Head unit, liquid injection device, and method for fixing the head unit

Abstract

Reduces deviation in the point of impact of liquids. [Solution] A head unit fixed to a main frame, comprising: a head module having a plurality of liquid spray heads having spray surfaces including nozzles that spray liquid in a first direction, and a head support member that supports the plurality of liquid spray heads; a first module support member having a reference surface with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction; and a first position adjustment mechanism that adjusts the relative position between the head module and the first module support member in order to adjust the relative position between the spray surface and the reference surface, wherein the first position adjustment mechanism is capable of relatively rotating the head module and the first module support member with each of the following as a pivot axis: a first axis along the first direction, a second axis along the second direction, and a third axis along the third direction perpendicular to both the first and second directions.

Description

Technical Field

[0001] The present disclosure relates to a head unit, a liquid ejection device, and a method for fixing a head unit.

Background Art

[0002] Patent Document 1 describes a liquid ejection device that is an inkjet printing device. The liquid ejection device described in Patent Document 1 includes a head unit including a plurality of liquid ejection heads, a sub carriage, and a carriage. Here, a plurality of liquid ejection heads are fixed to the sub carriage, and the sub carriage is fixed to the carriage by screws.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the liquid ejection device described in Patent Document 1, since a structure composed of a plurality of liquid ejection heads and a sub carriage is directly fixed to a highly rigid carriage, if there are manufacturing errors on the mutual mounting surfaces of the structure and the carriage, when fixing the structure and the carriage, warping may occur in the structure due to stress. As a result, there is a risk that the landing position of the ink on the printing medium will shift when ink is ejected from the liquid ejection head toward the printing medium.

Means for Solving the Problems

[0005] To solve the above problems, a head unit according to a preferred embodiment of the present disclosure is a head unit fixed to a main frame, comprising: a head module having a plurality of liquid injection heads having injection surfaces including nozzles for injecting liquid in a first direction; and a head support member for supporting the plurality of liquid injection heads; a first module support member having a reference surface with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction; and a first position adjustment mechanism for adjusting the relative position between the head module and the first module support member in order to adjust the relative position between the injection surface and the reference surface, wherein the first position adjustment mechanism is capable of relatively rotating the head module and the first module support member with each of the following as a pivot axis: a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions.

[0006] A liquid injection device according to a preferred embodiment of the present disclosure comprises a head unit as described above and a main body frame, wherein the main body frame supports the head unit by being fixed to the first module support member with the reference plane supporting the first module support member.

[0007] A preferred embodiment of the present disclosure is a head unit fixing method for fixing a head unit to a main frame, comprising: a head module having a plurality of liquid injection heads having injection surfaces including nozzles for injecting liquid in a first direction, and a head support member for supporting the plurality of liquid injection heads; a first module support member having a reference surface with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction; and a first position adjustment mechanism for adjusting the relative position between the head module and the first module support member in order to adjust the relative position between the injection surface and the reference surface, wherein the relative position between the head module and the first module support member is adjusted by using the first position adjustment mechanism to rotate the head module and the first module support member relative to each of the following axes: a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a liquid injection device according to an embodiment. [Figure 2] This is a plan view of the head unit according to the embodiment. [Figure 3] This is a disassembled perspective view of the liquid spray head. [Figure 4] This is a cross-sectional view along line AA in Figure 2. [Figure 5] This is a view of the first position adjustment mechanism in the Y2 direction. [Figure 6] This is a diagram showing the first position adjustment mechanism as viewed in the Z2 direction. [Figure 7] This is a view of the first position adjustment mechanism in the X2 direction. [Figure 8] This is an explanatory diagram of the head fixing method according to the embodiment. [Modes for carrying out the invention]

[0009] 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.

[0010] 1. Embodiment 1-1. Schematic Configuration of Liquid Injection System Figure 1 is a schematic diagram of a liquid injection device 100 according to an embodiment. For convenience, the following explanation will use the X, Y, and Z axes, which intersect with each other, as appropriate. In the following, one direction along the X axis is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. The X1 or X2 direction is an example of a "second direction". Similarly, opposite directions along the Y axis are the Y1 and Y2 directions. The Y1 or Y2 direction is an example of a "third direction". Also, opposite directions along the Z axis are the Z1 and Z2 directions. The Z2 direction is a "first direction". Typically, the Z axis is a vertical axis, and the Z2 direction corresponds to the downward direction in the vertical direction. However, the Z axis does not have to be a vertical axis. In the following, the X1 and X2 directions may be collectively referred to as the X-axis direction. The Y1 and Y2 directions may be collectively referred to as the Y-axis direction. The Z1 and Z2 directions are sometimes collectively referred to as the X-axis direction.

[0011] The liquid ejection device 100 is an inkjet printing device that ejects ink, which is an example of a "liquid," as droplets onto the printing medium M. The printing medium M is typically printing paper. However, the printing medium M is not limited to printing paper and may be any material to be printed on, such as resin film or fabric.

[0012] As shown in Figure 1, the liquid injection device 100 includes a liquid storage unit 10, a control unit 20, a transport mechanism 30, and a head unit 40.

[0013] The liquid storage section 10 is a container for storing ink. Specific examples of the liquid storage section 10 include, for example, a cartridge detachable from the liquid injection device 100, a bag-shaped ink pack made of a flexible film, and an ink tank from which ink can be refilled.

[0014] Although not shown in the diagram, the liquid storage section 10 has multiple containers for storing different types of ink. The inks stored in these multiple containers are not particularly limited, but examples include cyan ink, magenta ink, yellow ink, black ink, clear ink, white ink, and processing liquid, and a combination of two or more of these is used. The composition of the ink is not particularly limited, and may be, for example, an aqueous ink in which a colorant such as a dye or pigment is dissolved in an aqueous solvent, a solvent-based ink in which a colorant is dissolved in an organic solvent, or an ultraviolet-curable ink.

[0015] The control unit 20 controls the operation of each element of the liquid injection device 100. For example, the control unit 20 includes 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. The control unit 20 outputs a drive signal D and a control signal S toward the liquid injection head 50. The drive signal D is a signal that includes a drive pulse that drives the drive element of the liquid injection head 50. The control signal S is a signal that specifies whether or not to supply the drive signal D to the drive element.

[0016] The transport mechanism 30 transports the printing medium M in the transport direction DM under the control of the control unit 20. In the example shown in Figure 1, the transport direction DM is the Y1 direction. In the example shown in Figure 1, the transport mechanism 30 includes a long transport roller along the X axis and a motor (not shown) that rotates the transport roller. The transport mechanism 30 is not limited to a configuration using a transport roller; for example, it may also use a drum or an endless belt that transports the printing medium M while it is attracted to the outer surface by electrostatic force or the like.

[0017] Under the control of the control unit 20, the head unit 40 injects the ink supplied from the liquid storage unit 10 as droplets toward the printing medium M in the Z2 direction. In the present embodiment, the head unit 40 is a line head unit having the longitudinal direction in the X-axis direction and can inject ink over the entire width of the printing medium M. By performing this injection in parallel with the conveyance of the printing medium M by the conveyance mechanism 30, a predetermined image by ink is formed on the surface of the printing medium M.

[0018] 1-2. Head Unit FIG. 2 is a plan view of the head unit 40 according to the embodiment. In FIG. 2, a view of the head unit 40 in the Z1 direction is shown. In FIG. 2, for convenience of explanation, the first module support member 70-1, the second module support member 70-2, and the main body frame 90, which will be described later, are schematically shown by a two-dot chain line.

[0019] The liquid injection device 100 includes a main body frame 90 in addition to the head unit 40 and the like.

[0020] The main body frame 90 is a main structure that supports the entire liquid injection device 100, and is, for example, a housing of the liquid injection device 100 or a member fixed to the housing. The main body frame 90 is a substantially rigid body and is made of, for example, metal or the like. Note that the shape of the main body frame 90 is not limited to the example shown in FIG. 2 and is arbitrary.

[0021] The head unit 40 is an assembly fixed to the main body frame 90 and having a function of injecting ink. The head unit 40 includes a head module 5, a first module support member 70-1, a first position adjustment mechanism 80-1, a second module support member 70-2, and a second position adjustment mechanism 80-2. Hereinafter, the outline of each part of the head unit 40 will be described in order.

[0022] The head module 5 is a structure having multiple liquid injection heads 50 and a head support member 60. In this embodiment, the head module 5 is a line head module with the X-axis direction as the longitudinal direction so that multiple nozzles N are distributed across the entire width of the printing medium M. The number of liquid injection heads 50 in the head module 5 is not limited to the example shown in Figure 2, but is arbitrary.

[0023] The liquid spray head 50 has a spray surface FN that includes a nozzle N that sprays ink in the Z2 direction. In the example shown in Figure 2, each liquid spray head 50 has multiple head tips 54. Note that the number of head tips 54 on the liquid spray head 50 is not limited to the example shown in Figure 2 and can be arbitrary.

[0024] Each head chip 54 has multiple nozzles N. In the example shown in Figure 2, the multiple nozzles N are divided into two nozzle rows. Each nozzle row is a collection of multiple nozzles N arranged linearly in a direction inclined with respect to the Y axis. Although not shown, each nozzle N in the head chip 54 has a piezoelectric element, which is a driving element, and a cavity for containing ink. Here, the piezoelectric element causes ink to be ejected from the nozzle corresponding to the cavity by changing the pressure in the cavity corresponding to the piezoelectric element. Such a head chip 54 can be obtained, for example, by bonding together multiple substrates such as silicon substrates that have been appropriately processed by etching or the like using an adhesive. Note that instead of the piezoelectric element, a heater that heats the ink in the cavity may be used as the driving element for ejecting ink from the nozzle.

[0025] The injection surface FN is the surface of the nozzle plate of the head tip 54, which will be described later. The nozzle plate is a substrate through which the aforementioned multiple nozzles N open. The position and orientation of the nozzle plate are defined by the fixing plate 55, which will be described later.

[0026] The head support member 60 is a member that supports multiple liquid injection heads 50. The head support member 60 is essentially a rigid body and is made of, for example, metal. Multiple liquid injection heads 50 are fixed to the head support member 60 by screws or the like. Note that the shape of the head support member 60 is not limited to the example shown in Figure 2 and is arbitrary.

[0027] The head support member 60 is provided with two positioning holes 61-1 and 61-2. Positioning hole 61-1 is a hole that penetrates the head support member 60 in the Z-axis direction at the end of the head support member 60 in the X1 direction. A positioning pin 71-1 of the first module support member 70-1, described later, is inserted into positioning hole 61-1. Positioning hole 61-2 is a hole that penetrates the head support member 60 in the Z-axis direction at the end of the head support member 60 in the X2 direction. A positioning pin 71-2, described later, is inserted into positioning hole 61-2. Details of positioning holes 61-1 and 61-2 will be explained later with reference to Figure 4.

[0028] Furthermore, a flange 62-1 is provided at the end of the head support member 60 in the X1 direction. One end of spring 6-1 is attached to flange 62-1. The other end of spring 6-1 is attached to the first module support member 70-1. On the other hand, a flange 62-2 is provided at the end of the head support member 60 in the X2 direction. One end of spring 6-2 is attached to flange 62-2. The other end of spring 6-2 is attached to the second module support member 70-2. Details of springs 6-1 and 6-2 will be explained later with reference to Figure 4.

[0029] The first module support member 70-1 and the second module support member 70-2 are members that support the head module 5 and are fixed to the main frame 90 by screws or the like. Here, the first module support member 70-1 supports the head module 5 at its end in the X1 direction. On the other hand, the second module support member 70-2 supports the head module 5 at its end in the X2 direction, which is opposite to the XX1 direction.

[0030] The first module support member 70-1 and the second module support member 70-2 are essentially rigid bodies and are made of, for example, metal. The shape of the head support member 60 is not limited to the example shown in Figure 2, but is arbitrary.

[0031] Although not shown in Figure 2, the first module support member 70-1 is provided with a positioning pin 71-1, which will be described later. On the other hand, the second module support member 70-2 is provided with a positioning pin 71-2, which will be described later. Details of the positioning pins 71-1 and 71-2 will be explained later with reference to Figure 4.

[0032] The first position adjustment mechanism 80-1 and the second position adjustment mechanism 80-2 are mechanisms for adjusting the relative position between the head module 5 and the first module support member 70-1 or the second module support member 70-2. Here, the first position adjustment mechanism 80-1 adjusts the relative position between the head module 5 and the first module support member 70-1 in order to adjust the relative position between the injection surface FN and the reference surface FB described later. The second position adjustment mechanism 80-2 adjusts the relative position between the head module 5 and the second module support member 70-2 in order to adjust the relative position between the injection surface FN and the reference surface FB described later.

[0033] 1-3. Liquid spray head Figure 3 is an exploded perspective view of the liquid injection head 50. As shown in Figure 3, the liquid injection head 50 includes a flow channel structure 51, a substrate unit 52, a holder 53, a plurality of head tips 54, and a fixing plate 55.

[0034] The flow channel structure 51, substrate unit 52, holder 53, multiple head chips 54, and fixing plate 55 are arranged in that order, stacked in the Z2 direction. These are joined to each other as appropriate by screws or adhesive. The parts of the liquid injection head 50 will be described sequentially below.

[0035] The flow channel structure 51 is a structure that has one or more flow channels inside for supplying ink stored in the liquid reservoir 10 to a plurality of head chips 54. The flow channel structure 51 is not shown, but is composed of a laminate formed by stacking a plurality of substrates in the Z-axis direction. Each of the plurality of substrates is appropriately provided with grooves and holes for the supply channels described later, a filter chamber having a filter for capturing foreign matter contained in the ink, etc. The plurality of substrates are joined to each other by means of adhesive, brazing, welding or screw fastening, etc. Sheet-like sealing members made of rubber material or the like may be appropriately placed between the plurality of substrates as needed. The number or thickness of the substrates constituting the flow channel structure 51 is determined according to the shape of the supply channels, etc., and is not particularly limited and is arbitrary. Each of the plurality of substrates is not particularly limited and is composed of, for example, metal, ceramics or a resin composition.

[0036] Although not shown in the diagram, the flow channel structure 51 is provided with two supply channels, one for each of the two types of ink. Each of the two supply channels has one inlet for receiving ink and one outlet for discharging ink. Each inlet of each supply channel is located on the surface of the flow channel structure 51 facing the Z1 direction. Conversely, each outlet of each supply channel is located on the surface of the flow channel structure 51 facing the Z2 direction.

[0037] Multiple connecting pipes 51a are provided on the surface of the flow channel structure 51 facing the Z1 direction. Each of the multiple connecting pipes 51a is a tubular body that protrudes from the surface of the flow channel structure 51 facing the Z1 direction. In the example shown in Figure 3, two connecting pipes 51a corresponding to the two supply channels mentioned above are provided on the flow channel structure 51, and each connecting pipe 51a is connected to the inlet of the corresponding supply channel. Separate ink tubes are connected to the two connecting pipes 51a to receive the supply of different types of ink, and these ink tubes are connected to the liquid storage section 10 mentioned above.

[0038] Furthermore, the channel structure 51 is provided with multiple wiring holes 51b for passing the wiring 52c of the substrate unit 52, which will be described later. The channel structure 51 is also provided with holes (not shown), and is fixed to the holder 53 by screw fastening through these holes.

[0039] The substrate unit 52 is an assembly having mounting components for electrically connecting the liquid injection head 50 to the control unit 20. The substrate unit 52 includes a circuit board 52a, a connector 52b, and wiring 52c.

[0040] The circuit board 52a is a printed circuit board such as a rigid wiring board having wiring for electrically connecting each head chip 54 to the connector 52b. The circuit board 52a is positioned between the flow channel structure 51 and the holder 53, and the connector 52b is installed on the surface of the circuit board 52a facing the Z1 direction. The circuit board 52a is provided with a plurality of wiring holes 52d through which the wiring board 54i of the head chip 54 passes. As a result, the wiring board 54i is connected to the surface of the circuit board 52a facing the Z1 direction through the wiring holes 52d.

[0041] Connector 52b is a connecting component that is electrically connected to circuit board 52a. Wiring 52c is connected to connector 52b. Wiring 52c is a flexible wiring board such as COF (Chip On Film), FPC (Flexible Printed Circuit), or FFC (Flexible Flat Cable) for electrically connecting connector 52b and control unit 20. Circuit board 52a is fixed to the flow path structure 51 or holder 53 by screws or the like.

[0042] The holder 53 is a structure that houses and supports multiple head chips 54. The holder 53 is made of, for example, a metal, ceramic, or resin composition. The holder 53 is provided with a recess 53a and multiple wiring holes 53b. The recess 53a opens toward the Z2 direction and is a space in which multiple head chips 54 are arranged. Each of the multiple wiring holes 53b is a hole through which the wiring board 54i of the head chip 54 passes toward the board unit 52. The recess 53a may be composed of multiple recesses, each divided for each head chip 54.

[0043] Although not shown in the diagram, the holder 53 includes one or more channels for supplying each head chip 54 and also functions as a channel structure. Therefore, the supply channels of the channel structure 51 are connected to the head chips 54 via the channels of the holder 53. Such a holder 53 may be composed of a laminate of multiple substrates stacked in the Z-axis direction, similar to the channel structure 51. Note that the channels of the holder 53 may be provided as needed or omitted. In this case, the supply channels of the channel structure 51 are connected to the head chips 54 without going through the channels of the holder 53.

[0044] Each head chip 54 is provided with a wiring board 54i. The wiring board 54i is a mounting component for electrically connecting the control unit 20 and the head chip 54. The wiring board 54i is, for example, a flexible wiring board. In this embodiment, a drive circuit 54j for supplying a drive voltage to each piezoelectric element of the head chip 54 is mounted on the wiring board 54i. The drive circuit 54j is a circuit that includes a switching element that, based on a control signal S, switches whether or not to supply at least a portion of the waveform included in the drive signal D as a drive pulse to the drive element.

[0045] The fixing plate 55 is a plate-shaped member to which multiple head tips 54 and a holder 53 are fixed, and includes multiple exposed openings 55a corresponding to each head tip 54. Each exposed opening 55a exposes multiple nozzles N of the corresponding head tip 54 to the outside. The fixing plate 55 is positioned so as to sandwich the multiple head tips 54 between it and the holder 53, and each head tip 54 and holder 53 are fixed together with adhesive or the like.

[0046] 1-4. First position adjustment mechanism and second position adjustment mechanism Figure 4 is a cross-sectional view taken along line AA in Figure 2. In Figure 4, the relationship between the head support member 60, the first module support member 70-1, the second module support member 70-2, the first position adjustment mechanism 80-1, and the second position adjustment mechanism 80-2 in the head unit 40 is schematically shown. For the sake of explanation, springs 6-1 and 6-2 are shown in the foreground of Figure 4.

[0047] Each of the first module support member 70-1 and the second module support member 70-2 has a reference surface FB with respect to the main frame 90. In the example shown in Figure 4, the reference surface FB is the plate surface of each of the first module support member 70-1 and the second module support member 70-2 facing the Z2 direction.

[0048] Here, the main frame 90 supports the head unit 40 by being fixed to the first module support member 70-1 while supporting it on the reference surface FB. This makes it possible to reduce the deviation of the ink's landing position on the printing medium M when ink is sprayed from the liquid spray head 50 toward the printing medium M by adjusting the relative position and relative orientation between the reference surface FB and the spray surface FN.

[0049] As shown in Figure 4, a positioning pin 71-1 is inserted into a positioning hole 61-1 provided at the end of the head support member 60 in the X1 direction. On the other hand, a positioning pin 71-2 is inserted into a positioning hole 61-2 provided at the end of the head support member 60 in the X2 direction.

[0050] By inserting the positioning pins 71-1 and 71-2 into the positioning holes 61-1 and 61-2 in this manner, the orientation of the head support member 60 around the Z-axis is positioned. This positions the orientation of the head module 5 around the Z-axis. However, one or both of the positioning holes 61-1 and the positioning pins 71-1 are configured to allow adjustment by the first position adjustment mechanism 80-1. Similarly, one or both of the positioning holes 61-2 and the positioning pins 71-2 are configured to allow adjustment by the second position adjustment mechanism 80-2.

[0051] Furthermore, one end of spring 6-1 is attached to flange 62-1, which is provided at the X1 end of head support member 60, and the other end of spring 6-1 is attached to first module support member 70-1. When attached in this manner, spring 6-1 is extended in the Z-axis direction and biases the first module support member 70-1 toward head support member 60 in the Z1 direction. On the other hand, one end of spring 6-2 is attached to flange 62-2, which is provided at the X2 end of head support member 60, and the other end of spring 6-2 is attached to second module support member 70-2. When attached in this manner, spring 6-2 is extended in the Z-axis direction and biases the second module support member 70-2 toward head support member 60 in the Z1 direction.

[0052] Here, the first position adjustment mechanism 80-1 adjusts the relative position between the head module 5 and the first module support member 70-1 by adjusting the relative position between the head support member 60 and the first module support member 70-1. Specifically, the first position adjustment mechanism 80-1 is capable of relatively rotating the head module 5 and the first module support member 70-1 using the first axis Rz-1, the second axis Rx-1, and the third axis Ry-1 as pivot axes. The first axis Rz-1 is a virtual axis along the Z-axis direction. The second axis Rx-1 is a virtual axis along the X-axis direction. The third axis Ry-1 is a virtual axis along the Y-axis direction.

[0053] The first position adjustment mechanism 80-1 can adjust the relative position between the injection surface FN and the reference surface FB in the Z-axis direction. This allows for adjustment of the relative position between the injection surface FN and the reference surface FB in the Z-axis direction.

[0054] In the example shown in Figure 4, the first position adjustment mechanism 80-1 includes a first head-side fixing member 81-1, a first head-side rotating member 82-1, a first support-side fixing member 83-1, and a first support-side rotating member 84-1. As will be described in detail later, the first head-side fixing member 81-1 is fixed to the head module 5. The first head-side rotating member 82-1 is rotatably connected to the first head-side fixing member 81-1 with the third axis Ry-1 as the pivot axis. The first support-side fixing member 83-1 is fixed to the first module support member 70-1. The first support-side rotating member 84-1 is rotatably connected to the first support-side fixing member 83-1 with the first axis Rz-1 as the pivot axis. The first head-side rotating member 82-1 and the first support-side fixed member 83-1 are connected in such a way that their relative position in the Z-axis direction and their relative orientation around the second axis Rx-1 can be changed.

[0055] Similarly, the second position adjustment mechanism 80-2 adjusts the relative position between the head module 5 and the second module support member 70-2 by adjusting the relative position between the head support member 60 and the second module support member 70-2. Specifically, the second position adjustment mechanism 80-2 allows the head module 5 and the second module support member 70-2 to rotate relative to each other using the first axis Rz-2, the second axis Rx-2, and the third axis Ry-2 as pivot axes. The first axis Rz-2 is a virtual axis along the Z-axis direction. The second axis Rx-2 is a virtual axis along the X-axis direction. The third axis Ry-2 is a virtual axis along the Y-axis direction.

[0056] The second position adjustment mechanism 80-2 allows adjustment of the relative position between the injection surface FN and the reference surface FB in the Z-axis direction. This also allows adjustment of the relative position between the injection surface FN and the reference surface FB in the Z-axis direction.

[0057] In the example shown in Figure 4, the second position adjustment mechanism 80-2 includes a second head-side fixing member 81-2, a second head-side rotating member 82-2, a second support-side fixing member 83-2, and a second support-side rotating member 84-2. The second head-side fixing member 81-2 is fixed to the head module 5. The second head-side rotating member 82-2 is rotatably connected to the second head-side fixing member 81-2 with the third axis Ry-2 as the pivot axis. The second support-side fixing member 83-2 is fixed to the second module support member 70-2. The second support-side rotating member 84-2 is rotatably connected to the second support-side fixing member 83-2 with the first axis Rz-2 as the pivot axis. The second head-side rotating member 82-2 and the second support-side fixed member 83-2 are connected in such a way that their relative position in the Z-axis direction and their relative orientation around the second axis Rx-2 can be changed.

[0058] Figure 5 shows the first position adjustment mechanism 80-1 viewed in the Y2 direction. Figure 6 shows the first position adjustment mechanism 80-1 viewed in the Z2 direction. Figure 7 shows the first position adjustment mechanism 80-1 viewed in the X2 direction.

[0059] The first position adjustment mechanism 80-1 will be described in detail below. While the first position adjustment mechanism 80-1 will be described as representative, the second position adjustment mechanism 80-2 will be configured similarly to the first position adjustment mechanism 80-1, except that it is configured symmetrically with respect to a plane perpendicular to the X-axis. However, the second position adjustment mechanism 80-2 may have a different configuration from the first position adjustment mechanism 80-1.

[0060] As shown in Figures 5 to 7, the first position adjustment mechanism 80-1 includes a first head-side fixing member 81-1, a first head-side rotating member 82-1, a first support-side fixing member 83-1, and a first support-side rotating member 84-1.

[0061] As shown in Figures 5 and 6, the first head-side fixing member 81-1 is fixed to the head module 5. More specifically, the first head-side fixing member 81-1 is fixed to the end of the head support member 60 in the X1 direction by screw fastening with two screws B1. Although not shown, the end of the head support member 60 in the X1 direction is provided with screw holes that engage with the screws B1.

[0062] In this embodiment, as shown in Figure 5, the first head-side fixing member 81-1 has a portion 81a and a portion 81b.

[0063] Part 81a is plate-shaped with the X-axis direction as the thickness direction. Part 81a is provided with two holes H1 and two holes H2. Each hole H1 is a hole that penetrates part 81a in the X-axis direction. A screw B1 is inserted into each hole H1 in the X2 direction. The two holes H2 are screw holes provided on the side of part 81a facing the Y1 direction and the side facing the Y2 direction, so as to be coaxial with the third axis Ry-1 along the Y axis. A screw B2 fits into each hole H2. In this way, the screw B2 is fixed to the first head-side fixing member 81-1.

[0064] Part 81b extends in the X1 direction from the Z1 end of part 81a and has a plate-like shape with the Z axis direction as the thickness direction. Part 81b is provided with two holes H3. Each hole H3 is a screw hole that penetrates part 81b in the Z axis direction. An adjustment screw B3 is fitted into each hole H3 with the screw inserted in the Z2 direction.

[0065] Here, the adjustment screw B3 is a screw for adjusting the relative position of the first head-side rotating member 82-1 and the first support-side fixed member 83-1 in the Z2 direction (first direction) and the relative posture around the second axis Rx-1. The tip of the adjustment screw B3 contacts the Z1-facing surface of the first module support member 70-1. In addition, the distance between the tip of the adjustment screw B3 and part 81b changes depending on the amount the adjustment screw B3 is screwed into the hole H3. This makes it possible to change the relative position of the first head-side fixed member 81-1 and the first module support member 70-1 in the Z-axis direction, or to change the relative posture of the first head-side fixed member 81-1 and the first module support member 70-1 around the second axis Rx-1.

[0066] As described above, the first head-side fixing member 81-1 is fixed to the head module 5. Note that the shape of the first head-side fixing member 81-1 is not limited to the examples shown in Figures 5 to 7, but is arbitrary.

[0067] As shown in Figures 5 and 6, the first head-side rotating member 82-1 is rotatably connected to the first head-side fixed member 81-1 with the third axis Ry-1 as the pivot axis. More specifically, the first head-side rotating member 82-1 is rotatably connected to the first head-side fixed member 81-1 via two screws B2, around the third axis Ry-1.

[0068] In this embodiment, the first head-side rotating member 82-1 has a pair of parts 82a and 82b, as shown in Figure 6.

[0069] Each portion 82a is rod-shaped and extends along the X-axis. A pair of portions 82a are aligned along the Y-axis, and a portion 81b of the first head-side fixing member 81-1 is positioned between the pair of portions 82a. A hole H4 is provided in each portion 82a. A screw B2 is inserted into the hole H4 along the Y-axis toward portion 81b.

[0070] Here, screw B2 is a stepped screw in which the diameter of the cylindrical portion of the shaft is larger than the diameter of the threaded portion. As a result, the cylindrical portion of screw B2 supports the first head-side rotating member 82-1 so that it can rotate around the third axis Ry-1, with the hole H4 acting as the sliding surface of a sliding bearing. Note that screw B2 is not limited to a stepped screw, as long as it can support the first head-side rotating member 82-1 so that it can rotate around the third axis Ry-1.

[0071] In this way, the first head-side fixing member 81-1 and the first head-side rotating member 82-1 are connected to each other using a screw B2 that extends along the third axis Ry-1. This allows the head module 5 and the first module support member 70-1 to rotate relative to each other around the third axis Ry-1 with respect to the screw B2.

[0072] Part 82b is rod-shaped and extends in the Y-axis direction, and is connected to the X1-direction ends of a pair of parts 82a. Part 82b is provided with two holes H5 aligned in the Y-axis direction. Each hole H5 is a screw hole provided on the X1-direction-facing surface of part 82b. A first fixing screw B7 fits into each hole H5.

[0073] As described above, the first head-side rotating member 82-1 is rotatably connected to the first head-side fixed member 81-1 with the third axis Ry-1 as the pivot axis. Note that the shape of the first head-side rotating member 82-1 is not limited to the examples shown in Figures 5 to 7, but is arbitrary.

[0074] As shown in Figures 5 to 7, the first support-side fixing member 83-1 is fixed to the first module support member 70-1. More specifically, the first support-side fixing member 83-1 is fixed to the surface of the first module support member 70-1 facing the Z1 direction by screw fastening with two screws B4. Although not shown, the surface of the first module support member 70-1 facing the Z1 direction is provided with screw holes that engage with the screws B4.

[0075] In this embodiment, as shown in Figure 5, the first support-side fixing member 83-1 is plate-shaped or block-shaped with the Z-axis direction as the thickness direction. The first support-side fixing member 83-1 is provided with two holes H6 and hole H7. Each hole H6 is a hole that penetrates the first support-side fixing member 83-1 in the Z-axis direction. Screws B4 are inserted into each hole H6 in the Z2 direction. Hole H7 is a screw hole provided on the Z1-facing surface of the first support-side fixing member 83-1. Screws B5 are fitted into each hole H7.

[0076] As described above, the first support-side fixing member 83-1 is fixed to the first module support member 70-1. Note that the shape of the first support-side fixing member 83-1 is not limited to the examples shown in Figures 5 to 7, but is arbitrary.

[0077] As shown in Figures 5 to 7, the first support-side rotating member 84-1 is rotatably connected to the first support-side fixed member 83-1 with the first axis Rz-1 as the pivot axis. More specifically, the first support-side rotating member 84-1 is rotatably connected to the first support-side fixed member 83-1 via a screw B5, around the first axis Rz-1.

[0078] In this embodiment, the first support-side rotating member 84-1 has a portion 84a, a portion 84b, and a portion 84b.

[0079] Part 84a is plate-shaped with the X-axis direction as its thickness. Part 84a is provided with two holes H8. Each hole H8 penetrates part 84a in the X-axis direction. A first fixing screw B7 is inserted into each hole H8 in the X2 direction.

[0080] Here, the first fixing screw B7 is a screw for fixing the relative position of the first head-side rotating member 82-1 and the first support-side fixing member 83-1 in the Z-axis direction and their relative orientation around the second axis Rx-1. However, as shown in Figure 7, each hole H8 is an elongated hole that extends in the Z-axis direction when viewed in the X-axis direction. This allows the relative position of the first support-side rotating member 84-1 and the first head-side rotating member 82-1 to be changed in the Z-axis direction when the first fixing screw B7 is not fastened. Also, the width of each hole H8 is greater than the width of the shaft portion of the first fixing screw B7. This allows the relative orientation of the first support-side rotating member 84-1 and the first head-side rotating member 82-1 to be changed around the second axis Rx-1 when the first fixing screw B7 is not fastened. Furthermore, when the fastening with the first fixing screw B7 is completed, the relative position and relative orientation of the first support-side rotating member 84-1 and the first head-side rotating member 82-1 are fixed.

[0081] Part 84b is plate-shaped with the Z-axis direction as its thickness. Part 84b is provided with two holes H9 aligned in the Y-axis direction. Each hole H9 penetrates part 84b in the Z-axis direction. A second fixing screw B6 is inserted into each hole H9 in the Z2 direction.

[0082] Here, the second fixing screw B6 is a screw for fixing the relative position of the first support-side fixing member 83-1 and the first support-side rotating member 84-1 around the first axis Rz-1. However, in the unfastened state with the second fixing screw B6, the first support-side rotating member 84-1 is rotatable around the first axis Rz-1 with respect to the first support-side fixing member 83-1, with screw B5 as the pivot point. On the other hand, in the completed state with the second fixing screw B6, the tip of the second fixing screw B6 contacts the surface of the first support-side fixing member 83-1 facing the Z1 direction, thereby fixing the relative position of the first support-side fixing member 83-1 and the first support-side rotating member 84-1.

[0083] Part 84c is columnar in shape and extends in the Z-axis direction, and is connected to the X1-facing surface of part 84a and the Z1-facing surface of part 84b. A hole H10 is provided in part 84c. Hole H10 is a hole that penetrates part 84c in the Z-axis direction. A screw B5 is inserted into hole H10 in the Z2 direction.

[0084] Here, screw B5 is a stepped screw in which the diameter of the cylindrical portion of the shaft is larger than the diameter of the threaded portion. As a result, the cylindrical portion of screw B5 supports the first support-side rotating member 84-1 so that it can rotate around the first axis Rz-1, with the hole H10 acting as the sliding surface of a sliding bearing. Note that screw B5 is not limited to a stepped screw, as long as it can support the first support-side rotating member 84-1 so that it can rotate around the first axis Rz-1.

[0085] In this way, the first support-side fixing member 83-1 and the first support-side rotating member 84-1 are connected to each other using a screw B5 that extends along the first axis Rz-1. This allows the head module 5 and the first module support member 70-1 to rotate relative to each other around the first axis Rz-1 with respect to the screw B5.

[0086] As described above, the first support-side rotating member 84-1 is rotatably connected to the first support-side fixed member 83-1 with the first axis Rz-1 as the pivot axis, and is also rotatably connected to the first head-side rotating member with the second axis Rx-1 as the pivot axis. Note that the shape of the first support-side rotating member 84-1 is not limited to the examples shown in Figures 5 to 7, but is arbitrary.

[0087] With the above configuration, a first position adjustment mechanism 80-1 can be realized that allows the head module 5 and the first module support member 70-1 to rotate relative to each other using the first axis Rz-1, the second axis Rx-1, and the third axis Ry-1 as pivot axes.

[0088] In the first position adjustment mechanism 80-1 described above, the head module 5 and the first module support member 70-1 can be rotated relative to each other using the first axis Rz-1, the second axis Rx-1, and the third axis Ry-1 as pivot axes, thereby absorbing manufacturing errors in the mounting surfaces of the head module 5 and the first module support member 70-1. As a result, the head module 5 can be supported by the first module support member 70-1 via the first position adjustment mechanism 80-1 in a state where the spray surface FN and the reference surface FB are parallel to each other. This reduces the deviation of the ink landing position on the printing medium M when ink is sprayed from the liquid spray head 50 toward the printing medium M.

[0089] Furthermore, as described above, since the first head-side rotating member 82-1 and the first support-side fixing member 83-1 are connected in such a way that their relative positions in the Z-axis direction can be changed, the relative positions in the Z-axis direction between the reference surface FB and the injection surface FN can be adjusted.

[0090] Furthermore, as described above, the first position adjustment mechanism 80-1 includes an adjustment screw B3, a first fixing screw B7, and a second fixing screw B6. Therefore, by rotating the adjustment screw B3, the relative position of the reference surface FB and the injection surface FN in the Z2 direction (first direction) and the relative attitude around the second axis Rx-1 can be adjusted. The adjusted state can then be fixed using the first fixing screw B7 and the second fixing screw B6.

[0091] Furthermore, as described above, in the head module 5, which is a line head module with the X-axis direction as its longitudinal direction, by using the first position adjustment mechanism 80-1 and the second position adjustment mechanism 80-2, the deviation of the ink's landing position on the printing medium M when ink is sprayed from the liquid spray head 50 of the head module 5 toward the printing medium M can be suitably reduced.

[0092] 1-5. Head Fixing Method Figure 8 is an explanatory diagram of a head fixing method according to an embodiment. This head fixing method is a method of fixing the head unit 40 to the main frame 90, and is performed using a first position adjustment mechanism 80-1 and a second position adjustment mechanism 80-2. As shown in Figure 8, this head fixing method includes steps S10 to S30 in that order.

[0093] Step S10 involves preparing the head module 5, the first module support member 70-1, the first position adjustment mechanism 80-1, the second module support member 70-2, and the second position adjustment mechanism 80-2. Step S10 includes steps S11 and S12.

[0094] In step S11, the positioning pin 71-1 of the first module support member 70-1 is inserted into the positioning hole 61-1 of the head support member 60, and the positioning pin 71-2 of the second module support member 70-2 is inserted into the positioning hole 61-2 of the head support member 60. Also in step S11, the spring 6-1 is attached to the first module support member 70-1 and the head support member 60, and the spring 6-2 is attached to the second module support member 70-2 and the head support member 60.

[0095] Meanwhile, in step S12, with the fastenings by the second fixing screw B6 and the first fixing screw B7 loosened, the first head-side fixing member 81-1 is fixed to the head module 5 by fastening with screw B1, and the first support-side fixing member 83-1 is fixed to the first module support member 70-1 by fastening with screw B4.

[0096] At this time, the relative position of the first head-side rotating member 82-1 and the first support-side rotating member 84-1 is rotatable around the second axis Rx-1, and the relative position of the first head-side rotating member 82-1 and the first support-side rotating member 84-1 is changeable in the Z-axis direction. In addition, although screws B2 and B5 are fastened, as described above, the first head-side rotating member 82-1 is rotatable with respect to the first head-side fixed member 81-1 with respect to the third axis Ry-1 as the pivot axis, and the first support-side rotating member 84-1 is rotatable with respect to the first support-side fixed member 83-1 with respect to the first axis Rz-1 as the pivot axis.

[0097] Similarly, in step S12, the second head-side fixing member 81-2 is fixed to the head module 5, and the second support-side fixing member 83-2 is fixed to the second module support member 70-2.

[0098] Following step S10, step S20 adjusts the relative position between the head module 5 and the first module support member 70-1. This adjustment is performed by using the first position adjustment mechanism 80-1 to relatively rotate the head module 5 and the first module support member 70-1, using the first axis Rz-1, the second axis Rx-1, and the third axis Ry-1 as pivot axes, respectively. Step S20 includes step S21.

[0099] In step S21, the relative position and orientation of the injection surface FN with respect to the reference surface FB are adjusted by rotating the two adjustment screws B3 using the first position adjustment mechanism 80-1. Similarly, the relative position and orientation of the injection surface FN with respect to the reference surface FB are adjusted using the second position adjustment mechanism 80-2.

[0100] Here, as the amount of screwing adjustment screw B3 into hole H3 increases, the distance between the tip of adjustment screw B3 and portion 81b increases against the biasing force of spring 6-1. This adjusts the relative position of the injection surface FN with respect to the reference plane FB in the Z-axis direction, and consequently, the relative position of the first head-side rotating member 82-1 and the first support-side rotating member 84-1 in the Z-axis direction changes. Also, by rotating one of the two adjustment screws B3, the relative posture of the injection surface FN with respect to the reference plane FB around the X-axis is adjusted, and consequently, the relative posture of the first head-side rotating member 82-1 and the first support-side rotating member 84-1 around the second axis Rx-1 changes.

[0101] After step S20, step S30 fixes the adjusted state by the first position adjustment mechanism 80-1 and the second position adjustment mechanism 80-2. Step S30 includes step S31.

[0102] In step S31, after adjustment by rotating each of the two adjustment screws B3, the relative position of the first support-side fixing member 83-1 and the first support-side rotating member 84-1 is fixed by fastening with the second fixing screw B6. Subsequently, the relative position and relative position of the first head-side rotating member 82-1 and the first support-side rotating member 84-1 are fixed by fastening with the first fixing screw B7. Similarly, in step S31, after the relative position of the second support-side fixing member 83-2 and the second support-side rotating member 84-2 is fixed, the relative position and relative position of the second head-side rotating member 82-2 and the second support-side rotating member 84-2 are fixed.

[0103] In the above head fixing method, the first position adjustment mechanism 80-1 can absorb manufacturing errors in the mounting surface between the head module 5 and the first module support member 70-1. Therefore, the head module 5 can be supported by the first module support member 70-1 via the first position adjustment mechanism 80-1 while the spray surface FN and the reference surface FB are parallel to each other. This reduces the deviation of the ink's landing position on the printing medium M when ink is sprayed from the liquid spray head 50 toward the printing medium M. Furthermore, the second position adjustment mechanism 80-2 can absorb manufacturing errors in the mounting surface between the head module 5 and the second module support member 70-2, thereby reducing the deviation of the ink's landing position on the printing medium M when ink is sprayed from the liquid spray head 50 toward the printing medium M.

[0104] 3. Variant 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.

[0105] 3-1. Variation 1 In the above-described embodiment, an example is given in which a second position adjustment mechanism 80-2 is used in addition to the first position adjustment mechanism 80-1, but the embodiment is not limited to this, and the second position adjustment mechanism 80-2 may be omitted.

[0106] 3-2. Variation 2 In the above-described embodiment, an example is given in which the first module support member 70-1 and the second module support member 70-2 are separate from the main frame 90. However, the embodiment is not limited to this, and one or both of the first module support member 70-1 and the second module support member 70-2 may be integrated with the main frame 90. In this case, one or both of the first module support member 70-1 and the second module support member 70-2 can be said to be part of the main frame 90. Furthermore, the first module support member 70-1 and the second module support member 70-2 may be connected to each other or may be formed as a single unit.

[0107] 3-3. Modified Example 3 In the embodiments described above, an example is given in which the head unit 40 is of the line type, but the present disclosure is not limited to this embodiment and can also be applied to serial type head units.

[0108] 3-4. Variation 4 In the above-described embodiment, the number, arrangement, or orientation of the head tips 54 of the liquid injection head 50 are illustrative examples and may be appropriately modified within the scope that achieves the effects of this disclosure, depending on the type or configuration of the head unit.

[0109] 3-5. Modification 5 The liquid spraying devices exemplified in the above-described form can be used in various devices such as facsimile machines or photocopiers, in addition to equipment dedicated to printing. However, the applications of liquid spraying devices are not limited to printing. For example, a liquid spraying device that sprays a solution of colorants is used as a manufacturing device for forming color filters for display devices such as liquid crystal display panels. A liquid spraying device that sprays a solution of conductive material is used as a manufacturing device for forming wiring or electrodes on a wiring board. Furthermore, a liquid spraying device that sprays a solution of organic matter related to living organisms is used, for example, as a manufacturing device for producing biochips.

[0110] 4. Addendum A summary of this disclosure is provided below.

[0111] (Note 1) A first embodiment of the head unit of the present disclosure is a head unit fixed to a main frame, comprising: a head module having a plurality of liquid spray heads having spray surfaces including nozzles for spraying liquid in a first direction; and a head support member for supporting the plurality of liquid spray heads; a first module support member having a reference surface with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction; and a first position adjustment mechanism for adjusting the relative position between the head module and the first module support member in order to adjust the relative position between the spray surface and the reference surface, wherein the first position adjustment mechanism is capable of relatively rotating the head module and the first module support member with respect to a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions as pivot axes.

[0112] In the above embodiment, the first position adjustment mechanism can rotate the head module and the first module support member relative to each other using the first, second, and third axes as pivot axes, thereby absorbing manufacturing errors in the mounting surfaces of the head module and the first module support member. As a result, the head module can be supported on the first module support member via the first position adjustment mechanism while the spray surface and the reference surface are parallel to each other. This reduces the deviation of the liquid's impact position on the printing medium when liquid is sprayed from the liquid spray head toward the printing medium.

[0113] (Note 2) In a second embodiment, which is a preferred example of the first embodiment, the first position adjustment mechanism includes a first head-side fixing member fixed to the head module, a first head-side rotating member rotatably connected to the first head-side fixing member with the third axis as the pivot axis, a first support-side fixing member fixed to the first module support member, and a first support-side rotating member rotatably connected to the first support-side fixing member with the first axis as the pivot axis, wherein the first head-side rotating member and the first support-side fixing member are connected in such a way that the relative position of the first head-side rotating member and the first support-side fixing member in the first direction and the relative orientation around the second axis can be changed.

[0114] In the above embodiment, a first position adjustment mechanism can be realized in which the head module and the first module support member can be rotated relative to each other using the first axis, second axis, and third axis as pivot axes. Furthermore, since the first head-side rotating member and the first support-side fixing member are connected in such a way that the relative position between the first head-side rotating member and the first support-side fixing member in the first direction can be changed, the relative position between the reference plane and the spraying surface in the first direction can be adjusted.

[0115] (Note 3) In a third embodiment, which is a preferred example of the second embodiment, the first head-side fixing member and the first head-side rotating member are connected to each other using a screw extending along the third axis. In this embodiment, the head module and the first module support member can be rotated relative to each other around the third axis with respect to the screw.

[0116] (Note 4) In a fourth embodiment, which is a preferred example of the second or third embodiment, the first support-side fixing member and the first support-side rotating member are connected to each other using a screw extending along the first axis. In this embodiment, the head module and the first module support member can be rotated relative to each other around the first axis with respect to the screw.

[0117] (Note 5) In a fifth embodiment, which is a preferred example of any of the second to fourth embodiments, the first position adjustment mechanism includes an adjustment screw for adjusting the relative position of the first head-side rotating member and the first support-side fixed member in the first direction and their relative posture around the second axis; a first fixing screw for fixing the relative position of the first head-side rotating member and the first support-side fixed member in the first direction and their relative posture around the second axis; and a second fixing screw for fixing the relative posture of the first support-side fixed member and the first support-side rotating member around the first axis. In the above embodiments, the relative position of the reference surface and the spray surface in the first direction and their relative posture around the second axis can be adjusted by rotating the adjustment screw. Furthermore, the adjusted state can be fixed by the first fixing screw and the second fixing screw.

[0118] (Note 6) In the sixth embodiment, which is a preferred example of any of the first to fifth embodiments, the first position adjustment mechanism is capable of adjusting the relative position between the injection surface and the reference surface in the first direction. In the embodiments described above, the relative position between the injection surface and the reference surface in the first direction can be adjusted.

[0119] (Note 7) In a seventh embodiment, which is a preferred example of any of the first to sixth embodiments, the head module is further provided with a second module support member that supports the head module at an end opposite to the second direction, and a second position adjustment mechanism that adjusts the relative position between the head module and the second module support member, wherein the head module is a line head module with the second direction as its longitudinal direction. In the above embodiments, the deviation of the liquid's impact position on the printing medium when liquid is sprayed from the liquid spray head of the line head module toward the printing medium can be suitably reduced.

[0120] (Note 8) An eighth preferred embodiment of the liquid spraying device of the present disclosure comprises a head unit according to any of the first to seventh embodiments and the main body frame, wherein the main body frame supports the head unit by being fixed to the first module support member with the reference plane supporting the first module support member. In the above embodiments, the deviation of the liquid's impact position on the printing medium when liquid is sprayed from the liquid spraying head toward the printing medium can be reduced by adjusting the relative position and relative orientation between the reference plane and the spraying surface.

[0121] (Note 9) A ninth aspect of the head fixing method of the present disclosure is a head fixing method for fixing a head unit to a main frame, comprising: a head module having a plurality of liquid spray heads having spray surfaces including nozzles for spraying liquid in a first direction; a head support member for supporting the plurality of liquid spray heads; a first module support member having a reference surface with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction; and a first position adjustment mechanism for adjusting the relative position between the head module and the first module support member in order to adjust the relative position between the spray surface and the reference surface, wherein the relative position between the head module and the first module support member is adjusted by using the first position adjustment mechanism to rotate the head module and the first module support member relative to each of the following axes: a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions.

[0122] In the above embodiment, manufacturing errors in the mounting surface between the head module and the first module support member can be absorbed. Therefore, the head module can be supported on the first module support member via the first position adjustment mechanism while the spray surface and the reference surface are parallel to each other. This reduces the deviation of the liquid's landing position on the printing medium when liquid is sprayed from the liquid spray head toward the printing medium. [Explanation of symbols]

[0123] 5...Head module, 40...Head unit, 50...Liquid spray head, 60...Head support member, 70-1...First module support member, 70-2...Second module support member, 80-1...First position adjustment mechanism, 81-1...First head-side fixing member, 82-1...First head-side rotating member, 83-1...First support-side fixing member, 84-1...First support-side rotating member, 90...Main frame, 100...Liquid spray device, B3...Adjustment screw, B6...Second fixing screw, B7...First fixing screw, FB...Reference surface, FN...Spray surface, N...Nozzle, Rx-1...Second axis, Ry-1...Third axis, Rz-1...First axis, S10...Step, S20...Step.

Claims

1. A head unit that is fixed to the main frame, A head module having a plurality of liquid spray heads having spray surfaces including nozzles that spray liquid in a first direction, and a head support member that supports the plurality of liquid spray heads, A first module support member having a reference plane with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction, The system includes a first position adjustment mechanism for adjusting the relative position between the head module and the first module support member in order to adjust the relative position between the injection surface and the reference surface, The first position adjustment mechanism is capable of relatively rotating the head module and the first module support member with each of the following as pivot axes: a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions. A head unit characterized by the following features.

2. The first position adjustment mechanism is, A first head-side fixing member fixed to the head module, A first head-side rotating member is rotatably connected to the first head-side fixing member with the third axis as the pivot axis, A first support-side fixing member fixed to the first module support member, The first support-side rotating member is rotatably connected to the first support-side fixing member with the first shaft as the pivot axis, The first head-side rotating member and the first support-side fixing member are connected in such a way that their relative position in the first direction and their relative orientation around the second axis can be changed. The head unit according to feature 1.

3. The first head-side fixing member and the first head-side rotating member are connected to each other using a screw that extends along the third axis. The head unit according to feature 2.

4. The first support-side fixing member and the first support-side rotating member are connected to each other using screws extending along the first axis. The head unit according to feature 2.

5. The first position adjustment mechanism is, An adjustment screw for adjusting the relative position of the first head-side rotating member and the first support-side fixing member in the first direction and their relative position around the second axis, A first fixing screw for fixing the relative position of the first head-side rotating member and the first support-side fixing member in the first direction and their relative orientation around the second axis, The device includes a second fixing screw for fixing the relative position of the first support-side fixing member and the first support-side rotating member around the first axis, The head unit according to feature 2.

6. The first position adjustment mechanism is capable of adjusting the relative position between the injection surface and the reference surface in the first direction. The head unit according to feature 1.

7. A second module support member supports the head module at the end opposite to the second direction, The system further includes a second position adjustment mechanism for adjusting the relative position between the head module and the second module support member, The head module is a line head module with the second direction as the longitudinal direction. The head unit according to feature 1.

8. A head unit according to any one of claims 1 to 7, The main frame and, The main frame is fixed to the first module support member with the reference plane supporting the first module support member, thereby supporting the head unit. A liquid injection device characterized by the following features.

9. A head fixing method for fixing the head unit to the main frame, A head module having a plurality of liquid spray heads having spray surfaces including nozzles that spray liquid in a first direction, and a head support member that supports the plurality of liquid spray heads, A first module support member having a reference plane with respect to the main frame and supporting the head module at its end in a second direction perpendicular to the first direction, To adjust the relative position between the injection surface and the reference surface, a first position adjustment mechanism is provided for adjusting the relative position between the head module and the first module support member. The relative position between the head module and the first module support member is adjusted by using the first position adjustment mechanism to rotate the head module and the first module support member relative to each other using a first axis along the first direction, a second axis along the second direction, and a third axis along a third direction perpendicular to both the first and second directions as pivot axes. A method for fixing a head unit, characterized by the features described above.

Images