Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head and a liquid discharge device capable of suppressing stress generated in a tube connected to a head.SOLUTION: A liquid discharge head includes: a head module (12); a tube (100A) which functions as a flow channel of liquid supplied to the head module, or as a flow channel of liquid recovered from the head module, and whose one end is fixed and the other end is connected to the head module; and a move part for moving the head module in a first direction. The tube with flexibility has stress reduction shapes (104B, 104C) for reducing stress in accordance with deformation of the tube caused by movement of the head module.SELECTED DRAWING: Figure 5

Description

[Technical field]

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

[0002] Long heads having a length corresponding to the entire width of a print medium are known as inkjet heads provided in inkjet printing devices. Long heads may have a structure in which a plurality of head modules are arranged in a line relative to a guide plate. Long heads may also have a structure in which components such as an ink collecting pipe and a control board are integrated.

[0003] In recent years, inkjet printers have been widely used in the field of printing on flexible packaging. In the field of printing on flexible packaging, inkjet printers are required to have technology that can print with high precision on a web transported on a path roller. The web can be transported not only horizontally along a horizontal plane, but also inclinedly along a surface that is inclined relative to the horizontal plane. In this case, the inkjet head is required to have the function of printing on a web transported along an inclined surface.

[0004] Patent document 1 describes an inkjet recording device equipped with a carriage including a frame on which an ink storage section is fixedly mounted, an inkjet head attached to the frame for ejecting ink supplied from the ink storage section, and an attachment angle adjustment section for adjusting the relative attachment angle between the frame and the inkjet head.

[0005] The carriage is equipped with a plurality of inkjet heads. The inkjet heads are aligned in a line along the X direction. The carriage equipped with the plurality of inkjet heads is a transport surface along which the recording medium is transported, and the relative angle between the fixed frame and the inkjet heads is adjusted so that the inkjet heads face the transport surface, which is not flat.

[0006] Patent Document 2 describes a liquid supply system capable of supplying liquid from a stationary reservoir to a reciprocating discharge mechanism without imposing undue stress and fatigue on the tube. Specifically, the liquid supply system supplies fluid from a reservoir to a relatively reciprocating fluid discharge mechanism via a coiled tube structure. The tube structure extends and retracts with the reciprocating motion of the fluid discharge mechanism. The tube structure is constructed using a plurality of concentric coiled tubes. Adjacent coils in the tube structure are wound in opposite rotational directions to form a web-like matrix that supports each other in an extended state. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-053966 [Patent Document 2] Japanese Patent Application Publication No. 08-039823 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when the head module is tilted relative to the frame on which the head module is supported, stress is generated in the tube connecting the head module and the ink collection channel due to bending of the tube. As a result of the stress of the tube acting on the head module, there is a risk that the position of the head module will fluctuate.

[0009] Patent Document 1 does not disclose any stress that occurs in the ink flow path connecting the ink reservoir and the inkjet head when the relative angle between the fixed frame and the inkjet head is adjusted.

[0010] Patent document 2 describes a tube structure that can prevent the tube connecting the stationary reservoir and the reciprocating release mechanism from folding or bending excessively when the reciprocating release mechanism moves linearly back and forth relative to the stationary reservoir, but does not describe how to reduce the stress on the tube that is bent when the angle of the head module relative to the frame is adjusted.

[0011] The present invention has been made in view of the above circumstances, and has an object to provide a liquid ejection head and a liquid ejection apparatus that are capable of suppressing stress generated in a tube connected to the head. [Means for solving the problem]

[0012] A liquid ejection head according to a first aspect of the present disclosure is a liquid ejection head comprising: one or more head modules; a tube that functions as a flow path for liquid supplied to the head module or functions as a flow path for liquid recovered from the head module, the tube having one end fixed and the other end connected to the head module; and a moving part that moves the head module in a first direction, wherein the tube is flexible and has a stress reducing shape that reduces stress corresponding to deformation of the tube caused by movement of the head module.

[0013] According to the liquid ejection head of the first aspect of the present disclosure, a tube having one end fixed and the other end connected to a head module has a shape that reduces stress corresponding to bending of the tube caused by movement of the head module in a first direction, thereby making it possible to relatively reduce stress in the tube that occurs when the head module is moved in the first direction and the tube is bent.

[0014] A liquid ejection head according to a second aspect is the liquid ejection head of the first aspect, wherein the tube has at least one of a curved shape, a loop shape, a bellows shape, and a spiral shape as the stress reducing shape.

[0015] According to this aspect, the shape of the tube itself is devised, and a relative reduction in stress caused by bending the tube can be achieved.

[0016] A liquid ejection head according to a third aspect is the liquid ejection head according to the first or second aspect, wherein the tube has a friction reducing shape on its outer circumferential surface that reduces friction on the outer circumferential surface.

[0017] According to this aspect, when multiple tubes are arranged closely to each other, a relative reduction in frictional force occurring between the tubes can be achieved.

[0018] A liquid ejection head according to a fourth aspect is the liquid ejection head of the third aspect, wherein the friction reducing shape includes a grained shape.

[0019] In this embodiment, the grain shape may have a regular pattern or an irregular pattern.

[0020] A liquid ejection head according to a fifth aspect is a liquid ejection head according to any one of the first to fourth aspects, and includes a plurality of head modules, and the plurality of head modules may be arranged along a second direction that intersects the first direction and is parallel to the liquid ejection surface of the head module.

[0021] The second direction in this embodiment may be a direction perpendicular to the first direction and parallel to the liquid ejection surface of the head module.

[0022] A liquid ejection head according to a sixth aspect is a liquid ejection head according to any one of the first to fifth aspects, wherein the moving section rotates the head module around a rotation axis extending in a third direction that intersects the first direction and is parallel to a specified reference plane, thereby tilting the liquid ejection surface of the head module relative to the reference plane.

[0023] According to this aspect, as the movement of the head module in the first direction, an aspect in which the head module is rotated around a rotation axis extending in the third direction can be applied.

[0024] The third direction in this embodiment may be a direction parallel to the second direction in the fifth embodiment.

[0025] A liquid ejection head according to a seventh aspect is a liquid ejection head according to any one of the first to sixth aspects, and includes a collecting pipe that is fixed to and supported by a frame in which the head module is housed, and that stores liquid supplied to the head module or liquid recovered from the head module, and one end of a tube may be connected to and fixed to the collecting pipe.

[0026] According to this aspect, one end of the tube can be connected to the collecting pipe.

[0027] A liquid ejection head according to an eighth aspect is the liquid ejection head of the seventh aspect, wherein the collecting conduit includes a supply collecting conduit that stores liquid to be supplied to the head module, and the tube may include a supply tube through which liquid flows from the supply collecting conduit to the head module.

[0028] According to this aspect, a mode can be adopted in which one end of the supply tube is connected to a supply manifold that stores liquid to be supplied to the head module.

[0029] A liquid ejection head according to a ninth aspect is a liquid ejection head according to the seventh or eighth aspect, wherein the collecting conduit includes a recovery collecting conduit that stores liquid recovered from the head module, and the tube may include a recovery tube through which liquid flows from the head module toward the recovery collecting conduit.

[0030] According to this aspect, a mode can be adopted in which one end of the recovery tube is connected to a recovery collecting pipe that stores the liquid recovered from the head module.

[0031] A liquid ejection head according to a tenth aspect is the liquid ejection head according to any one of the first to ninth aspects, wherein the head module uses any one of ink, treatment liquid, and cleaning liquid as the liquid.

[0032] According to this aspect, in a liquid ejection head using any one of ink, treatment liquid, and cleaning liquid, the same effects as those of the liquid ejection heads according to the first to ninth aspects can be obtained.

[0033] A liquid ejection head according to an eleventh aspect is a liquid ejection head according to any one of the first to tenth aspects, and includes a guide plate that supports the head module, and the moving section may move the head module together with the guide plate when moving the head module.

[0034] According to this aspect, a guide plate that supports the head module can be moved to move the head module. In particular, when a plurality of head modules are supported integrally using the guide plate, the plurality of head modules can be moved collectively.

[0035] A liquid ejection head according to a twelfth aspect may be the liquid ejection head according to any one of the first to eleventh aspects, further comprising a position adjustment section that adjusts the position of the head module in a fourth direction intersecting with the first direction.

[0036] The fourth direction in this embodiment may be parallel to the second direction in the fifth embodiment, and the fourth direction in this embodiment may be parallel to the third direction in the sixth embodiment.

[0037] A liquid ejection device according to a thirteenth aspect of the present disclosure is a liquid ejection device comprising a liquid ejection head that ejects liquid onto a medium, and a medium support device that supports the medium, wherein the liquid ejection head is one or more head modules, a tube that functions as a flow path for liquid supplied to the head module or functions as a flow path for liquid recovered from the head module, the tube having one end fixed and the other end connected to the head module, and a moving part that moves the head module in a first direction, wherein the tube is a flexible tube and has a stress reducing shape that reduces stress corresponding to deformation of the tube caused by movement of the head module.

[0038] According to the liquid ejection device according to the thirteenth aspect of the present disclosure, it is possible to obtain the same operational effects as the liquid ejection head according to the first aspect of the present disclosure. The constituent elements of the liquid ejection heads according to the second to twelfth aspects can be applied to the constituent elements of the liquid ejection devices according to the other aspects. Effect of the Invention

[0039] According to the present disclosure, a tube having one end fixed and the other end connected to a head module has a shape that reduces stress corresponding to bending of the tube caused by movement of the head module in a first direction, thereby making it possible to relatively reduce stress in the tube that occurs when the head module is moved in the first direction and the tube is bent. [Brief description of the drawings]

[0040] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a liquid ejection head according to an embodiment. [Diagram 2] FIG. 2 is a side view of the liquid ejection head shown in FIG. 1, seen in the longitudinal direction. [Diagram 3] FIG. 3 is a side view of the liquid ejection head, in which the head module shown in FIG. 2 is tilted. [Figure 4]FIG. 4 is a schematic diagram showing the shape of a tube applied to a liquid ejection head according to a comparative example. [Diagram 5] FIG. 5 is a schematic diagram showing a first shape of a tube that is applied to the liquid ejection head according to the embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a second shape of the tube that is applied to the liquid ejection head according to the embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a third shape of the tube that is applied to the liquid ejection head according to this embodiment. [Figure 8] FIG. 8 is a schematic diagram showing a fourth shape of the tube that is applied to the liquid ejection head according to this embodiment. [Figure 9] FIG. 9 is a schematic diagram showing a fifth shape of the tube that is applied to the liquid ejection head according to this embodiment. [Figure 10] FIG. 10 is a schematic diagram of a friction reducing feature applied to the surface of a tube. [Figure 11] FIG. 11 is a schematic diagram showing measurement of the displacement of the head module with respect to the stress generated in the tube. [Figure 12] FIG. 12 is a graph showing the results of measurements of the amount of displacement of the head module relative to the stress generated in the tube. [Figure 13] FIG. 13 is a schematic diagram of stress measurement of a tube. [Figure 14] FIG. 14 is a graph showing the results of stress measurement of the tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification, the same components are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, when multiple components are exemplified in the following embodiments, it can be interpreted that at least one of the multiple components is included.

[0042] [Example of configuration of liquid ejection head according to embodiment] Fig. 1 is a perspective view showing a schematic configuration of a liquid ejection head according to an embodiment. The liquid ejection head 10 shown in the figure includes a plurality of head modules 12, and has an integrated structure in which the plurality of head modules 12 are aligned in a line along the X direction. Each of the plurality of head modules 12 is attached to a guide plate 16 extending in the X direction, and is fixed and supported by the guide plate 16.

[0043] The X direction shown in FIG. 1 is an example of the first direction and an example of the fourth direction. The Y direction perpendicular to the X direction is an example of the second direction intersecting with the first direction and an example of the third direction intersecting with the first direction. A horizontal plane may be applied as the XY plane. The Z direction is a direction perpendicular to the X and Y directions. When the XY plane is a horizontal plane, the vertical direction is applied as the Z direction.

[0044] The liquid ejection head 10 includes a rotating unit 18 that rotates the head modules 12 around a rotation axis extending in the Y direction. The rotating unit 18 rotatably supports both ends in the Y direction of the multiple head modules 12. FIG. 1 illustrates an embodiment in which the rotating unit 18 includes a first support portion 18A that supports one end in the Y direction of the guide plate 16, and a second support portion 18B that supports the other end in the Y direction. Note that the rotation axis is omitted in FIG. 1. The rotation axis is indicated by the symbol YA and is illustrated in FIG. 2.

[0045] The liquid ejection head 10 includes a frame 20. The frame 20 functions as a case that houses the components that make up the liquid ejection head 10. The frame 20 also functions as a support member that fixes and supports the components of the liquid ejection head 10. Note that Fig. 1 illustrates a state in which some of the plates that make up the frame 20 have been removed.

[0046] The liquid ejection head 10 includes a position adjustment unit that adjusts the positions of the multiple head modules 12 in the X direction. The position adjustment unit may adjust the positions of the head modules 12 in the X direction based on the detection results of the positions of the head modules 12 in the X direction.

[0047] The liquid ejection head 10 includes a supply passage assembly that supplies liquid to each of the plurality of head modules 12, and a recovery passage assembly that recovers liquid from each of the plurality of head modules 12.

[0048] The supply flow path assembly includes a supply collecting pipe 30 and a plurality of supply tubes 32. The supply collecting pipe 30 stores liquid to be supplied to each of the plurality of head modules 12. The supply collecting pipe 30 is fixed to and supported by a plate 20A that constitutes the frame 20.

[0049] The supply collecting pipe 30 is connected to an internal supply flow path 34. The internal supply flow path 34 is connected to a liquid supply port of the liquid ejection head 10. The supply collecting pipe 30 is supplied with liquid from an external supply flow path of the liquid ejection head 10 via the liquid supply port and the internal supply flow path 34. It should be noted that the liquid supply port and the external supply flow path are not shown in the drawings.

[0050] The supply tubes 32 are flow paths for liquid supplied from the supply collecting pipe 30 to each of the multiple head modules 12, and one end is connected to the supply collecting pipe 30 and the other end is connected to each of the multiple head modules 12. Note that in FIG. 1, some of the multiple supply tubes 32 are not shown.

[0051] The supply flow path assembly is equipped with a supply valve that opens and closes the supply tube 32, and a supply pressure sensor that detects the pressure of the liquid contained inside the supply manifold 30. Note that the supply valve, supply pressure sensor, etc. are omitted from the illustration.

[0052] The recovery flow path assembly has the same configuration as the supply flow path assembly. That is, the recovery flow path assembly includes a recovery collector pipe, a recovery internal flow path, and a recovery tube. The recovery collector pipe stores liquid recovered from each of the multiple head modules 12. The recovery collector pipe is fixed to and supported by the plate 20A.

[0053] The recovery collecting conduit is connected to the internal recovery flow path. The internal recovery flow path is connected to a liquid outlet of the liquid ejection head 10. The recovery collecting conduit discharges liquid to an external recovery flow path of the liquid ejection head 10 via the liquid supply port and the internal recovery flow path. The recovery collecting conduit is equipped with a recovery pressure sensor that detects the pressure of the liquid contained inside the recovery collecting conduit.

[0054] The recovery tube may have a similar shape to the supply tube 32. The recovery tube is a flow path for liquid recovered from each of the multiple head modules 12 to the recovery collecting pipe, with one end connected to the recovery collecting pipe and the other end connected to each of the multiple head modules 12. The recovery tube is equipped with a recovery valve that opens and closes the recovery tube. Note that illustration of the recovery flow path structure and the components of the recovery flow path structure is omitted.

[0055] A flexible substrate 36 is electrically connected to the electrical connection terminals provided in each of the multiple head modules 12. The flexible substrate 36 has electrical wiring formed thereon for a drive voltage supplied to the ejection pressure generating elements provided in the head modules 12, and is electrically connected to an output circuit for the drive voltage.

[0056] The ejection pressure generating element may be a piezoelectric element or a heater. That is, the ejection method of the liquid ejection head 10 may be a piezo-jet method or a thermal method. The ejection method of the liquid ejection head 10 may be an electrostatic method. Note that the ejection pressure generating element provided in the head module 12 and the electrical wiring formed on the flexible substrate 36 are not shown in the drawings.

[0057] [Head module posture] 2 is a side view of the liquid ejection head shown in FIG. 1, seen in the longitudinal direction. FIG. 2 illustrates the position of the head module 12 in which the nozzle surface 12A of the head module 12 is parallel to the surface SA of the film-like sheet S, which is horizontally transported by the first transport roller 40 and the second transport roller 42. The horizontal transport of the sheet S refers to a transport form in which the sheet S is transported along a horizontal plane in an area receiving the liquid ejected from the liquid ejection head 10. In other words, the horizontal transport of the sheet S refers to a transport form in which the surface SA of the sheet S, which is located between the first transport roller 40 and the second transport roller 42, is parallel to the horizontal plane. The nozzle surface 12A illustrated in FIG. 2 is an example of a liquid ejection surface.

[0058] Moreover, the liquid ejection head 10 shown in Fig. 2 has a frame 20 supporting the head module 12 extending along the vertical direction. Fig. 2 also shows a schematic diagram of a moving unit 44 that tilts the head module 12 with respect to the frame 20. The moving unit 44 rotates the head module 12 around a rotation axis YA along the Y direction. Note that the rotation axis YA along the Y direction shown in Fig. 2 is an example of a rotation axis extending in a third direction intersecting the first direction.

[0059] 2 includes a pressing bolt 46 supported so as to be movable in the Y direction. The pressing bolt 46 abuts against a position away from the rotation axis YA in a direction perpendicular to the rotation axis YA of the guide plate 16. The moving unit 44 moves the pressing bolt 46 in the Y-axis direction to rotate the head module 12 together with the guide plate 16 around the rotation axis YA.

[0060] Fig. 3 is a side view of the liquid ejection head, showing a state in which the head module shown in Fig. 2 is tilted. Fig. 3 shows the liquid ejection head 10 in which the angle of the nozzle surface 12A with respect to the horizontal plane HP is adjusted to θ. Note that the horizontal plane HP shown in Fig. 3 is an example of a specified reference plane.

[0061] The sheet S is transported between the first transport roller 40A and the second transport roller 42A at an angle θ with respect to the horizontal plane HP. The liquid ejection head 10 is adjusted to a position where the nozzle surface 12A is parallel to the surface SA of the sheet S between the first transport roller 40A and the second transport roller 42A. Specifically, the head module 12 together with the guide plate 16 is rotated around the rotation axis YA with respect to the frame 20, and the inclination angle α of the head module 12 with respect to the frame 20 is adjusted.

[0062] The tilt angle α of the head module 12 with respect to the frame 20 coincides with the angle of the nozzle surface 12A with respect to the horizontal plane. The adjustment range of the tilt angle α of the head module 12 with respect to the frame 20 may be greater than 0 degrees and less than 90 degrees.

[0063] An example of tilting the head module 12 with respect to the frame 20 is to tilt the head module 12 with respect to components of the liquid ejection head 10 that are accommodated inside the frame 20 and are fixed to and supported by the frame 20. Examples of the components of the liquid ejection head 10 include the supply manifold 30 and the plate 20A shown in FIG.

[0064] [Challenges in adjusting the head module's tilt angle] Fig. 4 is a schematic diagram showing the shape of a tube applied to a liquid ejection head according to a comparative example, which illustrates the orientation of the liquid ejection head 10 in which the nozzle surface 12A is parallel to the horizontal plane.

[0065] The tube 100 functions as a flow path for liquid between the collecting pipe 102 and the head module 12. That is, the tube 100 corresponds to the supply tube 32 shown in FIG.

[0066] 4 has a length equal to the distance between the connection port 101 of the tube 100 provided in the collecting pipe 102 and the connection port 103 of the tube 100 provided in the head module 12. That is, the length of the tube 100 is the distance between the connection port 101 of the collecting pipe 102 and the connection port 103 of the head module 12 plus an extra length for preventing the tube 100 from coming loose and breaking. The tube 100 linearly connects the connection port 101 of the collecting pipe 102 and the connection port 103 of the head module 12 in the Z direction.

[0067] The collecting pipe 102 may have a connection port 101 disposed on a lower surface 102A facing the head module 12. Further, the head module 12 may have a connection port 103 disposed on an upper surface 12B facing the lower surface 102A of the collecting pipe 102.

[0068] When the guide plate 16 on which the head module 12 is supported is tilted relative to the frame 20 shown in Figure 1 etc., the straight-shaped tube 100 connected to the head module 12 stretches and becomes braced, and stress caused by the stretching of the tube 100 acts on the head module 12.

[0069] The stress of the tube 100 can cause the head module 12 to be misaligned in at least one of the X direction, Y direction, and Z direction. For example, the stress of the tube 100 reduces the positional accuracy of the arrangement interval of the multiple head modules 12 in the X direction. Furthermore, the stress of the tube 100 reduces the positional accuracy of the nozzle surface 12A in the Z axis direction.

[0070] The shape of the tubes that realizes a relative reduction in the stress generated in the tubes in response to the movement of the head module 12 will be described in detail below.

[0071] [Primary tube shape] 5 is a schematic diagram showing a first shape of a tube applied to a liquid ejection head according to an embodiment. The tube 100A shown in the drawing has a stress reducing shape that relatively reduces the stress caused by deformation of the tube 100.

[0072] That is, the tube 100A has a total length that is sufficiently longer than that of the tube 100 illustrated in Fig. 4. The tube 100A has a curved shape including a straight portion 104A connected to the collecting pipe 102, a curved portion 104B, a curved portion 104C, and a straight portion 104D connected to the head module 12. The number of curved shapes may be two or more.

[0073] In addition, the tube 100A has a curved shape in which one side of the curved portion 104B is not folded back from the other side. The curved portion 104C also does not have a folded back. The curved shape may be called an S-shape, a crank shape, or the like.

[0074] 5 illustrates an example in which the position in the X direction of the connecting port 101 of the collecting pipe 102 is different from the position in the X direction of the connecting port 103 of the head module 12. The position in the X direction of the connecting port 101 of the collecting pipe 102 may match the position in the X direction of the connecting port 103 of the head module 12.

[0075] [Secondary tube shape] Fig. 6 is a schematic diagram showing a second shape of the tube applied to the liquid ejection head according to the embodiment. The following mainly describes the difference between the stress reducing shape applied to the tube 100B shown in Fig. 6 and the stress reducing shape of the tube 100A shown in Fig. 5.

[0076] Tube 100B shown in Fig. 6 has a curved shape including two curved portions 104B and 104C, similar to tube 100A shown in Fig. 5. On the other hand, tube 100B has a shape in which one side and the other side are folded back at curved portion 104B, and also has a shape in which one side and the other side are folded back at curved portion 104C.

[0077] [Third shape of tube] 7 is a schematic diagram showing a third shape of the tube applied to the liquid ejection head according to the embodiment. The tube 100C shown in the drawing has a stress reducing shape including a straight portion 104A connected to a connecting port 101 of a collecting pipe 102, a loop portion 104E having a loop shape, and a straight portion 104D connected to a connecting port 103 of the head module 12.

[0078] The loop portion 104E of the tube 100C is annular, and the planar shape of the loop portion 104E projected onto the XZ plane is a circle or an ellipse. The planar shape of the loop portion 104E described above may be a shape that includes a line segment as part of a circle or an ellipse.

[0079] 7 illustrates an example in which the position in the X direction of the connecting port 101 of the collecting pipe 102 coincides with the position in the X direction of the connecting port 103 of the head module 12. The position in the X direction of the connecting port 101 of the collecting pipe 102 may be different from the position in the X direction of the connecting port 103 of the head module 12.

[0080] [4th shape of tube] 8 is a schematic diagram showing a fourth shape of the tube applied to the liquid ejection head according to the embodiment. The tube 100D shown in the figure has a bellows shape as a stress reducing shape. The bellows shape is a shape in which concave and convex portions are alternately continuous in the extension direction of the tube 100D. The tube 100D may be linear in the extension direction.

[0081] The length of each recess, the length of each protrusion, and the distance between the recesses and the protrusions of the tube 100D may be appropriately specified. Also, the height of each recess and the depth of each protrusion of the tube 100D may be appropriately specified.

[0082] [5th ​​shape of tube] 9 is a schematic diagram showing a fifth shape of the tube applied to the liquid ejection head according to the embodiment. The tube 100E shown in the drawing has a stress reducing shape including a straight portion 104A connected to a connecting port 101 of a collecting pipe 102, a spiral portion 104F, and a straight portion 104D connected to a connecting port 103 of the head module 12.

[0083] The spiral portion 104F of the tube 100E has one or more spiral shapes. The number of spiral shapes included in the spiral portion 104F may be one or more. The planar shape of a spiral shape projected onto the XY plane is a circle or an ellipse. The spiral shape may be referred to as a helical shape.

[0084] 1 may have the same shape as the supply tube 32 and the recovery tube. Also, tubes of the same shape may be applied to all of the multiple head modules 12, or tubes of a different shape from the other head modules 12 may be applied to any one or more head modules 12. Furthermore, three or more types of tubes of different shapes may be applied to the multiple head modules 12.

[0085] [Variations in the tube surface shape] Fig. 10 is a schematic diagram of a friction reducing shape applied to the surface of a tube. Fig. 10 shows an enlarged view of a part of the outer circumferential surface of the supply tube 32 shown in Fig. 1. The supply tube 32 shown in Fig. 10 has a textured shape applied as a friction reducing shape that reduces friction on the outer circumferential surface.

[0086] 1, if adjacent supply tubes 32 come into contact with each other, friction may occur on the outer circumferential surfaces of the supply tubes 32, and an external force may be transmitted to the head module 12. In order to reduce the friction on the outer circumferential surfaces of the supply tubes 32, a grain 122 is formed on the outer circumferential surface 120 of the tube 100A.

[0087] The texture 122 shown in Fig. 10 has a pattern in which linear recesses 124 and linear protrusions 126 parallel to each other are continuous. The pattern of the texture 122 shown in Fig. 10 is an example, and for example, a mode in which dot-like protrusions are distributed, a mode in which recesses on the ceiling are distributed, and a combination of these may be applied as the pattern of the texture 122. In addition, the texture 122 is not limited to a regular pattern, and may be an irregular pattern. The texture 122 shown in Fig. 10 may be applied to any of the tubes 100A shown in Figs. 5 to 7 and Fig. 9, etc.

[0088] [Tube stress evaluation test] 5 to 9 are applied to the tubes 100A etc. connecting the collecting pipe 102 and the head module 12, in order to confirm that the interval between the head modules 12 in the X direction and the height of the nozzle surface 12A can be maintained, a design target for the stress generated in the tubes 100A etc. is determined. The design target for the stress generated in the tubes 100A etc. may be derived based on the results of the evaluation tests shown below.

[0089] Fig. 11 is a schematic diagram of measurement of the displacement of the head module against the stress generated in the tube. The head module 12 is fixed to the test device in the same manner as the fixing method of the head module 12 to the guide plate 16 shown in Fig. 1. Note that the members for fixing the head module are not shown.

[0090] The probe MC of the force gauge FG is brought into contact with the position of the connection port 101 of the head module 12, and furthermore, a downward external force FZ in the Z direction is applied from the probe MC of the force gauge FG to the position of the connection port 101. The magnitude of the Z-direction external force FZ is changed, and the Z-direction displacement and the Y-direction displacement are measured for each magnitude of the Z-direction external force FZ.

[0091] The X-displacement measuring laser sensor LSX measures the displacement in the X direction of a surface 12C facing the X direction of the nozzle plate 13 having the nozzle surface 12A. The Z-displacement measuring laser sensor LSZ measures the displacement in the Z direction of the nozzle surface 12A.

[0092] The force gauge FG used was a digital force gauge, model ZTS-1000N, manufactured by Imada Corporation. The laser sensor LSX for measuring the X-displacement amount and the laser sensor LSZ for measuring the Z-displacement amount were laser displacement meters, model LK-H027, manufactured by Keyence Corporation.

[0093] 12 is a graph showing the results of measuring the amount of displacement of the head module against the stress generated in the tube. Graph G1 shown in the figure is a graph showing the relationship between the Z-direction external force FZ applied to the head module 12 and the X-direction displacement and Z-direction displacement of the head module 12. The horizontal axis of graph G1 is the Z-direction external force FZ. The unit of the Z-direction external force FZ is Newton. The Z-direction external force FZ is the measured value of a force gauge FG.

[0094] The vertical axis of graph G1 represents the amount of displacement in the X direction of the head module 12 and the amount of displacement in the Z direction of the nozzle surface 12A. The units of the amount of displacement in the X direction and the amount of displacement in the Z direction are micrometers.

[0095] Graph G1 shows that when the external force FZ in the Z direction is in the range of 25 Newtons or less, the X displacement is 5.0 micrometers or less. Graph G1 also shows that when the external force FZ in the Z direction is in the range of 16 Newtons or less, the Z displacement is 10 micrometers or less.

[0096] A margin is taken into consideration for the test results of the X displacement amount and the Z displacement amount described above, and the design target for the stress of the tube 100A etc. corresponding to the external force FZ in the Z direction is set to 10 Newtons or less.

[0097] [Evaluation test of tube shape to reduce tube stress] Fig. 13 is a schematic diagram of a stress measurement for a tube. For each of the tubes 100A etc. shown in Fig. 3 to Fig. 8, an external force FZ in the Z direction applied to the tube 100A etc. is measured.

[0098] 13, one end of the tubes 100A, etc. is fixed to a lower surface PLU of a plate PL simulating the collecting pipe 102 shown in Fig. 5 etc., and a probe MC of a force gauge FG simulating a head module 12 is connected to the other end of the tubes 100A, etc. The positions of the plate PL and the force gauge FG are fixed so that the distance from the lower surface PLU of the plate PL to the joint JO matches the distance from the lower surface 102A of the collecting pipe 102 to the connection position of the tubes 100A, etc. of the nozzle plate 13.

[0099] Each of the tubes 100A etc. is connected between the lower surface PLU of the plate PL and a probe MC of the force gauge FG, and stress is measured for each of the tubes 100A etc. The stress value of the tubes 100A etc. is obtained as the measurement value of the force gauge FG.

[0100] FIG. 14 is a graph showing the results of measuring the stress on the tube. Graph G2 shown in the figure shows the stress on the tube for each tube shape. The horizontal axis of graph G2 represents tube 100A, etc., and the vertical axis of graph G2 represents the external force in the Z direction. The unit of the external force in the Z direction is Newton.

[0101] "Straight" on the horizontal axis of graph G2 indicates the straight-shaped tube 100 shown in Fig. 4. Also, "curve," "loop," "bellows," and "spiral" indicate tubes 100A, 100C, 100D, and 100E shown in Fig. 5 and Figs. 7 to 9, respectively.

[0102] The external force in the Z direction of the tube 100 shown in Fig. 4 is 16 Newtons, which does not satisfy the condition of 10 Newtons or less. On the other hand, the tubes 100A, 100C, 100D, and 100E shown in Fig. 5 and Fig. 7 to Fig. 9, respectively, all satisfy the condition of 10 Newtons or less for the external force in the Z direction. The external force in the Z direction of the tube 100B shown in Fig. 6 is considered to be smaller than that of the tube 100A shown in Fig. 5, and is considered to satisfy the condition of 10 Newtons or less for the external force in the Z direction.

[0103] The tubes used in the evaluation tests were two-layer tubes, with an outer layer made of polyurethane and an inner layer made of ETFE. ETFE is an abbreviation of Ethylene Tetra Fluoro Ethylen, a copolymer of tetrafluoroethylene and ethylene. An example of a two-layer tube is the Super Flexible Tube E-SJ, manufactured by Hakkosha Co., Ltd., with an inner diameter of 4 mm and an outer diameter of 8 mm.

[0104] When the head module 12 is rotated around a rotation axis extending in the X direction to tilt the nozzle surface 12A with respect to the horizontal plane, the tubes 100A etc. are also tilted with respect to the Z direction in accordance with the tilt of the head module 12 with respect to the horizontal plane. Then, the stress in the tubes 100A etc. has an X-direction component, a Y-direction component, and a Z-direction component.

[0105] Ideally, the X direction is parallel to the horizontal plane, and no X component of stress is generated in the tube 100A, etc. If the rotation axis YA is inclined to the horizontal plane, the X component of stress is generated in the tube 100A, etc., but generally, the inclination of the rotation axis YA to the horizontal plane is about several degrees, and the X component of stress in the tube 100A, etc. is considered negligible.

[0106] Moreover, the magnitude of the Y-direction component of the stress of the tube 100A, etc. is a value obtained by multiplying the absolute value of the stress of the tube 100A, etc. by the cosine. The magnitude of the Z-direction component of the stress of the tube 100A, etc. is a value obtained by multiplying the absolute value of the stress of the tube 100A, etc. by the sine. The magnitude of the Y-direction component of the stress of the tube 100A, etc. and the magnitude of the Z-direction component of the stress of the tube 100A, etc. are both values ​​greater than or equal to 0 and less than the absolute value of the stress.

[0107] That is, the external force in the Z direction shown in Fig. 14 is the maximum value of the stress of the tubes 100A and the like acting on the head module 12, and is the strictest condition for the positional accuracy in the X direction and the Z direction of the head module 12. Therefore, the results of the evaluation test shown in Figs. 12 and 14 are valid even when the nozzle surface 12A is inclined with respect to the horizontal plane.

[0108] The stress of the tube 100A etc. acting on the head module 12 varies depending on the type and size of the tube 100A etc. The size of the tube 100A etc. includes the total length, the outer diameter and the inner diameter. On the other hand, the tube structure for reducing the stress shown in Fig. 5 to Fig. 9 is a tube applied to a liquid flow path connected to one or more head modules provided in a liquid ejection head, and is widely effective for flexible tubes.

[0109] [Effects of the embodiment] The liquid ejection head according to the embodiment can provide the following advantageous effects.

[0110] [1] The tubes 100A etc. connecting the collecting pipe 102 and the head module 12 have a stress reducing shape that relatively reduces stress corresponding to deformation of the tubes 100A etc. This suppresses misalignment of the head module caused by deformation of the tubes 100A etc. when the attitude of the head module 12 with respect to the frame in which the head module is housed is adjusted.

[0111] [2] The stress reducing shape of the tube 100A etc. may be a curved shape, a loop shape, a bellows shape, a spiral shape, or an appropriate combination of these. In this way, the stress reducing shape of the tube 100A etc. is realized by devising the shape itself of the tube 100A etc.

[0112] [3] The outer circumferential surfaces of the tubes 100A etc. have a friction reducing shape that reduces friction on the outer circumferential surfaces, thereby suppressing misalignment of the head module caused by frictional force generated on the outer circumferential surfaces of the tubes 100A etc.

[0113] In particular, in the case of including a supply tube 32 that supplies liquid to the head module 12 and a recovery tube that recovers liquid from the head module 12, the frictional force generated between the supply tube 32 and the recovery tube, which are arranged in close proximity, can be reduced.

[0114] Furthermore, even when a plurality of head modules 12 are provided, it is possible to reduce the frictional force generated between the tubes 100A and the like that are arranged closely to each other.

[0115] [4] The friction reducing shape of the outer circumferential surface of the tube 100A etc. includes a textured shape, whereby the friction reducing shape is realized by applying processing to the outer circumferential surface of the tube 100A etc.

[0116] [5] To adjust the attitude of the head module 12 relative to the frame in which the head module is housed, the nozzle surface 12A is inclined relative to the horizontal plane HP. This makes it possible to adjust the nozzle surface to be parallel to the transport surface of the medium when the medium is transported along an inclined surface that is inclined relative to the horizontal plane HP.

[0117] [6] When the multiple head modules 12 are moved, the multiple head modules 12 are supported as a unit and moved together with the guide plate 16 to which they are fixed. This allows the multiple head modules 12 to be moved together.

[0118] [About liquids] As the liquid to be ejected from the jet head onto the ink, various liquids such as ink, treatment liquid, and cleaning liquid are applied. Examples of ink include a liquid in which colorant particles are dispersed in a solvent, and a liquid in which a colorant is dissolved in a solvent. The colorant may be referred to as a coloring material or the like. The solvent may be an aqueous solvent containing water as a main component, or may be an oil-based solvent.

[0119] Another example of the ink is a functional ink in which metal particles, resin particles, etc. are dispersed in a solvent. The functional ink is used when forming metal patterns such as electrical wiring and resin mask patterns.

[0120] Examples of the treatment liquid include a pre-treatment liquid applied to a medium before the ink is applied, and a post-treatment liquid applied to a medium after the ink is applied. Examples of the pre-treatment liquid include a liquid having a function of thickening the ink. Examples of the post-treatment liquid include a liquid that forms a coating layer, a protective layer, etc.

[0121] Examples of the cleaning liquid include a cleaning liquid having a component that peels off the deposit adhering to the substrate from the substrate, a cleaning liquid having a component that dissolves the deposit, etc. The physical properties such as viscosity of the ink, the treatment liquid and the cleaning liquid are adjusted so that they can be ejected from an inkjet type liquid ejection head.

[0122] [About the sheet] 2 and the like may be made of various materials such as a resin sheet, a metal sheet, a paper sheet, etc. The sheet S may be referred to as a film, etc.

[0123] [Application example to liquid ejection device] 2 and 3 can be understood as configuration diagrams of a liquid ejection device that ejects liquid from the liquid ejection head 10 onto a sheet S. The first transport roller 40 and the second transport roller 42 can be understood as components of a medium support device that supports the sheet S. The medium support device including the first transport roller 40 and the second transport roller 42 can function as a medium transport device that transports the sheet S along a specified transport direction.

[0124] The liquid ejection device includes a head attitude changing unit that changes the attitude of the head module 12 by tilting the head module 12 with respect to a frame 20 extending in the vertical direction in accordance with the angle of a support surface on which the sheet S is supported with respect to a horizontal plane. The head attitude changing unit sets the attitude of the head module 12 in accordance with the transport path of the sheet S when the liquid ejection device is raised. The attitude of the head module 12 is maintained while the liquid ejection device is in operation.

[0125] The above-described embodiment of the present invention may be modified, added, or deleted as appropriate within the scope of the gist of the present invention. The present invention is not limited to the above-described embodiment, and many modifications may be made by a person having ordinary knowledge in the relevant field within the technical concept of the present invention. In addition, the embodiment, modified example, and application example may be implemented in combination as appropriate. [Explanation of symbols]

[0126] 10 Liquid ejection head 12 Head module 12A Nozzle surface 12B Top surface 13 Nozzle plate 16 Guide plate 16 18 Rotating section 18A 1st support part 18B 2nd support part 20 Frames 20A Plate 30 Supply collection pipe 32 Supply tube 36 Flexible PCB 40 First conveyor roller 40A First conveyor roller 42 Second conveyor roller 42A Second conveyor roller 44 Mobile section 46 Push Bolt 100 tubes 100A Tube 100B Tube 100C Tube 100D Tube 100E Tube 101 Connection port 102 Collection pipe 102A Bottom 103 Connection port 104A Straight section 104B Curved section 104C Curved section 104D Straight section 104E Loop part 104F Spiral section 120 Outer surface 122 Grain 124 Recess 126 Convex FG Force Gauge FZ external force G1 Graph G2 Graph HP horizontal plane JO Fittings MC probe LSX X Laser sensor for measuring displacement LSZ Z displacement measurement laser sensor PL Plate PLU bottom side YA Rotation Axis

Claims

1. One or more head modules; a tube that functions as a flow path for liquid supplied to the head module or a flow path for liquid recovered from the head module, the tube having one end fixed and the other end connected to the head module; a moving unit that moves the head module in a first direction; Equipped with The liquid ejection head, wherein the tube is a flexible tube and has a stress reducing shape that reduces stress corresponding to deformation of the tube caused by movement of the head module.

2. The liquid ejection head according to claim 1 , wherein the stress reducing shape of the tube is at least one of a curved shape, a loop shape, a bellows shape, and a spiral shape.

3. The liquid ejection head according to claim 1 , wherein the tube has an outer circumferential surface having a friction reducing shape that reduces friction on the outer circumferential surface.

4. The liquid ejection head according to claim 3 , wherein the friction reducing shape includes a grained shape.

5. A plurality of the head modules are provided, The liquid ejection head according to claim 1 , wherein the plurality of head modules are arranged along a second direction that intersects with the first direction and is parallel to the liquid ejection surfaces of the head modules.

6. The liquid ejection head according to claim 1, wherein the moving section rotates the head module around a rotation axis extending in a third direction that intersects the first direction and is parallel to a specified reference plane, thereby tilting the liquid ejection surface of the head module relative to the reference plane.

7. a collecting pipe in which liquid supplied to the head module is stored or liquid recovered from the head module is stored, the collecting pipe being fixed to and supported by a frame in which the head module is housed; The liquid ejection head according to claim 1 , wherein one end of the tube is connected to the collecting pipe and fixed.

8. the collecting pipe includes a supply collecting pipe that accommodates the liquid to be supplied to the head module, The liquid ejection head according to claim 7 , wherein the tube includes a supply tube through which the liquid flows from the supply collecting pipe line toward the head module.

9. the collecting pipe includes a recovery collecting pipe that accommodates the liquid recovered from the head module, The liquid ejection head according to claim 7 , wherein the tubes include a recovery tube through which the liquid flows from the head module toward the recovery collecting pipe.

10. The liquid ejection head according to claim 1 , wherein the head module uses any one of an ink, a treatment liquid, and a cleaning liquid as the liquid.

11. a guide plate for supporting the head module; The liquid ejection head according to claim 1 , wherein the moving section moves the head module together with the guide plate when moving the head module.

12. The liquid ejection head according to claim 1 , further comprising a position adjustment section that adjusts a position of the head module in a fourth direction intersecting the first direction.

13. a liquid ejection head that ejects liquid onto a medium; A liquid ejection device including a medium support device that supports the medium, The liquid ejection head includes: One or more head modules; a tube that functions as a flow path for liquid supplied to the head module or a flow path for liquid recovered from the head module, the tube having one end fixed and the other end connected to the head module; a moving unit that moves the head module in a first direction; Equipped with The liquid ejection device, wherein the tube is a flexible tube and has a stress reducing shape that reduces stress corresponding to deformation of the tube caused by movement of the head module.

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