Positioning structure, liquid ejection head, and liquid ejection recording apparatus

Abstract

To accurately position a liquid jet head relative to a head installation part of a liquid jet recording device.SOLUTION: A positioning structure 100 includes a positioning pin 40 provided on a carriage 29, and a position adjustment mechanism 60 provided on an inkjet head 5, wherein the position adjustment mechanism 60 has a contact member 80 in contact with the positioning pin 40, and a displacement mechanism 90 for displacing the contact member 80 along a displacement axis O2 extending in an oblique direction crossing a vertical direction of an installation surface 29a, the contact part 41 of the positioning pin 40 is formed in a curved surface shape with a first crossing shaft O1 crossing the installation surface 29a as a central shaft, and the contact part 81 of the contact member 80 is formed in a curved surface shape with a second crossing shaft O3 which crosses a virtual plane including a vertical shaft (first crossing shaft O1) extending in the vertical direction of the installation surface 29a and a displacement shaft O2, and is not parallel to the first crossing shaft O1, as a central axis.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a positioning structure, a liquid ejection head, and a liquid ejection recording apparatus.

Background Art

[0002] Patent Document 1 below discloses a head unit in which a plurality of heads (liquid ejection heads) each having a plurality of nozzles for ejecting droplets are arranged on an array base member (head installation portion). This head unit has a positioning structure for finely adjusting the position of the head with respect to the array base member by bringing the inclined surface of an inclined member into contact with an end portion of a plate member that holds the head and moving the inclined member up and down with a bolt.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described positioning structure, since the inclined surface of the inclined member is brought into contact with the end portion of the plate member, the inclined member and the plate member are in line contact. However, since minute irregularities due to machining accuracy and the like exist on both members, the two members are actually in multi-point contact. In this multi-point contact state, since errors at individual contact points are likely to accumulate, it may be difficult to accurately position the liquid ejection head with respect to the head installation portion.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to accurately position a liquid ejection head with respect to a head installation portion of a liquid ejection recording apparatus.

Means for Solving the Problems

[0006] (1) The positioning structure according to one aspect of the present disclosure is a positioning structure for positioning a liquid ejection head with respect to a head installation portion of a liquid ejection recording apparatus, including a convex portion provided on one of the head installation portion and the liquid ejection head, and a position adjustment mechanism provided on the other of the head installation portion and the liquid ejection head for adjusting a position in a direction along the installation surface of the head installation portion with respect to the convex portion. The position adjustment mechanism includes a contact member that contacts the convex portion, and a displacement mechanism that displaces the contact member along a displacement axis extending in an oblique direction intersecting with a direction perpendicular to the installation surface. One of the contact portions of the convex portion and the contact member is formed in a curved surface shape centered on a first intersection axis intersecting with the installation surface, and the other of the contact portions is formed in a curved surface shape centered on a second intersection axis that intersects with a virtual plane including a vertical axis extending in a direction perpendicular to the installation surface and the displacement axis and is not parallel to the first intersection axis.

[0007] According to the positioning structure of this aspect, when the contact member is displaced in an oblique direction intersecting with the direction perpendicular to the installation surface by the displacement mechanism, the convex portion contacting the contact member is pushed in the direction along the installation surface, and the liquid ejection head is displaced with respect to the head installation portion. Here, one of the contact portions is formed in a curved surface shape centered on a first intersection axis intersecting with the installation surface, and the other of the contact portions intersects with a virtual plane including a vertical axis extending in a direction perpendicular to the installation surface and the displacement axis and is formed in a curved surface shape centered on a second intersection axis that is not parallel to the first intersection axis. Since the central axes of the curved surface shapes of the contact portions are in a twisted positional relationship, the convex portion and the contact member contact at one point. By the convex portion and the contact member contacting at one point, an error due to multi-point contact between the convex portion and the contact member can be avoided, and the liquid ejection head can be accurately positioned with respect to the head installation portion.

[0008] (2) In the positioning structure of the aspect of (1), one of the contact portions may include a first cylindrical surface centered on the first intersection axis, and the other of the contact portions may include a second cylindrical surface centered on the second intersection axis.

[0009] In this case, one of the convex portion and the contact portion of the contact member has a first cylindrical surface centered on the first intersection axis, and the other of the contact portions has a second cylindrical surface centered on the second intersection axis. Since the central axes of both (the first intersection axis and the second intersection axis) intersect each other, the convex portion and the contact member can always be stably brought into contact at one point.

[0010] (3) In the positioning structure of the aspect of (2), the contact portion of the convex portion may include the first cylindrical surface extending in the vertical direction of the installation surface, and the contact portion of the contact member may include the second cylindrical surface extending parallel to the installation surface.

[0011] In this case, since the contact portion of the convex portion includes the first cylindrical surface extending in the vertical direction of the installation surface, and the contact portion of the contact member includes the second cylindrical surface extending parallel to the installation surface, the convex portion and the contact member always stably come into contact at one point, and it is possible to prevent the contact member that comes into contact with the convex portion at one point from shifting in the direction along the installation surface with respect to the convex portion.

[0012] (4) In the positioning structure of any one of the aspects of (1) to (3), the displacement mechanism may have a guide portion that extends in the diagonal direction and guides the contact member.

[0013] In this case, the contact member can be accurately displaced in the diagonal direction along the guide portion.

[0014] (5) In the positioning structure of the aspect of (4), the contact member may have a clamping portion that clamps the guide portion in a direction orthogonal to the displacement axis.

[0015] In this case, by clamping the guide portion with the clamping portion provided on the contact member, it is possible to prevent the contact member from rotating about the displacement axis.

[0016] (6) In the positioning structure of the aspect of (4) or (5), the displacement mechanism may include a bolt that extends along the displacement axis and screws the contact member, a first support portion provided at one end of the guide portion, which supports the head of the bolt and has a first insertion hole through which the shaft portion of the bolt is inserted, and a compression spring disposed between the first support portion and the contact member.

[0017] In this case, when the bolt serving as the displacement axis is rotated, the contact member having the clamping portion and restricted from rotating with respect to the guide portion is screwed. At this time, the gap between the first support portion and the contact member widens, but since the compression spring extends to fill this gap, it is possible to prevent the head of the bolt from floating from the first support portion.

[0018] (7) In the positioning structure of the aspect of (6), the displacement mechanism may include a second support portion provided at the other end of the guide portion and having a second insertion hole through which the shaft portion of the bolt is inserted.

[0019] In this case, by inserting the shaft portion of the bolt into the second insertion hole of the second support portion, both ends of the bolt can be pivotally supported by the first support portion and the second support portion, so that the axial play of the bolt can be suppressed and the contact member can be displaced with high precision.

[0020] (8) In the positioning structure of any one of the aspects of (1) to (7), the position adjustment mechanism may include a preloading mechanism that applies a preload to the convex portion in a direction along the installation surface from the side opposite to the side where the contact member is disposed.

[0021] In this case, by applying a preload to the convex portion by the preloading mechanism and displacing the contact member that contacts the convex portion in the direction of the preload, the base member can be moved following the displacement of the contact member. By this preloading mechanism, it is not necessary to provide the contact member and the displacement mechanism on both sides sandwiching the convex portion, so that the structure of the position adjustment mechanism can be simplified, lightened, and space-saving.

[0022] (9) The liquid ejection head according to one aspect of the present disclosure includes either the position adjustment mechanism of the positioning structure according to any one of aspects (1) to (8) or the convex portion.

[0023] According to the liquid ejection head of this aspect, a liquid ejection head capable of performing highly accurate printing can be obtained.

[0024] (10) The liquid ejection recording apparatus according to one aspect of the present disclosure includes the positioning structure according to any one of aspects (1) to (8). According to the liquid ejection recording apparatus of this aspect, a liquid ejection recording apparatus capable of performing highly accurate printing can be obtained.

[0025] (11) The liquid ejection recording apparatus according to one aspect of the present disclosure includes a liquid ejection head, a carriage on which the liquid ejection head is installed, and a positioning structure according to any one of aspects (1) to (8) that positions the liquid ejection head with respect to the carriage.

[0026] According to the liquid ejection recording apparatus of this aspect, the liquid ejection head can be accurately positioned with respect to the carriage of the liquid ejection recording apparatus, and highly accurate printing can be performed.

Advantages of the Invention

[0027] According to one aspect of the present disclosure described above, the liquid ejection head can be accurately positioned with respect to the head installation portion of the liquid ejection recording apparatus.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings.

[0030] In the embodiments and modification examples described below, corresponding components may be denoted by the same reference numerals and the description thereof may be omitted. Further, in the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", "coaxial", etc. not only represent such arrangements precisely, but also represent states in which they are relatively displaced with tolerances and angles and distances that can obtain the same function.

[0031] In the following embodiments, an inkjet printer (hereinafter simply referred to as a printer) that performs recording on a recording medium using ink (liquid) will be described as an example. In the drawings used in the following description, the scales of the respective members are appropriately changed in order to make the respective members recognizable in size.

[0032] [Printer 1] FIG. 1 is a schematic configuration diagram of a printer 1 according to an embodiment. As shown in FIG. 1, the printer 1 (liquid jet recording apparatus) of the present embodiment includes a pair of transport mechanisms 2 and 3, an ink tank 4, an inkjet head 5 (liquid jet head), an ink circulation mechanism 6, and a scanning mechanism 7.

[0033] In the following description, an orthogonal coordinate system of X, Y, and Z will be used as necessary. The X direction is the transport direction (sub-scanning direction) of the recording medium P (for example, paper or the like). The Y direction is the scanning direction (main scanning direction) of the scanning mechanism 7. The Z direction is the height direction (gravity direction) orthogonal to the X direction and the Y direction. Note that the X direction is the printing width direction of the inkjet head 5.

[0034] Also, in the following description, among the X direction, the Y direction, and the Z direction, the side of the arrow in the figure is defined as the plus (+) side, and the side opposite to the arrow is defined as the minus (-) side. In the present embodiment, the +Z side corresponds to the upper side in the gravity direction, and the -Z side corresponds to the lower side in the gravity direction.

[0035] The transport mechanisms 2 and 3 transport the recording medium P to the +X side. The transport mechanisms 2 and 3 each include, for example, a pair of rollers 11 and 12 extending in the Y direction. A plurality of ink tanks 4 are provided, and for example, four colors of ink, yellow, magenta, cyan, and black, are separately accommodated.

[0036] A plurality of inkjet heads 5 are provided and are configured to be able to eject four colors of ink, yellow, magenta, cyan, and black, respectively, according to the connected ink tank 4.

[0037] FIG. 2 is a schematic configuration diagram of the inkjet head 5 and the ink circulation mechanism 6 according to an embodiment. As shown in FIGS. 1 and 2, the ink circulation mechanism 6 circulates ink between the ink tank 4 and the inkjet head 5. Specifically, the ink circulation mechanism 6 includes a circulation channel 23 having an ink supply pipe 21 and an ink discharge pipe 22, a pressure pump 24 connected to the ink supply pipe 21, and a suction pump 25 connected to the ink discharge pipe 22.

[0038] The pressure pump 24 pressurizes the inside of the ink supply pipe 21 and sends ink out to the inkjet head 5 through the ink supply pipe 21. As a result, the ink supply pipe 21 side becomes a positive pressure with respect to the inkjet head 5.

[0039] The suction pump 25 decompresses the inside of the ink discharge pipe 22 and sucks ink from the inkjet head 5 through the inside of the ink discharge pipe 22. As a result, the ink discharge pipe 22 side becomes a negative pressure with respect to the inkjet head 5. The ink circulates between the inkjet head 5 and the ink tank 4 through the circulation channel 23 by the driving of the pressure pump 24 and the suction pump 25.

[0040] As shown in FIG. 1, the scanning mechanism 7 reciprocally scans the inkjet head 5 in the Y direction. The scanning mechanism 7 includes a guide rail 28 extending in the Y direction, a carriage 29 (head installation part) movably supported on the guide rail 28, and a driving device for moving the carriage 29. The driving device is composed of, for example, a motor, a pulley, a belt, etc.

[0041] <Inkjet head 5> The inkjet head 5 is mounted on the carriage 29. The inkjet head 5 of the present embodiment is an electromechanical conversion type inkjet head that discharges ink from a head chip including an actuator plate formed of a piezoelectric element such as PZT (lead zirconate titanate).

[0042] In this inkjet head 5, to eject ink, a voltage is applied between the electrodes of the drive wall of the ejection channel formed in the actuator plate to cause the drive wall to undergo a thickness-shear deformation. As a result, the volume within the ejection channel changes, causing the ink within the ejection channel to be ejected through the nozzle holes. Note that the liquid ejection method is not limited to the above-described electromechanical conversion method, and may also be a charge control method, a pressure vibration method, an electrothermal conversion method, an electrostatic attraction method, or the like.

[0043] The charge control method involves imparting charge to a material using a charging electrode and controlling the flying direction of the material using a deflection electrode to eject it from the nozzle. Also, the pressure vibration method involves applying an ultra-high pressure to a material to eject the material toward the nozzle tip side. When no control voltage is applied, the material travels straight and is ejected from the nozzle. When a control voltage is applied, an electrostatic repulsion occurs between the materials, causing the materials to scatter and not be ejected from the nozzle.

[0044] Furthermore, the electrothermal conversion method involves rapidly vaporizing a material using a heater provided within a space storing the material to generate bubbles, and ejecting the material within the space by the pressure of the bubbles. The electrostatic attraction method involves applying a minute pressure within a space storing the material, forming a meniscus of the material at the nozzle, and then applying an electrostatic attraction force to draw out the material. Additionally, other techniques such as a method utilizing a change in the viscosity of a fluid due to an electric field and a method of ejecting by a discharge spark can also be applied.

[0045] FIG. 3 is a plan view showing the arrangement of the inkjet head 5 installed on the carriage 29 according to one embodiment. As shown in FIG. 3, a plurality of inkjet heads 5 are installed on the installation surface 29a of the carriage 29. The inkjet head 5 has a substantially rectangular shape extending in the X direction in plan view. On one side (+X side) in the X direction, an inlet port 5a to which the above-described ink supply pipe 21 is connected is provided, and on the other side (-X side) in the X direction, an outlet port 5b to which the above-described ink discharge pipe 22 is connected is provided.

[0046] The inkjet head 5 is installed on the installation surface 29a of the carriage 29 in a direction where the long side extends in the X direction and the short side extends in the Y direction. The inkjet heads 5 are installed on the installation surface 29a at a predetermined pitch in the X direction. On the upper surface of each inkjet head 5, a connection connector (not shown) is provided and is electrically connected to the printer 1 via a cable (not shown).

[0047] The carriage 29 is formed with insertion holes 29b into which the lower ends of the inkjet heads 5 are inserted. The insertion holes 29b are rectangular long holes extending in the X direction in plan view and penetrate the installation surface 29a of the carriage 29 in the thickness direction (Z direction). The insertion holes 29b are formed to be slightly larger than the lower ends of the inkjet heads 5, ensuring a clearance for position adjustment of the inkjet heads 5. Each of the inkjet heads 5 is adjusted in its position in the X direction, position in the Y direction, and rotation angle on the X - Y plane by a positioning structure 100 described below and is fixed to the carriage 29.

[0048] <Positioning structure 100> FIG. 4 is a perspective view of the positioning structure 100 of the inkjet head 5 according to an embodiment. FIG. 5 is an exploded perspective view of the positioning structure 100 of the inkjet head 5 according to an embodiment. FIG. 6 is a plan view of the positioning structure 100 of the inkjet head 5 according to an embodiment. As shown in these figures, the inkjet head 5 includes a head body 5A (injection part) that injects ink, and a base member 30 that supports the head body 5A and is installed on the installation surface 29a of the carriage 29.

[0049] The head body 5A has a rectangular box shape as shown in FIG. 5 and is provided with a nozzle row (not shown) for injecting ink on its lower surface. The base member 30 is connected to the lower end of the head body 5A. The base member 30 includes a plate part 31 placed on the installation surface 29a of the carriage 29 and a base part 32 surrounding the lower end of the head body 5A.

[0050] The base portion 32 has a rectangular box shape with an open top. A long hole (not shown) for exposing the nozzle row of the head body 5A is formed in the bottom surface of the base portion 32. The plate portion 31 has a plate shape extending from the upper opening edge of the base portion 32 to both sides in the X direction. The plate portion 31 is fixed by a screw member 101 attached to the installation surface 29a of the carriage 29 via a spring washer 101a. A fixing hole 29d into which the screw member 101 is screwed is provided in the installation surface 29a of the carriage 29.

[0051] In the plate portion 31 of the base member 30, a first through-hole 33 for arranging the positioning pin 40 (protrusion) and a second through-hole 34 for arranging the screw member 101 are formed. The first through-hole 33 has an elongated hole shape extending in the X direction and is formed to be slightly larger than the positioning pin 40. The second through-hole 34 has an elongated hole shape extending in the X direction and is formed to be slightly larger than the shaft portion of the screw member 101.

[0052] Due to these gaps, the base member 30 can adjust the fixed position in the direction along the installation surface 29a of the carriage 29 (X - Y plane direction). A plurality of fixing holes 35 for fixing a position adjustment unit 50 described later are formed between the first through-hole 33 and the second through-hole 34 in the plate portion 31. An internal thread for screwing a screw member 102 for fixing the position adjustment unit 50 is formed on the inner wall surface of the fixing hole 35.

[0053] The positioning structure 100 includes a positioning pin 40 provided on the carriage 29 and a position adjustment unit 50 provided on the inkjet head 5 for adjusting the position in the direction along the installation surface 29a of the carriage 29 of the base member 30 with respect to the positioning pin 40. The positioning structure 100 includes, as the positioning pin 40, a first positioning pin 40A and a second positioning pin 40B arranged with the head body 5A sandwiched therebetween in the X direction.

[0054] The first positioning pin 40A is disposed on the +X side of the head body 5A. The second positioning pin 40B is disposed on the -X side of the head body 5A. Further, the positioning structure 100 includes, as a position adjustment unit 50, a first position adjustment unit 50A that adjusts the position of the base member 30 with respect to the first positioning pin 40A, and a second position adjustment unit 50B that adjusts the position of the base member 30 with respect to the second positioning pin 40B.

[0055] <Position adjustment unit 50> FIG. 7 is a perspective view of the first position adjustment unit 50A according to an embodiment. FIG. 8 is a perspective view of the second position adjustment unit 50B according to an embodiment. FIG. 9 is a cross-sectional view taken along the arrow IX-IX shown in FIG. 6. As shown in FIG. 7, the first position adjustment unit 50A includes a frame member 51 and two position adjustment mechanisms 60 in the X and Y directions supported by the frame member 51. In the following description, first, based on the position adjustment mechanism 60 in the Y direction (hereinafter referred to as the second position adjustment mechanism 60B), the basic structure of the position adjustment mechanism 60 will be described.

[0056] The second position adjustment mechanism 60B adjusts the position in the Y direction along the installation surface 29a of the base member 30 with respect to the positioning pin 40 provided on the installation surface 29a of the carriage 29 described above. The second position adjustment mechanism 60B includes a preloading mechanism 70 that applies a preload in the Y direction along the installation surface 29a with respect to the positioning pin 40, a contact member 80 that contacts the positioning pin 40 from the side opposite to the side (-Y side) where the preloading mechanism 70 is disposed in the Y direction in which the preloading mechanism 70 applies the preload (+Y side), and a displacement mechanism 90 that displaces the contact member 80 in the Y direction in which the preloading mechanism 70 applies the preload.

[0057] As shown in Fig. 9, the preloading mechanism 70 includes two leaf springs 71 and 72. The leaf spring 71 is bent in a crank shape, and its tip abuts against the -Y side of the positioning pin 40. The leaf spring 72 is bent in an L shape and overlaps the back side of the leaf spring 71 to adjust the biasing force of the preloading mechanism 70. Note that multiple leaf springs 72 may be stacked on the leaf spring 71. Also, if the biasing force of the leaf spring 71 is sufficient, the leaf spring 72 may not be provided.

[0058] As shown in Fig. 7, the leaf springs 71 and 72 are fixed to the bottom 52 of the frame member 51 by screw members 103. In the vicinity of the screw member 103, a plurality of third through-holes 52a penetrating the leaf springs 71 and 72 and the bottom 52 of the frame member 51 in the Z direction are formed. As shown in Fig. 9, a screw member 102 for fixing the second position adjustment unit 50B is disposed in the third through-hole 52a. The screw member 102 is screwed into a fixing hole 35 formed in the plate portion 31 of the base member 30. That is, the second position adjustment unit 50B (two position adjustment mechanisms 60) is detachably attached to the base member 30 by the screw member 102.

[0059] The displacement mechanism 90 displaces a contact member 80 that abuts against the +Y side of the positioning pin 40 along a displacement axis O2 extending in an oblique direction intersecting the vertical direction (Z direction) of the installation surface 29a. The frame member 51 includes a mounting portion 53 to which the displacement mechanism 90 is mounted. The mounting portion 53 bends at a right angle with respect to the bottom 52 and further bends from a substantially intermediate position in the height direction (Z direction) toward the bottom 52 side (the positioning pin 40 side) at the same angle as the displacement axis O2. An opening 54 is formed in the mounting portion 53 to avoid interference with the lower end portion of the guide portion 91 of the displacement mechanism 90. The back side of the guide portion 91 is fixed to the mounting portion 53 via a screw member 104.

[0060] The guide portion 91 is an orbital member that extends obliquely along the displacement axis O2 and guides the contact member 80. The guide portion 91 has an inclined surface that contacts the back side (+Y side) of the contact member 80. The contact member 80 has a clamping portion 82 that clamps the guide portion 91 in the direction (X direction) orthogonal to the displacement axis O2. That is, the contact member 80 can be displaced in an oblique direction along the guide portion 91 while sliding on the inclined surface and both side surfaces of the guide portion 91.

[0061] The displacement mechanism 90 includes the above-described guide portion 91, a bolt 92, a compression spring 93, a first support portion 94, and a second support portion 95. The contact member 80 is screwed onto the bolt 92 so as to be threadable. The bolt 92 extends along the displacement axis O2 and feeds the contact member 80 by screwing it by rotation around the displacement axis O2. The first support portion 94 is provided at the upper end portion (one end portion) of the guide portion 91 and supports the head of the bolt 92. A first insertion hole 94a through which the shaft portion of the bolt 92 is inserted is formed in the first support portion 94. The first insertion hole 94a pivotally supports a portion (neck portion) of the shaft portion of the bolt 92 where no thread is formed.

[0062] The compression spring 93 is, for example, a coil spring disposed around the bolt 92 and is interposed between the first support portion 94 and the contact member 80. The compression spring 93 expands and contracts so as to fill the gap between the contact member 80 and the first support portion 94 that varies due to the screw feed of the bolt 92. The second support portion 95 is provided at the lower end portion (the other end portion) of the guide portion 91. A second insertion hole 95a through which the shaft portion of the bolt 92 is inserted is formed in the second support portion 95. The second insertion hole 95a pivotally supports the tip portion of the shaft portion of the bolt 92 where no thread is formed. The above-described guide portion 91, the first support portion 94, and the second support portion 95 are integrally formed and have a substantially C-shaped overall shape.

[0063] The positioning pin 40 stands perpendicular to the installation surface 29a of the carriage 29. The positioning pin 40 includes a contact portion 41, a chamfered portion 42 (see FIG. 7), and a threaded portion 43 (see FIG. 9). The threaded portion 43 is provided at the lower end of the positioning pin 40 and is screwed into a fixing hole 29c formed in the installation surface 29a of the carriage 29. As shown in FIG. 7, the chamfered portion 42 chamfers at least two parallel surfaces of a part of the circumferential surface of the positioning pin 40, enabling the positioning pin 40 to be turned by screwing. That is, the positioning pin 40 is detachably attached to the carriage 29. Note that the chamfered portion 42 may be chamfered on four or six surfaces.

[0064] As shown in FIG. 7, the positioning pin 40 has a curved contact portion 41 that contacts the contact member 80. Further, the contact member 80 has a curved contact portion 81 that contacts the positioning pin 40. Hereinafter, with reference to FIG. 10, the relationship between the curved surface shapes of the contact portions 41 and 81 of the positioning pin 40 and the contact member 80 will be described.

[0065] FIG. 10 is a conceptual diagram for explaining the curved surface shapes of the contact portions 41 and 81 according to an embodiment. As shown in FIG. 10, the contact portion 41 of the positioning pin 40 is formed in a curved surface shape with the first intersection axis O1 intersecting the installation surface 29a as the central axis. The first intersection axis O1 of the present embodiment intersects the installation surface 29a perpendicularly (at a right angle), but it may intersect the installation surface 29a obliquely.

[0066] The contact portion 41 of the present embodiment includes a first cylindrical surface with the first intersection axis O1 as the central axis. Note that the "first cylindrical surface" refers to a surface formed with a constant radius with respect to the first intersection axis O1. Also, "including the first cylindrical surface" means that at least the portion that contacts the contact member 80 may be the first cylindrical surface, and there may be a flat surface (for example, the chamfered portion 42 shown in FIG. 7) or the like outside the contacting portion.

[0067] On the other hand, the contact portion 81 of the contact member 80 is formed in a curved surface shape centered on a second intersection axis O3 that is not parallel to the first intersection axis O1. The second intersection axis O3 intersects a virtual plane 110 that includes a vertical axis O4 (which may be the first intersection axis O1 in this embodiment) extending in the vertical direction of the installation surface 29a and the displacement axis O2 of the contact member 80. The second intersection axis O3 of this embodiment extends parallel to the installation surface 29a and intersects the virtual plane 110 perpendicularly (at a right angle), but it may intersect the virtual plane 110 obliquely.

[0068] The contact portion 81 of this embodiment includes a second cylindrical surface centered on the second intersection axis O3. Note that the "second cylindrical surface" refers to a surface formed with a constant radius with respect to the second intersection axis O3. Also, "including the second cylindrical surface" means that at least the portion that contacts the positioning pin 40 may be the second cylindrical surface, and there may be planes (for example, the upper and lower parallel planes and the left and right inclined planes of the contact portion 81 shown in FIG. 7) or the like other than the contacting portion.

[0069] Incidentally, if the positioning pin 40 is a block-shaped convex portion and the contact portion 81 of the contact member 80 is an inclined surface, and the inclined surface is brought into contact with the corner portion of the convex portion, the corner portion and the inclined surface are in line contact. However, since there are minute irregularities due to machining accuracy and the like at the corner portion and the inclined surface, the corner portion and the inclined surface are actually in multi-point contact strictly speaking. This multi-point contact state is likely to accumulate errors at each individual contact point, so it may be difficult to accurately position the inkjet head 5 with respect to the carriage 29. On the other hand, according to the above configuration, since the central axes (the first intersection axis O1 and the second intersection axis O3) of the curved surface shapes of the contact portions 41 and 81 are in a twisted positional relationship, the positioning pin 40 and the contact member 80 contact at a single point. By the positioning pin 40 and the contact member 80 contacting at a single point, errors due to multi-point contact between the positioning pin 40 and the contact member 80 can be avoided, and the inkjet head 5 can be accurately positioned with respect to the carriage 29. Further, since the displacement axis O2 extends in an oblique direction intersecting the installation surface 29a, the amount of displacement of the contact member 80 along the installation surface 29a per rotation of the bolt 92 is reduced, and the contact member 80 can be finely displaced with high precision.

[0070] The above is the basic structure of the position adjustment mechanism 60. The second position adjustment unit 50B shown in FIG. 8 is also provided with the same configuration as the Y-direction position adjustment mechanism 60 (the second position adjustment mechanism 60B) of the first position adjustment unit 50A. The X-direction position adjustment mechanism (the first position adjustment mechanism 60A) is provided with its configuration divided between the first position adjustment unit 50A and the second position adjustment unit 50B. Although details will be described later, the first position adjustment unit 50A shown in FIG. 7 is provided with the contact member 80 and the displacement mechanism 90 of the first position adjustment mechanism 60A, and the second position adjustment unit 50B shown in FIG. 8 is provided with the preload mechanism 70 of the first position adjustment mechanism 60A. The preload mechanism 70 of the first position adjustment mechanism 60A is composed of a single leaf spring 70A and is fixed to the side wall portion 56 erected on the -X side of the frame member 51 via a screw member 105.

[0071] <Arrangement of the positioning structure 100> As shown in FIG. 6, the positioning structure 100 includes a first position adjustment mechanism 60A that adjusts the position in the X direction (the first direction) along the installation surface 29a of the base member 30, and a pair of second position adjustment mechanisms 60B that are arranged at intervals in the X direction with respect to the base member 30 and adjust the positions in the Y direction (the second direction) orthogonal to the X direction along the installation surface 29a of the base member 30.

[0072] Further, the positioning structure 100 includes a first positioning pin 40A (first convex portion) and a second positioning pin 40B (second convex portion) disposed with the head body 5A interposed therebetween in the X direction. One of the pair of second position adjustment mechanisms 60B (the second position adjustment mechanism 60B on the side of the first position adjustment unit 50A) adjusts the position of the base member 30 in the Y direction with respect to the first positioning pin 40A. The other of the pair of second position adjustment mechanisms 60B (the second position adjustment mechanism 60B on the side of the second position adjustment unit 50B) adjusts the position of the base member 30 in the Y direction with respect to the second positioning pin 40B.

[0073] The preloading mechanism 70 (leaf spring 70A) of the first position adjustment mechanism 60A is provided on the side of the second position adjustment unit 50B and applies a preload to the second positioning pin 40B in the X direction. The contact member 80 and the displacement mechanism 90 of the first position adjustment mechanism 60A are provided on the side of the first position adjustment unit 50A. The contact member 80 contacts the first positioning pin 40A from the side opposite to the side (-X side) where the preloading mechanism 70 (leaf spring 70A) is disposed in the X direction and displaces in the X direction.

[0074] Each position adjustment mechanism 60 is supported by the base member 30, and at least a part of the position adjustment mechanism 60 is disposed inside the outer shape of the base member 30 in a plan view when viewed from the vertical direction (Z direction) of the installation surface 29a. Note that "inside the outer shape of the base member 30" means inside the outer contour of the plate portion 31 that forms the outermost shape of the base member 30 in a plan view when viewed from the vertical direction (Z direction) of the installation surface 29a.

[0075] Also, each positioning pin 40 is disposed inside the outer shape of the base member 30. That is, as shown in FIG. 5, a first through-hole 33 for disposing the positioning pin 40 is formed inside the outer shape of the base member 30 in the plate portion 31 of the base member 30. That is, the positioning pin 40 is disposed through the base member 30, and since the base member 30 supports the position adjustment mechanism 60, most of the positioning structure 100 is disposed overlapping within the footprint of the inkjet head 5.

[0076] On the plate portion 31 of the base member 30, in the direction in which the preloading mechanism 70 applies preloading, there are provided pressing portions 36, 37 (dovetails) that protrude on the side where the preloading mechanism 70 receives a reaction force from the positioning pin 40. The pressing portion 36 protrudes on the side (-Y side) where the preloading mechanism 70 receives a reaction force from the positioning pin 40 in the Y direction in which the preloading mechanism 70 of the second position adjustment mechanism 60B applies preloading. Further, the pressing portion 37 protrudes on the side (-X side) where the preloading mechanism 70 receives a reaction force from the positioning pin 40 in the X direction in which the preloading mechanism 70 of the first position adjustment mechanism 60A applies preloading.

[0077] On the other hand, the carriage 29 is provided with receiving portions 36A, 37A against which the pressing portions 36, 37 are pressed. The receiving portions 36A, 37A roughly position the inkjet head 5 with respect to the carriage 29 when the pressing portions 36, 37 are pressed. Note that it suffices if the positioning of the inkjet head 5 can be completed when the pressing portions 36, 37 are pressed against the receiving portions 36A, 37A. However, since the pressing portions 36, 37 and the receiving portions 36A, 37A need to be processed with high precision and this is costly, in most cases, fine adjustment of the inkjet head 5 is required. For this reason, it is necessary to adjust the position in the direction along the installation surface 29a of the inkjet head 5 using the positioning structure 100 described above.

[0078] <Method for Positioning the Inkjet Head 5> For example, when the inkjet head 5 shown in FIG. 6 is translated parallel to the +X side with respect to the carriage 29, the bolt 92 of the displacement mechanism 90 of the first position adjustment mechanism 60A is turned to displace the contact member 80 to the -X side with respect to the displacement mechanism 90. Then, the base member 30 to which the displacement mechanism 90 is fixed receives a reaction force from the first positioning pin 40A and translates parallel to the +X side along the installation surface 29a of the carriage 29 against the biasing force of the preloading mechanism 70. As described above, the inkjet head 5 can be translated parallel to the +X side with respect to the carriage 29.

[0079] When the inkjet head 5 is translated parallel to the -X side with respect to the carriage 29, the bolt 92 of the displacement mechanism 90 of the first position adjustment mechanism 60A is turned, and the contact member 80 is displaced to the +X side with respect to the displacement mechanism 90. Then, the base member 30 to which the displacement mechanism 90 is fixed receives a reaction force from the second positioning pin 40B due to the biasing force of the preloading mechanism 70, and is translated parallel to the -X side along the installation surface 29a of the carriage 29. Thus, the inkjet head 5 can be translated parallel to the -X side with respect to the carriage 29.

[0080] When the inkjet head 5 is translated parallel to the +Y side with respect to the carriage 29, the bolts 92 of the displacement mechanisms 90 of the pair of second position adjustment mechanisms 60B are turned, and the contact member 80 is displaced to the -Y side with respect to the displacement mechanism 90. Then, the base member 30 to which the displacement mechanism 90 is fixed receives a reaction force from each of the positioning pins 40, and is translated parallel to the +Y side along the installation surface 29a of the carriage 29 against the biasing force of the preloading mechanism 70. Thus, the inkjet head 5 can be translated parallel to the +Y side with respect to the carriage 29.

[0081] When the inkjet head 5 is translated parallel to the -Y side with respect to the carriage 29, the bolts 92 of the displacement mechanisms 90 of the pair of second position adjustment mechanisms 60B are turned, and the contact member 80 is displaced to the +Y side with respect to the displacement mechanism 90. Then, the base member 30 to which the displacement mechanism 90 is fixed receives a reaction force from the respective positioning pins 40 due to the biasing force of the preloading mechanism 70, and is translated parallel to the -Y side along the installation surface 29a of the carriage 29. Thus, the inkjet head 5 can be translated parallel to the -Y side with respect to the carriage 29.

[0082] When the inkjet head 5 is rotated on the X-Y plane with respect to the carriage 29, the bolts 92 of the displacement mechanisms 90 of the pair of second position adjustment mechanisms 60B are turned to make the displacement amounts (adjustment amounts) in the Y direction of the respective contact members 80 different. Then, the base member 30 to which the displacement mechanism 90 is fixed receives different reaction forces from the respective positioning pins 40 and rotates along the installation surface 29a of the carriage 29. Thus, the inkjet head 5 can be rotated on the X-Y plane with respect to the carriage 29.

[0083] As a procedure for positioning the inkjet head 5 with respect to the carriage 29, first, the spring washer 101a interposed between the screw member 101 and the base member 30 is tightened to some extent by the screw member 101, and the inkjet head 5 is temporarily fixed to the carriage 29 by the biasing force of the spring washer 101a (temporary fixing step). Next, the rotation angle of the inkjet head 5 is adjusted using the pair of second position adjustment mechanisms 60B, and then the inkjet head 5 is translated in the X direction and the Y direction using the first position adjustment mechanism 60A and the pair of second position adjustment mechanisms 60B. When the positioning of the inkjet head 5 with respect to the carriage 29 is completed, the screw member 101 is tightened to fix the base member 30 to the carriage 29. Thus, the installation of the inkjet head 5 with respect to the carriage 29 is completed. Note that the positioning of the inkjet head 5 in the Y direction can be adjusted at the ink ejection timing. Therefore, if the positioning of the inkjet head 5 in the Y direction is not required, the positioning is completed in two steps: the rotation of the inkjet head 5 and the translation of the inkjet head 5 in the X direction. If the positioning of the inkjet head 5 in the Y direction is required, the positioning is completed in three steps: the rotation of the inkjet head 5, the translation of the inkjet head 5 in the Y direction, and the translation of the inkjet head 5 in the X direction.

[0084] FIG. 11 is an explanatory diagram showing the steps after the positioning of the inkjet head 5 according to one embodiment. Once the positioning of the carriage 29 of the inkjet head 5 is completed, as shown in FIG. 11, the positioning structure 100 may be removed. Specifically, the screw member 102 shown in FIG. 9 is removed, and the position adjustment unit 50 is removed from the base member 30. Next, the positioning pin 40 provided with the chamfered portion 42 is turned with a tool such as a driver bit to remove the positioning pin 40 from the carriage 29. Finally, another screw member 101 is screwed into the fixing hole 29c where the positioning pin 40 was fixed, and the base member 30 is fixed to the carriage 29. The positioning structure 100 removed here can be diverted for positioning other inkjet heads 5.

[0085] The above-described positioning structure 100 can also adopt the following modification examples. In the following description, the same or equivalent components as those described above are denoted by the same reference numerals, and the description thereof is simplified or omitted.

[0086] FIG. 12 is a cross-sectional view showing a modification example of the positioning structure 100 according to an embodiment. The positioning structure 100 shown in FIG. 12 is different from the above-described positioning structure 100 in that the positioning pin 40 is provided on the base member 30 side of the inkjet head 5, and the position adjustment mechanism 60 (position adjustment unit 50) is provided on the carriage 29 side.

[0087] The base member 30 shown in FIG. 12 is fixed by a screw member 101 attached via a spring washer 101a to the installation surface 29e facing downward of the carriage 29. The carriage 29 is provided with a fourth through portion 29g through which the positioning pin 40 provided on the base member 30 penetrates in the Z direction, and a groove portion 29h that communicates with the -Z side of the fourth through portion 29g and avoids interference with the flange portion 44 of the positioning pin 40 and the screw member 106.

[0088] The positioning pin 40 has a flange portion 44 at its lower end, and this flange portion 44 is fixed to the upper surface of the base member 30 via a screw member 106. A fixing hole 38 into which the screw member 106 is screwed is formed in the base member 30. A fixing hole 29f for fixing the position adjustment unit 50 is formed in the installation surface 29a (upper surface) of the carriage 29. The position adjustment unit 50 is detachably attached to the installation surface 29a of the carriage 29 by a screw member 102 that is screwed into the fixing hole 29f. Even in the above configuration, by displacing the contact member 80 along the displacement axis O2, the position in the direction along the installation surface 29a of the base member 30 can be adjusted.

[0089] According to the above-described embodiment, the following operational effects can be obtained.

[0090] As shown in FIG. 6, the inkjet head 5 of the present embodiment includes a head body 5A that ejects ink, a base member 30 that supports the head body 5A and is installed on the installation surface 29a of the carriage 29, and a position adjustment mechanism 60 that adjusts the position of the base member 30 in the direction along the installation surface 29a with respect to the positioning pin 40 provided on the installation surface 29a. The position adjustment mechanism 60 is supported by the base member 30, and at least a part of the position adjustment mechanism 60 is disposed inside the outer shape of the base member 30 in a plan view when the installation surface 29a is viewed from the vertical direction.

[0091] According to this configuration, the position adjustment mechanism 60 that positions the inkjet head 5 with respect to the positioning pin 40 provided on the installation surface 29a of the carriage 29 is supported by the base member 30 together with the head body 5A, and at least a part of it is disposed inside the outer shape of the base member 30 in a plan view when the installation surface 29a is viewed from the vertical direction. Therefore, the position adjustment mechanism 60 can be arranged so as to be within the footprint of the inkjet head 5, and the area required for installing the inkjet head 5 can be reduced. As a result, the length of the inkjet head 5 in the printing width direction (X direction) can be suppressed, and the length of the carriage 29 in the printing width direction (X direction) required when installing a plurality of inkjet heads 5 can be shortened.

[0092] Further, in the inkjet head 5 of the present embodiment, as shown in FIG. 5, the base member 30 has a first through portion 33 in which the positioning pin 40 is disposed inside the outer shape of the base member 30. According to this configuration, by providing the first through portion 33 in the base member 30, the positioning pin 40 can be disposed within the footprint of the inkjet head 5, and the area required for installing the inkjet head 5 can be made smaller.

[0093] Further, in the inkjet head 5 of the present embodiment, as shown in FIG. 9, the position adjustment mechanism 60 includes a preloading mechanism 70 that applies a preload to the positioning pin 40 in a direction along the installation surface 29a, a contact member 80 that contacts the positioning pin 40 from the side opposite to the side where the preloading mechanism 70 is disposed in the direction in which the preloading mechanism 70 applies the preload, and a displacement mechanism 90 that displaces the contact member 80 in the direction in which the preloading mechanism 70 applies the preload. According to this configuration, by applying a preload to the positioning pin 40 by the preloading mechanism 70 and displacing the contact member 80 that contacts the positioning pin 40 in the direction of the preload, the base member 30 can be moved following the displacement of the contact member 80. Since it is not necessary to provide the contact member 80 and the displacement mechanism 90 on both sides sandwiching the positioning pin 40 by the preloading mechanism 70, the structure of the position adjustment mechanism 60 can be simplified, lightened, and space-saving.

[0094] Further, in the inkjet head 5 of the present embodiment, the position adjustment mechanism 60 (position adjustment unit 50) is detachably attached to the base member 30. According to this configuration, after the positioning and installation of the inkjet head 5 are completed, the position adjustment mechanism 60 (position adjustment unit 50) can be removed from the base member 30 and reused for positioning other inkjet heads 5, which can contribute to cost reduction.

[0095] Also, in the inkjet head 5 of the present embodiment, as shown in FIG. 6, the position adjustment mechanism 60 includes a first position adjustment mechanism 60A that adjusts the position in the X direction (first direction) along the installation surface 29a of the base member 30, and a pair of second position adjustment mechanisms 60B that are arranged at intervals in the X direction with respect to the base member 30 and adjust the positions in the Y direction (second direction) orthogonal to the X direction along the installation surface 29a of the base member 30, respectively. According to this configuration, the positions in the X direction and Y direction along the installation surface 29a of the base member 30 can be adjusted by the first position adjustment mechanism 60A and the second position adjustment mechanism 60B. Further, by making the adjustment amounts of the positions in the Y direction of the pair of second position adjustment mechanisms 60B different, the rotation angle of the base member 30 can be adjusted.

[0096] Also, in the inkjet head 5 of the present embodiment, the positioning pins 40 include a first positioning pin 40A and a second positioning pin 40B arranged with the head body 5A interposed therebetween in the X direction. One of the pair of second position adjustment mechanisms 60B (the second position adjustment mechanism 60B on the first position adjustment unit 50A side) adjusts the position of the base member 30 in the Y direction with respect to one of the first positioning pin 40A and the second positioning pin 40B (the first positioning pin 40A), and the other of the pair of second position adjustment mechanisms 60B (the second position adjustment mechanism 60B on the second position adjustment unit 50B side) adjusts the position of the base member 30 in the Y direction with respect to the other of the first positioning pin 40A and the second positioning pin 40B (the second positioning pin 40B). According to this configuration, the inkjet head 5 can be positioned by two positioning pins 40 without providing three positioning pins 40 corresponding to each of the three position adjustment mechanisms 60 of the first position adjustment mechanism 60A and the pair of second position adjustment mechanisms 60B. Therefore, the number of positioning pins 40 arranged within the footprint of the inkjet head 5 can be reduced, and the area required for installing the inkjet head 5 can be made smaller.

[0097] Also, in the inkjet head 5 of the present embodiment, the first position adjustment mechanism 60A includes a preloading mechanism 70 that applies a preload in the X direction to one of the first positioning pin 40A and the second positioning pin 40B (the second positioning pin 40B), a contact member 80 that contacts the other of the first positioning pin 40A and the second positioning pin 40B (the first positioning pin 40A) from the side opposite to the side where the preloading mechanism 70 is disposed in the X direction, and a displacement mechanism 90 that displaces the contact member 80 in the X direction. According to this configuration, by disposing the preloading mechanism 70 on the side opposite to the side sandwiching the head body 5A with respect to the contact member 80 and the displacement mechanism 90, the length of the base member 30 in the printing width direction (X direction) can be suppressed compared to the case where all of the preloading mechanism 70, the contact member 80, and the displacement mechanism 90 are disposed on one side of the head body 5A. Thereby, the degree of freedom of the installation space of the inkjet head 5 can be ensured.

[0098] Also, in the inkjet head 5 of the present embodiment, on the outer shape of the base member 30, pressing portions 36, 37 that protrude toward the side where the preloading mechanism 70 receives a reaction force from the positioning pin 40 in the direction in which the preloading mechanism 70 applies the preload are provided. According to this configuration, if the accuracy of the pressing portions 36, 37 is high, the inkjet head 5 can be easily positioned by pressing the pressing portions 36, 37 against the carriage 29 by the reaction force received by the preloading mechanism 70 from the positioning pin 40. Further, when there is a lack of accuracy in the pressing portions 36, 37, the inkjet head 5 can be positioned by displacing the contact member 80 to the side opposite to the pressing direction of the pressing portions 36, 37 to adjust the position of the inkjet head 5.

[0099] The printer 1 according to the present embodiment includes the above-described inkjet head 5 and a carriage 29 as an object for installing the inkjet head 5. According to this printer 1, a printer 1 that reduces the area required for installing the inkjet head 5 and enables compact and highly accurate printing can be obtained.

[0100] Further, in the printer 1 of the present embodiment, the positioning pin 40 is detachably attached to the carriage 29. According to this configuration, once the positioning and installation of the inkjet head 5 are completed, the positioning pin 40 can be removed from the carriage 29 and used for positioning other inkjet heads 5, so that the positioning pin 40 can be reused, contributing to cost reduction. Further, the base member 30 can be fixed to the carriage 29 using the portion where the positioning pin 40 was removed.

[0101] As shown in FIG. 12, the printer 1 according to a modification of the present embodiment includes an inkjet head 5 and a carriage 29 on which the inkjet head 5 is installed. The inkjet head 5 includes a head body 5A that ejects ink, a base member 30 that supports the head body 5A and is installed on the installation surface 29e of the carriage 29, and a positioning pin 40 that protrudes from the base member 30 toward the carriage 29. The carriage 29 includes a position adjustment mechanism 60 that adjusts the position of the positioning pin 40 in a direction along the installation surface 29e of the base member 30. At least a part of the position adjustment mechanism 60 is arranged inside the outer shape of the base member 30 in a plan view when the installation surface 29a is viewed from the vertical direction.

[0102] According to this printer 1, since the positioning pin 40 is provided on the inkjet head 5, the position adjustment mechanism 60 is provided on the carriage 29, and at least a part of the position adjustment mechanism 60 is arranged inside the outer shape of the base member 30 of the inkjet head 5 in a plan view when the installation surface 29e is viewed from the vertical direction, the position adjustment mechanism 60 can be arranged so as to be within the footprint of the inkjet head 5, and the area required for installing the inkjet head 5 can be reduced. As a result, the length of the inkjet head 5 in the printing width direction can be suppressed, and the length of the carriage 29 in the printing width direction required when installing a plurality of inkjet heads 5 can be shortened.

[0103] Further, according to the above-described present embodiment, the following operational effects can be obtained.

[0104] The positioning structure 100 of the present embodiment is a positioning structure 100 for positioning the inkjet head 5 with respect to the carriage 29 of the printer 1, and includes a positioning pin 40 provided on one of the carriage 29 and the inkjet head 5, and a position adjustment mechanism 60 provided on the other of the carriage 29 and the inkjet head 5 for adjusting the position in the direction along the installation surface 29a of the carriage 29 with respect to the positioning pin 40. The position adjustment mechanism 60 includes a contact member 80 that contacts the positioning pin 40, and a displacement mechanism 90 that displaces the contact member 80 along a displacement axis O2 extending in an oblique direction intersecting the vertical direction of the installation surface 29a. One of the contact portions 41 and 81 of the positioning pin 40 and the contact member 80 is formed in a curved surface shape centered on a first intersection axis O1 intersecting the installation surface 29a, and the other of the contact portions 41 and 81 intersects with respect to a virtual plane 110 (see FIG. 10) including a vertical axis O4 (first intersection axis O1) extending in the vertical direction of the installation surface 29a and the displacement axis O2, and is formed in a curved surface shape centered on a second intersection axis O3 that is not parallel to the first intersection axis O1.

[0105] According to this configuration, when the contact member 80 is displaced in an oblique direction intersecting the vertical direction of the installation surface 29a by the displacement mechanism 90, the positioning pin 40 contacting the contact member 80 is pushed in the direction along the installation surface 29a, and the inkjet head 5 is displaced with respect to the carriage 29. Here, one of the contact portions 41 and 81 is formed in a curved surface shape centered on the first intersection axis O1 intersecting the installation surface 29a, and the other of the contact portions 41 and 81 intersects with respect to a virtual plane 110 including a vertical axis extending in the vertical direction of the installation surface 29a and the displacement axis O2, and is formed in a curved surface shape centered on a second intersection axis O3 that is not parallel to the first intersection axis O1. Since the central axes of the curved surface shapes of the contact portions 41 and 81 are in a twisted positional relationship, the positioning pin 40 and the contact member 80 contact at one point. By the positioning pin 40 and the contact member 80 contacting at one point, it is possible to avoid errors due to multi-point contact between the positioning pin 40 and the contact member 80, and it is possible to accurately position the inkjet head 5 with respect to the carriage 29.

[0106] In addition, in the positioning structure 100 of the present embodiment, one of the contact portions 41 and 81 (contact portion 41) includes a first cylindrical surface centered on the first intersecting axis O1, and the other of the contact portions 41 and 81 (contact portion 81) includes a second cylindrical surface centered on the second intersecting axis O3. According to this configuration, one of the contact portions 41 of the positioning pin 40 has a first cylindrical surface centered on the first intersecting axis O1, and the contact portion 81 of the contact member 80 has a second cylindrical surface centered on the second intersecting axis O3. Since the central axes of both (the first intersecting axis O1 and the second intersecting axis O3) intersect each other, the positioning pin 40 and the contact member 80 can always be stably brought into contact at one point.

[0107] In addition, in the positioning structure 100 of the present embodiment, the contact portion 41 of the positioning pin 40 includes a first cylindrical surface extending in the vertical direction of the installation surface 29a, and the contact portion 81 of the contact member 80 includes a second cylindrical surface extending parallel to the installation surface 29a. According to this configuration, since the contact portion 41 of the positioning pin 40 includes a first cylindrical surface extending in the vertical direction of the installation surface 29a, and the contact portion 81 of the contact member 80 includes a second cylindrical surface extending parallel to the installation surface 29a, the positioning pin 40 and the contact member 80 always stably come into contact at one point, and the contact member 80 that comes into contact with the positioning pin 40 at one point can be prevented from shifting in the direction along the installation surface 29a (X-Y plane direction) with respect to the positioning pin 40.

[0108] In addition, in the positioning structure 100 of the present embodiment, the displacement mechanism 90 has a guide portion 91 that extends obliquely along the displacement axis O2 and guides the contact member 80. According to this configuration, the contact member 80 can be accurately displaced obliquely along the guide portion 91.

[0109] In addition, in the positioning structure 100 of the present embodiment, the contact member 80 has a clamping portion 82 that clamps the guide portion 91 in a direction orthogonal to the displacement axis O2. According to this configuration, by clamping the guide portion 91 with the clamping portion 82 provided on the contact member 80, it is possible to prevent the contact member 80 from rotating about the displacement axis O2.

[0110] Further, in the positioning structure 100 of the present embodiment, the displacement mechanism 90 extends along the displacement axis O2, and includes a bolt 92 that screw-feeds the contact member 80, and a first support portion 94 provided at one end of the guide portion 91, which supports the head of the bolt 92 and has a first insertion hole 94a through which the shaft portion of the bolt 92 is inserted, and a compression spring 93 disposed between the first support portion 94 and the contact member 80. According to this configuration, when the bolt 92 serving as the displacement axis O2 is rotated, the contact member 80 having the clamping portion 82 and restricted from rotating with respect to the guide portion 91 is screw-fed. At this time, the gap between the first support portion 94 and the contact member 80 widens, but since the compression spring 93 extends to fill this gap, it is possible to prevent the head of the bolt 92 from floating from the first support portion 94.

[0111] Further, in the positioning structure 100 of the present embodiment, the displacement mechanism 90 has a second support portion 95 provided at the other end of the guide portion 91 and having a second insertion hole 95a through which the shaft portion of the bolt 92 is inserted. According to this configuration, by inserting the shaft portion of the bolt 92 into the second insertion hole 95a of the second support portion 95, both ends of the bolt 92 can be pivotally supported by the first support portion and the second support portion 95, so that the axial play of the bolt 92 can be suppressed and the contact member 80 can be displaced with high precision.

[0112] Further, in the positioning structure 100 of the present embodiment, the position adjustment mechanism 60 includes a preloading mechanism 70 that applies a preload to the positioning pin 40 in the direction along the installation surface 29a from the side opposite to the side where the contact member 80 is disposed. According to this configuration, by applying a preload to the positioning pin 40 by the preloading mechanism 70 and displacing the contact member 80 that contacts the positioning pin 40 in the direction of the preload, the base member 30 can be moved following the displacement of the contact member 80. With this preloading mechanism 70, it is not necessary to provide the contact member 80 and the displacement mechanism 90 on both sides sandwiching the positioning pin 40, so that the structure of the position adjustment mechanism 60 can be simplified, lightened, and space can be saved.

[0113] The inkjet head 5 according to this embodiment includes either the position adjustment mechanism 60 or the positioning pin 40 of the positioning structure 100 described above. According to this inkjet head 5, an inkjet head 5 capable of performing high-precision printing can be obtained.

[0114] The printer 1 according to this embodiment includes the positioning structure 100 described above. According to this printer 1, high-precision printing can be performed.

[0115] The printer 1 according to this embodiment includes an inkjet head 5, a carriage 29 on which the inkjet head 5 is installed, and the positioning structure 100 described above that positions the inkjet head 5 with respect to the carriage 29. According to this printer 1, the inkjet head 5 can be accurately positioned with respect to the carriage 29 of the printer 1, and high-precision printing can be performed.

[0116] As described above, the preferred embodiments of the present disclosure have been described and explained. However, it should be understood that these are exemplary of the present disclosure and should not be considered as limiting. Additions, omissions, substitutions, and other changes can be made without departing from the scope of the present disclosure. Therefore, the present disclosure should not be regarded as being limited by the foregoing description, but rather by the scope of the claims.

[0117] For example, in the above-described embodiment, the detachable positioning pin 40 is exemplified as the convex portion of the positioning structure 100, but the present invention is not limited to this configuration. The convex portion of the positioning structure 100 may be integrally provided on the inkjet head 5 or the carriage 29 and may be non-detachable.

[0118] Also, for example, in the above-described embodiment, the positioning unit 50 in which a part of the first position adjustment mechanism 60A and the second position adjustment mechanism 60B are unitized is exemplified, but the present invention is not limited to this configuration. The first position adjustment mechanism 60A and the second position adjustment mechanism 60B may be individually attached to the inkjet head 5 or the carriage 29.

[0119] Further, for example, in the above-described embodiment, the contact portion 41 of the positioning pin 40 and the contact portion 81 of the contact member 80 are exemplified in a form including cylindrical surfaces, but the present invention is not limited to this configuration. The contact portions 41 and 81 may have any curved surface as long as they are in contact with each other at a single point. That is, the "curved surface" may be not only a curved surface having a true circle cross-section formed with a constant radius from the central axis, but also, for example, a curved surface having an elliptical cross-section, a curved surface definable by a quadratic function or the like.

[0120] Further, for example, in the above-described embodiment, as an example of the liquid ejection recording apparatus, an inkjet printer has been described as an example, but the present invention is not limited to printers. For example, a facsimile machine, an on-demand printer, or the like may be used. In the above-described embodiment, the configuration in which the inkjet head moves with respect to the recording medium during printing (so-called shuttle mechanism) has been described as an example, but the present invention is not limited to this configuration. The configuration according to the present disclosure may be adopted in a configuration in which the recording medium is moved with respect to the inkjet head while the inkjet head is fixed (so-called fixed head mechanism). In the above-described embodiment, the case where the recording medium P is paper has been described, but the present invention is not limited to this configuration. The recording medium P is not limited to paper, and may be a metal material, a resin material, or food. In the above-described embodiment, the configuration in which the liquid ejection head is mounted on the liquid ejection recording apparatus has been described, but the present invention is not limited to this configuration. That is, the liquid ejected from the liquid ejection head is not limited to that which lands on the recording medium, and may be, for example, a chemical solution to be blended in a preparation, a food additive such as a seasoning or a fragrance to be added to food, an aromatic agent to be ejected into the air, or the like. In the above-described embodiment, the configuration in which the Z direction coincides with the gravitational direction has been described, but the present invention is not limited to this configuration only, and the Z direction may be along the horizontal direction. In the above-described embodiment, the configuration in which the first direction coincides with the X direction and the second direction coincides with the Y direction has been described, but the present invention is not limited to this configuration. The first direction and the second direction may be defined separately from the X direction and the Y direction.

Explanation of Reference Numerals

[0121] 1 … Printer (Liquid Jet Recording Device) 5 … Ink Jet Head (Liquid Jet Head) 5A … Head Body (Injection Section) 29 … Carriage (Head Installation Section) 29a … Installation Surface 29e … Installation Surface 30 … Base Member 33 … First Through Hole (Through Hole) 36 … Pressing Section 37 … Pressing Section 40 … Positioning Pin (Protrusion) 40A … First Positioning Pin (First Protrusion) 40B … Second Positioning Pin (Second Protrusion) 41 … Contact Section 60 … Position Adjustment Mechanism 60A … First Position Adjustment Mechanism 60B … Second Position Adjustment Mechanism 70 … Preloading Mechanism 80 … Contact Member 81 … Contact Section 82 … Clamping Section 90 … Displacement Mechanism 91 … Guide Section 92 … Bolt 93 … Compression Spring 94 … First Support Section 94a … First Insertion Hole 95 … Second Support Section 95a … Second Insertion Hole 100 … Positioning Structure 110 … Virtual Plane O1 … First Intersecting Axis O2 … Displacement Axis O3 … Second Intersecting Axis O4 … Vertical Axis

Claims

1. A positioning structure for positioning a liquid ejection head with respect to a head installation portion of a liquid ejection recording apparatus, a convex portion provided on one of the head installation portion and the liquid ejection head, and a position adjustment mechanism provided on the other of the head installation portion and the liquid ejection head for adjusting a position in a direction along the installation surface of the head installation portion with respect to the convex portion, wherein the position adjustment mechanism includes a contact member that contacts the convex portion, and a displacement mechanism that displaces the contact member along a displacement axis extending in an oblique direction intersecting the vertical direction of the installation surface, wherein one of the contact portions of the convex portion and the contact member is formed in a curved surface shape having a first intersection axis intersecting the installation surface as a central axis, and the other of the contact portions is formed in a curved surface shape intersecting a virtual plane including a vertical axis extending in the vertical direction of the installation surface and the displacement axis and having a second intersection axis not parallel to the first intersection axis as a central axis, one of the contact portions includes a first cylindrical surface having the first intersection axis as a central axis, the other of the contact portions includes a second cylindrical surface having the second intersection axis as a central axis, the contact portion of the convex portion includes the first cylindrical surface extending in the vertical direction of the installation surface, and the contact portion of the contact member includes the second cylindrical surface extending parallel to the installation surface. The positioning structure is characterized by this.

2. The displacement mechanism has a guide portion that extends in the oblique direction and guides the contact member. The positioning structure according to claim 1 is characterized by this.

3. The contact member has a clamping portion that clamps the guide portion in a direction orthogonal to the displacement axis. The positioning structure according to claim 2 is characterized by this.

4. A positioning structure for positioning a liquid ejection head with respect to a head installation portion of a liquid ejection recording apparatus, a convex portion provided on one of the head installation portion and the liquid ejection head, and a position adjustment mechanism provided on the other of the head installation portion and the liquid ejection head for adjusting a position in a direction along the installation surface of the head installation portion with respect to the convex portion, wherein the position adjustment mechanism includes a contact member that contacts the convex portion, and a displacement mechanism that displaces the contact member along a displacement axis extending in an oblique direction intersecting the vertical direction of the installation surface, One of the contact portions of the convex portion and the contact member is formed in a curved surface shape with a first intersection axis intersecting the installation surface as a central axis, and the other of the contact portions intersects with a virtual plane including a vertical axis extending in the vertical direction of the installation surface and the displacement axis, and is formed in a curved surface shape with a second intersection axis that is not parallel to the first intersection axis as a central axis. The displacement mechanism has a guide portion that extends in the diagonal direction and guides the contact member. The contact member has a sandwiching portion that sandwiches the guide portion in a direction orthogonal to the displacement axis. The positioning structure is characterized by this.

5. The displacement mechanism is a bolt that extends along the displacement axis and feeds the contact member by screw, a first support portion provided at one end of the guide portion, supporting the head of the bolt, and having a first insertion hole through which the shaft portion of the bolt is inserted, and a compression spring disposed between the first support portion and the contact member. The positioning structure according to any one of claims 2 to 4 is characterized by this.

6. A positioning structure for positioning a liquid ejection head with respect to a head installation portion of a liquid ejection recording apparatus, a convex portion provided on one of the head installation portion and the liquid ejection head, and a position adjustment mechanism provided on the other of the head installation portion and the liquid ejection head, and adjusting the position of the convex portion in a direction along the installation surface of the head installation portion. The position adjustment mechanism is a contact member that contacts the convex portion, and a displacement mechanism that displaces the contact member along a displacement axis extending in an oblique direction intersecting the vertical direction of the installation surface. One of the contact portions of the convex portion and the contact member is formed in a curved surface shape with a first intersection axis intersecting the installation surface as a central axis, and the other of the contact portions intersects with a virtual plane including a vertical axis extending in the vertical direction of the installation surface and the displacement axis, and is formed in a curved surface shape with a second intersection axis that is not parallel to the first intersection axis as a central axis. The displacement mechanism is a guide portion that extends in the diagonal direction and guides the contact member, a bolt that extends along the displacement axis and feeds the contact member by screw, a first support portion provided at one end of the guide portion, supporting the head of the bolt, and having a first insertion hole through which the shaft portion of the bolt is inserted, and a compression spring disposed between the first support portion and the contact member. The positioning structure is characterized by this.

7. The positioning structure according to claim 5 or 6, wherein the displacement mechanism has a second support portion provided at the other end of the guide portion and having a second insertion hole through which the shaft portion of the bolt is inserted.

8. The positioning structure according to any one of claims 1 to 7, wherein the position adjustment mechanism includes a preloading mechanism that applies a preload to the convex portion in a direction along the installation surface from the side opposite to the side where the contact member is disposed.

9. An inkjet head, comprising any one of the position adjustment mechanism and the convex portion of the positioning structure according to any one of claims 1 to 8.

10. An inkjet recording apparatus, comprising the positioning structure according to any one of claims 1 to 8.

11. An inkjet head, a carriage on which the inkjet head is installed, and a positioning structure according to any one of claims 1 to 8 for positioning the inkjet head with respect to the carriage.

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