface of the flexible membrane 3861a, the opening of the support plate 3861b, and the Z1 direction surface of the fixing plate 39 is connected to the atmosphere through an atmospheric communication path (not shown). Through this space, the flexible membrane 3861a deforms in the Z1 and Z2 directions, thereby absorbing pressure variations generated within the head chip 38.

[0080] A housing 385 is provided in the Z1 direction of the connecting plate 382. The housing 385 is a member that extends in the direction along the V-axis, forming a flow path for ink. Specifically, a supply chamber RB1 and a discharge chamber RB2 are formed in the housing 385. The supply chamber RB1 is configured to communicate with the supply chamber RA1, and when viewed from the supply chamber RA1, it is located in the Z1 direction and extends in the direction along the V-axis. The discharge chamber RB2 is configured to communicate with the discharge chamber RA2, and when viewed from the discharge chamber RA2, it is located in the Z1 direction. When viewed from the supply chamber RB1, it is located in the W2 direction and extends in the direction along the V-axis.

[0081] Additionally, an inlet 3851 communicating with the supply liquid chamber RB1 and an outlet 3852 communicating with the discharge liquid chamber RB2 are provided in the housing 385. Furthermore, ink is supplied from the liquid container 93 to the supply-side common liquid chamber MN1 via the inlet 3851 to the supply-side common liquid chamber MN1. The ink supplied to the supply-side common liquid chamber MN1 is stored in the discharge-side common liquid chamber MN2 via a flow path communicating with the nozzle N. The ink stored in the discharge-side common liquid chamber MN2 is recovered via the outlet 3852.

[0082] Additionally, an opening 3850 is provided in the housing 385. A pressure chamber substrate 383, a vibrating plate 384, and a wiring member 388 are disposed inside the opening 3850. The housing 385 is formed, for example, by injection molding of a resin material. However, any known materials or manufacturing methods can be used in the manufacture of the housing 385.

[0083] Return to the instructions Figure 4 .exist Figure 5 and Figure 6 The description focuses on head chip 38_1, but the structures of head chips 38_2 to 38_6 are identical to those of head chip 38_1. The wiring components 388 of each of head chips 38_1 to 38_6 are all identical in shape. The wiring components 388 of head chips 38_2, 38_4, and 38_6 are arranged with their orientation based on the orientation of the wiring component 388 of head chip 38_1, rotated 180 degrees around the Z-axis.

[0084] 1-5. Deviation in drip position

[0085] According to Figure 3 As can be understood, by arranging multiple nozzles N that constitute the nozzle array Ln along the V-axis, which is inclined relative to the direction along the Y-axis, the resolution of the nozzle array Ln along the X-axis direction can be improved compared to a scheme in which multiple nozzles N are arranged in a straight line along the X-axis direction. Hereinafter, the direction along which the nozzle array Ln is located, i.e., the V1 direction, is sometimes referred to as the "nozzle array direction".

[0086] However, when the nozzle array direction is tilted relative to the conveying direction of the medium PP, which is the Y1 direction in this embodiment, a deviation may occur at the position where the ink drips onto the medium PP.

[0087] The inventors discovered that in a scheme where multiple nozzles N are arranged in a straight line along the X-axis, the airflow generated by the medium PP being conveyed in the Y1 direction eliminates or reduces the jet stream generated by ink ejection from the nozzles N. Therefore, the jet stream generated by ink ejection can suppress drop position deviation. Hereinafter, the airflow generated by the medium PP being conveyed is sometimes referred to as "conveyor airflow," and the jet stream generated by ink ejection is sometimes referred to as "self-flowing stream." In addition, the uneven concentration caused by the deviation in drop position due to the vortex generated near the nozzles N by the self-flowing stream is sometimes referred to as "wind pattern." When the nozzle array direction is inclined relative to the conveying direction of the medium PP, there are nozzles N located upstream in the conveying direction and nozzles N located downstream in the conveying direction among the multiple nozzles N. Sometimes the nozzle N located upstream in the conveying direction is referred to as "upstream nozzle Nu," and sometimes the nozzle N located downstream in the conveying direction is referred to as "downstream nozzle Nd."

[0088] When the nozzle array direction is tilted relative to the conveying direction, the generation of wind patterns can be suppressed in the upstream nozzle Nu by the conveying airflow. However, the inventors discovered that when the conveying airflow collides with the self-flowing flow of the upstream nozzle Nu, the conveying airflow disappears or decreases, making it impossible to suppress the deviation in drip position caused by the self-flowing flow of the downstream nozzle Nd, which is located further downstream than the upstream nozzle Nu, thus generating wind patterns. Therefore, uneven printing may occur in the upstream nozzle Nu and the downstream nozzle Nd.

[0089] Therefore, in this embodiment, the liquid injection device 100 includes an air supply mechanism 96, which blows airflow to each nozzle N of the nozzle array Ln without any omissions, thereby suppressing deviations in the dripping position. Regarding the air supply mechanism 96, using... Figure 7 Please provide an explanation.

[0090] 1-6. Air supply mechanism 96

[0091] Figure 7 This is a diagram showing the head module 3 viewed in the X1 direction. However, in Figure 7 The liquid injection head 30 is omitted from the display. Figure 8 yes Figure 7 A cross-sectional view of line VIII-VIII in the diagram. Figure 9 yes Figure 2 A cross-sectional view of line IX-IX in the diagram. (See also...) Figure 7 and Figure 8 As shown, the air supply mechanism 96 includes a fan housing 962, a collecting section 964, and a rectifying section 966. Line VIII-VIII is an imaginary straight line parallel to the XY plane and passing through the rectifying section 966. Line IX-IX is an imaginary straight line extending in the direction of air supply from the air supply mechanism 96, i.e., the U1 direction, when viewed from above along the Z-axis. The direction opposite to the U1 direction is called the U2 direction. Sometimes, the U1 and U2 directions are collectively referred to as directions along the U-axis. Furthermore, directions perpendicular to both the Z-axis and the U-axis are called the T1 and T2 directions. The T1 direction is the direction between the X1 and Y1 directions, and the T2 direction is the direction between the X2 and Y2 directions. Sometimes, the T1 and T2 directions are collectively referred to as directions along the T-axis. Additionally, in Figure 8 and Figure 9 To avoid complicating the accompanying drawings, the internal structure of the liquid injection head 30 has been omitted. Additionally, in... Figure 9 In order to avoid complicating the accompanying drawings, the periphery of the collecting section 964 and the rectifier section 966 is enlarged and shown, while other parts are omitted from the drawings.

[0092] According to Figure 7As can be understood, in the Z-axis, the Z2 direction end of the rectifier 966 is slightly positioned in the Z2 direction relative to the Z2 direction end of the liquid injection head 30.

[0093] The fan housing 962 is a generally rectangular box extending along the X-axis. Inside, the fan housing 962 has a space 962A for accommodating multiple fans 962F. Additionally, an opening 962K for drawing air into the space 962A is provided on the side wall of the fan housing 962 facing the Y2 direction. There may be one opening 962K or two or more openings. The opening 962K connects the space 962A to the outside of the air supply mechanism 96. Furthermore, an opening 962M for supplying air to the collection section 964 is provided in the Y1 direction of the fan housing 962. The multiple fans 962F are arranged along the X-axis. The multiple fans 962F draw air in through the opening 962K and supply air to the opening 962M.

[0094] The collecting section 964 collects air supplied by the fan 962F. The collecting section 964 is a hollow component forming a trapezoidal shape. The size of the surface of the collecting section 964 facing the Y1 direction is larger than the size of the surface facing the Y2 direction. The length of the surface of the collecting section 964 facing the Y1 direction along the Z-axis is shorter than the length of the surface facing the Y2 direction along the Z-axis. On the other hand, the length of the surface of the collecting section 964 facing the Y2 direction along the X-axis is shorter than the length of the surface facing the Y1 direction along the Z-axis. The collecting section 964 has an internal space 964A. An opening 964K is provided on the surface of the collecting section 964 facing the Y2 direction. The space 964A and the space 962A are connected by the opening 964K and the opening 962M. Furthermore, a plurality of openings 964M are provided in the Y1 direction of the collecting section 964.

[0095] The rectifier 966 rectifies the airflow direction of the air collected by the collector 964 in the U1 direction. The rectifier 966, viewed from above, has a plurality of through holes 966A extending along the U-axis and a plurality of partition walls 966B extending in the direction along the U-axis. Two adjacent through holes 966A are separated by partition walls 966B. Specifically, the through hole 966A has a first space 966A1 along the U-axis and a second space 966A2 communicating with the first space 966A1 and extending in the S1 direction. The S1 direction is a direction inclined towards the Z2 direction relative to the U1 direction. The first space 966A1 communicates with the collector 964 via an opening 964M at its end in the U2 direction. The second space 966A2 communicates with the outside of the air supply mechanism 96 via an opening 966M provided at its end in the S1 direction. Figure 9The diagram shows the airflow FL1 passing through the through-hole 966A. As shown in flow FL1, air collected by the collector 964 is drawn into the through-hole 966A through the opening 964M. The air discharged from the opening 966M moves along the injection surface FN in the U1 direction, as shown in flow FL1. That is, when viewed along the Z-axis, the airflow FL1 is along the U1 direction. Therefore, when viewed along the Z-axis, the air supply mechanism 96 generates an airflow FL1 toward the U1 direction.

[0096] 1-7. Regarding the air supply direction of the air supply mechanism 96

[0097] Figure 10 This is a diagram illustrating the air supply direction of the air supply mechanism 96. Figure 10 In this document, the liquid injection head 30 positioned in the X1 direction is shown as liquid injection head 30a, and the liquid injection head 30 positioned in the X2 direction is shown as liquid injection head 30b. Furthermore, hereinafter, for any variable i from 1 to 6, the nozzle array Ln consisting of the M nozzles N of the head chip 38_i of liquid injection head 30a is sometimes referred to as nozzle array Lnai. Similarly, for any variable i from 1 to 6, the nozzle array Ln consisting of the M nozzles N of the head chip 38_i of liquid injection head 30b is sometimes referred to as nozzle array Lnbi.

[0098] exist Figure 10 The image shows the U1 direction, which serves as the air supply direction of the air supply mechanism 96. For example... Figure 10 As shown, the U1 direction intersects with any one of the Y1 direction, the direction along the X-axis, and the direction along the V-axis. Furthermore, the Y1 direction is an example of a "first direction for transporting the medium," the direction along the X-axis is an example of a "second direction orthogonal to both the first direction and the injection direction," and the U1 direction is an example of a "third direction."

[0099] In the first embodiment, all of the multiple nozzles N of the two liquid jet heads 30 are used in the printing operation. In this specification, the nozzle N used in the printing operation refers to the nozzle N that jets ink onto the medium PP for directly forming a portion of the image when the medium PP forms an image. On the other hand, the nozzle N not used in the printing operation refers to the nozzle N that does not jet ink onto the medium PP for directly forming a portion of the image when the medium PP forms an image. That is, the ink jetted into the medium PP by the rinsing operation for the purpose of removing ink that has thickened during the printing operation is not ink for directly forming a portion of the image; therefore, the nozzle N that jets ink onto the medium PP only during the rinsing operation is the nozzle N not used in the printing operation. Hereinafter, the nozzle N used in the printing operation will sometimes be described as "used nozzle Ns," and the nozzle N not used in the printing operation will sometimes be described as "non-used nozzle Ns." As described above, in the first embodiment, all of the multiple nozzles N of the liquid jet device 100 are used nozzles Ns.

[0100] exist Figure 10 In the example, regarding all the nozzle rows Ln of the two liquid injection heads 30, a nozzle segment Lk connecting the end of the nozzle assembly located in the V1 direction (the direction of the nozzle row) and the end of the nozzle assembly located in the V2 direction (the opposite direction of V1) is shown. Hereinafter, for a given nozzle row Ln, the nozzle segment Lk connecting the end of the nozzle assembly located in the V1 direction and the end of the nozzle assembly located in the V2 direction will sometimes be referred to as the nozzle segment Lk corresponding to the nozzle row Ln. Figure 10 In the example, for any variable i from 1 to 6, the nozzle segment Lk corresponding to the nozzle row Ln of the head chip 38_i included in the liquid injection head 30a is sometimes referred to as nozzle segment Lkai. Additionally, for any variable i from 1 to 6, the nozzle segment Lk corresponding to the nozzle row Ln of the head chip 38_i included in the liquid injection head 30b is sometimes referred to as nozzle segment Lkbi. Hereinafter, nozzle segment Lkai and nozzle segment Lkbi will sometimes be collectively referred to as nozzle segment Lk without distinction. Figure 10 The image shows 12 nozzle columns Ln, which in turn shows 12 nozzle segments Lk.

[0101] exist Figure 10The diagram shows imaginary lines LW1 and LW2 projected onto the injection surface FN. Hereinafter, they will sometimes be referred to as imaginary line LW without distinction. Imaginary line LW is a straight line extending in the U1 direction. That is, the airflow generated by the air supply mechanism 96 flows in the U1 direction along imaginary line LW at a position opposite to the injection surface FN. Imaginary line LW can be projected onto the injection surface FN at any position along the X-axis, but... Figure 10 To avoid overcomplication, only imaginary straight lines LW1 and LW2 are displayed.

[0102] According to Figure 10 As can be understood, the number of nozzle segments Lk overlapping with one imaginary straight line LW is 1 or less, regardless of where the imaginary straight line LW is positioned along the X-axis. The imaginary straight line LW1, viewed from above, passes through the center of the nozzle N at the end of the nozzle array Lna4 positioned in the V1 direction. Therefore, the number of nozzle segments Lk overlapping with the imaginary straight line LW1 is one of nozzle segments Lka4. The imaginary straight line LW2, viewed from above, passes between nozzle segments Lkb4 and Lkb5. Therefore, the number of nozzle segments Lk overlapping with the imaginary straight line LW2 is 0. Hereinafter, the operating nozzle Ns at the end of the nozzle array Lna4 positioned in the V1 direction is sometimes referred to as operating nozzle Ns[a4V1]. Furthermore, the nozzle array Lna4 is an example of a "first nozzle array," and the operating nozzle Ns[a4V1] is an example of a "first operating nozzle."

[0103] In addition, Figure 10 The diagram shows a first straight line LZ1. The first straight line LZ1 uses a nozzle Ns[a4V1] and a nozzle Ns configured at the V2 direction end of the nozzle array Lna3. Hereinafter, the nozzle Ns configured at the V2 direction end of the nozzle array Lna3 will sometimes be referred to as nozzle Ns[a3V2]. Furthermore, nozzle array Lna3 is an example of a "second nozzle array," and nozzle Ns[a3V2] is an example of a "second nozzle."

[0104] In addition, the first angle θ1 formed by the imaginary straight line LW1 and the first straight line LZ1 is less than half of the second angle θ2 formed by the first straight line LZ1 and the nozzle line segment Lka4 corresponding to the nozzle column Lna4.

[0105] The smaller the first angle θ1, the better; for example, it should be less than half the size of the second angle θ2. The first angle θ1 and the second angle θ2 are acute angles.

[0106] In addition, the first straight line LZ1 overlaps with nozzle segments Lka4 and Lka3, but does not overlap with other nozzle segments Lk besides Lka4 and Lka3.

[0107] Furthermore, the distance d12 between the nozzle Ns[a4V1] and the nozzle Ns[a3V2] in the nozzle Ns is longer than the distance d34 between the nozzle Ns[a4V2] at the V2 end of the nozzle row Lna4 and the nozzle Ns[a3V1] at the V1 end of the nozzle row Lna3. Moreover, the nozzle Ns[a4V2] is an example of a "third nozzle," and the nozzle Ns[a3V1] is an example of a "fourth nozzle."

[0108] From the 12 nozzle segments Lk, the group of two nozzle segments Lk with the highest repetition when viewed in the Y1 direction is the group of two adjacent nozzle segments Lk along the Y-axis. Specifically, the groups of two nozzle segments Lk with the highest repetition are: Lka1 and Lka2, Lka3 and Lka4, Lka5 and Lka6, Lkb1 and Lkb2, Lkb3 and Lkb4, and Lkb5 and Lkb6.

[0109] 1-8. Summary of the First Implementation Method

[0110] Hereinafter, the first embodiment will be summarized by designating "first nozzle array" as nozzle array Lna4 and "second nozzle array" as nozzle array Lna3.

[0111] The liquid jetting device 100 in the first embodiment includes: a liquid jetting head 30 having a jetting surface FN with a plurality of nozzle rows Ln, wherein the plurality of nozzle rows Ln are configured such that a plurality of nozzles N that jet ink in the Z2 direction (which is the jetting direction) are arranged side by side in the V1 direction (which is the nozzle row direction); a conveying mechanism 92 for conveying medium PP in the Y1 direction at a position opposite to the jetting surface FN; and an air supply mechanism 96. The nozzle row direction intersects both the Y1 direction and the X-axis direction, which is orthogonal to both the Y1 and Z2 directions. The air supply mechanism 96 generates airflow in the U1 direction, which intersects the Y1 direction, the X-axis direction, and the V1 direction, along the jetting surface FN.

[0112] According to the first embodiment, even when the V1 direction, which is the direction of the nozzle array, is inclined relative to the Y1 direction, which is the direction of the medium PP, the airflow can easily reach the nozzle N, which is difficult to reach in the scheme without the air supply mechanism 96, by means of the air supply mechanism 96, and the self-flow can also be suppressed. Therefore, the deviation of the dripping position caused by the self-flow can be suppressed.

[0113] Furthermore, the plurality of nozzles N includes a plurality of application nozzles Ns used in the printing operation of spraying ink toward the medium PP. When the line segment connecting the application nozzles Ns arranged at the end in the V1 direction, which is the nozzle row direction, and the application nozzles Ns arranged at the end in the V2 direction, which is the opposite direction of the V1 direction, in the plurality of nozzle rows Ln is defined as nozzle line segment Lk, the number of nozzle line segments Lk that overlap with the imaginary straight line LW1 extending in the U1 direction projected onto the spraying surface FN is 1 or less.

[0114] When the number of nozzle segments Lk overlapping with the imaginary straight line LW1 is two or more, there exists a nozzle segment Lk located in the Y2 direction and another nozzle segment Lk not located in the Y2 direction among the two or more nozzle segments Lk overlapping with the imaginary straight line LW1. Furthermore, the airflow generated by the air supply mechanism 96 disappears or decreases due to the self-flow of the nozzle N corresponding to the nozzle segment Lk located in the Y2 direction, thus creating the possibility that the self-flow of the nozzle N corresponding to the nozzle segment other than the nozzle segment Lk located in the Y2 direction cannot be suppressed. Therefore, according to the first embodiment, compared to the solution where the number of nozzle segments Lk overlapping with the imaginary straight line LW1 is two or more, the airflow generated by the air supply mechanism 96 encounters more nozzles Ns, thus enabling the suppression of drip position deviation caused by self-flow with more nozzles Ns.

[0115] In addition, the multiple nozzle rows Ln include adjacent nozzle rows Lna4 and nozzle rows Lna3. The first angle θ1 formed by the imaginary straight line LW1 and the first straight line LZ1 is less than half of the second angle θ2 formed by the first straight line LZ1 and the nozzle line segment Lka4 corresponding to the nozzle row Lna4.

[0116] When the first angle θ1 increases, for example, when the imaginary straight line LW1 becomes approximately parallel to the nozzle line segment Lk, the airflow generated by the air supply mechanism 96 disappears or decreases due to the self-flow of the nozzle N located in the Y2 direction among the M application nozzles Ns corresponding to the nozzle line segment Lk. The self-flow of the application nozzles Ns located in the Y1 direction closer to the nozzle N may become difficult to suppress. According to the first embodiment, compared with the scheme where the first angle θ1 is more than half of the second angle θ2, the airflow generated by the air supply mechanism 96 can be made to uniformly contact each application nozzle Ns of the nozzle array Ln.

[0117] In addition, nozzle array Lna4 and nozzle array Lna3 refer to one of the two nozzle arrays Ln with the smallest interval in the direction of the W axis orthogonal to the V1 direction.

[0118] Of the multiple nozzle rows Ln, the nozzle row Ln located in the Y2 direction among the two nozzle rows Ln with the smallest spacing along the W axis is the least likely to encounter the conveying airflow. Therefore, according to the first embodiment, the airflow generated by the air supply mechanism 96 can be made to encounter the nozzle row Ln that is least likely to be encountered by the conveying airflow.

[0119] In addition, the liquid injection head 30 is configured as a row head with the direction along the X-axis as the long side, and multiple nozzle rows Ln are arranged side by side along the X-axis. When viewed in the Y1 direction, which is the conveying direction, two adjacent nozzle rows Ln overlap at least partially.

[0120] When two adjacent nozzle rows Ln overlap at least partially when viewed in the Y1 direction, nozzle N that is encountered by the conveying airflow and nozzle N that is difficult for the conveying airflow to encounter are generated. Therefore, according to the first embodiment, for nozzle N that is difficult for the conveying airflow to encounter, the airflow generated by the air supply mechanism 96 can also suppress the deviation of the dripping position caused by the self-jetting flow.

[0121] 2. Second Implementation Method

[0122] The head chip 38 in the first embodiment has one nozzle row Ln, but is not limited thereto. Hereinafter, the second embodiment will be described.

[0123] 2-1. Regarding the air supply direction in the second embodiment

[0124] Figure 11 This is a diagram illustrating the air supply direction of the air supply mechanism 96 in the second embodiment.

[0125] The liquid injection device 100A in the second embodiment differs from the liquid injection device 100 in that it has a liquid injection head 30A instead of a liquid injection head 30. The liquid injection head 30A also differs from the liquid injection head 30 in that it has three head chips 38A instead of six head chips 38. Furthermore, three head chips 38A is an example of "multiple head chips". In the second embodiment, the liquid injection head 30A has three head chips 38A, but it is sufficient to have two or more head chips 38A.

[0126] Each of the three head chips 38A differs from the head chip 38 in that it has a nozzle group GN consisting of 2M nozzles N, which are divided into nozzle rows Ln1 and Ln2 arranged side by side with gaps between them along the W-axis. Hereinafter, nozzle rows Ln1 and Ln2 will sometimes be referred to as nozzle row Ln without distinguishing between them. Furthermore, to avoid complicating the drawings, only a portion of the nozzles N included in the nozzle group GN will be labeled with reference numerals.

[0127] The liquid injection head 30A comprises three head chips 38A, namely head chips 38A_1, 38A_2, and 38A_3. Hereinafter, they will be referred to as head chip 38A without distinction. The three head chips 38A are arranged along the X-axis.

[0128] like Figure 11 As shown, in the second embodiment, the injection surface FN of a liquid injection head 30 facing the Z2 direction has 6 nozzle rows Ln.

[0129] In the second embodiment, similar to the first embodiment, all of the multiple nozzles N of the liquid injection device 100A are nozzles Ns.

[0130] exist Figure 11 The diagram shows the smallest convex polygon encompassing all nozzles Ns within the nozzle group GN of a single head chip 38A. Figure 11 In this context, the convex polygon is a parallelogram. Hereinafter, the area enclosed by this convex polygon will sometimes be referred to as the nozzle region NRA. Furthermore, for ease of understanding, for any variable i from 1 to 3, the nozzle region NRA enclosed by the smallest convex polygon of the 2M nozzles Ns included in the nozzle group GN of the head chip 38A_i will sometimes be referred to as nozzle region NRA_i. Hereinafter, nozzle regions NRA_1 to NRA_3 will sometimes be referred to as nozzle region NRA without distinction. The nozzle region NRA is long in the V1 direction. Furthermore, the V1 direction is an example of a "fourth direction".

[0131] The spacing dw3 on the W axis of two adjacent nozzle regions NRA within a single liquid injection head 30A is approximately the same. The spacing dw3 is sufficiently large compared to the spacing dwLn of the two nozzle rows Ln in a single head chip 38A.

[0132] like Figure 11 As shown, the three nozzle regions (NRA) are arranged side-by-side along the X-axis. Figure 11 As shown, two adjacent nozzle regions NRAs partially overlap when viewed in the Y1 direction. For example, when viewed in the Y1 direction, nozzle region NRA_1 and nozzle region NRA_2 partially overlap.

[0133] In the second embodiment, the air supply mechanism 96 generates airflow in the U1A direction, which intersects any one of the Y1 direction, the X-axis direction, and the V1 direction, in a manner that is along the injection surface FN. Furthermore, in the second embodiment, the U1A direction is an example of a "third direction".

[0134] exist Figure 11The diagram shows imaginary lines LWA1 and LWA2 projected onto the injection surface FN. Hereinafter, imaginary lines LWA1 and LWA2 will sometimes be referred to simply as imaginary line LWA. The imaginary line LWA is a straight line extending in the U1A direction. That is, the airflow generated by the air supply mechanism 96 flows in the U1A direction along the imaginary line LWA at a position opposite the injection surface FN. The imaginary line LWA can be projected onto the injection surface FN at any position along the X-axis, but... Figure 11 To avoid overcomplication, only imaginary straight lines LWA1 and LWA2 are displayed.

[0135] According to Figure 11 As can be understood, the number of nozzle regions NRAs that overlap with the imaginary line LWA is less than 1, regardless of where the imaginary line LWA is positioned along the X-axis. Specifically, the imaginary line LWA1, when viewed from above, passes through the center of the nozzle N located at the end in the V1 direction within nozzle region NRA_3. Therefore, the number of nozzle regions NRAs overlapping with the imaginary line LWA1 is 1 for nozzle region NRA_3. The imaginary line LWA2, when viewed from above, passes between nozzle regions NRA_1 and NRA_2. Therefore, the number of nozzle regions NRAs overlapping with the imaginary line LWA2 is 0.

[0136] In addition, Figure 11 The diagram shows a second straight line LZA2 and a third straight line LZA3. The second straight line LZA2 is a straight line circumscribed at the V1 direction end of nozzle region NRA_3 and the V2 direction end of nozzle region NRA_2. The third straight line LZA3 is a straight line extending in the V1 direction. The third angle θA3 formed by the imaginary straight line LWA1 and the second straight line LZA2 is less than half of the fourth angle θA4 formed by the second straight line LZA2 and the third straight line LZA3. A smaller third angle θA3 is preferred; for example, it is preferable to be less than half of the fourth angle θA4.

[0137] In addition, the second straight line LZA2 is external to nozzle regions NRA_2 and NRA_3, and does not contact or overlap with other nozzle regions NRA besides nozzle regions NRA_2 and NRA_3.

[0138] 2-2. Summary of the Second Implementation Method

[0139] Hereinafter, the term "first nozzle group" will be defined as the nozzle group GN of the head chip 38A_3, the term "second nozzle group" will be defined as the nozzle group GN of the head chip 38A_2, the term "nozzle area corresponding to the first nozzle group" will be defined as nozzle area NRA_3, and the term "nozzle area corresponding to the second nozzle group" will be defined as nozzle area NRA_2 to summarize the second embodiment. For the sake of simplicity, the nozzle group GN of the head chip 38A_3 will sometimes be referred to as nozzle group GNA_3, and the nozzle group GN of the head chip 38A_2 will sometimes be referred to as nozzle group GNA_2.

[0140] The liquid jetting apparatus 100A comprises: a liquid jetting head 30A having multiple head chips 38A, each having a nozzle group GN consisting of multiple nozzles N that jet ink toward the Z2 direction, which is the jetting direction; a conveying mechanism 92 that conveys the medium PP toward the Y1 direction at a position opposite to the jetting surface FN of the liquid jetting head 30A; and an air supply mechanism 96. The multiple nozzles N include multiple application nozzles Ns used in the printing operation of jetting ink toward the medium PP. When the area enclosed by the smallest convex polygon surrounding the multiple application nozzles Ns in each of the multiple nozzle groups GN is defined as the nozzle region NRA, the nozzle region NRA extends in the V1 direction, which intersects both the Y1 direction and the X-axis direction, which is orthogonal to both the Y1 and Z2 directions. The air supply mechanism 96 generates airflow along the jetting surface FN in the U1A direction, which intersects any one of the Y1 direction, the X-axis direction, and the V1 direction.

[0141] According to the second embodiment, similarly to the first embodiment, for nozzle N that is difficult to reach in a scheme without an air supply mechanism 96, since the air supply mechanism 96 allows the air to reach it, the self-flow can be suppressed, and thus the deviation of the dripping position caused by the self-flow can also be suppressed.

[0142] Furthermore, the number of nozzle regions NRAs that overlap with the imaginary straight line LWA1 extending in the U1A direction and projected onto the injection surface FN in the nozzle region NRAs corresponding to each of the multiple nozzle groups GN is 1 or less.

[0143] According to the second embodiment, similarly to the first embodiment, compared to the scheme where the number of nozzle regions NRA overlapping with the imaginary straight line LWA1 is 2 or more, the airflow generated by the air supply mechanism 96 encounters more of the used nozzles Ns, thus enabling the use of more used nozzles Ns to suppress the deviation of the dripping position caused by the self-flowing flow.

[0144] In addition, the multiple nozzle groups GN include adjacent nozzle groups GNA_3 and GNA_2. When the straight line circumscribed by the end of the nozzle region NRA_3 corresponding to nozzle group GNA_3 in the V1 direction and the end of the nozzle region NRA_2 corresponding to nozzle group GNA_2 in the V2 direction is set as the second straight line LZA2, the third angle θA3 formed by the imaginary straight line LWA1 and the second straight line LZA2 is less than half of the fourth angle θA4 formed by the second straight line LZA2 and the third straight line LZA3 extending in the V1 direction.

[0145] According to the second embodiment, compared with the scheme where the third angle θA3 is more than half of the fourth angle θA4, the airflow generated by the air supply mechanism 96 can be made to uniformly contact each of the nozzles Ns of the nozzle group GN.

[0146] 3. Variations

[0147] The methods illustrated above can be varied. The following examples illustrate specific variations applicable to the aforementioned methods. Two or more solutions selected from the following examples can be appropriately combined without contradiction.

[0148] 3-1. First Variation Example

[0149] In the first embodiment, all of the plurality of nozzles N of the liquid injection head 30 are nozzles Ns, but it is not limited thereto and may also include nozzles Ns that do not use nozzles Ns. Hereinafter, a first modified example will be described.

[0150] 3-1-1. Regarding the air supply direction in the first variation example

[0151] Figure 12 This diagram illustrates the air delivery direction of the air delivery mechanism 96 in the first modification. The liquid injection device 100B in the first modification differs from the liquid injection device 100 in that it has a liquid injection head 30B instead of a liquid injection head 30. The liquid injection head 30B also differs from the liquid injection head 30 in that it does not use a nozzle Ni. Figure 12 In the middle, the Ni markings are not used for nozzles.

[0152] exist Figure 12 In this context, for any variable i from 1 to 6, the nozzle array Ln consisting of M nozzles N possessed by the head chip 38_i of the liquid injection head 30B is sometimes referred to as nozzle array LnBi. Figure 12In the example, the four nozzles N at the end of nozzle array LnB1 in the V2 direction, the four nozzles N at the end of nozzle array LnB2 in the V2 direction, the two nozzles N at the end of nozzle array LnB3 in the V1 direction, the two nozzles N at the end of nozzle array LnB3 in the V2 direction, the two nozzles N at the end of nozzle array LnB4 in the V1 direction, the two nozzles N at the end of nozzle array LnB5 in the V1 direction, and the four nozzles N at the end of nozzle array LnB6 in the V1 direction do not use nozzles Ni. However, among the multiple nozzle arrays LnB, there may be a nozzle array LnB that does not use nozzles Ni.

[0153] exist Figure 12 The diagram shows imaginary straight lines LWB1 and LWB2 projected onto the injection surface FN. Hereinafter, imaginary straight lines LWB1 and LWB2 will sometimes be referred to simply as imaginary straight line LWB. Imaginary straight line LWB is a straight line extending in the U1B direction, which is the flow direction of the airflow generated by the air supply mechanism 96. In other words, the airflow generated by the air supply mechanism 96 flows in the U1B direction along imaginary straight line LWB at a position opposite to the injection surface FN.

[0154] exist Figure 12 In the diagram, regarding the entire nozzle array LnB of the liquid injection head 30B, a nozzle segment LkB is shown connecting the end of the application nozzle Ns disposed in the V1 direction and the end of the application nozzle Ns disposed in the V2 direction, which is the opposite direction to the V1 direction. Figure 12 In the example, for any variable i from 1 to 6, the nozzle segment corresponding to the head chip 38_i included in the liquid injection head 30B is recorded as nozzle segment LkBi. Hereinafter, nozzle segments LkBi are sometimes referred to collectively as nozzle segments LkB without distinguishing between them. In addition, each head chip 38 includes (M-4) used nozzles Ns, which is obtained by subtracting 4 unused nozzles Ni from M nozzles N, so the 6 nozzle segments LkB have the same length.

[0155] Similar to the first embodiment, the number of nozzle segments LkB overlapping with one imaginary straight line LWB is 1 or less, regardless of their position along the X-axis of the imaginary straight line LWB. Specifically, the number of nozzle segments LkB overlapping with imaginary straight line LWB1 is one of nozzle segments LkB2. The number of nozzle segments LkB overlapping with imaginary straight line LWB2 is 0.

[0156] The imaginary line LWB can also overlap with one or more unused nozzles Ni. Specifically, the imaginary line LWB1 overlaps with the two unused nozzles Ni at the ends of the nozzle array LnB1 in the V2 direction. The imaginary line LWB2 does not overlap with the unused nozzles Ni.

[0157] In addition, Figure 12 The diagram shows a first straight line LZB1. The first straight line LZB1 passes through the nozzle Ns[B2V1] at the V1 direction end of the nozzle array LnB2 and the nozzle Ns[B1V2] at the V2 direction end of the nozzle array LnB1. The first angle θB1 formed by the imaginary straight line LWB1 and the first straight line LZB1 is less than half of the second angle θB2 formed by the first straight line LZB1 and the nozzle segment LkB4.

[0158] 3-1-2. Summary of the First Variation

[0159] Multiple nozzles N may also include one or more unused nozzles Ni that are not used during the printing operation, and the imaginary straight line LWB overlaps with any one or more of the unused nozzles Ni. According to the first variation, the first angle θB1 can be reduced in the same way as in the second embodiment, so that the airflow generated by the air supply mechanism 96 can uniformly contact each used nozzle Ns of the nozzle array Ln.

[0160] 3-2. Second variation example

[0161] In the above-described embodiments, the W-axis spacing dw1 of two adjacent nozzle rows Ln within a single liquid injection head 30 is approximately the same, but is not limited to this. The following describes a second variation.

[0162] Figure 13 This diagram illustrates the air delivery direction of the air delivery mechanism 96 in the second modification. The liquid injection device 100C in the second modification differs from the liquid injection device 100 in that it has a liquid injection head 30C instead of a liquid injection head 30. The liquid injection head 30C differs from the liquid injection head 30 in that it has six head chips 38C instead of six head chips 38. However, when viewed from above, the arrangement of each of the six head chips 38C differs from the head chip 38 only in relation to the injection surface FN. When distinguishing the six head chips 38C, they are referred to as head chips 38C_1, 38C_2, 38C_3, 38C_4, 38C_5, and 38C_6.

[0163] Each of the six head chips 38C has a nozzle array LnC. The nozzle array LnC is composed of M nozzles N arranged side-by-side in the V2 direction. Hereinafter, for any variable i from 1 to 6, the nozzle array Ln consisting of the M nozzles N of head chip 38C_i is sometimes referred to as nozzle array LnCi. Setting i to integers from 1 to 5, the interval dw1a between two adjacent nozzle arrays LnC along the W-axis between nozzle array LnCi and the nozzle array LnC of head chip 38C_i+1 is the smallest. Specifically, as an example of two adjacent nozzle arrays LnC along the Y-axis, the interval dw1a between nozzle array LnC1 and nozzle array LnC2 is smaller than the interval dw1b between nozzle array LnC2 and nozzle array LnC3.

[0164] exist Figure 13 The diagram shows imaginary straight lines LWC1 and LWC2 projected onto the injection surface FN. Hereinafter, imaginary straight lines LWC1 and LWC2 will sometimes be referred to simply as imaginary straight line LWC. Imaginary straight line LWC is a straight line extending in the U1C direction, which is the flow direction of the airflow generated by the air supply mechanism 96. In other words, the airflow generated by the air supply mechanism 96 flows along imaginary straight line LWC in the U1C direction at a position opposite to the injection surface FN.

[0165] exist Figure 13 In the diagram, regarding the entire nozzle array LnC of the liquid injection head 30C, a nozzle segment LkC is shown connecting the end of the application nozzle Ns disposed in the V1 direction and the end of the application nozzle Ns disposed in the V2 direction, which is the opposite direction to the V1 direction. Figure 13 In the example, for any variable i from 1 to 6, the nozzle segment corresponding to the head chip 38C_i contained in the liquid injection head 30C will be recorded as nozzle segment LkCi. Hereinafter, nozzle segment LkCi will sometimes be referred to as nozzle segment LkC without distinguishing between them.

[0166] In the second variation, the interval dw1a is smaller than the interval dw1b. Therefore, the manufacturer of the liquid injection device 100C adjusts the airflow direction generated by the air supply mechanism 96 to suppress the deviation of the dripping position caused by the self-flow of each nozzle N in the nozzle row Ln located in the Y1 direction of the two nozzle rows Ln located at both ends of the interval dw1a.

[0167] Similar to the first embodiment, the number of nozzle segments LkC overlapping with one imaginary straight line LWC is 1 or less, regardless of where the imaginary straight line LWC is positioned along the X-axis. Specifically, the number of nozzle segments LkC overlapping with imaginary straight line LWC1 is one of nozzle segments LkC4. The number of nozzle segments LkC overlapping with imaginary straight line LWC2 is 0.

[0168] In addition, Figure 13 The diagram shows a first straight line LZC1. The first straight line LZC1 passes through the nozzle Ns[C4V1] at the V1 direction end of nozzle array LnC4 and the nozzle Ns[C3V2] at the V2 direction end of nozzle array LnC3. The first angle θC1 formed by the imaginary straight line LWC1 and the first straight line LZC1 is less than half of the second angle θC2 formed by the first straight line LZC1 and the nozzle segment LkC4. Furthermore, in the second variation, nozzle array LnC4 is an example of a "first nozzle array," and nozzle array LnD3 is an example of a "second nozzle array."

[0169] In the liquid injection device 100C of the second modified example, the nozzle row LnC4, which corresponds to the "first nozzle row", and the nozzle row LnC3, which corresponds to the "second nozzle row", are the two nozzle rows LnC with the smallest interval along the W axis among the six nozzle rows LnC.

[0170] According to the second modified example, the deviation of the dripping position caused by the self-flow of each nozzle N in the nozzle row LnC4 located in the Y1 direction of the two nozzle rows LnC with the smallest spacing along the W axis can be suppressed, so that the airflow generated by the air supply mechanism 96 can evenly contact each nozzle N of the six nozzle rows LnC.

[0171] 3-3. Third variation example

[0172] In the above-described embodiments other than the second embodiment, the multiple head chips 38 are configured in an alternating pattern, but are not limited to this. The third variation will be described below.

[0173] Figure 14 This diagram illustrates the air delivery direction of the air delivery mechanism 96 in the third modification. The liquid injection device 100E in the third modification differs from the liquid injection device 100 in that it has a liquid injection head 30E instead of a liquid injection head 30. The liquid injection head 30E also differs from the liquid injection head 30 in that it has three head chips 38E instead of six head chips 38. However, each of the three head chips 38E has the same function as the head chip 38. Hereinafter, when distinguishing the head chips 38E, they will be referred to as head chips 38E_1, 38E_2, and 38E_3. The three head chips 38E are arranged along the X-axis.

[0174] Each of the three head chips 38E has a nozzle array LnE. The nozzle array LnE is composed of M nozzles N arranged side-by-side in the V2 direction. Hereinafter, for any variable i from 1 to 3, the nozzle array Ln consisting of the M nozzles N of head chip 38E_i will sometimes be referred to as nozzle array LnEi. The spacing dw1E between any two adjacent nozzle arrays LnE on the W-axis within a single liquid injection head 30E is approximately the same.

[0175] Three nozzle rows LnE are arranged side-by-side along the X-axis. When viewed in the Y1 direction, two adjacent nozzle rows LnE partially overlap. Therefore, in the scheme assuming no air supply mechanism 96 as in the first embodiment, the delivery airflow has difficulty reaching the nozzle N downstream of the delivery airflow in each of the two adjacent nozzle rows LnE, thus causing a deviation in the dripping position due to the self-flow. Therefore, in the third modification, by having an air supply mechanism 96, it is also possible to suppress the deviation in the dripping position caused by the self-flow.

[0176] exist Figure 14 The diagram shows imaginary straight lines LWE1 and LWE2 projected onto the injection surface FN. Hereinafter, imaginary straight lines LWE1 and LWE2 will sometimes be referred to simply as imaginary straight line LWE. The imaginary straight line LWE is a straight line extending in the U1E direction, which is the flow direction of the airflow generated by the air supply mechanism 96. In other words, the airflow generated by the air supply mechanism 96 flows in the U1E direction along the imaginary straight line LWE at a position opposite to the injection surface FN.

[0177] exist Figure 14 In the diagram, regarding the entire nozzle array LnE of the liquid injection head 30E, a nozzle segment LkE is shown connecting the end of the application nozzle Ns disposed in the V1 direction and the end of the application nozzle Ns disposed in the V2 direction. Figure 14 In the example, for any variable i from 1 to 3, the nozzle segment corresponding to the head chip 38E_i contained in the liquid injection head 30E will be recorded as nozzle segment LkEi. Hereinafter, nozzle segment LkEi will sometimes be referred to as nozzle segment LkE without distinguishing between them.

[0178] The number of nozzle segments LkE that overlap with one imaginary straight line LWE is always one or less, regardless of where the imaginary straight line LWE is positioned along the X-axis. Specifically, the number of nozzle segments LkE that overlap with imaginary straight line LWE1 is one of nozzle segments LkE3. The number of nozzle segments LkE that overlap with imaginary straight line LWE2 is zero.

[0179] In addition, Figure 14The diagram shows a first straight line LZE1. The first straight line LZE1 passes through the end of nozzle Ns[E3V1] in nozzle array LnE3, which is positioned in the V1 direction, and the end of nozzle Ns[E2V2] in nozzle array LnE2, which is positioned in the V2 direction. The first angle θE1 formed by the imaginary straight line LWE1 and the first straight line LZE1 is less than half of the second angle θE2 formed by the first straight line LZE1 and the nozzle segment LkE3.

[0180] 3-4. Fourth variation example

[0181] In the second embodiment, one head chip 38A has two nozzle rows Ln, but the number of nozzle rows Ln in one head chip 38A may also be three or more. The fourth variation will be described below.

[0182] Figure 15 This is a diagram illustrating the air delivery direction of the air delivery mechanism 96 in the fourth modification. The liquid injection device 100F in the fourth modification differs from the liquid injection device 100 in that it has a liquid injection head 30F instead of a liquid injection head 30. The liquid injection head 30F also differs from the liquid injection head 30 in that it has four head chips 38F instead of head chips 38. Furthermore, in this modification, the multiple head chips 38F are fixed to the same support 37F, and the multiple nozzle surfaces SN provided on each of the multiple head chips 38F fixed to the same support 37F constitute one injection surface FN. That is, as according to... Figure 15 As can be understood, the injection surface FN of the liquid injection head 30F can be composed of multiple nozzle surfaces SN arranged with gaps between them, or it can be not a single continuous surface. Furthermore, in Figure 15 The image shows four head chips 38F, but the number of head chips 38F disposed on the liquid injection head 30F is arbitrary. Furthermore, four head chips 38F is an example of "multiple head chips".

[0183] The four head chips 38F differ from head chip 38 in that they have nozzle rows LnF1 and LnF3 arranged side-by-side with spacing between them along the V-axis, and nozzle rows LnF2 and LnF4 arranged side-by-side with spacing between them along the V-axis. Nozzle rows LnF1 and LnF3 are arranged on approximately the same straight line along the V-axis.

[0184] Nozzle rows LnF2 and LnF4 are arranged approximately in a straight line along the V-axis. Furthermore, nozzle rows LnF1 and LnF2 are arranged side-by-side with a gap between them along the X-axis, and nozzle rows LnF3 and LnF4 are also arranged side-by-side with a gap between them along the X-axis. Hereinafter, nozzle rows LnF1 to LnF4 will sometimes be referred to as nozzle row LnF without distinction. Additionally, to avoid complicating the drawings, only a portion of the nozzles N included in nozzle group GNF will be labeled with reference numerals.

[0185] In the fourth variation, all of the multiple nozzles N of the liquid injection device 100F are nozzles Ns. Figure 15 The diagram shows a nozzle region NRF surrounded by the smallest convex polygon enclosed by nozzles Ns within the nozzle group GNF of one head chip 38F. Furthermore, for ease of understanding, for any variable i from 1 to 4, the nozzle region NRF surrounded by the smallest convex polygon enclosed by all nozzles Ns within the nozzle group GNF of head chip 38F_i is sometimes referred to as nozzle region NRF_i. The nozzle region NRF is long in the V1 direction.

[0186] The four nozzle regions (NRFs) are arranged side-by-side along the X-axis. When viewed in the Y1 direction, two adjacent nozzle regions (NRFs) partially overlap.

[0187] In the fourth variation, the air supply mechanism 96 also generates airflow in the U1F direction, which intersects any one of the Y1 direction, the X-axis direction, and the V1 direction, in a manner along the injection surface FN. Furthermore, in the fourth variation, the U1F direction is an example of a "third direction".

[0188] exist Figure 15 The diagram shows imaginary straight lines LWF1 and LWF2 projected onto the injection surface FN. Hereinafter, imaginary straight lines LWF1 and LWF2 will sometimes be referred to simply as imaginary straight line LWF. Imaginary straight line LWF is a straight line extending in the U1F direction. That is, the airflow generated by the air supply mechanism 96 flows in the U1F direction along imaginary straight line LWF at a position opposite to the injection surface FN. Imaginary straight line LWF can be projected onto the injection surface FN at any position along the X-axis, but... Figure 11 To avoid overcomplication, only imaginary straight lines LWF1 and LWF2 are displayed.

[0189] According to Figure 15As can be understood, the number of nozzle regions NRFs that overlap with the imaginary line LWF, regardless of where the imaginary line LWF is positioned along the X-axis, is always one or less. Specifically, the imaginary line LWF1, when viewed from above, passes through the end of nozzle region NRF_4 in the V1 direction, and more specifically through the nozzle N of nozzle row LnF4 positioned at the end of the V1 direction. Therefore, the number of nozzle regions NRFs overlapping with the imaginary line LWF1 is one for nozzle region NRF_4. The imaginary line LWF2, when viewed from above, passes between nozzle regions NRF_2 and NRF_3. Therefore, the number of nozzle regions NRFs overlapping with the imaginary line LWF2 is zero.

[0190] In addition, Figure 15 The diagram shows a second straight line LZF2 and a third straight line LZF3. The second straight line LZF2 is a straight line circumscribed in the V1 direction of nozzle region NRF_4 and the V2 direction of nozzle region NRF_3. The third straight line LZF3 is a straight line extending along the long side of nozzle region NRF_4 in the V1 direction. The third angle θF3 formed by the imaginary straight line LZF1 and the second straight line LZF2 is less than half of the fourth angle θF4 formed by the second straight line LZF2 and the third straight line LZF3. A smaller third angle θF3 is preferred; for example, it is preferable to be less than half of the fourth angle θF4. Furthermore, the nozzle group GNF of head chip 38F_4 is an example of a "first nozzle group," and the nozzle group GNF of head chip 38F_3 is an example of a "second nozzle group." Nozzle region NRF_4 is an example of a "nozzle region corresponding to the first nozzle group," and nozzle region NRF_3 is an example of a "nozzle region corresponding to the second nozzle group."

[0191] In addition, the second straight line LZF2 is external to nozzle regions NRF_3 and NRF_4, and does not contact or overlap with other nozzle regions NRF outside of nozzle regions NRF_3 and NRF_4.

[0192] Next, regarding Figure 16 Please provide an explanation. Figure 15 The liquid injection head 30F shown is... Figure 16 The liquid injection head shown is the same as the 30F. Figure 16As shown, regarding each head chip 38F, the nozzle rows LnF1 and LnF3, which are arranged with a gap along the V-axis, can be considered as one nozzle row LnF, and the nozzle rows LnF2 and LnF4, which are arranged with a gap along the V-axis, can be considered as one nozzle row LnF. Therefore, the line segment connecting the nozzle N at the end of nozzle row LnF1 in the V2 direction and the nozzle N at the end of nozzle row LnF3 in the V1 direction is called the nozzle segment LkF. In this modified example, a total of 8 nozzle segments LkF are provided, and nozzle segments LkF1, LkF2, LkF3, LkF4, LkF5, LkF6, LkF7, and LkF8 are arranged side-by-side in the X1 direction in this order.

[0193] exist Figure 16 The diagram shows imaginary lines LWF1 and LWF2 that project a straight line extending in the U1F direction onto the injection surface FN. Without distinguishing between imaginary lines LWF1 and LWF2, they are referred to as imaginary line LWF. As per... Figure 16 As can be understood, the number of nozzle segments LkF that overlap with the imaginary line LWF out of the eight nozzle segments LkF is less than one, regardless of the position of the imaginary line LWF along the X-axis. Specifically, the imaginary line LWF1 passes through nozzle segment LkF8 when viewed from above. Therefore, the number of nozzle segments LkF that overlap with the imaginary line LWF1 is one of nozzle segments LkF8. The imaginary line LWF2 passes between nozzle segments LKF6 and LKF7 when viewed from above. Therefore, the number of nozzle segments LKF that overlap with the imaginary line LWF2 is zero.

[0194] In addition, Figure 16 The diagram shows a first straight line LZF1. The first straight line LZF1 is a straight line passing through nozzle Ns[F8V1] at the end of nozzle row LnF corresponding to nozzle segment LkF8 in the V1 direction, and nozzle Ns[F7V2] at the end of nozzle row LnF corresponding to nozzle segment LkF7 in the V2 direction. The first angle θF1 formed by the hypothetical straight line LZF1 and the first straight line LZF1 is less than half of the second angle θF2 formed by the first straight line LZF1 and nozzle segment LkF8. A smaller first angle θF1 is preferred; for example, it is preferred to be less than half of the second angle θF2. Furthermore, the nozzle row LnF corresponding to nozzle segment LkF8 is an example of a "first nozzle row," and the nozzle row LnF corresponding to nozzle segment LkF7 is an example of a "second nozzle row." Nozzle Ns[F8V1] is an example of a "first-use nozzle," and nozzle Ns[F7V2] is an example of a "second-use nozzle."

[0195] Furthermore, in this modified example, the distances between all adjacent nozzle segments LkF are equal along the X-axis. Therefore, it is possible to define the nozzle column LnF corresponding to nozzle segment LkF7 as the "first nozzle column" and the nozzle column LnF corresponding to nozzle segment LkF6 as the "second nozzle column".

[0196] In addition, the first straight line LZF1 does not contact or overlap with other nozzle segments LkF besides nozzle segments LkF7 and LkF8.

[0197] 3-5. Fifth variation example

[0198] In the above-described embodiments, the liquid injection head 30 constitutes a linear head, but this disclosure is not limited thereto. For example, this disclosure can also be applied to a serial manner in which the liquid injection head 30 reciprocates along the X-axis.

[0199] Figure 17 This is an explanatory diagram showing an example of a fifth modified liquid injection device 100D. The liquid injection device 100D differs from the liquid injection device 100 in that it has a head module 3D instead of a head module 3, and also has a moving mechanism 91.

[0200] The moving mechanism 91 causes the head module 3D to reciprocate along the X-axis under the control of the control device 90. For example... Figure 17 As shown, the moving mechanism 91 includes a generally box-shaped carriage 911 that mounts the head module 3D, and an annular belt 912 on which the head module 3D is fixed. Alternatively, a configuration in which the liquid container 93 and the circulation mechanism 94 are mounted together with the head module 3D on the carriage 911 may also be adopted.

[0201] The head module 3D is rotated 90 degrees counterclockwise around the Z-axis when viewed in the Z1 direction, and its shape and function are the same as the head module 3. The head module 3D includes multiple liquid injection heads 30D, a head fixing plate 13D holding the multiple liquid injection heads 30D, and an air supply mechanism 96D. The liquid injection heads 30D, the head fixing plate 13D, and the air supply mechanism 96D are also rotated 90 degrees counterclockwise around the Z-axis when viewed in the Z2 direction, respectively, so descriptions are omitted.

[0202] Airflow is generated by the head module 3D moving along the X-axis. Hereinafter, the airflow generated by the head module 3D moving along the X-axis will sometimes be referred to as "moving airflow". The moving airflow can also suppress the generation of wind patterns caused by the self-flow. However, when the nozzle array Ln is tilted relative to the X-axis, among the multiple nozzles N, there are nozzles N located upstream of the moving airflow and nozzles N located downstream of the moving airflow. Sometimes, the generation of wind patterns caused by the self-flow based on the moving airflow cannot be suppressed by the nozzles N located downstream of the moving airflow. Therefore, in the fifth variation, similar to the first embodiment, by providing the air supply mechanism 96D, the airflow is made to reach each nozzle N of the nozzle array Ln without omission, thereby suppressing the deviation of the dripping position.

[0203] Figure 18 This is a diagram illustrating the air supply direction of the air supply mechanism 96D in the fifth modification. Figure 18 To avoid overcomplication, only one liquid injection head 30D is shown in the diagram. The nozzle array direction of each of the six head chips 38 of the liquid injection head 30D is the VD1 direction after rotating it 90 degrees counterclockwise around the Z-axis when viewed in the Z2 direction. Figure 18 In this diagram, the direction opposite to VD1 is designated as VD2. Sometimes, both VD1 and VD2 are collectively referred to as directions along the VD axis. Additionally, the direction along the Z-axis and the direction perpendicular to the direction along the VD axis are designated as WD1 and WD2. WD1 is the direction between X2 and Y2, and WD2 is the direction between X1 and Y1. Sometimes, both WD1 and WD2 are collectively referred to as directions along the WD axis.

[0204] Moreover, in Figure 18 The diagram shows imaginary straight lines LWD1 and LWD2 projected onto the injection surface FN. Hereinafter, imaginary straight lines LWD1 and LWD2 will sometimes be referred to simply as imaginary straight line LWD. The imaginary straight line LWD is a straight line extending in the UD1 direction. That is, the airflow generated by the air supply mechanism 96 flows in the UD1 direction along the imaginary straight line LWD at a position opposite the injection surface FN. The UD1 direction intersects with any of the following: the Y1 direction, the direction along the X-axis, and the VD1 direction, which is the direction of the nozzle array. The UD1 direction is an example of a "third direction".

[0205] The nozzle arrays LnD of each of the six head chips 38 are arranged side-by-side in the Y1 direction. For ease of explanation, the nozzle array LnD of the head chip 38_i included in the liquid injection head 30D is sometimes referred to as nozzle array LnD_i for any variable i from 1 to 6. Alternatively, it is sometimes referred to simply as nozzle array LnD without distinguishing between nozzle arrays LnD_1 to LnD_6. Two adjacent nozzle arrays LnD of the six nozzle arrays LnD of the liquid injection head 30D overlap at least partially when viewed along the X-axis. For example, when viewed along the X-axis, nozzle array LnD_1 and nozzle array LnD_2 completely overlap. Furthermore, when viewed along the X-axis, nozzle array LnD_2 and nozzle array LnD_3 partially overlap.

[0206] Furthermore, regarding the entire nozzle array LnD of the liquid injection head 30D, a nozzle segment LkD is shown connecting the end of the application nozzle Ns disposed in the VD1 direction and the end of the application nozzle Ns disposed in the VD2 direction, which is the opposite direction to the VD1 direction. Figure 18 In the example, for any variable i from 1 to 6, the nozzle segment corresponding to the head chip 38_i included in the liquid injection head 30D is recorded as nozzle segment LkDi. Hereinafter, nozzle segment LkDi is sometimes referred to as nozzle segment LkD without distinguishing between them.

[0207] In addition, Figure 18 The diagram shows a first straight line LZD1. The first straight line LZD1 passes through the nozzle Ns[D4V1] at the end of nozzle array LnD_4 configured in the VD1 direction and the nozzle Ns[D3V2] at the end of nozzle array LnD_3 configured in the VD2 direction. The first angle θD1 formed by the imaginary straight line LWD1 and the first straight line LZD1 is less than half of the second angle θD2 formed by the first straight line LZD1 and the nozzle segment LkD4. In the fifth variation, nozzle array LnD_4 is an example of a "first nozzle array," and nozzle array LnD_3 is an example of a "second nozzle array."

[0208] Furthermore, similar to the first embodiment, the group of two nozzle segments LkD with the highest repetition when viewed along the X-axis, selected from the six nozzle segments LkD, consists of two adjacent nozzle segments LkD along the X-axis. Specifically, the group of two nozzle segments LkD with the highest repetition is the group of nozzle segment LkD1 and nozzle segment LkD2, the group of nozzle segment LkD3 and nozzle segment LkD4, and the group of nozzle segment LkD5 and nozzle segment LkD6. Therefore, when nozzle column LnD_4 is equivalent to "first nozzle column" and nozzle column LnD_3 is equivalent to "second nozzle column", the nozzle segment LkD4 corresponding to nozzle column LnD_4 and the nozzle segment LkD3 corresponding to nozzle column LnD_3 are the group with the largest repetition when viewed in the Y1 direction from the combination of two nozzle segments LkD selected from the nozzle segments LkD corresponding to the nozzle columns LnD of the six nozzle columns LnD respectively.

[0209] The liquid injection device 100D of the fifth modification described above includes a carriage 911 that carries a liquid injection head 30D and reciprocates along the X-axis. The liquid injection head 30D has multiple nozzle rows LnD arranged side-by-side in the Y1 direction, and adjacent nozzle rows LnD of the liquid injection head 30D at least partially overlap when viewed along the X-axis. According to the fifth modification, even in a serial configuration, deviations in the dripping position caused by the self-flowing liquid can be suppressed. In this modification, the Y1 direction is an example of a "first direction," and the X1 direction is an example of a "second direction."

[0210] 3-6. Sixth Variation

[0211] The liquid injection head 30D shown in the third variation is a solution in which the liquid injection head 30 of the first embodiment is rotated 90 degrees counterclockwise around the Z-axis when viewed in the Z2 direction, but it is not limited to this. For example, in order to apply the serial method, other solutions other than the first embodiment may be used, such as rotating the liquid injection head 30A of the second embodiment 90 degrees counterclockwise around the Z-axis when viewed in the Z2 direction.

[0212] 3-7. Seventh Variation

[0213] Figure 19This diagram illustrates the air delivery direction of the air delivery mechanism 96 in the seventh modification, which is a variation of the second embodiment. The liquid injection device 100G in the seventh modification differs from the liquid injection device 100A in that it has a liquid injection head 30G instead of a liquid injection head 30A. The liquid injection head 30G also differs from the liquid injection head 30A in that it has four head chips 38G instead of three head chips 38A. Furthermore, four head chips 38G is an example of "multiple head chips". In this modification, the liquid injection head 30G has four head chips 38G, but it is sufficient to have two or more head chips 38G.

[0214] The liquid injection head 30G consists of four head chips 38G, namely head chips 38G_1 to 38G_4. The head chips 38G_1 to 38G_4 are arranged in this order along X1.

[0215] Each of the four head chips 38G has a nozzle group GN, which consists of 2M nozzles N divided into nozzle rows Ln1 and Ln2 arranged side-by-side at intervals along the W-axis. Hereinafter, nozzle rows Ln1 and Ln2 will sometimes be referred to as nozzle row Ln without distinguishing between them. Furthermore, to avoid complicating the drawings, only a portion of the nozzles N included in the nozzle group GN are labeled with reference numerals. In this modified example, a portion of the multiple nozzles N in the liquid injection device 100G are used nozzles Ns, and the remaining portion are unused nozzles Ni. Figure 19 In the image, the absence of a nozzle (Ni) is indicated by black dots. Figure 19 In the middle, there are two unused nozzles Ni in one head chip 38G.

[0216] The spacing dw4 on the W axis of two adjacent nozzle regions NR within the liquid injection head 30G is approximately the same. Furthermore, the spacing dw4 is sufficiently wide than the spacing dwLn of the two nozzle rows Ln in a single head chip 38G.

[0217] exist Figure 19 The diagram shows the smallest convex polygon encompassing all nozzles Ns within the nozzle group GN of a single head chip 38G. Figure 19 In this context, the convex polygon is a parallelogram. Hereinafter, the region enclosed by this convex polygon will sometimes be referred to as the nozzle region NRG. Furthermore, for ease of understanding, for any variable i from 1 to 4, the nozzle region NRG enclosed by the smallest convex polygon (2M-2) of the nozzles Ns contained in the nozzle group GN of the head chip 38G_i will sometimes be referred to as the nozzle region NRG_i. The nozzle region NRG is long in the V1 direction. Moreover, the V1 direction is an example of a "fourth direction".

[0218] exist Figure 19 The diagram shows the smallest convex polygon surrounding the unused nozzles Ni of a single head chip 38G. Hereinafter, the area surrounded by this convex polygon will sometimes be referred to as the unused area IR. However, when a single head chip 38G has two or more unused nozzles Ni, and these two or more unused nozzles Ni are adjacent, they are surrounded by a single smallest convex polygon. Figure 19 In the example, multiple unused regions IR1, IR2, IR3, and IR4 are shown as unused regions IR. Unused region IR1 includes two unused nozzles Ni arranged in the V2 direction of head chip 38G_1. Unused region IR2 includes two unused nozzles Ni arranged in the V2 direction of head chip 38G_2. Unused region IR3 includes two unused nozzles Ni arranged in the V1 direction of head chip 38G_3. Unused region IR4 includes two unused nozzles Ni arranged in the V1 direction of head chip 38G_4. Figure 19 In the meantime, when not using the regional IR view from above, it does not overlap with the nozzle region NRG.

[0219] The four nozzle regions (NRGs) are arranged side-by-side in a staggered pattern along the X-axis. When viewed in the Y1 direction, any two adjacent nozzle regions (NRGs) will approximately overlap. "Approximately overlap" means that due to manufacturing errors or to improve resolution, the two adjacent nozzle regions (NRGs) will be offset by half or less of the nozzle spacing along the X-axis of the nozzle column Ln. When viewed in the Y1 direction, nozzle regions NRG_1 and NRG_2 approximately overlap, while NRG_3 and NRG_4 do not. Similarly, when viewed in the Y1 direction, nozzle regions NRG_3 and NRG_4 approximately overlap.

[0220] In this variation, the air supply mechanism 96 generates airflow in the U1G direction, which intersects any one of the Y1 direction, the X-axis direction, and the V1 direction, in a manner that is along the injection surface FN. The U1G direction is also an example of a "third direction".

[0221] exist Figure 19 The diagram shows imaginary lines LWG1 and LWG2 projected onto the injection surface FN. Hereinafter, imaginary lines LWG1 and LWG2 will sometimes be referred to simply as imaginary line LWG without distinction. Imaginary line LWG is a straight line extending in the U1G direction. That is, the airflow generated by the air supply mechanism 96 flows along imaginary line LWG in the U1G direction at a position opposite to the injection surface FN. Imaginary line LWG can be projected onto the injection surface FN at any position along the X-axis, but... Figure 19 To avoid overcomplication, only imaginary straight lines LWG1 and LWG2 are displayed.

[0222] According to Figure 19 As can be understood, the number of nozzle regions NRGs that overlap with the imaginary line LWG is less than 1, regardless of where the imaginary line LWG is positioned along the X-axis. Specifically, imaginary line LWG1 passes through the end of nozzle region NRG_2 in the V1 direction when viewed from above. Therefore, the number of nozzle regions NRGs that overlap with imaginary line LWG1 is 1 for nozzle region NRG_2. Imaginary line LWG2 passes between nozzle region NRG_2 and nozzle region NRG_3 when viewed from above. Therefore, the number of nozzle regions NRGs that overlap with imaginary line LWG2 is 0.

[0223] In addition, Figure 19 The diagram shows a second straight line LZG2 and a third straight line LZG3. The second straight line LZG2 is a straight line circumscribed at the V1 direction end of nozzle region NRG_2 and the V2 direction end of nozzle region NRG_1. The third straight line LZG3 is a straight line extending in the V1 direction. The third angle θG3 formed by the hypothetical straight line LWG1 and the second straight line LZG2 is less than half of the fourth angle θG4 formed by the second straight line LZG2 and the third straight line LZG3. A smaller third angle θG3 is preferred; for example, it is preferable to be less than half of the fourth angle θG4. Therefore, compared to a scheme where the third angle θG3 is more than half of the fourth angle θG4, the airflow generated by the air supply mechanism 96 can uniformly contact each of the nozzles Ns in the nozzle group GN. Furthermore, the nozzle group GN of the head chip 38G_2 is an example of a "first nozzle group," and the nozzle group GN of the head chip 38G_1 is an example of a "second nozzle group." Nozzle region NRG_2 is an example of "nozzle region corresponding to the first nozzle group", and nozzle region NRG_1 is an example of "nozzle region corresponding to the second nozzle group".

[0224] In addition, the second straight line LZG2 is external to nozzle regions NRG_1 and NRG_2, and does not contact or overlap with other nozzle regions NRG outside of nozzle regions NRG_1 and NRG_2.

[0225] In addition, as according to Figure 19 As can be understood, the distance between the line segments connecting the end of nozzle region NRG_1 in the V2 direction and the end of nozzle region NRG_2 in the V1 direction is longer than the distance between the line segments connecting the end of nozzle region NRG_1 in the V1 direction and the end of nozzle region NR_2 in the V2 direction.

[0226] Furthermore, among the four nozzle regions NRGs of a single liquid injection head 30G, the group of two nozzle region NRGs with the highest repetition when viewed in the Y1 direction is the group of adjacent nozzle region NRGs along the Y-axis. Specifically, the groups of two nozzle region NRGs with the highest repetition are the group of nozzle region NRG_1 and nozzle region NRG_2, and the group of nozzle region NRG_3 and nozzle region NRG_4.

[0227] The imaginary line LWG can also overlap with one or more unused areas IR. Specifically, the imaginary line LWG1 overlaps with unused area IR1. The imaginary line LWG2 does not overlap with unused area IR. During the printing operation, no ink is ejected from the unused nozzle Ni, so no self-flow is generated near the unused nozzle Ni. That is to say, the airflow of the air supply mechanism 96 easily passes through the unused area IR, so if the imaginary line LWG overlaps with the unused area IR, the third angle θG3 can be reduced, and the airflow generated by the air supply mechanism 96 can be made to evenly contact each used nozzle Ns of the nozzle array Ln.

[0228] 3-8. Eighth Variation

[0229] In the embodiments described above, excluding the fifth and sixth modifications, an air supply mechanism 96 is provided in the Y2 direction of the liquid injection head 30, but this is not a limitation. For example, the air supply mechanism 96 may be replaced by a mechanism that draws air into the Y1 direction of the liquid injection head 30, or the air supply mechanism 96 may be based on the air supply mechanism 96. Alternatively, the air supply mechanism 96 may be provided in the Y1 direction of the liquid injection head 30 to generate airflow in a direction opposite to the airflow direction shown in the embodiments described above, excluding the fifth and sixth modifications. That is, if the first embodiment is used as an example, the air supply mechanism 96 may also be used to generate airflow in a direction opposite to the U1 direction. Similarly, in the fifth and sixth modifications, an air supply mechanism 96D is provided in the X1 direction of the liquid injection head 30D, but this is not a limitation. For example, the air supply mechanism 96D may be replaced by a mechanism that draws air into the X2 direction of the liquid injection head 30D or the liquid injection head 30E, or the air supply mechanism 96D may be based on the air supply mechanism 96D.

[0230] 3-9. Ninth Variation Example

[0231] Furthermore, as in the first modified example described above, when only one nozzle row LnB is provided on one head chip 38B, this one nozzle row LnB can also be regarded as one nozzle group GN as described in the eighth modified example, one nozzle line segment LkB can be regarded as one nozzle region as described in the eighth modified example, and the line segment connecting the unused nozzle Ni at the end in the V1 direction and the unused nozzle Ni at the end in the V2 direction can be regarded as the unused region IR as described in the eighth modified example. Furthermore, when the number of unused nozzles N1 provided on one nozzle row LnB is one, this one unused nozzle Ni can also be regarded as the unused region IR.

[0232] 3-10. Tenth Variation Example

[0233] In the above-mentioned schemes, the liquid injection head 30 has a piezoelectric element PZq, but it can also have a heating element instead of the piezoelectric element PZq.

[0234] 3-11. Other variations

[0235] The liquid jetting device 100 described above can be used not only in printing equipment, but also in various other equipment such as fax machines and copiers.

Claims

1. A liquid injection device, characterized in that, have: A liquid injection head has an injection surface, the injection surface having multiple nozzles that inject liquid in the injection direction arranged side by side in the nozzle array direction to form multiple nozzle arrays; The conveying mechanism conveys the medium in a first direction at a position opposite to the spray surface; as well as Air supply mechanism The nozzle array direction intersects both the first direction and the second direction, and the second direction is orthogonal to both the first direction and the injection direction. The air supply mechanism generates airflow in a third direction that intersects any one of the first direction, the second direction, and the nozzle array direction, in a manner that follows the jet surface.

2. The liquid injection device according to claim 1, characterized in that, The plurality of nozzles includes: a plurality of application nozzles used in a printing action that sprays liquid toward the medium. When the line segment connecting the end of the nozzle in the direction of the nozzle column and the end of the nozzle in the opposite direction of the nozzle column is defined as a nozzle line segment, the number of nozzle line segments that overlap with an imaginary straight line projected onto the spray surface extending upwards in the third direction among the plurality of nozzle line segments corresponding to each of the plurality of nozzle columns is 1 or less.

3. The liquid injection device according to claim 2, characterized in that, The plurality of nozzles includes: one or more unused nozzles that are not used in the printing operation. The imaginary straight line overlaps with any one or more of the one or more unused nozzles.

4. The liquid injection device according to claim 2, characterized in that, All of the nozzles are the nozzles used in the printing operation.

5. The liquid injection device according to claim 2, characterized in that, The plurality of nozzle columns include a first nozzle column and a second nozzle column that are adjacent to each other. When the straight line passing through the first use nozzle, which is disposed at one end of the plurality of use nozzles included in the first nozzle column and disposed at the other end of the plurality of use nozzles included in the second nozzle column in the opposite direction of the nozzle column direction, is defined as the first straight line, The first angle formed by the imaginary straight line and the first straight line is less than half of the second angle formed by the first straight line and the nozzle segment.

6. The liquid injection device according to claim 5, characterized in that, The first straight line does not overlap with any of the nozzle segments other than the nozzle segment corresponding to the first nozzle column and the nozzle segment corresponding to the second nozzle column.

7. The liquid injection device according to claim 5, characterized in that, The distance between the first and second nozzles is greater than the distance between the third nozzle in the first nozzle array, which is located at the opposite end of the nozzle array direction, and the fourth nozzle in the second nozzle array, which is located at the opposite end of the nozzle array direction.

8. The liquid injection device according to claim 5, characterized in that, The liquid injection head is configured as a row head with the second direction as its long side. The nozzle segment corresponding to the first nozzle column and the nozzle segment corresponding to the second nozzle column are selected from the combination of two nozzle segments from the plurality of nozzle segments, and the group with the largest repetition when viewed in the first direction.

9. The liquid injection device according to claim 5, characterized in that, The liquid injection device includes a carriage that carries the liquid injection head and reciprocates along the second direction. The nozzle segment corresponding to the first nozzle column and the nozzle segment corresponding to the second nozzle column are selected from the combination of two nozzle segments from the plurality of nozzle segments, and the group with the largest repetition when viewed in the second direction.

10. The liquid injection device according to claim 5, characterized in that, The first nozzle array and the second nozzle array are the two nozzle arrays with the smallest spacing in a direction orthogonal to the direction of the nozzle array among the plurality of nozzle arrays.

11. The liquid injection device according to claim 1, characterized in that, The liquid injection head is configured as a row head with the second direction as its long side. The plurality of nozzles are arranged side by side in the second direction. Two adjacent nozzle arrays of the plurality of nozzle arrays overlap at least partially when viewed in the first direction.

12. The liquid injection device according to claim 1, characterized in that, The liquid injection device includes a carriage that carries the liquid injection head and reciprocates along the second direction. The plurality of nozzles are arranged side by side in the first direction. Two adjacent nozzle arrays of the plurality of nozzle arrays overlap at least partially when viewed in the second direction.

13. A liquid injection device, characterized in that, have: A liquid jetting head having multiple head chips, each of which has a nozzle group consisting of multiple nozzles that jet liquid in the jetting direction; The conveying mechanism conveys the medium in a first direction at a position opposite to the spray surface of the liquid injection head; as well as Air supply mechanism The plurality of nozzles includes: a plurality of application nozzles used in a printing action that sprays liquid toward a medium. When a nozzle region is defined as the area enclosed by the smallest convex polygon surrounding the plurality of nozzles in each of the plurality of nozzle groups, each nozzle region corresponding to each of the plurality of nozzle groups extends in a fourth direction that intersects both the first direction and the second direction, wherein the second direction is orthogonal to both the first direction and the jet direction. The air supply mechanism generates airflow in a third direction that intersects any one of the first, second, and fourth directions, in a manner that follows the jet surface.

14. The liquid injection device according to claim 13, characterized in that, The number of nozzle regions among the plurality of nozzle regions that overlap with an imaginary straight line projected onto the jet surface extending upward from the third party is 1 or less.

15. The liquid injection device according to claim 14, characterized in that, The plurality of nozzles includes: one or more unused nozzles that are not used in the printing operation. When the smallest convex polygon surrounding one or more unused nozzles in each of the plurality of nozzle groups is defined as the unused region... The imaginary straight line overlaps with one or more of the unused regions.

16. The liquid injection device according to claim 14, characterized in that, The plurality of nozzle groups includes a first nozzle group and a second nozzle group that are adjacent to each other. When the straight line circumscribed at the end of the nozzle region corresponding to the first nozzle group in the fourth direction and at the end of the nozzle region corresponding to the second nozzle group in the opposite direction in the fourth direction is defined as the second straight line, The third angle formed by the imaginary line and the second line is less than half of the fourth angle formed by the second line and the third line extending in the fourth direction.

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