Liquid spray head, support, and liquid spray device

Abstract

To improve the attachment / detachment property while securing required positioning accuracy of a liquid jet head to a support body.SOLUTION: A liquid jet head includes a first positioning part into which a first positioning pin of a support body is inserted. When a virtual column which is inserted to the deepest position of the first positioning part and whose cross-sectional area becomes maximum when viewed from a first direction being the depth direction of the first positioning part is the first virtual column, the side surface of the first virtual column includes a first region, a second region and a third region therebetween as the three regions divided in the first direction; the first region contacts the first positioning part on a first side being one side in a second direction orthogonal to the first direction with respect to a first center line of the first virtual column but does not contact the first positioning part on a second side being the other side in the second direction; the second region does not contact the first positioning part on the first side with respect to the first center line but contacts the first positioning part on the second side; and the third region does not contact the first positioning part on both of the first side and the second side with respect to the first center line.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to a liquid ejection head, a support, and a liquid ejection device.

Background Art

[0002] Conventionally, a liquid ejection device typified by an inkjet printer generally includes a liquid ejection head that ejects a liquid such as ink as droplets.

[0003] For example, Patent Document 1 discloses a head (liquid ejection head) having a positioning pin member (positioning pin) and an array base member (support) having a positioning hole (positioning portion), and the head is positioned with respect to the array base member by inserting the positioning pin member into the positioning hole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a configuration in which a liquid ejection head is positioned with respect to a support by inserting a positioning pin into a positioning portion as in Patent Document 1, it is desirable to enable the liquid ejection head to be easily attached to and detached from the support.

Means for Solving the Problems

[0006] To solve the above problems, a liquid spray head according to a preferred embodiment of the present disclosure is a liquid spray head that sprays a liquid, supported on a support having a first positioning pin, and includes a first positioning part into which the first positioning pin is inserted to position the liquid spray head relative to the support, and when a first virtual cylinder is defined as a virtual cylinder that is inserted to the deepest position of the first positioning part and has the largest cross-sectional area when viewed in a first direction which is the depth direction of the first positioning part, the side surface of the first virtual cylinder is divided into three regions in the first direction: a first region and a second region The region includes a region and a third region positioned between the first region and the second region, wherein the first region contacts the first positioning portion on a first side which is one side in a second direction perpendicular to the first direction with respect to a first center line which is the center line of the first virtual cylinder, but does not contact the first positioning portion on the second side which is the other side in the second direction; the second region does not contact the first positioning portion on the first side with respect to the first center line, but contacts the first positioning portion on the second side; and the third region does not contact the first positioning portion on both the first and second sides with respect to the first center line.

[0007] A support according to a preferred embodiment of the present disclosure is a support for supporting a liquid spraying head that sprays a liquid, comprising a first positioning portion into which a first positioning pin provided on the liquid spraying head is inserted to position the liquid spraying head relative to the support, wherein a first virtual cylinder is defined as a virtual cylinder that is inserted to the deepest position of the first positioning portion and has the largest cross-sectional area when viewed in a first direction which is the depth direction of the first positioning portion, the side surface of the first virtual cylinder is divided into three regions in the first direction: a first region, a second region, and the first The region includes a third region positioned between the first region and the second region, wherein the first region contacts the first positioning portion on a first side which is one side in a second direction perpendicular to the first direction with respect to a first center line which is the center line of the first virtual cylinder, and does not contact the first positioning portion on a second side which is the other side in the second direction; the second region does not contact the first positioning portion on the first side with respect to the first center line, but contacts the first positioning portion on the second side; and the third region does not contact the first positioning portion on both the first and second sides with respect to the first center line.

[0008] A liquid injection device according to a preferred embodiment of the present disclosure comprises a liquid injection head as described above and a support body having the first positioning pin.

[0009] A liquid injection device according to another preferred embodiment of the present disclosure comprises a support body as described above and a liquid injection head having the first positioning pin. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing an example of the configuration of a liquid injection device according to the first embodiment. [Figure 2] This is a perspective view of a head module having a liquid injection head according to the first embodiment. [Figure 3] This is an exploded perspective view of the liquid injection head according to the first embodiment. [Figure 4] This is a plan view of the liquid injection head according to the first embodiment. [Figure 5]It is a perspective view of a support according to the first embodiment. [Figure 6] It is a plan view of a liquid ejection head according to the first embodiment. [Figure 7] It is a view of the first positioning portion of the liquid ejection head shown in FIG. 6 as seen in the Z2 direction. [Figure 8] It is a cross-sectional view taken along line A-A in FIG. 7. [Figure 9] It is a view of the first positioning portion shown in FIG. 7 as seen in the Z1 direction. [Figure 10] It is a plan view for explaining a first virtual cylinder set in the first positioning portion shown in FIG. 7. [Figure 11] It is a cross-sectional view for explaining a first virtual cylinder set in the first positioning portion shown in FIG. 7. [Figure 12] It is a view showing a state where a first positioning pin of the support is inserted into the first positioning portion shown in FIG. 7. [Figure 13] It is a view showing a state where the first positioning portion shown in FIG. 7 is inclined with respect to the first positioning pin of the support. [Figure 14] It is a schematic view for explaining attachment and detachment of a liquid ejection head according to the first embodiment to a support. [Figure 15] It is a view of the second positioning portion of the liquid ejection head shown in FIG. 6 as seen in the Z2 direction. [Figure 16] It is a cross-sectional view taken along line B-B in FIG. 15. [Figure 17] It is a view of the second positioning portion shown in FIG. 15 as seen in the Z1 direction. [Figure 18] It is a plan view for explaining a second virtual cylinder set in the second positioning portion shown in FIG. 15. [Figure 19] It is a cross-sectional view for explaining a second virtual cylinder set in the second positioning portion shown in FIG. 15. [Figure 20] It is a view showing a state where a second positioning pin of the support is inserted into the second positioning portion shown in FIG. 15. [Figure 21] It is a view of the first positioning portion of a liquid ejection head according to the second embodiment as seen in the Z2 direction. [Figure 22]It is a cross-sectional view taken along the line E-E in FIG. 21. [Figure 23] It is a view of the first positioning portion shown in FIG. 21 as seen in the Z1 direction. [Figure 24] It is a view of the first positioning portion of the liquid injection head according to the third embodiment as seen in the Z2 direction. [Figure 25] It is a cross-sectional view taken along the line F-F in FIG. 24. [Figure 26] It is a view of the first positioning portion shown in FIG. 24 as seen in the Z1 direction. [Figure 27] It is a view of the first positioning portion of the liquid injection head according to the fourth embodiment as seen in the Z2 direction. [Figure 28] It is a cross-sectional view taken along the line G-G in FIG. 27. [Figure 29] It is a cross-sectional view taken along the line G-G in FIG. 27. [Figure 30] It is a view of the second positioning portion of the liquid injection head according to the fourth embodiment as seen in the Z2 direction. [Figure 31] It is a cross-sectional view taken along the line H-H in FIG. 30. [Figure 32] It is a cross-sectional view taken along the line H-H in FIG. 30. [Figure 33] It is a cross-sectional view showing a state where the first positioning pin is inserted into the first positioning portion of the liquid injection head according to the fifth embodiment. [Figure 34] It is a cross-sectional view showing a state where the first positioning pin is inserted into the first positioning portion of the liquid injection head according to the sixth embodiment. [Figure 35] It is a view of the first positioning portion of the liquid injection head according to the first modification as seen in the Z2 direction. [Figure 36] It is a cross-sectional view taken along the line J-J in FIG. 35. [Figure 37] It is a view of the first positioning portion shown in FIG. 35 as seen in the Z1 direction. [Figure 38] It is a plan view of the liquid injection head according to the second modification. [Figure 39] It is a view of the first positioning portion of the liquid injection head according to the second modification as seen in the Z2 direction. [Figure 40] It is a cross-sectional view taken along the line K-K in FIG. 39. [Figure 41]This is a view of the second positioning portion of the liquid injection head according to modified example 2, as seen in the Z2 direction. [Figure 42] Figure 41 is a cross-sectional view along line LL. [Figure 43] This is a plan view of the liquid spray head according to Modification 3. [Figure 44] This is a schematic diagram illustrating the attachment and detachment of the liquid spray head to the support according to Modification 4. [Figure 45] This is a cross-sectional view of the first positioning portion according to modified example 4. [Figure 46] This is a cross-sectional view of the second positioning portion according to modified example 4. [Figure 47] This is a schematic diagram illustrating the attachment and detachment of the liquid spray head to the support according to Modification 5. [Figure 48] This is a cross-sectional view of the first positioning portion according to modified example 5. [Figure 49] This is a cross-sectional view of the second positioning portion according to modified example 5. [Modes for carrying out the invention]

[0011] Preferred embodiments of the present disclosure will be described below with reference to the attached drawings. Note that the dimensions and scale of parts in the drawings may differ from actual dimensions as appropriate, and some parts are shown schematically for ease of understanding. Furthermore, the scope of the present disclosure is not limited to these embodiments unless otherwise stated in the following description.

[0012] For convenience, the following explanation will use the X, Y, and Z axes intersecting each other as appropriate. In the following, one direction along the X axis is the X1 direction, and the direction opposite to the X1 direction is the X2 direction. Similarly, opposite directions along the Y axis are the Y1 and Y2 directions. Also, opposite directions along the Z axis are the Z1 and Z2 directions.

[0013] Here, the Z1 or Z2 direction is an example of a "first direction." The Y1 or Y2 direction is an example of a "second direction." The Y2 direction is an example of a "first side which is one side of the second direction," and the Y1 direction is an example of a "second side which is the other side of the second direction." The X1 or X2 direction is an example of a "third direction." In the following, viewing along the Z axis may be referred to as a "planar view."

[0014] 1. First Embodiment 1-1. Schematic Configuration of Liquid Injection System Figure 1 is a schematic diagram showing an example configuration of a liquid injection device 100 according to the first embodiment. The liquid injection device 100 is an inkjet printing device that sprays ink, which is an example of a liquid, as droplets onto a medium M. The medium M is typically printing paper. However, the medium M is not limited to printing paper and may be any material to be printed on, such as resin film or fabric.

[0015] In the first embodiment, the X, Y, and Z axes are coordinate axes of a local coordinate system based on the liquid spray head 1, which is arranged in three dimensions and described later. Therefore, Figures 1 to 5, 12 to 14, and 20 show the coordinate axes of the local coordinate system based on the liquid spray head 1 when it is supported by the support 51, which is described later. Accordingly, in the following description of the first embodiment, other components besides the liquid spray head 1 may be described using the local coordinate system based on the liquid spray head 1 when it is supported by the support 51.

[0016] As shown in Figure 1, the liquid injection device 100 includes a liquid container 10, a control unit 20, a transport mechanism 30, a moving mechanism 40, a head module 50, and a circulation mechanism 60. These will be briefly described below in order based on Figure 1.

[0017] The liquid container 10 stores ink. Specific examples of the liquid container 10 include a cartridge that can be attached to or detached from the liquid ejection device 100, a bag-shaped ink pack made of a flexible film, and an ink tank that can be refilled with ink.

[0018] The liquid container 10 of this embodiment, although not shown, has a plurality of containers for storing different types of ink. The inks stored in the plurality of containers are not particularly limited, but examples include water-based inks obtained by dissolving colorants such as dyes or pigments in an aqueous solvent, solvent-based inks obtained by dissolving colorants in an organic solvent, and ultraviolet-curable inks.

[0019] The control unit 20 includes, for example, a processing circuit such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array) and a storage circuit such as a semiconductor memory, and controls the operation of each element of the liquid ejection device 100. The control unit 20 controls the ink ejection operation by the head module 50.

[0020] The transport mechanism 30, under the control of the control unit 20, transports the medium M in the transport direction DM, which is the Y1 direction. The moving mechanism 40, under the control of the control unit 20, moves the head module 50 back and forth in the X1 and X2 directions. In the example shown in Figure 1, the moving mechanism 40 has a roughly box-shaped transport body 41 called a carriage that houses the head module 50, and a transport belt 42 to which the transport body 41 is fixed. In addition to the head module 50, the aforementioned liquid container 10 may also be mounted on the transport body 41.

[0021] The head module 50, under the control of the control unit 20, sprays ink supplied from the liquid container 10 via the circulation mechanism 60 onto the medium M from each of its multiple nozzles in the Z2 direction. This spraying occurs in parallel with the transport of the medium M by the transport mechanism 30 and the reciprocating movement of the head module 50 by the moving mechanism 40, thereby forming an image of ink on the surface of the medium M. The head module 50 has multiple liquid spray heads 1. Details of the liquid spray heads 1 will be described later with reference to Figures 2 to 20.

[0022] In the example shown in Figure 1, the liquid container 10 is connected to the head module 50 via a circulation mechanism 60. The circulation mechanism 60 supplies ink to the head module 50 and also recovers the ink discharged from the head module 50 for resupply to the head module 50.

[0023] 1-2. Liquid spray head Figure 2 is a perspective view of a head module 50 having a liquid injection head 1 according to the first embodiment. As shown in Figure 2, the head module 50 has a support 51 and a plurality of liquid injection heads 1. The liquid injection heads 1 are elongated in the direction along the Y axis.

[0024] The support 51 is a plate-shaped member that supports multiple liquid spray heads 1. The support 51 is provided with multiple openings 51a, multiple positioning pins 51b, and multiple screw holes 51c. The support 51 is fixed to the transport body 41 by fixing means (not shown). The support 51 itself may be the transport body 41. Furthermore, the shape of the support 51 does not have to be plate-shaped; for example, it may be a box shape with a recess that can accommodate multiple liquid spray heads 1.

[0025] The opening 51a is a hole for inserting the liquid injection head 1 with the injection surface FN facing the Z2 direction, and penetrates the support 51 in the thickness direction. In the example shown in Figure 2, each opening 51a extends in the direction along the Y axis, and two liquid injection heads 1 are inserted into one opening 51a.

[0026] The positioning pin 51b is positioned near the periphery of the opening 51a and is a rod-shaped projection that protrudes from the protruding surface FP, which is the surface of the support 51 facing the Z1 direction. In this embodiment, the shape of the positioning pin 51b in plan view is circular, specifically a perfect circle. The positioning pin 51b is inserted by press-fitting into the positioning portion 13e provided on the liquid spray head 1, which will be described later. The shape of the positioning portion 13e may be a through hole or a blind hole, but in this embodiment it is a through hole. Press-fitting will be described in more detail later, but it is a so-called interference fit or intermediate fit. In the example shown in Figure 2, two positioning pins 51b are provided for one liquid spray head 1. Details of the positioning pin 51b will be described later with reference to Figure 5.

[0027] The screw hole 51c is a female screw located near the periphery of the opening 51a and provided on the surface of the support 51 facing the Z1 direction. A screw (not shown) is fitted into the screw hole 51c. This screw is inserted through the hole 13f of the liquid spray head 1, which will be described later, and fixes the liquid spray head 1 to the support 51. In the example shown in Figure 2, two screw holes 51c are provided for one liquid spray head 1.

[0028] As described above, multiple liquid spray heads 1 are attached to the support 51. In the example shown in Figure 2, the multiple liquid spray heads 1 are arranged in a matrix along the X and Y axes.

[0029] The number and arrangement of liquid injection heads 1 in the head module 50 are not limited to the example shown in Figure 2 and are arbitrary. Similarly, the shape of the support 51 is not limited to the example shown in Figure 2 and is arbitrary. Furthermore, the opening 51a may be provided for each of one or three or more liquid injection heads 1.

[0030] Figure 3 is an exploded perspective view of the liquid injection head 1 according to the first embodiment. As shown in Figure 3, the liquid injection head 1 includes a flow channel structure 11, a wiring board 12, a holder 13, four head chips HC, a fixing plate 14, a reinforcing plate 15, a cover 16, and a sealing member 17. These are arranged in the order of cover 16, wiring board 12, flow channel structure 11, sealing member 17, holder 13, four head chips HC, reinforcing plate 15, and fixing plate 14 in the Z2 direction. The holder 13 is an example of the "first member". The parts of the liquid injection head 1 will be described sequentially below.

[0031] The flow channel structure 11 is a structure in which a flow channel is provided for supplying ink from the circulation mechanism 60 to four head chips HC. The flow channel structure 11 has a flow channel member 11a and four connecting pipes 11b to 11e. The flow channel member 11a is provided with two supply channels for supplying ink to the four head chips HC and two discharge channels for discharging ink from the four head chips HC, although these are not shown in Figure 3. The flow channel member 11a has a plurality of substrates Su1 to Su5, which are stacked in this order in the Z2 direction and joined to each other, for example, by adhesive. Each of the connecting pipes 11b to 11e is a tubular body that protrudes from the surface of the flow channel member 11a facing the Z1 direction. Each of the connecting pipes 11b and 11c is connected to each of the two supply channels, and each of the connecting pipes 11d and 11e is connected to each of the two discharge channels. Furthermore, the flow channel member 11a is provided with multiple holes 11f. Screws SC are inserted into each hole 11f. The screws SC fix the flow channel member 11a to the holder 13.

[0032] The wiring board 12 is a mounting component for electrically connecting the liquid injection head 1 to the control unit 20, and is located on the flow path structure 11. A connector 12a is installed on the surface of the wiring board 12 facing the Z1 direction. The connector 12a is a connecting component for electrically connecting the liquid injection head 1 and the control unit 20. Although not shown, wiring connected to four head chips HC is also connected to the wiring board 12.

[0033] The holder 13 is a structure that houses and supports four head chips HC. The holder 13 is provided with a plurality of holder channels 13a, a plurality of wiring holes 13b, a plurality of recesses 13c, a plurality of screw holes 13d, a plurality of holes 13f, and a plurality of positioning parts 13e.

[0034] The holder 13 is made of, for example, a resin material or a metal material. In this embodiment, since the positioning pin 51b is press-fitted into the positioning part 13e, both the holder 13 and the positioning pin 51b are made of a metal material. Examples of metal materials include iron, titanium, aluminum, magnesium, or alloys containing at least one of these metal elements. Examples of alloys include stainless steel, 42 alloy, and Invar. In this embodiment, the material of the holder 13 and the material of the positioning pin 51b are the same metal material, specifically stainless steel. The positioning pin 51b and the support 51 may be formed as a single unit, or the positioning pin 51b and the support 51, which are separate parts, may be joined together to form a single unit.

[0035] Each of the multiple holder channels 13a is a hole for flowing ink between the head chip HC and the channel structure 11. The holder channels 13a are provided corresponding to the inlet R_in and outlet R_out, respectively, which will be described later. Each of the multiple wiring holes 13b is a hole through which wiring (not shown) connecting the head chip HC and the wiring board 12 passes. Each of the multiple recesses 13c opens in the Z2 direction and is a space in which the head chip HC is positioned. Each of the multiple screw holes 13d is a female screw that fits into a screw SC. By tightening the screw SC, which is inserted into the hole 11f of the channel member 11a, into the screw hole 13d, the channel member 11a is pressed toward the holder 13. Screws (not shown) for fixing the liquid spray head 1 to the support 51 are inserted into each of the multiple holes 13f. Positioning pins 51b of the support 51 are inserted into each of the multiple positioning parts 13e. Details of the multiple positioning units 13e will be described later with reference to Figures 6 to 20.

[0036] Each print head HC ejects ink. Each print head HC is provided with an inlet R_in for introducing ink and an outlet R_out for discharging ink. The inlet R_in and outlet R_out are joined to the print head HC and the holder 13 by adhesive, thereby creating a liquid-tight connection to the corresponding holder flow path 13a.

[0037] Figure 4 is a plan view of the liquid spray head 1 as seen in the Z1 direction according to the first embodiment. As shown in Figure 4, each head tip HC has a nozzle forming surface FN_A on which a plurality of nozzles N are formed. The nozzle forming surface FN_A is the surface of the nozzle plate on which the plurality of nozzles N are formed that faces in the Z2 direction. The plurality of nozzles N are arranged in a direction along the Y axis to form a nozzle row. Although not shown, each head tip HC has a piezoelectric element, which is a driving element, and a pressure chamber that contains ink supplied from the inlet R_in for each nozzle N. Here, the piezoelectric element causes ink to be ejected from the nozzle corresponding to the pressure chamber by changing the pressure of the ink in the pressure chamber corresponding to the piezoelectric element. Such a head tip HC can be obtained, for example, by bonding together a plurality of substrates such as silicon substrates that have been appropriately processed by etching or the like with an adhesive. Note that instead of the piezoelectric element, a heater that heats the ink in the pressure chamber may be used as the driving element for ejecting ink from the nozzle N.

[0038] The fixing plate 14 is a plate member for fixing the four head chips HC to the holder 13. Specifically, the fixing plate 14 is positioned between the holder 13 and the four head chips HC, and is fixed to the holder 13 with adhesive. The fixing plate 14 is made of, for example, a metal material. The fixing plate 14 is provided with multiple openings 14a for exposing the multiple nozzles N that each of the four head chips HC has. Here, the surface FN_B of the fixing plate 14 facing the Z2 direction and the four nozzle-forming surfaces FN_A constitute the spray surface FN of the liquid spray head 1 facing the Z2 direction. In other words, the spray surface FN is a surface having multiple nozzles N. The multiple openings 14a are provided individually for each head chip HC.

[0039] The reinforcing plate 15 is a plate-shaped member positioned between the holder 13 and the fixing plate 14, reinforcing the fixing plate 14. The reinforcing plate 15 is placed on top of the fixing plate 14 and fixed to the fixing plate 14 with adhesive. The reinforcing plate 15 is provided with a plurality of openings 15a in which four head chips HC are positioned. The reinforcing plate 15 is made of, for example, a metal material.

[0040] The cover 16 is a box-shaped member that houses the flow channel member 11a and the wiring board 12 of the flow channel structure 11, and is made of, for example, a resin material. The cover 16 is provided with four through holes 16a and an opening 16b. One of the connecting pipes 11b to 11e is inserted into the four through holes 16a. A connector 12a is passed through the opening 16b from the inside of the cover 16 to the outside.

[0041] The sealing member 17 is an elastic member for liquid-tightly connecting the flow path of the flow path structure 11 and the holder flow path 13a of the holder 13. In the example shown in Figure 3, the sealing member 17 is in the form of a sheet and is provided with a plurality of ink holes 17a, a plurality of wiring holes 17b, and a plurality of holes 17c. The plurality of ink holes 17a are holes for flowing ink between the flow path structure 11 and the holder 13 and are provided corresponding to the inlet R_in and outlet R_out. Each of the plurality of wiring holes 17b is a hole through which wiring (not shown) connecting the head chip HC and the wiring board 12 passes. Each of the plurality of holes 17c is a hole for inserting a screw SC.

[0042] 1-3. Positioning of the liquid injection head relative to the support. Figure 5 is a perspective view of the support 51 according to the first embodiment. As shown in Figure 5, the support 51 is provided with a plurality of first positioning pins 51b_1 and a plurality of second positioning pins 51b_2, and a plurality of screw holes 51c_1 and a plurality of screw holes 51c_2 near the outer edge of each of the plurality of openings 51a.

[0043] The first positioning pin 51b_1 and the second positioning pin 51b_2 are the positioning pins 51b shown in Figure 2 above. The first positioning pin 51b_1 is inserted into the first positioning section 13e_1 of the liquid spray head 1, which will be described later. On the other hand, the second positioning pin 51b_2 is inserted into the second positioning section 13e_2 of the liquid spray head 1, which will be described later.

[0044] In the example shown in Figure 5, one first positioning pin 51b_1 and one second positioning pin 51b_2 are provided for each liquid spray head 1. Furthermore, the first positioning pin 51b_1 and the second positioning pin 51b_2 corresponding to one liquid spray head 1 are aligned along the Y-axis. More specifically, the first positioning pin 51b_1 is positioned in the Y2 direction relative to the second positioning pin 51b_2.

[0045] Screw holes 51c_1 and 51c_2 are the same screw holes 51c shown in Figure 2 above. A screw corresponding to hole 13f_1 of the liquid spray head 1, described later, is fitted into screw hole 51c_1. On the other hand, a screw corresponding to hole 13f_2 of the liquid spray head 1, described later, is fitted into screw hole 51c_2.

[0046] In the example shown in Figure 5, one screw hole 51c_1 and one screw hole 51c_2 are provided for each liquid spray head 1. Furthermore, the screw holes 51c_1 and 51c_2 corresponding to one liquid spray head 1 are aligned along the Y axis. More specifically, screw hole 51c_1 is positioned in the Y2 direction relative to screw hole 51c_2. Here, in the positioning pin 51b and screw hole 51c corresponding to one liquid spray head 1, the first positioning pin 51b_1 is located closer to screw hole 51c_1 than to screw hole 51c_2, and the second positioning pin 51b_2 is located closer to screw hole 51c_2 than to screw hole 51c_1.

[0047] Figure 6 is a plan view of the liquid injection head 1 as seen in the Z2 direction according to the first embodiment. As shown in Figure 6, the liquid injection head 1 has a flange portion 13h that protrudes from the cover 16 when viewed in the Z2 direction. As shown in Figure 4, the shape of the flange portion 13h in a plan view in the Z1 direction protrudes outward from the entire circumference of the side surface of the holder 13. The second surface F2 of the flange portion 13h, which faces in the Z2 direction, contacts the protruding surface FP of the aforementioned support 51, which faces in the Z1 direction. The flange portion 13h is provided with a first positioning portion 13e_1, a second positioning portion 13e_2, a hole 13f_1, and a hole 13f_2.

[0048] The first positioning section 13e_1 and the second positioning section 13e_2 are the positioning section 13e shown in Figure 2 above. The first positioning pin 51b_1 of the support 51 is inserted into the first positioning section 13e_1. On the other hand, the second positioning pin 51b_2 of the support 51 is inserted into the second positioning section 13e_2.

[0049] In the example shown in Figure 6, one first positioning section 13e_1 and one second positioning section 13e_2 are provided for each liquid injection head 1. The first positioning section 13e_1 and the second positioning section 13e_2 are aligned along the Y-axis. More specifically, the first positioning section 13e_1 is positioned in the Y2 direction relative to the second positioning section 13e_2. In a plan view in the Z1 direction, at least a portion of the injection surface FN is interposed between the first positioning section 13e_1 and the second positioning section 13e_2.

[0050] Holes 13f_1 and 13f_2 are the same holes 13f shown in Figure 2 above. A screw that fits into the screw hole 51c_1 of the support 51 is inserted into hole 13f_1. On the other hand, a screw that fits into the screw hole 51c_2 of the support 51 is inserted into hole 13f_2.

[0051] In the example shown in Figure 6, one hole 13f_1 and one hole 13f_2 are provided for each liquid injection head 1. Furthermore, holes 13f_1 and 13f_2 are aligned along the Y-axis. More specifically, hole 13f_1 is positioned in the Y2 direction relative to hole 13f_2. Here, the first positioning part 13e_1 is located closer to hole 13f_1 than to hole 13f_2. The second positioning part 13e_2 is located closer to hole 13f_2 than to hole 13f_1.

[0052] Figure 7 is a view of the first positioning portion 13e_1 of the liquid injection head 1 shown in Figure 6, as seen in the Z2 direction. Figure 8 is a cross-sectional view taken along line AA in Figure 7. Figure 9 is a view of the first positioning portion 13e_1 shown in Figure 7, as seen in the Z1 direction. As shown in Figures 7 to 9, the first positioning portion 13e_1 has a first through hole 2, a first recess 3, and a second recess 4. The first through hole 2 is positioned between the first recess 3 and the second recess 4 with respect to the direction along the Y axis. More specifically, the first recess 3, the first through hole 2, and the second recess 4 are aligned in this order in the Y2 direction.

[0053] The first through-hole 2 is a hole that penetrates the flange portion 13h of the holder 13. Here, the flange portion 13h has a first surface F1 which faces in the Z1 direction and a second surface F2 which faces in the Z2 direction, and the first through-hole 2 penetrates from the first surface F1 to the second surface F2 in a direction along the Z axis. In this embodiment, as shown in Figures 7 and 9, the first through-hole 2 is circular in plan view. Note that the plan view shape of the first through-hole 2 is not limited to the examples shown in Figures 7 and 9.

[0054] The first recess 3 is provided on the first surface F1 and is adjacent to the Y1 direction side of the first through hole 2 in a plan view. On the other hand, the second recess 4 is provided on the second surface F2 and is adjacent to the Y2 direction side of the first through hole 2 in a plan view.

[0055] Here, the sum of the depths of the first recess 3 and the second recess 4 is greater than the distance between the first surface F1 and the second surface F2 (i.e., the thickness of the flange portion 13h of the holder 13). In other words, the sum of the length of the first contact portion CT1 along the Z-axis and the length of the second contact portion CT2 along the Z-axis is less than the distance between the first surface F1 and the second surface F2 (i.e., the thickness of the flange portion 13h of the holder 13). Note that the plan view shape of the first recess 3 is not limited to the example shown in Figure 7 and is arbitrary. Similarly, the plan view shape of the second recess 4 is not limited to the example shown in Figure 9 and is arbitrary.

[0056] Figure 10 is a plan view illustrating the first virtual cylinder VC1 set in the first positioning unit 13e_1 shown in Figure 7. Figure 11 is a cross-sectional view illustrating the first virtual cylinder VC1 set in the first positioning unit 13e_1 shown in Figure 7. The first virtual cylinder VC1 is a virtual cylinder that is inserted to the deepest position of the first positioning unit 13e_1 and has the largest cross-sectional area when viewed in the depth direction (along the Z-axis) of the first positioning unit 13e_1. The first virtual cylinder VC1 is a right circular cylinder, not an oblique cylinder. In the example shown in Figure 10, the plan view shape of the first virtual cylinder VC1 is a perfect circle. That is, the bottom surface of the first virtual cylinder VC1 is a perfect circle. Note that the plan view shape of the first virtual cylinder VC1 is defined based on the plan view shape of the first positioning unit 13e_1, so it may be elliptical. In that case, the first virtual cylinder VC1 becomes an elliptical cylinder.

[0057] As shown in Figure 11, the side surface of the first virtual cylinder VC1 includes three regions divided along the Z-axis: a first region RE1, a second region RE2, and a third region RE3 positioned between the first region RE1 and the second region RE2. In this embodiment, the second region RE2 is positioned in the Z2 direction, which is the direction in which the injection surface FN faces relative to the first region RE1, with respect to the direction along the Z-axis.

[0058] The first region RE1 is the region that contacts the first positioning part 13e_1 on the Y2 direction side with respect to the first center line LC1, which is the center line of the first virtual cylinder VC1, but does not contact the first positioning part 13e_1 on the Y1 direction side. The second region RE2 is the region that does not contact the first positioning part 13e_1 on the Y2 direction side with respect to the first center line LC1, but contacts the first positioning part 13e_1 on the Y1 direction side. The third region RE3 is the region that does not contact the first positioning part 13e_1 on both the Y2 and Y1 directions with respect to the first center line LC1. The first center line LC1 is a straight line that passes through the center of the bottom surface of the first virtual cylinder VC1 and extends in a direction along the Z axis.

[0059] Here, the first recess 3 is adjacent to the portion of the first region RE1 on the Y1 direction side with respect to the first centerline LC1. The second recess 4 is adjacent to the portion of the second region RE2 on the Y2 direction side with respect to the first centerline LC1. The first recess 3 and the second recess 4 are adjacent to the third region RE3. The first virtual cylinder VC1 extends along the first through hole 2 from the first surface F1 to the second surface F2. In this embodiment, the first virtual cylinder VC1 extends from one end to the other in the direction along the Z axis of the first through hole 2, and corresponds to the shape of the first through hole 2. In other words, the deepest position of the first positioning portion 13e_1 is the end of the first through hole 2 in the Z1 direction (i.e., the position of the first surface F1 on the Z axis) when the first virtual cylinder VC1 is inserted in the Z1 direction from the opening of the first positioning portion 13e_1 formed on the second surface F2, and the end of the first through hole 2 in the Z2 direction (i.e., the position of the second surface F2 on the Z axis) when the first virtual cylinder VC1 is inserted in the Z2 direction from the opening of the first positioning portion 13e_1 formed on the first surface F1.

[0060] In the example shown in Figure 11, the length of the first region RE1 along the Z-axis and the length of the second region RE2 along the Z-axis are equal. However, these lengths may be different. However, in order to ensure the rigidity of the first positioning part 13e_1 necessary to prevent damage to the first positioning part 13e_1 due to the pressure acting on the first positioning part 13e_1 when the first positioning pin 51b_1 is pressed in, and to facilitate insertion and removal of the first positioning pin 51b_1 from the first positioning part 13e_1, the lengths of the first region RE1 and the second region RE2 along the Z-axis are preferably 20% to 45%, more preferably 25% to 40%, and more preferably 28% to 38% of the length of the first virtual cylinder VC1 along the Z-axis. Furthermore, the length of the third region RE3 along the Z-axis is preferably 10% to 40%, more preferably 20% to 50%, and more preferably 24% to 44% of the length of the first virtual cylinder VC1 along the Z-axis.

[0061] Thus, the first positioning unit 13e_1 contacts the portion of the first region RE1 on the Y2 direction side with respect to the first centerline LC1, without contacting the portions of the second region RE2 and the third region RE3 on the Y2 direction side with respect to the first centerline LC1, and contacts the portion of the second region RE2 on the Y1 direction side with respect to the first centerline LC1, without contacting the portions of the first region RE1 and the third region RE3 on the Y1 direction side with respect to the first centerline LC1.

[0062] Therefore, the first positioning portion 13e_1 has a first contact portion CT1 that contacts the portion of the first region RE1 on the Y2 direction side with respect to the first center line LC1, and a second contact portion CT2 that contacts the portion of the second region RE2 on the Y1 direction side with respect to the first center line LC1. In this embodiment, the first contact portion CT1 and the second contact portion CT2 each extend continuously in the direction along the Z axis.

[0063] Furthermore, due to the presence of the third region RE3 as described above, the shortest distance Ds (see Figure 8) between the first contact portion CT1 and the second contact portion CT2 in the cross-section shown in Figure 11 is greater than or equal to the maximum length Da (see Figure 13) of the first positioning pin 51b_1 along the Y-axis. It is preferable that the shortest distance Ds is greater than the maximum length Da. The cross-section shown in Figure 11 is a cross-section obtained by cutting the first positioning portion 13e_1 with a plane perpendicular to the Z-axis at the position along the X-axis where the length of the first virtual cylinder VC1 along the Y-axis is maximum in a plan view.

[0064] Furthermore, in this embodiment, the maximum length Da is greater than or equal to the maximum dimension Dv in the direction along the Y-axis of the first virtual cylinder VC1. This maximum dimension Dv corresponds to the diameter of the cross-section perpendicular to the Z-axis direction of the first virtual cylinder VC1. Moreover, the shortest distance Ds is greater than the maximum dimension Dv. Note that the shortest distance Ds, the maximum length Da, and the maximum dimension Dv are the distance, length, or dimension measured before the first positioning pin 51b_1 is inserted into the first positioning part 13e_1, that is, before the first positioning pin 51b_1 is inserted into the first positioning part 13e_1.

[0065] Here, press-fitting the positioning pin 51b into the positioning portion 13e means that the maximum length of the positioning pin 51b as viewed in the depth direction of the positioning portion 13e is greater than or equal to the diameter of the cross-section perpendicular to the depth direction of a hypothetical perfect cylinder that is inserted to the deepest position of the positioning portion 13e and has the largest cross-sectional area as viewed in the depth direction of the positioning portion 13e. When the positioning portion 13e is press-fitted onto the positioning pin 51b, insertion is generally possible because the positioning portion 13e deforms outward relative to the positioning pin 51b.

[0066] As shown in Figure 10, the first positioning portion 13e_1 has two boundary portions BO_1 that face each other in the direction along the X-axis. In a plan view along the Z-axis, the boundary portion BO_1 is the boundary between the portion of the thin-walled part of the first positioning portion 13e_1 that defines the bottom surface of the second recess 4 and defines the first through hole 2, and the portion of the thin-walled part of the first positioning portion 13e_1 that defines the bottom surface of the first recess 3 and defines the first through hole 2, that is, the boundary between the first contact portion CT1 and the second contact portion CT2. Each of the two boundary portions BO_1 extends linearly from the first surface F1 to the second surface F2 along the Z-axis direction. Therefore, the two boundary portions BO_1 are not included in the Y1 direction side and the Y2 direction side of the first virtual cylinder VC1 (in other words, the first region RE1, the second region RE2, and the third region RE3, respectively) with respect to the first centerline LC1.

[0067] Figure 12 shows the state in which the first positioning pin 51b_1 of the support 51 is inserted into the first positioning part 13e_1 shown in Figure 7. Figure 13 shows the state in which the first positioning part 13e_1 shown in Figure 7 is tilted relative to the first positioning pin 51b_1 of the support 51. Figure 14 is a schematic diagram illustrating the attachment and detachment of the liquid spray head 1 to the support 51 according to the first embodiment.

[0068] Figure 12 shows the state after insertion of the first positioning pin 51b_1 into the first positioning part 13e_1, where the side surface of the first positioning pin 51b_1 has a portion that matches the side surface of the first virtual cylinder VC1. In this state, as shown in Figure 12, the first contact part CT1 and the second contact part CT2 each contact the side surface of the first positioning pin 51b_1. Although not shown, the two boundary parts BO_1 also each contact the side surface of the first positioning pin 51b_1. These contacts position the first positioning part 13e_1 relative to the first positioning pin 51b_1. In this embodiment, since the first positioning pin 51b_1 and the first through hole 2 fit together in this state, the insertion of the first positioning pin 51b_1 into the first positioning part 13e_1 restricts the movement of the liquid spray head 1 relative to the support 51 in a plane perpendicular to the Z axis.

[0069] In the state shown in Figure 12, a gap is provided between the first positioning pin 51b_1 and the first positioning portion 13e_1 by the first recess 3 and the second recess 4. Therefore, as shown in Figure 13, the first positioning pin 51b_1 can be inserted into the first positioning portion 13e_1 by tilting the first positioning portion 13e_1 with respect to the direction in which the first positioning pin 51b_1 extends.

[0070] Therefore, as shown in Figure 14, when attaching the liquid spray head 1 to the support 51, the insertion of the first positioning part 13e_1 into the first positioning pin 51b_1 can be performed before the insertion of the second positioning part 13e_2 into the second positioning pin 51b_2. Also, when removing the liquid spray head 1 from the support 51, the removal of the second positioning part 13e_2 into the second positioning pin 51b_2 can be performed before the removal of the first positioning part 13e_1 into the first positioning pin 51b_1. Below, an example of the configuration of the second positioning part 13e_2 that facilitates the attachment and detachment of the liquid spray head 1 to the support 51 will be described.

[0071] Figure 15 is a view of the second positioning portion 13e_2 of the liquid injection head 1 shown in Figure 6, as seen in the Z2 direction. Figure 16 is a cross-sectional view taken along line BB in Figure 15. Figure 17 is a view of the second positioning portion 13e_2 shown in Figure 15, as seen in the Z1 direction. As shown in Figures 15 to 17, the second positioning portion 13e_2 has a second through hole 5, a third recess 6, and a fourth recess 7. The second through hole 5 is positioned between the third recess 6 and the fourth recess 7 with respect to the direction along the Y axis. More specifically, the third recess 6, the second through hole 5, and the fourth recess 7 are aligned in this order in the Y2 direction.

[0072] The second through-hole 5 is a hole that penetrates the flange portion 13h of the holder 13. Here, the second through-hole 5 penetrates from the first surface F1 to the second surface F2 in a direction along the Z axis. In this embodiment, as shown in Figures 15 and 17, the second through-hole 5 has a substantially oval shape with the direction along the Y axis as its longitudinal direction in a plan view. That is, the length of the second through-hole 5 in the direction along the Y axis is longer than the length of the second through-hole 5 in the direction along the X axis. Here, the length of the second through-hole 5 in the direction along the X axis is equal to the length of the first through-hole 2 in the direction along the X axis. Also, the length of the second through-hole 5 in the direction along the Y axis is longer than the length of the first through-hole 2 in the direction along the Y axis. Furthermore, the first positioning pin 51b_1 and the second positioning pin 51b_2 in this embodiment have substantially the same shape. Therefore, even if the first positioning pin 51b_1 and the second positioning pin 51b_2 corresponding to one liquid spray head 1 shown in Figure 5 are misaligned in the Y-axis direction due to manufacturing errors, the second through-hole 5 can absorb these manufacturing errors because its longitudinal direction is aligned with the Y-axis in plan view. Note that the plan view shape of the second through-hole 5 is not limited to the examples shown in Figures 15 and 17. Furthermore, the relative dimensions of the first through-hole 2 and the second through-hole 5 in plan view depend on the relative dimensions of the first positioning pin 51b_1 and the second positioning pin 51b_2 in plan view, and are not limited to the examples shown in Figures 15 and 17.

[0073] The third recess 6 is provided on the first surface F1 and is adjacent to the Y1 direction side portion of the second through hole 5 in a plan view. On the other hand, the fourth recess 7 is provided on the second surface F2 and is adjacent to the Y2 direction side portion of the second through hole 5 in a plan view.

[0074] Here, the sum of the depths of the third recess 6 and the fourth recess 7 is greater than the distance between the first surface F1 and the second surface F2 (i.e., the thickness of the flange portion 13h of the holder 13). In other words, the sum of the length of the third contact portion CT3 along the Z-axis and the length of the fourth contact portion CT4 along the Z-axis is less than the distance between the first surface F1 and the second surface F2 (i.e., the thickness of the flange portion 13h of the holder 13). Note that the plan view shape of the third recess 6 is not limited to the example shown in Figure 15 and is arbitrary. Similarly, the plan view shape of the fourth recess 7 is not limited to the example shown in Figure 17 and is arbitrary. Furthermore, the depths of the third recess 6 and the fourth recess 7 are not particularly limited and are arbitrary, but if the depths of the first recess 3 and the third recess 6 are equal to each other, and the depths of the second recess 4 and the fourth recess 7 are equal to each other, there is an advantage in simplifying the manufacturing and design of the holder 13.

[0075] Figure 18 is a plan view illustrating the second virtual cylinder VC2 set in the second positioning section 13e_2 shown in Figure 15. Figure 19 is a cross-sectional view illustrating the second virtual cylinder VC2 set in the second positioning section 13e_2 shown in Figure 15. Figure 20 is a diagram showing the state in which the second positioning pin 51b_2 of the support 51 is inserted into the second positioning section 13e_2 shown in Figure 15. The second virtual cylinder VC2 is a virtual cylinder that is inserted to the deepest position of the second positioning section 13e_2 and has the largest cross-sectional area when viewed in the depth direction (direction along the Z axis) of the second positioning section 13e_2. The second virtual cylinder VC2 is a right cylinder, similar to the first virtual cylinder VC1. In the example shown in Figure 18, the plan view shape of the second virtual cylinder VC2 is elliptical. That is, the bottom surface of the second virtual cylinder VC2 is elliptical. Furthermore, since the plan view shape of the second virtual cylinder VC2 is defined based on the plan view shape of the second positioning unit 13e_2, it may be a perfect circle. In that case, the second virtual cylinder VC2 will be a perfect cylinder.

[0076] As shown in Figure 18, the side surface of the second virtual cylinder VC2 includes three regions divided along the Z-axis: a fourth region RE4, a fifth region RE5, and a sixth region RE6 positioned between the fourth region RE4 and the fifth region RE5. In this embodiment, the fifth region RE5 is positioned in the Z2 direction, which is the direction in which the injection surface FN faces relative to the fourth region RE4, with respect to the direction along the Z-axis.

[0077] The fourth region RE4 is the region that contacts the second positioning part 13e_2 on the Y2 direction side with respect to the second center line LC2, which is the center line of the second virtual cylinder VC2, but does not contact the second positioning part 13e_2 on the Y1 direction side. The fifth region RE5 is the region that does not contact the second positioning part 13e_2 on the Y2 direction side with respect to the second center line LC2, but contacts the second positioning part 13e_2 on the Y1 direction side. The sixth region RE6 is the region that does not contact the second positioning part 13e_2 on both the Y2 and Y1 directions with respect to the second center line LC2. The second center line LC2 is a straight line that passes through the center of the bottom surface of the second virtual cylinder VC2 and extends in a direction along the Z axis.

[0078] Here, the third recess 6 is adjacent to the portion of the fourth region RE4 on the Y1 direction side with respect to the second centerline CL2. The fourth recess 7 is adjacent to the portion of the fifth region RE5 on the Y2 direction side with respect to the second centerline CL2. The third recess 6 and the fourth recess 7 are each adjacent to the sixth region RE6. The second virtual cylinder VC2 extends along the second through hole 5 from the first surface F1 to the second surface F2. In this embodiment, the second virtual cylinder VC2 extends from one end to the other in the Z-axis direction of the second through hole 5. In other words, the deepest position of the second positioning portion 13e_2 is the end of the second through-hole 5 in the Z1 direction (i.e., the position of the first surface F1 on the Z axis) when the second virtual cylinder VC2 is inserted in the Z1 direction from the opening of the second positioning portion 13e_2 formed on the second surface F2, and the deepest position of the second through-hole 5 in the Z2 direction (i.e., the position of the second surface F2 on the Z axis) when the second virtual cylinder VC2 is inserted in the Z2 direction from the opening of the second positioning portion 13e_2 formed on the first surface F1.

[0079] In the example shown in Figure 18, the length of the fourth region RE4 along the Z-axis and the length of the fifth region RE5 along the Z-axis are equal. However, these lengths may be different. However, the lengths of the fourth region RE4 and the fifth region RE5 along the Z-axis are preferably 20% to 45%, more preferably 25% to 40%, and more preferably 28% to 38% of the length of the second virtual cylinder VC2 along the Z-axis. Furthermore, the length of the sixth region RE6 along the Z-axis is preferably 10% to 40%, more preferably 20% to 50%, and more preferably 24% to 44% of the length of the second virtual cylinder VC2 along the Z-axis.

[0080] Thus, the second positioning unit 13e_2 contacts the portion of the fourth region RE4 on the Y2 direction side with respect to the second centerline LC2, without contacting the portions of the fifth region RE5 and the sixth region RE6 on the Y2 direction side with respect to the second centerline LC2, and contacts the portion of the fifth region RE5 on the Y1 direction side with respect to the second centerline LC2, without contacting the portions of the fourth region RE4 and the sixth region RE6 on the Y1 direction side with respect to the second centerline LC2.

[0081] Therefore, the second positioning portion 13e_2 has a third contact portion CT3 that contacts the portion of the fourth region RE4 on the Y2 direction side with respect to the second centerline LC2, and a fourth contact portion CT4 that contacts the portion of the fifth region RE5 on the Y1 direction side with respect to the second centerline LC2. The third contact portion CT3 and the fourth contact portion CT4 each extend continuously in the direction along the Z axis.

[0082] As shown in Figure 17, the second positioning portion 13e_2 has two boundary portions BO_2 that face each other in the direction along the X axis. In a plan view along the Z axis, the boundary portion BO_2 is the boundary between the portion of the thin-walled second positioning portion 13e_2 that defines the bottom surface of the third recess 6 and defines the second through hole 5, and the portion of the thin-walled second positioning portion 13e_2 that defines the bottom surface of the fourth recess 7 and defines the second through hole 5, that is, the boundary between the third contact portion CT3 and the fourth contact portion CT4. Each of the two boundary portions BO_2 has a predetermined length in the direction along the Y axis in a plan view, and therefore extends planarly from the first surface F1 to the second surface F2 along the Z axis. Therefore, the two boundary portions BO_2 are not included in the Y1 direction side and the Y2 direction side of the second virtual cylinder VC2 (in other words, the fourth region RE4, the fifth region RE5, and the sixth region RE6, respectively) with respect to the second centerline LC2.

[0083] As mentioned above, since the length of the second through-hole 5 in the direction along the Y-axis is longer than the length of the second through-hole 5 in the direction along the X-axis, if the plan view shape of the second positioning pin 51b_2 is circular, then, as shown in Figure 20, one or both of the third contact portion CT3 and the fourth contact portion CT4 will not contact the side surface of the second positioning pin 51b_2. In other words, since the length of the second through-hole 5 in the direction along the Y-axis is greater than the maximum length of the second positioning pin 51b_2 in the direction along the Y-axis, the liquid spray head 1 can be easily attached to and detached from the support 51 as shown in Figure 14.

[0084] Furthermore, due to the presence of the fourth region RE4 and the sixth region RE6 as described above, the shortest distance between the third contact portion CT3 and the fourth contact portion CT4 in the cross-section shown in Figure 18 is greater than the maximum length along the Y-axis of the second virtual cylinder VC2. Therefore, attaching and detaching the liquid spray head 1 to the support 51 as shown in Figure 14 above can be made easier. Note that the shortest distance between the third contact portion CT3 and the fourth contact portion CT4 and the maximum length along the Y-axis of the second positioning pin 51b_2 are lengths or distances measured before the second positioning pin 51b_2 is inserted into the second positioning portion 13e_2, that is, when the second positioning pin 51b_2 is not inserted into the second positioning portion 13e_2.

[0085] Furthermore, when the second positioning pin 51b_2 is inserted into the second positioning part 13e_2, the second positioning part 13e_2 contacts both ends of the side surface of the second positioning pin 51b_2 in the direction along the X axis. This contact restricts the movement of the second positioning part 13e_2 in the direction along the X axis relative to the second positioning pin 51b_2. In addition to inserting the first positioning pin 51b_1 into the first positioning part 13e_1 as described above, inserting the second positioning pin 51b_2 into the second positioning part 13e_2 restricts the rotation of the liquid spray head 1 relative to the support 51 in a plane perpendicular to the Z axis.

[0086] As described above, the liquid spraying device 100 comprises a liquid spraying head 1 and a support 51 equipped with a first positioning pin 51b_1. The liquid spraying head 1 is supported by the support 51 having the first positioning pin 51b_1 and sprays ink, which is an example of a "liquid". Here, as mentioned above, the liquid spraying head 1 is equipped with a first positioning part 13e_1 that positions the liquid spraying head 1 relative to the support 51 when the first positioning pin 51b_1 is inserted into it.

[0087] When the first virtual cylinder VC1 is defined as a virtual cylinder that is inserted to the deepest position of the first positioning part 13e_1 and has the largest cross-sectional area when viewed in the first direction (direction along the Z-axis), which is the depth direction of the first positioning part 13e_1, the side surface of the first virtual cylinder VC1 includes three regions divided in the first direction: a first region RE1, a second region RE2, and a third region RE3 located between the first region RE1 and the second region RE2.

[0088] In the first region RE1, with respect to the first centerline LC1, which is the centerline of the first virtual cylinder VC1, the first positioning part 13e_1 is in contact with the first positioning part 13e_1 on the first side (Y2 direction side), which is one side of the second direction (direction along the Y axis) perpendicular to the first direction, but not on the second side (Y1 direction side), which is the other side of the second direction. In the second region RE2, with respect to the first centerline LC1, the first positioning part 13e_1 is not in contact with the first positioning part 13e_1 on the first side (Y2 direction side), but is in contact with the first positioning part 13e_1 on the second side (Y1 direction side). In the third region RE3, with respect to the first centerline LC1, the first positioning part 13e_1 is not in contact with the first positioning part 13e_1 on both the first side (Y2 direction side) and the second side (Y1 direction side).

[0089] In the liquid spray head 1 described above, the first region RE1 contacts the first positioning portion 13e_1 on the first side (Y2 direction side) with respect to the first center line LC1, and the second region RE2 contacts the first positioning portion 13e_1 on the second side (Y1 direction side) with respect to the first center line LC1. Therefore, when the side surface of the first positioning pin 51b_1 corresponds to the side surface of the first virtual cylinder VC1, the first positioning pin 51b_1 is inserted into the first positioning portion 13e_1, thereby positioning the liquid spray head 1 with respect to the support 51.

[0090] Here, we consider a comparative example in which the positioning portion of the liquid spray head into which the support positioning pin is inserted consists only of a through hole extending in the direction along the Z axis. In the comparative example, there is no first recess 3 or second recess 4 like the first positioning portion 13e_1. Therefore, in the comparative example, in order to insert and remove the positioning portion from the positioning pin, it is necessary to slide the liquid spray head relative to the support along the direction in which the positioning pin protrudes. In such a comparative example, the insertion and removal of the positioning portion from the positioning pin is poor. Specifically, the narrower the gap between the positioning pin and the positioning portion when the positioning pin is inserted, the worse the insertion and removal. In particular, when the positioning pin is inserted into the positioning portion by press-fitting, friction occurs between the positioning pin and the positioning portion when inserting and removing them, so strong force is required for insertion and removal. Also, when inserting the positioning pins into the positioning portion, it is necessary to insert two positioning pins into two positioning portions simultaneously, which is not easy. Furthermore, in this case, it is difficult for the operator to see the position of the spray surface of the liquid spray head, so there is a risk of damaging the spray surface by hitting it against the positioning pin or the like.

[0091] On the other hand, in this embodiment, the first region RE1 does not contact the first positioning portion 13e_1 on the second side (Y1 direction side) with respect to the first centerline LC1, the second region RE2 does not contact the first positioning portion 13e_1 on the first side (Y2 direction side) with respect to the first centerline LC1, and the third region RE3 does not contact the first positioning portion 13e_1 on both the first side (Y2 direction side) and the second side (Y1 direction side) with respect to the first centerline LC1. Therefore, the liquid spray head 1 can be attached to and detached from the support 51 by tilting the liquid spray head 1 with respect to the direction in which the first positioning pin 51b_1 extends. In other words, with this configuration, the shortest distance Ds between the first contact portion CT1 and the second contact portion CT2 becomes larger than the maximum dimension Dv of the first virtual cylinder VC1 in the direction along the Y axis (corresponding to the maximum dimension of the first through hole 2 in the direction along the Y axis). Therefore, compared to the comparative example described above, the insertion and removal of the first positioning part 13e_1 from the first positioning pin 51b_1 is superior, thus improving the ease of attaching and detaching the liquid spray head 1 to the support 51. Furthermore, since the first positioning part 13e_1 can be inserted into the first positioning pin 51b_1 before the second positioning part 13_2 is inserted into the second positioning pin 51b_2, it is no longer necessary to insert the two positioning parts into the two positioning pins simultaneously as in the comparative example, thus improving the ease of attaching and detaching the liquid spray head 1 to the support 51. Moreover, when attaching and detaching the liquid spray head 1 to the support 51, tilting the liquid spray head 1 with respect to the direction in which the first positioning pin 51b_1 extends makes it easier for the operator to see the position of the spray surface FN, thus reducing the possibility of the spray surface FN contacting the positioning pin 51b, etc.

[0092] As described above, the liquid spray head 1 includes a holder 13, which is an example of a "first member". The holder 13 has a first positioning portion 13e_1, a first surface F1, and a second surface F2 opposite to the first surface F1. The first positioning portion 13e_1 includes a first through hole 2 that penetrates from the second surface F2 to the first surface F1 in a first direction (Z1 direction), a first recess 3 provided on the first surface F1, and a second recess 4 provided on the second surface F2.

[0093] Here, the first through-hole 2 is positioned between the first recess 3 and the second recess 4 with respect to the second direction (direction along the Y-axis). The first recess 3 is adjacent to the second side (Y1 direction side) of the first region RE1 with respect to the first centerline LC1. The second recess 4 is adjacent to the first side (Y2 direction side) of the second region RE2 with respect to the first centerline LC1. The first recess 3 and the second recess 4 are each adjacent to the third region RE3. The first virtual cylinder VC1 extends from the first surface F1 to the second surface F2 along the first through-hole 2. Therefore, the first through-hole 2, the first recess 3 and the second recess 4 can be formed by machining both surfaces of the first surface F1 and the second surface F2. As a result, the manufacturing of the liquid injection head 1 can be simplified compared to a configuration in which the first positioning portion 13e_1 is a blind hole (bottomed hole).

[0094] Furthermore, as mentioned above, the length of the first region RE1 along the first direction (along the Z-axis) and the length of the second region RE2 along the first direction (along the Z-axis) are equal to each other. Therefore, the rigidity of the first contact portion CT1 and the second contact portion CT2 of the first positioning portion 13e_1 can be made equal, and it is possible to effectively prevent one of the first contact portion CT1 and the second contact portion CT2 from having insufficient rigidity relative to the other.

[0095] Furthermore, as mentioned above, the lengths of the first region RE1 and the second region RE2 along their respective first directions (directions along the Z-axis) are between 20% and 45% of the length of the first virtual cylinder VC1 along its first direction (directions along the Z-axis). Therefore, it is possible to improve the insertability of the first positioning pin 51b_1 into the first positioning portion 13e_1 while increasing the rigidity of the first positioning portion 13e_1.

[0096] Furthermore, as described above, the first positioning portion 13e_1 has a first contact portion CT1 that contacts the first side (Y2 direction side) of the first region RE1 with respect to the first center line LC1, and a second contact portion CT2 that contacts the second side (Y1 direction side) of the second region RE2 with respect to the first center line LC1. Each of the first contact portion CT1 and the second contact portion CT2 extends continuously in the first direction (direction along the Z axis). Therefore, each of the first contact portion CT1 and the second contact portion CT2 can be made to surface contact with the first positioning pin 51b_1 along the first direction (direction along the Z axis). As a result, the liquid spray head 1 can be positioned with high precision relative to the support 51.

[0097] Here, as described above, among the positions in the third direction (along the X-axis) which is perpendicular to the first direction (along the Z-axis) and the second direction (along the Y-axis), at the position where the length of the first virtual cylinder VC1 along the second direction (along the Y-axis) is maximum when viewed in the first direction (along the Z-axis), in the cross section obtained by cutting the first positioning part 13e_1 with a plane that is along both the first direction (along the Z-axis) and the second direction (along the Y-axis), the shortest distance Ds between the first contact part CT1 and the second contact part CT2 is greater than or equal to the maximum length Da of the first positioning pin 51b_1 along the second direction (along the Y-axis). Therefore, when the first positioning part 13e_1 is tilted with respect to the direction in which the first positioning pin 51b_1 extends, the amount of clearance between the first positioning part 13e_1 and the first positioning pin 51b_1 can be reduced compared to the case where the shortest distance Ds is less than the maximum length Da. As a result, the ease of attaching and detaching the liquid spray head 1 to the support 51 can be improved. It is more preferable that the shortest distance Ds is greater than the maximum length Da. This allows for a gap to be created between the first positioning part 13e_1 and the first positioning pin 51b_1 when the first positioning part 13e_1 is tilted with respect to the direction in which the first positioning pin 51b_1 extends, thereby further improving the ease of attaching and detaching the liquid spray head 1 to the support 51.

[0098] Furthermore, as described above, the liquid spray head 1 is equipped with a spray surface FN having multiple nozzles N for spraying ink, and the spray surface FN is positioned on the second side (Y1 direction side) when viewed from the first positioning unit 13e_1. The second region RE2 is positioned in the direction (Z2 direction) that the spray surface FN faces relative to the first region RE1 with respect to the first direction (direction along the Z axis). In other words, the second region RE2 is closer to the protruding surface FP than the first region RE1 with respect to the first direction (direction along the Z axis). This allows the liquid spray head 1 to be attached to and detached from the support 51 so as to tilt the liquid spray head 1 with respect to the direction in which the first positioning pin 51b_1 extends. In addition, it is preferable that the longitudinal direction of the liquid spray head 1 is along the Y axis, as in this embodiment, and in this case, the visibility of the spray surface FN is further improved by combining it with the above configuration. As shown in Figures 4 and 6, if the injection surface FN is not positioned on the first side (Y2 direction side) when viewed from the first positioning unit 13e_1, a portion of the injection surface FN may exist at a position shifted in the direction along the X axis relative to the first positioning unit 13e_1.

[0099] Furthermore, as described above, the liquid spray head 1 is further equipped with a second positioning section 13e_2 into which a second positioning pin 51b_2 provided on the support 51 is inserted, thereby positioning the liquid spray head 1 relative to the support 51. The first positioning section 13e_1 and the second positioning section 13e_2 are arranged side by side in the second direction (along the Y-axis). Therefore, the position and orientation of the liquid spray head 1 relative to the support 51 can be controlled by the first positioning section 13e_1 and the second positioning section 13e_2. In addition, the second positioning pin 51b_2 can be inserted into the second positioning section 13e_2 after the first positioning pin 51b_1 has been inserted into the first positioning section 13e_1. This improves the ease of attaching and detaching the liquid spray head 1 from the support 51. Furthermore, for high-precision positioning, it is preferable that the second direction (along the Y-axis) in which the first positioning section 13e_1 and the second positioning section 13e_2 are aligned coincides with the longitudinal direction (along the Y-axis) of the liquid injection head 1, as shown in Figures 4 and 6.

[0100] Furthermore, as described above, the second positioning portion 13e_2 is positioned on the second side (Y1 direction side) relative to the first positioning portion 13e_1. The second region RE2 is positioned closer to the protruding surface FP on which the first positioning pin 51b_1 of the support 51 protrudes than the first region RE1, with respect to the first direction (direction along the Z axis).

[0101] Furthermore, as described above, when the second virtual cylinder VC2 is defined as a virtual cylinder that is inserted to the deepest position of the second positioning part 13e_2 and has the largest cross-sectional area when viewed in the first direction (direction along the Z axis), the side surface of the second virtual cylinder VC2 includes three regions divided in the first direction (direction along the Z axis): the fourth region RE4, the fifth region RE5, and the sixth region RE6 located between the fourth region RE4 and the fifth region RE5.

[0102] In the fourth region RE4, with respect to the second centerline LC2, which is the centerline of the second virtual cylinder VC2, the second positioning part 13e_2 is in contact with the second positioning part 13e_2 on the first side (Y2 direction side) but not on the second side (Y1 direction side). In the fifth region RE5, with respect to the second centerline LC2, the second positioning part 13e_2 is not in contact with the second positioning part 13e_2 on the first side (Y2 direction side) but is in contact with the second positioning part 13e_2 on the second side (Y1 direction side). In the sixth region RE6, with respect to the second centerline LC2, the second positioning part 13e_2 is not in contact with the second positioning part 13e_2 on both the first side (Y2 direction side) and the second side (Y1 direction side). The direction from the second region RE2 to the first region RE1 is the same as the direction from the fifth region RE5 to the fourth region RE4. Therefore, the insertion and removal of the second positioning part 13e_2 from the second positioning pin 51b_2 is excellent, which improves the ease of attaching and detaching the liquid spray head 1 from the support 51.

[0103] As described above, in the first embodiment, the second positioning portion 13e_2 was composed of a second through hole 5, a third recess 6, and a fourth recess 7. However, the second positioning portion 13e_2 may be composed only of the second through hole 5, thereby omitting the third recess 6 and the fourth recess 7. This is because the second positioning portion 13e_2 is elongated in the direction along the Y axis, and the inclination angle of the spray surface FN when inserting the second positioning pin 51b_2 into the second positioning portion 13e_2 with respect to the spray surface FN when the liquid spray head 1 is supported on the support 51 is smaller than the inclination angle of the spray surface FN when inserting the first positioning pin 51b_1 into the first positioning portion 13e_1. This simplifies the structure of the second positioning portion 13e_2.

[0104] Furthermore, in the first embodiment described above, since the first recess 3 and the second recess 4 are point-symmetric with respect to the center of the first positioning portion 13e_1, the maximum dimension D1_a of the first recess 3 along the Y-axis and the maximum dimension D1_b of the second recess 4 along the Y-axis coincide. Also, this maximum dimension D1_a is equal at any position on the X-axis. The same applies to the maximum dimension D1_b. Furthermore, since the third recess 6 and the fourth recess 7 are point-symmetric with respect to the center of the second positioning portion 13e_2, the maximum dimension D2_a of the third recess 6 along the Y-axis and the maximum dimension D2_b of the fourth recess 7 along the Y-axis coincide. Also, this maximum dimension D2_a is equal at any position on the X-axis. The same applies to the maximum dimension D2_b.

[0105] Furthermore, as mentioned above, since the second positioning section 13e_2 is elongated in the direction along the Y axis, and the inclination angle of the spray surface FN when inserting the second positioning pin 51b_2 into the second positioning section 13e_2 with respect to the spray surface FN when the liquid spray head 1 is supported on the support 51 is smaller than the inclination angle of the spray surface FN when inserting the first positioning pin 51b_1 into the first positioning section 13e_1. Therefore, the maximum dimensions D2_a and D2_b can be made smaller than the maximum dimensions D1_a and D1_b, respectively, and the dimensions of the second positioning section 13e_2 along the Y axis can be reduced.

[0106] As shown in Figure 14, it is preferable that the gap G2 between the side surface of the liquid spray head 1 facing the Y1 direction and the inner circumferential surface of the opening 51a is larger than the gap G1 between the side surface of the liquid spray head 1 facing the Y2 direction and the inner circumferential surface of the opening 51a. Furthermore, it is preferable that the positioning portion 13e is positioned closer to the spray surface FN than to the center of the liquid spray head 1 in the direction along the Z axis. With this configuration, it becomes easier to attach and detach the liquid spray head 1 from the support 51 at an angle with respect to the direction in which the first positioning pin 51b_1 extends.

[0107] 2. Second Embodiment The second embodiment of this disclosure will be described below. The following description will focus on the differences from the first embodiment. The second to sixth embodiments and the first to fourth modifications described later will also be described based on coordinate axes based on a local coordinate system based on the liquid injection head, similar to the first embodiment.

[0108] Figure 21 is a view of the first positioning section 13e_1 of the liquid injection head according to the second embodiment, as seen in the Z2 direction. Figure 22 is a cross-sectional view taken along the EE line in Figure 21. Figure 23 is a view of the first positioning section 13e_1 shown in Figure 21, as seen in the Z1 direction. The first positioning section 13e_1 of this embodiment is configured similarly to the first positioning section 13e_1 of the first embodiment, except that it has a first through hole 2A, a first recess 3A, and a second recess 4A instead of a first through hole 2, a first recess 3, and a second recess 4. Figures 21 to 23 show a part of the holder 13A having a first through hole 2A, a first recess 3A, and a second recess 4A.

[0109] The first through-hole 2A is constructed in the same manner as the first through-hole 2 of the first embodiment, except that its plan view shape is different. The plan view shape of the first through-hole 2A is approximately square. Here, the first through-hole 2A has a pair of sides along the Y-axis and a pair of sides along the X-axis in plan view. Also, the length of the first through-hole 2A in the direction along the Y-axis is equal to the length of the first through-hole 2A in the direction along the X-axis. Approximately square refers to a shape such that the corners of a square are rounded or chamfered. Note that the plan view shape of the first through-hole 2A may be approximately quadrilateral, quadrilateral, or square.

[0110] In Figure 21, the first virtual cylinder VC1 is shown by a dashed line. In this embodiment, the first virtual cylinder VC1 contacts the first positioning part 13e_1 at four points: both ends along the X-axis and both ends along the Y-axis. Specifically, in a plan view, the first region RE1 makes point contact with the first positioning part 13e_1 at the Y2, X1, and X2 sides relative to the first centerline LC1, but does not contact the first positioning part 13e_1 at the Y1 side relative to the first centerline LC1. In a plan view, the second region RE2 makes point contact with the first positioning part 13e_1 at the Y1 side relative to the first centerline LC1, but does not contact the first positioning part 13e_1 at the Y2, X1, and X2 sides relative to the first centerline LC1. In a plan view, the third region RE3 makes point contact with the first positioning portion 13e_1 at the X1 and X2 directions relative to the first centerline LC1, but does not make contact with the first positioning portion 13e_1 at the Y1 and Y2 directions relative to the first centerline LC1.

[0111] Therefore, the first contact portion CT1 and the second contact portion CT2 can be made to make line contact with the first positioning pin 51b_1 shown in the first embodiment along the direction along the Z axis. For this reason, even with the first through hole 2A having such a planar shape, the movement of the first positioning portion 13e_1 relative to the first positioning pin 51b_1 in a plane perpendicular to the Z axis can be restricted. The relationship between the length of the first through hole 2A along the Y axis and the length of the first through hole 2A along the X axis is determined according to the shape of the first positioning pin 51b_1, etc., and is not particularly limited.

[0112] The first recess 3A is constructed similarly to the first recess 3 of the first embodiment, except that its plan view shape is different. The plan view shape of the first recess 3A is approximately quadrilateral. Here, the first recess 3A has a longitudinal shape along the Y1 direction side of the first through hole 2A. In plan view, the first recess 3A has a pair of sides along the Y axis and a pair of sides along the X axis. Furthermore, the length of the first recess 3A in the direction along the Y axis is shorter than the length of the first recess 3A in the direction along the X axis. Also, the length of the first recess 3A in the direction along the X axis is equal to the length of the first through hole 2A in the direction along the X axis. Note that the relative lengths are not particularly limited.

[0113] The second recess 4A is configured similarly to the second recess 4 of the first embodiment, except that its plan view shape is different. The plan view shape of the second recess 4A is a roughly C-shape that follows the three sides of the first through hole 2A other than the side in the Y1 direction.

[0114] The second embodiment described above also makes it possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head relative to the support 51.

[0115] 3. Third Embodiment The following describes a third embodiment of this disclosure. The differences from the first embodiment will be the main focus of this description.

[0116] Figure 24 is a view of the first positioning section 13e_1 of the liquid injection head according to the third embodiment, as seen in the Z2 direction. Figure 25 is a cross-sectional view taken along the FF line in Figure 24. Figure 26 is a view of the first positioning section 13e_1 shown in Figure 24, as seen in the Z1 direction. The first positioning section 13e_1 of this embodiment is configured similarly to the first positioning section 13e_1 of the first embodiment, except that it has a first through hole 2B, a first recess 3B, and a second recess 4B instead of a first through hole 2, a first recess 3, and a second recess 4. Figures 24 to 26 show a part of the holder 13B having the first through hole 2B, the first recess 3B, and the second recess 4B.

[0117] The first through-hole 2B is configured similarly to the first through-hole 2 of the first embodiment, except that its plan view shape is different. The plan view shape of the first through-hole 2B is a combination of a semicircle and a quadrilateral. Here, in plan view, the first through-hole 2B has a pair of sides along the Y axis, one side connecting the ends of the pair of sides along the Y axis in the Y1 direction along the X axis, and a convex arc connecting the ends of the pair of sides along the Y axis in the Y2 direction. In Figure 24, the first virtual cylinder VC1 is shown by a dashed line. Even with the first through-hole 2B having such a plan view shape, it is possible to restrict the movement of the first positioning part 13e_1 relative to the first positioning pin 51b_1 in a plane perpendicular to the Z axis.

[0118] The first recess 3B is configured similarly to the first recess 3 of the first embodiment, except that its plan view shape is different. The plan view shape of the first recess 3B is semicircular. The first positioning portion 13e_1 has a first contact portion CT1 that contacts the portion of the first region RE1 on the Y2 direction side with respect to the first center line LC1.

[0119] The second recess 4B is configured similarly to the second recess 4 of the first embodiment, except that its plan view shape is different. The plan view shape of the second recess 4B is a substantially C-shape that follows the periphery of the first through hole 2B, excluding the side in the Y1 direction. The first positioning portion 13e_1 has a second contact portion CT2 that contacts the portion of the second region RE2 on the Y1 direction side with respect to the first center line LC1.

[0120] The third embodiment described above also makes it possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head relative to the support 51.

[0121] 4. Fourth Embodiment The following describes a fourth embodiment of this disclosure. The following description will focus on the differences from the first embodiment.

[0122] Figure 27 is a view of the first positioning portion 13e_1 of the liquid injection head according to the fourth embodiment, as seen in the Z2 direction. Figures 28 and 29 are cross-sectional views taken along the GG line in Figure 27. The first positioning portion 13e_1 of this embodiment is configured similarly to the first positioning portion 13e_1 of the first embodiment, except that it has a first recess 3C and a second recess 4C instead of the first recess 3 and the second recess 4. Figures 27 to 29 show a part of the holder 13C having a first through hole 2, a first recess 3C and a second recess 4C.

[0123] The first recess 3C is constructed in the same manner as the first recess 3 of the first embodiment, except that a chamfer is applied near the boundary with the first through hole 2. Similarly, the second recess 4C is constructed in the same manner as the second recess 4 of the first embodiment, except that a chamfer is applied near the boundary with the first through hole 2. In the figures, these chamfers are C-chamfers, but the diagram does not limit this to C-chamfers; for example, these chamfers may be R-chamfers.

[0124] In this embodiment, the first positioning portion 13e_1 includes a first contact portion CT1 that contacts the first side (Y2 direction side) of the first region RE1 with respect to the first center line LC1, and a first inclined surface FL1 that is continuous with the first contact portion CT1 and extends in a direction that intersects but is not perpendicular to the first direction (direction along the Z axis). Therefore, when the first positioning portion 13e_1 is tilted with respect to the direction in which the first positioning pin 51b_1 extends, the gap between the first positioning portion 13e_1 and the first positioning pin 51b_1 can be made larger compared to a configuration without the first inclined surface FL1. As a result, the ease of attaching and detaching the liquid spray head to the support 51 can be improved.

[0125] Here, the first positioning portion 13e_1 has a second contact portion CT2 that contacts the second side (Y1 direction side) of the second region RE2 with respect to the first center line LC1, and a second inclined surface FL2 that is continuous with the second contact portion CT2 and extends in a direction that intersects but is not perpendicular to the first direction (direction along the Z axis). The first inclined surface FL1 and the second inclined surface FL2 are parallel to each other. Such a first inclined surface FL1 and second inclined surface FL2 have the advantage of making it easier to secure the thickness of the material constituting the first positioning portion 13e_1. Note that the first positioning portion 13e_1 may be provided with only one of the first inclined surface FL1 and the second inclined surface FL2.

[0126] Furthermore, the first inclined surface FL1 and the second inclined surface FL2 have overlapping portions when viewed in the second direction (along the Y-axis). Such a configuration of the first inclined surface FL1 and the second inclined surface FL2 has the advantage of making it easier to secure the thickness of the members constituting the first positioning portion 13e_1. In this embodiment, a part of the first inclined surface FL1 and a part of the second inclined surface FL2 overlap when viewed in the second direction (along the Y-axis), but the entirety of the first inclined surface FL1 and the entirety of the second inclined surface FL2 may also overlap when viewed in the second direction (along the Y-axis). Note that the first inclined surface FL1 and the second inclined surface FL2 do not have to overlap when viewed in the second direction (along the Y-axis).

[0127] Furthermore, it is preferable that the length of the first inclined surface FL1 and the length of the second inclined surface FL2 are the same. Moreover, as shown in Figure 28, it is preferable that no side walls defining the second recess 4C of the first positioning portion 13e_1 are provided on the extension line of the first inclined surface FL1 that extends along the first inclined surface FL1. Similarly, it is preferable that no side walls defining the first recess 3C of the first positioning portion 13e_1 are provided on the extension line of the second inclined surface FL2.

[0128] Furthermore, it is preferable that the angle θ1 formed by the first inclined plane FL1 and the line along the Z-axis is equal to the angle θ2 formed by the second inclined plane FL2 and the line along the Z-axis. Note that, as shown in Figure 29, the angle θ1 can be rephrased as the rotation angle obtained by rotating the first inclined plane FL1 around the boundary between the first inclined plane FL1 and the first contact portion CT1 until it is parallel to the Z-axis, and is therefore an acute angle. The angle θ2 is defined similarly.

[0129] Furthermore, among the positions in the third direction (along the X-axis) which is perpendicular to the first direction (along the Z-axis) and the second direction (along the Y-axis), at the position where the length of the first virtual cylinder VC1 along the second direction (along the Y-axis) is maximized when viewed in the first direction (along the Z-axis), in the cross-section obtained by cutting the first positioning part 13e_1 with a plane parallel to both the first direction (along the Z-axis) and the second direction (along the Y-axis), the angle θ between the line segment LS that connects the first contact part CT1 and the second contact part CT2 in the shortest distance and the first inclined plane FL1 S The angle is 90 degrees or more. Therefore, when the first positioning portion 13e_1 is tilted with respect to the direction in which the first positioning pin 51b_1 extends, the gap between the first positioning portion 13e_1 and the first positioning pin 51b_1 can be made larger compared to a configuration in which the angle is less than 90 degrees. As a result, the ease of attaching and detaching the liquid spray head to the support 51 can be improved. In this embodiment, the line segment LS is a line segment connecting the boundary portion between the first inclined surface FL1 and the first contact portion CT1, and the boundary portion between the second inclined surface FL2 and the second contact portion CT2.

[0130] The angle θ S This can be rephrased as the angle of rotation obtained by rotating the first inclined surface FL1 around the boundary between the first inclined surface FL1 and the first contact portion CT1 as the axis of rotation until the first inclined surface FL1 becomes parallel to the line segment LS. S It is preferable that this angle is approximately 90 degrees. This ensures the rigidity of the first positioning portion 13e_1. Note that approximately 90 degrees refers to 90 degrees ± 2 degrees, taking into account manufacturing tolerances. Also, approximately 90 degrees includes 90 degrees.

[0131] Figure 30 is a view of the second positioning section 13e_2 of the liquid injection head according to the fourth embodiment, as seen in the Z2 direction. Figures 31 and 32 are cross-sectional views taken along the line HH in Figure 30. The second positioning section 13e_2 of this embodiment is configured similarly to the second positioning section 13e_2 of the first embodiment, except that it has a third recess 6C and a fourth recess 7C instead of a third recess 6 and a fourth recess 7. Figures 30 and 31 show a part of the holder 13C having a second through hole 5, a third recess 6C and a fourth recess 7C.

[0132] The third recess 6C is constructed in the same manner as the third recess 6 of the first embodiment, except that a chamfer is applied near the boundary with the second through hole 5. Similarly, the fourth recess 7C is constructed in the same manner as the fourth recess 7 of the first embodiment, except that a chamfer is applied near the boundary with the second through hole 5. In the figures, these chamfers are C-chamfers, but the diagram does not limit this to C-chamfers; for example, these chamfers may be R-chamfers.

[0133] The second positioning portion 13e_2 includes a third contact portion CT3 that contacts the first side (Y2 direction side) of the fourth region RE4 with respect to the second centerline LC2, a fourth contact portion CT4 that contacts the second side (Y1 direction side) of the fifth region RE5 with respect to the second centerline LC2, a third inclined surface FL3 that is continuous with the third contact portion CT3 and extends in a direction that intersects the first direction (direction along the Z axis) without being perpendicular to it, and a fourth inclined surface FL4 that is continuous with the fourth contact portion CT4 and extends in a direction that intersects the first direction (direction along the Z axis) without being perpendicular to it.

[0134] Furthermore, it is preferable that the angle θ3 formed by the third inclined plane FL3 and the line along the Z axis is equal to the angle θ4 formed by the fourth inclined plane FL4 and the line along the Z axis. It is also preferable that the angles θ3 and θ4 are smaller than the angles θ1 and θ2, respectively. This ensures the rigidity of the second positioning part 13e_2 without impairing the ease of insertion and removal of the second positioning part 13e_2 from the second positioning pin 51b_2. The angles θ3 and θ4 are defined in the same way as the angle θ1.

[0135] The fourth embodiment described above also makes it possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head relative to the support 51.

[0136] 5. Fifth Embodiment The fifth embodiment of this disclosure will be described below. The differences from the first embodiment will be the main focus of this description.

[0137] Figure 33 is a cross-sectional view showing the state in which the first positioning pin 51b_1 is inserted into the first positioning portion 13e_1 of the liquid injection head according to the fifth embodiment. The first positioning portion 13e_1 of this embodiment is configured the same as the first positioning portion 13e_1 of the first embodiment, except that it is composed of a bottomed hole 8 having a bottom wall FB. Figure 33 shows a part of the holder 13D having the bottomed hole 8.

[0138] The bottomed hole 8 is a hole with a shape that combines a substantially cylindrical bottomed hole with the first center line LC1 as its central axis and a substantially cylindrical bottomed hole with axis LL inclined around the X axis with respect to the first center line LC1. The bottomed hole 8 is formed on the hole-forming surface FO of the support 51 of the holder 13D, facing the protruding surface FP. Here, the first center line LC1 and axis LL intersect, and their intersection point is located within the bottomed hole 8. In the example shown in Figure 33, the depths of these bottomed holes are equal to each other. Also, the cross-sectional shapes of these bottomed holes are equal to each other. However, the depths of these bottomed holes may differ from each other, and the cross-sectional shapes of these bottomed holes may differ from each other. The bottom wall FB of the substantially cylindrical bottomed hole with the first center line LC1 as its central axis includes curved surfaces and planes. Also, the bottom wall FB of the substantially cylindrical bottomed hole with axis LL as its central axis also includes curved surfaces and planes. In other words, the bottom wall FB of the bottomed hole 8 in this embodiment includes curved surfaces and flat surfaces, as shown in Figure 33.

[0139] Thus, if the shape of the first positioning portion 13e_1 is a bottomed hole rather than a through hole, and the bottom wall FB includes a curved surface, or if the area of ​​the bottom wall FB in a plan view along the Z-axis is smaller than the cross-sectional area of ​​the first positioning pin 51b_1 in a plan view along the Z-axis, then the bottom wall FB is not provided in the area of ​​the first positioning portion 13e_1 into which the first positioning pin 51b_1 is inserted. For this reason, it is not desirable to interpret such a bottom wall FB as the deepest position of the first positioning portion 13e_1 into which the first virtual cylinder VC1 is inserted. Therefore, in such cases, it is desirable that the deepest position of the first positioning portion 13e_1 into which the first virtual cylinder VC1 is inserted be the tip of the first positioning pin 51b_1 (the end of the first positioning pin 51b_1 in the Z1 direction).

[0140] As described above, if we define the deepest position of the first positioning section 13e_1 into which the first virtual cylinder VC1 is inserted, then the first region RE1 contacts the first positioning section 13e_1 on the Y2 direction side with respect to the first center line LC1, but does not contact the first positioning section 13e_1 on the Y1 direction side. The second region RE2 does not contact the first positioning section 13e_1 on the Y2 direction side with respect to the first center line LC1, but contacts the first positioning section 13e_1 on the Y1 direction side. The third region RE3 does not contact the first positioning section 13e_1 on both the Y2 and Y1 directions with respect to the first center line LC1. In this way, the first positioning section 13e_1 can be obtained by forming a bottomed hole 8 to the depth required for insertion of the first positioning pin 51b_1. As a result, there is an advantage in that the rigidity of the holder 13D can be easily increased.

[0141] Furthermore, the wall surface of the bottomed hole 8 is provided with a first contact portion CT1 that contacts the first region RE1, a second contact portion CT2 that contacts the second region RE2, a first inclined surface FL1 that is continuous with the first contact portion CT1 and extends in a direction that intersects but is not perpendicular to the direction along the Z axis, and a second inclined surface FL2 that is continuous with the second contact portion CT2 and extends in a direction that intersects but is not perpendicular to the direction along the Z axis.

[0142] The fifth embodiment described above also makes it possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head relative to the support 51.

[0143] 6. Sixth Embodiment The sixth embodiment of this disclosure will be described below. The following description will focus on the differences from the first embodiment.

[0144] Figure 34 is a cross-sectional view showing the state in which the first positioning pin 51b_1 is inserted into the first positioning portion 13e_1 of the liquid injection head according to the sixth embodiment. The first positioning portion 13e_1 of this embodiment is configured the same as the first positioning portion 13e_1 of the first embodiment, except that it is composed of a bottomed hole 8A having a bottom wall FB. Figure 34 shows a part of the holder 13D' having the bottomed hole 8A. In Figure 34, the first virtual cylinder VC1 is shown with diamond-shaped hatching.

[0145] The bottomed hole 8A is formed on the hole-forming surface FO of the support 51 of the holder 13D, facing the protruding surface FP. The bottom wall FB of this embodiment extends along the X-Y plane perpendicular to the Z axis. The bottomed hole 8A has a recess formed in the hole-forming surface FO, a cylindrical hole recessed to the bottom wall FB, and a space that is not visible when the hole-forming surface FO is viewed in the Z1 direction. With respect to the direction along the Y axis, the cylindrical hole is located between the recess and the space that is not visible. Also, when viewed in the direction along the Y axis, the recess and the space that is not visible have overlapping portions.

[0146] The first region RE1 of the first virtual cylinder VC1 contacts the first contact portion CT1 of the first positioning portion 13e_1 in the Y2 direction relative to the first centerline LC1, but does not contact the first positioning portion 13e_1 in the Y1 direction. The second region RE2 contacts the second contact portion CT2 of the first positioning portion 13e_1 in the Y1 direction relative to the first centerline LC1, but does not contact the first positioning portion 13e_1 in the Y2 direction. The third region RE3 does not contact the first positioning portion 13e_1 in both the Y2 and Y1 directions relative to the first centerline LC1.

[0147] The liquid injection head of this embodiment includes a holder 13D', which is an example of a "first member," and the holder 13D' has a bottomed hole 8A with a bottom wall FB as the first positioning part 13e_1. The deepest position into which the first virtual cylinder VC1 is inserted is the bottom wall FB.

[0148] The sixth embodiment described above also makes it possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head relative to the support 51.

[0149] In the first embodiment, the first through-hole 2 is a through-hole into which the first positioning pin 51b_1 is inserted. Therefore, if, for example, the through-hole is formed in the bottom wall FB of the bottomed hole 8A at a position where the first positioning pin 51b_1 cannot be inserted, or if the through-hole is formed in the bottom wall FB so small that the first positioning pin 51b_1 cannot be inserted, then such through-holes are not considered part of the first through-hole 2. For this reason, if a through-hole different from the first through-hole 2 is formed in the bottom wall FB, it is desirable that the deepest position into which the first virtual cylinder VC1 is inserted is the bottom wall FB.

[0150] 6. Variations The forms exemplified above can be modified in various ways. Specific examples of modifications that can be applied to the aforementioned forms are given below. Two or more forms arbitrarily selected from the following examples can be merged as appropriate, provided they do not contradict each other.

[0151] 6-1. Variation 1 Figure 35 is a view of the first positioning portion 13e_1 of the liquid injection head according to the modified example 1, as seen in the Z2 direction. Figure 36 is a cross-sectional view taken along the JJ line in Figure 35. Figure 37 is a view of the first positioning portion 13e_1 shown in Figure 35, as seen in the Z1 direction. The first positioning portion 13e_1 of this modified example is configured similarly to the first positioning portion 13e_1 of the fourth embodiment, except that it has a first through hole 2E, a first recess 3E, and a second recess 4E instead of a first through hole 2, a first recess 3C, and a second recess 4C. Figures 35 to 37 show a part of the holder 13E having the first through hole 2E, the first recess 3E, and the second recess 4E.

[0152] Specifically, this modified example differs from the fourth embodiment in that the shape of the second recess 4E is modified so that the first inclined surface FL1 extends from the connection point between the first contact portion CT1 and the first inclined surface FL1 to the second surface F2. Similarly, this modified example differs from the fourth embodiment in that the shape of the first recess 3E is modified so that the second inclined surface FL2 extends from the connection point between the second contact portion CT2 and the second inclined surface FL2 to the first surface F1.

[0153] Here, it is preferable that the length of the first inclined surface FL1 along the first direction (direction along the Z axis) is greater than or equal to the sum of the lengths of the second region RE2 and the third region RE3 along the first direction (direction along the Z axis). In this embodiment, the length of the first inclined surface FL1 along the first direction (direction along the Z axis) is the same as the sum of the lengths of the second region RE2 and the third region RE3 along the first direction (direction along the Z axis). This has the advantage of making it easier to secure the wall thickness of the members constituting the first positioning portion 13e_1. Furthermore, the first inclined surface FL1 can be used as a guide for inserting the first positioning pin 51b_1 into the first positioning portion 13e_1, and as a result, the ease of attaching and detaching the liquid spray head to and from the support 51 can be improved. Similarly, it is preferable that the length of the second inclined surface FL2 along the first direction (direction along the Z axis) is greater than or equal to the sum of the lengths of the first region RE1 and the third region RE3 along the first direction (direction along the Z axis).

[0154] Even with the above modification 1, it is possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid spray head relative to the support 51. 6-2. Variation 2 Figure 38 is a plan view of the liquid spray head 1G according to Modification 2. In Figure 38, the liquid spray head 1G is schematically shown. The liquid spray head 1G is configured the same as the liquid spray head 1 of the first embodiment described above, except that it has a holder 13G instead of a holder 13.

[0155] The holder 13G has a pair of flange portions 13h that protrude in the Y1 and Y2 directions relative to the injection surface FN in a plan view. Each of the pair of flange portions 13h extends in a direction along the X axis, and the Z2-facing surface of each of the pair of flange portions 13h contacts the protruding surface FP, which is the Z1-facing surface of the support 51. Of the pair of flange portions 13h, the flange portion 13h_1 that protrudes from the injection surface FN in the Y2 direction is provided with a first positioning portion 13e_1 and a second positioning portion 13e_2, while the flange portion 13h_2 that protrudes from the injection surface FN in the Y1 direction is not provided with the first positioning portion 13e_1 and the second positioning portion 13e_2. Although not shown, the pair of flange portions 13h are appropriately provided with a plurality of holes 13f.

[0156] In Modification 2, the first positioning part 13e_1 and the second positioning part 13e_2 are aligned along the X-axis. Specifically, the first positioning part 13e_1 is provided near the end of the flange part 13h_1 in the X2 direction, and the second positioning part 13e_2 is provided near the end of the flange part 13h in the X1 direction. The direction in which the first positioning part 13e_1 and the second positioning part 13e_2 are aligned is perpendicular to the direction along the Z-axis and intersects (orthogonal in this modification) with the direction along the Y-axis. The direction along the X-axis in this modification is an example of a "third direction". In addition, the injection surface FN is elongated in the direction along the X-axis, which is the direction in which the first positioning part 13e_1 and the second positioning part 13e_2 are aligned. Incidentally, for example, if a first positioning portion 13e_1 is provided near the end of flange portion 13h_1 in the X2 direction, and a second positioning portion 13e_2 is provided near the end of flange portion 13h_2 in the X1 direction, then the direction in which the first positioning portion 13e_1 and the second positioning portion 13e_2 are aligned will be perpendicular to the direction along the Z axis and intersect with the direction along the Y axis without being perpendicular.

[0157] Here, the first positioning section 13e_1 and the second positioning section 13e_2 of the modified example 2 will be described. Figure 39 is a view of the first positioning section 13e_1 of the liquid spray head 1G according to the modified example 2, as seen in the Z2 direction. Figure 40 is a cross-sectional view taken along the KK line in Figure 39. Figure 41 is a view of the second positioning section 13e_2 of the liquid spray head according to the modified example 2, as seen in the Z2 direction. Figure 42 is a cross-sectional view taken along the LL line in Figure 41. The first positioning section 13e_1 of this modified example is configured similarly to the first positioning section 13e_1 of the first embodiment, except that its orientation around the Z axis is different. The second positioning section 13e_2 of this modified example is configured similarly to the second positioning section 13e_2 of the first embodiment, except that its orientation around the Z axis is different and its length in the directions along the X and Y axes is different.

[0158] In Modification 2, the first positioning portion 13e_1 is configured in the same way as the first positioning portion 13e_1 of the first embodiment, rotated 90° counterclockwise around the first center line LC1 when viewed in the Z2 direction. In Modification 2, the second positioning portion 13e_2 is configured in the same way as the second positioning portion 13e_2 of the first embodiment, rotated 90° counterclockwise around the second center line LC2 when viewed in the Z2 direction, and with the longitudinal direction of the second through hole 5 aligned with the X axis.

[0159] The first positioning part 13e_1 of the modified example 2 has a first contact part CT1 that contacts the Y2 direction side of the first region RE1 with respect to the first center line LC1, and a second contact part CT2 that contacts the Y1 direction side of the second region RE2 with respect to the first center line LC1. The first positioning part 13e_1 does not contact the Y1 direction side of the first region RE1 with respect to the first center line LC1, does not contact the Y2 direction side of the second region RE2 with respect to the first center line LC1, and does not contact both the Y1 direction side and the Y2 direction side of the third region RE3. Here, the direction along the Y axis is an example of the "second direction", the Y2 direction side is an example of the "first side" in this modification, and the Y1 direction side is an example of the "second side" in this modified example. The direction along the Z axis is also an example of the "first direction".

[0160] The second positioning portion 13e_2 of the modified example 2 has a third contact portion CT3 that contacts the Y2 direction side of the fourth region RE4 with respect to the second centerline LC2, and a fourth contact portion CT4 that contacts the Y1 direction side of the fifth region RE5 with respect to the second centerline LC2. The second positioning portion 13e_2 does not contact the Y1 direction side of the fourth region RE4 with respect to the second centerline LC2, does not contact the Y2 direction side of the fifth region RE5 with respect to the second centerline LC2, and does not contact both the Y1 direction side and the Y2 direction side of the sixth region RE6.

[0161] Similar to the first embodiment, the injection surface FN of the modified liquid injection head 1G is positioned on the Y1 side when viewed from the first positioning unit 13e_1. The second region RE2 is positioned in the Z2 direction relative to the first region RE1, with respect to the Z axis, which is the direction in which the injection surface FN faces. In other words, the second region RE2 is closer to the protruding surface FP than the first region RE1 with respect to the Z axis. The injection surface FN is not positioned on the Y2 side when viewed from the first positioning unit 13e_1.

[0162] Furthermore, the injection surface FN of the liquid injection head 1G is positioned on the Y1 direction side when viewed from the second positioning unit 13e_2. Also, the fifth region RE5 is positioned in the Z2 direction, which is the direction in which the injection surface FN faces relative to the fourth region RE4, with respect to the Z axis. In other words, the fifth region RE5 is closer to the protruding surface FP than the fourth region RE4 with respect to the Z axis. Note that the injection surface FN is not positioned on the Y2 direction side when viewed from the second positioning unit 13e_2. To put it another way, the direction from the second region RE2 to the first region RE1 (Z1 direction) is the same as the direction from the fifth region RE5 to the fourth region RE4 (Z1 direction).

[0163] Even with the above modified example 2, it is possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid spray head 1G relative to the support 51. In the above embodiments, the liquid spray head is attached to and detached from the support 51 by tilting it around an axis along the short direction of the liquid spray head, which has a longitudinal shape in a plan view. However, in modified example 2, the liquid spray head 1G can be attached to and detached from the support 51 by tilting it around the X-axis along the longitudinal direction of the liquid spray head 1G.

[0164] 6-3. Variation 3 Figure 43 is a plan view of the liquid spray head 1H according to the third modification. The liquid spray head 1H is configured similarly to the liquid spray head 1 of the first embodiment described above, except that it has a holder 13H instead of a holder 13.

[0165] In a plan view, the holder 13H has a pair of flange portions 13h that protrude in the X1 and X2 directions relative to the injection surface FN, near the end of the injection surface FN in the Y2 direction. The Z2-facing surfaces of each of the pair of flange portions 13h contact the protruding surface FP, which is the Z1-facing surface of the support 51. Of the pair of flange portions 13h, the flange portion 13h that protrudes in the X2 direction relative to the injection surface FN is provided with a first positioning portion 13e_1, and the flange portion 13h that protrudes in the X1 direction relative to the injection surface FN is provided with a second positioning portion 13e_2. Although not shown, the pair of flange portions 13h are appropriately provided with a plurality of holes 13f.

[0166] In Modification 3, the first positioning part 13e_1 and the second positioning part 13e_2 are aligned along the X-axis. The direction in which the first positioning part 13e_1 and the second positioning part 13e_2 are aligned is perpendicular to the direction along the Z-axis and intersects (orthogonal in this modification) with the direction along the Y-axis. The direction along the X-axis in this modification is an example of a "third direction". In addition, the injection surface FN is elongated in the direction along the X-axis, which is the direction in which the first positioning part 13e_1 and the second positioning part 13e_2 are aligned.

[0167] Here, the first positioning section 13e_1 of Modification 3 is configured in the same way as the first positioning section 13e_1 of Modification 2 described above. Also, the second positioning section 13e_2 of Modification 3 is configured in the same way as the second positioning section 13e_2 of Modification 2 described above. In other words, the first positioning section 13e_1 of this Modification is the same as the first positioning section 13e_1 of Modification 2 shown in Figures 39 and 40, except for the difference in the position of the first positioning section 13e_1 with respect to the injection surface FN. Specifically, the first region RE1, the third region RE3, and the second region RE2 of this Modification are arranged in this order in the Z2 direction, and the first contact section CT1 is located in the Y2 direction with respect to the second contact section CT2. Also, the second positioning section 13e_2 of this Modification is the same as the second positioning section 13e_2 of Modification 2 shown in Figures 41 and 42, except for the difference in the position of the second positioning section 13e_2 with respect to the injection surface FN. Specifically, in this modified example, the fourth region RE4, the sixth region RE6, and the fifth region RE5 are aligned in the Z2 direction in this order, and the third contact portion CT3 is located in the Y2 direction relative to the fourth contact portion CT4.

[0168] The injection surface FN of the modified liquid injection head 1H differs from Modification 2 in that it is positioned on the X1 side when viewed from the first positioning unit 13e_1 and on the X2 side when viewed from the second positioning unit 13e_2. Furthermore, the second region RE2 is positioned in the Z2 direction, which is the direction in which the injection surface FN faces relative to the first region RE1 with respect to the Z axis, and the fifth region RE5 is positioned in the Z2 direction, which is the direction in which the injection surface FN faces relative to the fourth region RE4 with respect to the Z axis. In other words, the second region RE2 is closer to the protruding surface FP than the first region RE1 with respect to the Z axis, and the fifth region RE5 is closer to the protruding surface FP than the fourth region RE4 with respect to the Z axis. To put it another way, the direction from the second region RE2 to the first region RE1 (Z1 direction) is the same as the direction from the fifth region RE5 to the fourth region RE4 (Z1 direction). Furthermore, the positions of the first positioning unit 13e_1 and the second positioning unit 13e_2 on the Y-axis are located in the Y2 direction rather than the center of the injection surface FN in the direction along the Y-axis, specifically at the same position as the end of the injection surface FN in the Y2 direction. Note that the injection surface FN is not positioned on the Y1 direction side or the Y2 direction side when viewed from the first positioning unit 13e_1, and the injection surface FN is not positioned on the Y1 direction side or the Y2 direction side when viewed from the second positioning unit 13e_2.

[0169] Even with the above modification 3, it is possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head 1H relative to the support 51.

[0170] 6-4. Variation 4 Figure 44 is a schematic diagram illustrating the attachment and detachment of the liquid spray head 1I to the support 51I according to Modification 4. In the above embodiments, the first positioning pin 51b_1 and the second positioning pin 51b_2 are provided on the protruding surface FP of the support 51, which is the surface facing the opposite direction (Z1 direction) to the direction facing the spray surface FN (Z2 direction). However, in Modification 4, the first positioning pin 51b_1 and the second positioning pin 51b_2 are provided on the surface of the support 51I that faces the same direction as the direction facing the spray surface FN. The liquid spray head 1I is then attached to the support 51I such that the surface opposite to the spray surface FN is inserted into the opening 51a of the support 51I.

[0171] Figure 45 is a cross-sectional view of the first positioning portion 13e_1 according to Modification 4, and corresponds to Figure 11 of the first embodiment. Figure 46 is a cross-sectional view of the second positioning portion 13e_2 according to Modification 4, and corresponds to Figure 19 of the first embodiment. The flange portion 13h of the holder 13I of the liquid injection head 1I of Modification 4 is provided with the first positioning portion 13e_1 and the second positioning portion 13e_2. The first surface F1 of the flange portion 13h of this modification faces the same Z2 direction as the injection surface FN. The second surface F2 of the flange portion 13h faces the Z1 direction, which is the opposite direction to the direction of the injection surface FN. The second surface F2 is the surface facing the protruding surface FP of the support 51I.

[0172] As will be described in detail later, the first positioning unit 13e_1 of Modification 4 has the same configuration as the first positioning unit 13e_1 of the first embodiment, except that the second region RE2, the third region RE3, and the first region RE1 are arranged in this order in the direction (Z2 direction) towards the injection surface FN. The second positioning unit 13e_2 of Modification 4 also has the same configuration as the second positioning unit 13e_2 of the first embodiment, except that the fifth region RE5, the sixth region RE6, and the fourth region RE4 are arranged in this order in the direction (Z2 direction) towards the injection surface FN.

[0173] The first positioning portion 13e_1 has a first through hole 2I that penetrates the flange portion 13h in a direction along the Z axis, a first recess 3I formed on the first surface F1, and a second recess 4I formed on the second surface F2. The second recess 4I, the first through hole 2I, and the first recess 3I are aligned in this order in the Y1 direction. In addition, the side surface of the first virtual cylinder VC1 set in the first positioning portion 13e_1 of this modified example includes three regions divided in a first direction (direction along the Z axis): a first region RE1, a second region RE2, and a third region RE3 positioned between the first region RE1 and the second region RE2. The second region RE2, the third region RE3, and the first region RE1 are aligned in this order in the direction the injection surface FN faces (Z2 direction). Although not shown in the figures, similar to the first embodiment, the shape of the first virtual cylinder VC1 in plan view is a perfect circle.

[0174] The first region RE1 contacts the first contact portion CT1 of the first positioning portion 13e_1 in the first side (Y2 direction side) in the second direction (direction along the Y axis) with respect to the first centerline LC1, but does not contact the first positioning portion 13e_1 in the second side (Y1 direction side) in the second direction (direction along the Y axis) with respect to the first centerline LC1. The second region RE2 contacts the second contact portion CT2 of the first positioning portion 13e_1 in the second side (Y1 direction side) in the second direction (direction along the Y axis) with respect to the first centerline LC1, but does not contact the first positioning portion 13e_1 in the first side (Y2 direction side) in the second direction (direction along the Y axis) with respect to the first centerline LC1. The third region RE3 does not contact the first positioning portion 13e_1 in both the second side (Y1 direction side) and the first side (Y2 direction side) with respect to the first centerline LC1.

[0175] The second positioning section 13e_2 has a second through hole 5I that penetrates the flange section 13h in a direction along the Z axis, a third recess 6I formed on the first surface F1, and a fourth recess 7I formed on the second surface F2. The fourth recess 7I, the second through hole 5I, and the third recess 6I are aligned in this order in the Y1 direction. Furthermore, the side surface of the second virtual cylinder VC2 set in the second positioning section 13e_2 of this modified example includes three regions divided in the first direction (direction along the Z axis): a fourth region RE4, a fifth region RE5, and a sixth region RE6 positioned between the fourth region RE4 and the fifth region RE5. The fifth region RE5, the sixth region RE6, and the fourth region RE4 are aligned in this order in the direction the injection surface FN faces (Z2 direction). Although not shown in the illustration, similar to the first embodiment, the shape of the second virtual cylinder VC2 in plan view is an ellipse with its longitudinal direction along the Y-axis.

[0176] The fourth region RE4 contacts the third contact portion CT3 of the second positioning portion 13e_2 on the first side (Y2 direction side) with respect to the second centerline LC2, but does not contact the second positioning portion 13e_2 on the second side (Y1 direction side) with respect to the second centerline LC2. The fifth region RE5 contacts the fourth contact portion CT4 of the second positioning portion 13e_2 on the second side (Y1 direction side) with respect to the second centerline LC2, but does not contact the second positioning portion 13e_2 on the first side (Y2 direction side) with respect to the second centerline LC2. The sixth region RE6 does not contact the second positioning portion 13e_2 on both the second side (Y1 direction side) and the first side (Y2 direction side) with respect to the second centerline LC2.

[0177] Here, as shown in Figure 44, the injection surface FN is positioned on the second side (Y1 direction side) when viewed from the first positioning unit 13e_1. The first region RE1 is positioned in the direction (Z2 direction) relative to the second region RE2 with respect to the first direction (direction along the Z axis), where the injection surface FN is facing. In other words, the second region RE2 is positioned closer to the protruding surface FP of the support 51I than the first region RE1 with respect to the first direction (direction along the Z axis). Similarly, the injection surface FN is positioned on the first side (Y2 direction side) when viewed from the second positioning unit 13e_2, and the fourth region RE4 is positioned in the direction (Z2 direction) relative to the fifth region RE5 with respect to the first direction (direction along the Z axis), where the injection surface FN is facing. In other words, the fifth region RE5 is positioned closer to the protruding surface FP of the support 51I than the fourth region RE4 with respect to the first direction (direction along the Z axis). Even with the above modification 5, it is possible to improve the ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head 1I relative to the support 51I.

[0178] 6-5. Variation 5 Figure 47 is a schematic diagram illustrating the attachment and detachment of the liquid spray head 1J to the support 51J according to Modification 5. The liquid spray head 1J is configured similarly to the liquid spray head 1 of the first embodiment, except that it has a first positioning pin 13g_1 and a second positioning pin 13g_2 instead of a first positioning part 13e_1 and a second positioning part 13e_2. The support 51J is configured similarly to the support 51 of the first embodiment, except that it has a first positioning part 51d_1 and a second positioning part 51d_2 instead of a first positioning pin 51b_1 and a second positioning pin 51b_2.

[0179] In Modification Example 5, the X, Y, and Z axes are coordinate axes of a local coordinate system based on the support 51J, which is arranged in three dimensions. Therefore, Figure 47 shows the coordinate axes of the local coordinate system based on the support 51J in the state in which the liquid spray head 1J is supported by the support 51J. Note that the local coordinate system based on the support 51J in the state in which the liquid spray head 1J is supported by the support 51J may be used to explain the liquid spray head 1J, which is a configuration other than the support 51J.

[0180] The first positioning pin 13g_1 and the second positioning pin 13g_2 are configured in the same way as the first positioning pin 51b_1 and the second positioning pin 51b_2. However, each of the first positioning pin 13g_1 and the second positioning pin 13g_2 protrudes in the Z2 direction from the protruding surface FP. The protruding surface FP is a surface facing the Z2 direction, which is the same direction as the injection surface FN of the holder 13J.

[0181] The first positioning section 51d_1 and the second positioning section 51d_2 are configured similarly to the first positioning section 13e_1 and the second positioning section 13e_2. In the first positioning section 51d_1, the first positioning pin 13g_1 is inserted into the support 51J in the Z2 direction. In the second positioning section 51d_2, the second positioning pin 13g_2 is inserted into the support 51J in the Z2 direction.

[0182] Figure 48 is a cross-sectional view of the first positioning section 51d_1 according to Modification 5, and corresponds to Figure 11 of the first embodiment. Figure 49 is a cross-sectional view of the second positioning section 51d_2 according to Modification 5, and corresponds to Figure 19 of the first embodiment. The support 51J has a first surface F1 that faces the same Z2 direction as the injection surface FN, and a second surface F2 that is opposite to the first surface F1 and faces the Z1 direction. The second surface F2 of the support 51J is the surface that faces the protruding surface FP of the liquid injection head 1J and is in contact with each other.

[0183] The first positioning section 51d_1 includes a first through-hole 2J that penetrates the support 51J in a direction along the Z-axis, a first recess 3J formed on the first surface F1 of the support 51J, and a second recess 4J formed on the second surface F2 of the support 51J. The second recess 4J, the first through-hole 2J, and the first recess 3J are aligned in the Y1 direction in this order.

[0184] The second positioning section 51d_2 includes a second through-hole 5J that penetrates the support 51J in a direction along the Z-axis, a third recess 6J formed on the first surface F1 of the support 51J, and a fourth recess 7J formed on the second surface F2 of the support 51J. The fourth recess 7J, the second through-hole 5J, and the third recess 6J are aligned in this order in the Y1 direction.

[0185] Here, the side surface of the first virtual cylinder VC1 set on the first positioning unit 51d_1 includes three regions divided in the first direction (direction along the Z axis): a first region RE1, a second region RE2, and a third region RE3 positioned between the first region RE1 and the second region RE2. The first region RE1 contacts the first positioning unit 51d_1 on the first side (Y2 direction side), which is one side of the second direction (direction along the Y axis) that is perpendicular to the first direction (direction along the Z axis) with respect to the first center line LC1, which is the center line of the first virtual cylinder VC1, but does not contact the first positioning unit 51d_1 on the second side (Y1 direction side), which is the other side of the second direction (direction along the Y axis). The second region RE2 does not contact the first positioning part 51d_1 on the first side (Y2 direction side) with respect to the first center line LC1, but contacts the first positioning part 51d_1 on the second side (Y1 direction side). The third region RE3 does not contact the first positioning part 51d_1 on both the first side (Y2 direction side) and the second side (Y1 direction side) with respect to the first center line LC1. Although not shown in the figures, the shape of the first virtual cylinder VC1 in plan view is a perfect circle, similar to the first embodiment.

[0186] Furthermore, the side surface of the second virtual cylinder VC2 set on the second positioning unit 51d_2 includes three regions divided in the first direction (direction along the Z axis): a fourth region RE4, a fifth region RE5, and a sixth region RE6 positioned between the fourth region RE4 and the fifth region RE5. The fourth region RE4 contacts the second positioning unit 51d_2 on the Y2 direction side with respect to the second center line LC2, which is the center line of the second virtual cylinder VC2, but does not contact the second positioning unit 51d_2 on the Y1 direction side. The fifth region RE5 does not contact the second positioning unit 51d_2 on the Y2 direction side with respect to the second center line LC2, but contacts the second positioning unit 51d_2 on the Y1 direction side. The sixth region RE6 does not contact the second positioning unit 51d_2 on both the Y2 and Y1 directions with respect to the second center line LC2. Although not shown in the diagram, similar to the first embodiment, the shape of the second virtual cylinder VC2 in plan view is an ellipse with its longitudinal direction along the Y-axis.

[0187] Furthermore, the support 51J is provided with an opening 51a into which a portion of the liquid spray head 1J is inserted. In this modified example, a portion of the liquid spray head 1J, including the spray surface FN, is inserted into the opening 51a. The opening 51a is located on the second side (Y1 direction side) when viewed from the first positioning unit 51d_1. Note that when multiple liquid spray heads 1J are inserted into a single opening 51a, as in the first embodiment, the "opening 51a" described here refers only to the space in the opening 51a into which one liquid spray head 1J is inserted. In other words, the opening 51a corresponding to the liquid spray head 1J is not located on the first side (Y2 direction side) when viewed from the first positioning unit 51d_1. The second region RE2 is located closer to the protruding surface FP from which the first positioning pin 13g_1 of the liquid spray head 1J protrudes than the first region RE1 with respect to the first direction (direction along the Z axis).

[0188] Similarly, the opening 51a is positioned on the first side (Y2 direction side) when viewed from the second positioning unit 51d_2. To reiterate, when multiple liquid injection heads 1J are inserted into one opening 51a, the "opening 51a" described here refers only to the space in the opening 51a into which one liquid injection head 1J is inserted. In other words, the opening 51a corresponding to the liquid injection head 1J is not positioned on the second side (Y1 direction side) when viewed from the second positioning unit 51d_2. Furthermore, the fifth region RE5 is positioned closer to the protruding surface FP of the liquid injection head 1J than the fourth region RE4 with respect to the first direction (direction along the Z axis). In other words, the direction from the first region RE1 to the second region RE2 (Z1 direction) and the direction from the fourth region RE4 to the fifth region RE5 (Z1 direction) are the same.

[0189] Furthermore, the first positioning portion 51d_1 may have a first inclined surface FL1 and a second inclined surface FL2, similar to the first positioning portion 13e_1 of the fourth embodiment, fifth embodiment, or modified example 1 described above. In this case, the first positioning portion 51d_1 includes a first contact portion CT1 that contacts the portion of the first region RE1 on the first side (Y2 direction side) with respect to the first center line LC1, and a first inclined surface FL1 that is a surface continuous with the first contact portion CT1 and extends in a direction that intersects the first direction (direction along the Z axis) without being perpendicular to it. In addition, the first positioning portion 51d_1 includes a second contact portion CT2 that contacts the portion of the second region RE2 on the second side (Y1 direction side) with respect to the first center line LC1, and a second inclined surface FL2 that is a surface continuous with the second contact portion CT2 and extends in a direction that intersects the first direction (direction along the Z axis) without being perpendicular to it.

[0190] Similarly, the second positioning portion 51d_2 may have a third inclined surface FL3 and a fourth inclined surface FL4, similar to the second positioning portion 13e_2 of the fourth embodiment described above. In this case, the second positioning portion 51d_2 includes a third contact portion CT3 that contacts the portion of the first region RE1 on the first side (Y2 direction side) with respect to the second centerline LC2, a fourth contact portion CT4 that contacts the portion of the fifth region RE5 on the second side (Y1 direction side) with respect to the second centerline LC2, a third inclined surface FL3 that is continuous with the third contact portion CT3 and extends in a direction that intersects but is not perpendicular to the first direction (direction along the Z axis), and a fourth inclined surface FL4 that is continuous with the fourth contact portion CT4 and extends in a direction that intersects but is not perpendicular to the first direction (direction along the Z axis).

[0191] As described above, the support 51J includes a second positioning part 51d_2 that positions the liquid spray head 1J by being inserted into a second positioning pin 13g_2 provided on the liquid spray head 1J. The first positioning part 51d_1 and the second positioning part 51d_2 are arranged side by side in the second direction (the direction along the Y axis). Specifically, the second positioning part 51d_2 is positioned in the Y1 direction relative to the first positioning part 51d_1.

[0192] The liquid injection device comprising the support body 51J and liquid injection head 1J as in the modified example 5 described above also improves ease of attachment and detachment while ensuring the necessary positioning accuracy of the liquid injection head 1J relative to the support body 51J.

[0193] Furthermore, some or all of the above embodiments and modifications, and combinations thereof, may be applied to the support 51J of this modification to the extent that no inconsistencies arise.

[0194] 6-6. Variation 6 In the above embodiments and modifications, the positioning pin was press-fitted into the positioning section, but this is not the only method. The liquid spray head may also be positioned relative to the support by inserting the positioning pin into the positioning section by clearance fitting. Here, clearance fitting of the positioning pin into the positioning section means that the maximum length of the positioning pin as viewed in the depth direction of the positioning section is less than the diameter of the cross-section perpendicular to the depth direction of a hypothetical perfect cylinder that is inserted to the deepest position of the positioning section and has the largest cross-sectional area as viewed in the depth direction of the positioning section. In other words, the insertion method may be such that the positioning pin does not contact the positioning section, or that the positioning pin contacts the positioning section at only one point. Even with such an insertion method, the configuration of the positioning section shown in each embodiment and example can improve the ease of attaching and detaching the liquid spray head from the support.

[0195] 6-7. Variation 7 In the embodiments and modifications described above, the printing operation was performed by spraying ink from a liquid spray head while a carriage including a support moved back and forth in a direction perpendicular to the transport direction DM of the medium M, and the printer was a so-called serial printer. However, the invention is not limited to this form. For example, it may be a line printer equipped with a line head in which multiple liquid spray heads are arranged in a direction perpendicular to the transport direction DM of the medium M, so that the printing area is larger than the width in the direction perpendicular to the transport direction DM of the medium M. In other words, the support may be a print bar that supports multiple liquid spray heads to form a line head.

[0196] 6-8. Variation 8 The liquid spraying devices exemplified in the above-described form can be used in various devices such as facsimile machines and photocopiers, in addition to equipment dedicated to printing. However, the applications of liquid spraying devices are not limited to printing. For example, liquid spraying devices that spray colorant solutions are used as manufacturing equipment to form color filters for display devices such as liquid crystal display panels. Liquid spraying devices that spray conductive material solutions are used as manufacturing equipment to form wiring and electrodes on wiring boards. Furthermore, liquid spraying devices that spray solutions of organic substances related to living organisms are used, for example, as manufacturing equipment to produce biochips. [Explanation of Symbols]

[0197] 1…Liquid injection head, 1G…Liquid injection head, 1H…Liquid injection head, 1I…Liquid injection head, 1J…Liquid injection head, 2…First through hole, 2A…First through hole, 2B…First through hole, 2E…First through hole, 3…First recess, 3A…First recess, 3B…First recess, 3C…First recess, 3E…First recess, 4…Second recess, 4A…Second recess, 4B…Second recess, 4C…Second recess, 4E…Second recess, 5…Second through hole, 6…Third recess, 6C…Third recess, 7… 7C…Fourth recess, 8…Bottomed hole, 10…Liquid container, 13…Holder, 13A…Holder, 13B…Holder, 13C…Holder, 13D…Holder, 13E…Holder, 13G…Holder, 13H…Holder, 13e…Positioning part, 13e_1…First positioning part, 13e_2…Second positioning part, 13g_1…First positioning pin, 13g_2…Second positioning pin, 14…Fixing plate, 14a…Opening, 20…Control unit, 3 0...Conveying mechanism, 40...Moving mechanism, 41...Conveyor body, 42...Conveyor belt, 50...Head module, 51...Support, 51I...Support, 51J...Support, 51a...Opening, 51b...Positioning pin, 51b_1...First positioning pin, 51b_2...Second positioning pin, 51d_1...First positioning part, 51d_2...Second positioning part, 60...Circulation mechanism, 100...Liquid injection device, CT1...First contact part, CT2...Second contact part, CT3...Third contact part, CT4...Fourth contact point, DM...Conveying direction, F1...First surface, F2...Second surface, FB...Bottom wall, FL1...First slope, FL2...Second slope, FN...Spray surface, FP...Protruding surface, HC...Head tip, LC1...First centerline, LC2...Second centerline, LL...Axis, M...Media, N...Nozzle, RE1...First region, RE2...Second region, RE3...Third region, RE4...Fourth region, RE5...Fifth region, RE6...Sixth region, VC1...First virtual cylinder, VC2...Second virtual cylinder.

Claims

1. A liquid spray head supported by a support having a first positioning pin, which sprays liquid, The first positioning unit is provided, which positions the liquid spray head relative to the support when the first positioning pin is inserted. When the first virtual cylinder is defined as a virtual cylinder that is inserted to the deepest position of the first positioning portion and has the largest cross-sectional area when viewed in the first direction, which is the depth direction of the first positioning portion, The side surface of the first virtual cylinder includes three regions divided in the first direction: a first region, a second region, and a third region positioned between the first and second regions. The first region contacts the first positioning portion on the first side, which is one side in the second direction perpendicular to the first direction with respect to the first center line, which is the center line of the first virtual cylinder, and does not contact the first positioning portion on the second side, which is the other side in the second direction. The second region, with respect to the first center line, does not contact the first positioning portion on the first side, but contacts the first positioning portion on the second side. The third region does not contact the first positioning portion on both the first and second sides with respect to the first center line. A liquid spray head characterized by the following features.

2. The first member comprises the first positioning portion, The first member has a first surface and a second surface opposite to the first surface, The first positioning unit is, A first through hole that penetrates from the second surface to the first surface in the first direction, The first recess provided on the first surface, The second recess provided on the second surface, The first through hole is positioned between the first recess and the second recess with respect to the second direction. The first virtual cylinder extends along the first through hole from the first surface to the second surface, The liquid spray head according to feature 1.

3. The first member comprises a bottomed hole having a bottom wall, which serves as the first positioning portion. The deepest point is the bottom wall. The liquid spray head according to feature 1.

4. The length of the first region along the first direction and the length of the second region along the first direction are equal to each other. A liquid spray head according to any one of claims 1 to 3.

5. The length of the first region and the second region along the first direction is 20% to 45% of the length of the first virtual cylinder along the first direction. A liquid spray head according to any one of claims 1 to 4.

6. The first positioning unit is, A first contact portion that contacts the first side of the first region with respect to the first center line, It has a second contact portion that contacts the second side of the second region with respect to the first center line, The first contact portion and the second contact portion each extend continuously in the first direction. A liquid spray head according to any one of claims 1 to 5.

7. It has a spray surface with multiple nozzles for spraying liquid, The injection surface is positioned on the second side when viewed from the first positioning unit. The second region is arranged in a direction with respect to the first direction, in a direction that the injection surface faces the first region. A liquid spray head according to any one of claims 1 to 6.

8. It has a spray surface with multiple nozzles for spraying liquid, The injection surface is positioned on the second side when viewed from the first positioning unit. The first region is arranged in a direction with respect to the first direction, in a direction that the injection surface faces the second region. A liquid spray head according to any one of claims 1 to 6.

9. The first positioning unit is, A first contact portion that contacts the first side of the first region with respect to the first center line, A surface continuous with the first contact portion, and including a first inclined surface extending in a direction that intersects but is not perpendicular to the first direction, A liquid spray head according to any one of claims 1 to 8.

10. The length of the first slope along the first direction is greater than or equal to the sum of the lengths of the second and third regions along the first direction. The liquid spray head according to feature 9.

11. The first positioning unit is, The second contact portion that contacts the second side of the second region with respect to the first center line, It has a second inclined surface that is continuous with the second contact portion and extends in a direction that intersects but is not perpendicular to the first direction, The first slope and the second slope are parallel to each other. The liquid spray head according to claim 9 or 10.

12. The first slope and the second slope have overlapping portions when viewed in the second direction. The liquid spray head according to feature 11.

13. The first positioning portion has a second contact portion that contacts the second side of the second region with respect to the first center line, In a cross-section obtained by cutting the first positioning portion with a plane parallel to both the first and second directions, at a position in a third direction perpendicular to the first and second directions where the length of the first virtual cylinder along the second direction is maximized when viewed in the first direction, The angle between the line segment connecting the first contact portion and the second contact portion in the shortest possible distance and the first inclined plane is 90 degrees or greater. A liquid spray head according to any one of claims 9 to 12.

14. The system further includes a second positioning unit into which a second positioning pin provided on the support is inserted, thereby positioning the liquid spray head relative to the support. The first positioning unit and the second positioning unit are arranged side by side in the second direction. A liquid spray head according to any one of claims 1 to 13.

15. The second positioning unit is positioned on the second side relative to the first positioning unit. The second region is positioned closer to the protruding surface of the support from which the first positioning pin protrudes than the first region, with respect to the first direction. The liquid spray head according to feature 14.

16. Let the second virtual cylinder be defined as the virtual cylinder that is inserted to the deepest position of the second positioning part and has the largest cross-sectional area when viewed in the first direction. The side surface of the second virtual cylinder includes three regions divided in the first direction: a fourth region, a fifth region, and a sixth region positioned between the fourth and fifth regions. The fourth region, with respect to the second centerline which is the centerline of the second virtual cylinder, contacts the second positioning portion on the first side, but does not contact the second positioning portion on the second side. The fifth region, with respect to the second center line, does not contact the second positioning portion on the first side, but contacts the second positioning portion on the second side. The sixth region does not contact the second positioning portion on both the first and second sides with respect to the second centerline. The direction from the second region to the first region is the same as the direction from the fifth region to the fourth region. The liquid spray head according to claim 14 or 15.

17. The device further includes a second positioning unit which is inserted into a second positioning pin provided on the support, thereby positioning the liquid spray head relative to the support, The first positioning unit and the second positioning unit are arranged side by side in a third direction that is perpendicular to the first direction and intersects the second direction. Let the second virtual cylinder be defined as the virtual cylinder that is inserted to the deepest position of the second positioning part and has the largest cross-sectional area when viewed in the first direction. The side surface of the second virtual cylinder includes three regions divided in the first direction: a fourth region, a fifth region, and a sixth region positioned between the fourth and fifth regions. The fourth region, with respect to the second centerline which is the centerline of the second virtual cylinder, contacts the second positioning portion on the first side, but does not contact the second positioning portion on the second side. The fifth region, with respect to the second center line, does not contact the second positioning portion on the first side, but contacts the second positioning portion on the second side. The sixth region does not contact the second positioning portion on both the first and second sides with respect to the second centerline. The direction from the second region to the first region is the same as the direction from the fifth region to the fourth region. A liquid spray head according to any one of claims 1 to 13.

18. A liquid spray head according to any one of claims 1 to 17, A support having the first positioning pin, Equipped with, A liquid injection device characterized by the following features.

19. The first positioning unit is, A first contact portion that contacts the first side of the first region with respect to the first center line, It has a second contact portion that contacts the second side of the second region with respect to the first center line, In a cross-section obtained by cutting the first positioning portion with a plane that is perpendicular to both the first and second directions, at a position in a third direction perpendicular to the first and second directions where the length of the first virtual cylinder along the second direction is maximum when viewed in the first direction, The shortest distance between the first contact portion and the second contact portion is greater than or equal to the maximum length of the first positioning pin along the second direction. The liquid injection device according to feature 18.

20. A support for a liquid spraying head that sprays liquid, The liquid spray head is provided with a first positioning unit into which a first positioning pin is inserted, thereby positioning the liquid spray head relative to the support. When the first virtual cylinder is defined as a virtual cylinder that is inserted to the deepest position of the first positioning portion and has the largest cross-sectional area when viewed in the first direction, which is the depth direction of the first positioning portion, The side surface of the first virtual cylinder includes three regions divided in the first direction: a first region, a second region, and a third region positioned between the first and second regions. The first region contacts the first positioning portion on the first side, which is one side in the second direction perpendicular to the first direction with respect to the first center line, which is the center line of the first virtual cylinder, and does not contact the first positioning portion on the second side, which is the other side in the second direction. The second region, with respect to the first center line, does not contact the first positioning portion on the first side, but contacts the first positioning portion on the second side. The third region does not contact the first positioning portion on both the first and second sides with respect to the first center line. A support characterized by the following features.

21. It has an opening into which a part of the liquid spray head is inserted, The opening is located on the second side when viewed from the first positioning portion. The support according to claim 20.

22. The first positioning unit is, A first contact portion that contacts the first side of the first region with respect to the first center line, A surface continuous with the first contact portion, and including a first inclined surface extending in a direction that intersects but is not perpendicular to the first direction, The support according to claim 20 or 21, characterized by the features described above.

23. The device further includes a second positioning unit which is inserted into a second positioning pin provided on the liquid spray head to position the liquid spray head relative to the support, The first positioning unit and the second positioning unit are arranged side by side in the second direction. The support according to any one of claims 20 to 22.

24. A support according to any one of claims 20 to 23, A liquid spray head comprising the first positioning pin, A liquid injection device characterized by the following features.

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