Inkjet recording device

Abstract

To provide an ink jet recording device which can record a pattern in accordance with a recording surface of a recording medium.SOLUTION: A second mover relatively moves a recording medium and a first mover in a second coordinate axis direction. An ink jet head discharges ink to a recording surface from a plurality of nozzles in a moving state that a recording unit is moved in a first coordinate axis direction by the first mover. When the recording surface is convex or concave and has a surface shape along the second coordinate axis direction, a rotary machine rotates the ink jet head around a rotary shaft and makes a discharge surface parallel to a virtual straight line in a moving state. A third mover moves the ink jet head in a third coordinate axis direction and keeps a constant clearance in a vertical direction between a reference position of the discharge surface and an opposite position of the recording surface in a moving state. The virtual straight line passes the nearest opposite position of the recording surface from the reference position of the discharge surface in a vertical direction vertical to the discharge surface and is orthogonal to the vertical direction.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to an inkjet recording apparatus. [Background Art]

[0002] Patent Document 1 discloses a printing apparatus. The printing apparatus prints a predetermined image by ejecting droplets onto a workpiece having a three-dimensional curved surface. The printing apparatus comprises a printing unit, a workpiece drive unit, and a control unit. The printing apparatus has a frame and a gantry. The gantry is erected from the frame. The frame is equipped with a workpiece drive unit. The gantry is equipped with a printing unit. The printing unit is positioned above the printing surface of the workpiece. The printing unit has an X-axis linear motion mechanism and a plurality of inkjet units. The X-axis linear motion mechanism is attached to the gantry. The plurality of inkjet units are each attached to the X-axis linear motion mechanism. The plurality of inkjet units move in the main scanning direction by the X-axis linear motion mechanism. The X-axis linear motion mechanism is composed of a linear motor drive mechanism. The X-axis linear motion mechanism drives the plurality of inkjet units separately in the X direction. The inkjet units print an image on the surface of the workpiece by ejecting droplets toward the workpiece while moving in the main scanning direction. The workpiece drive unit moves the workpiece relative to the inkjet unit. Images are also printed in the sub-scanning direction. The sub-scanning direction is perpendicular to the main scanning direction. The inkjet unit has a head unit and a curing unit. The curing unit hardens the ink. A fixing jig is attached to the front of the workpiece drive unit. The workpiece is fixed to the fixing jig. The workpiece drive unit transports the workpiece fixed to the fixing jig to the bottom of the printing unit. The workpiece drive unit has four drive mechanisms: a Y-axis linear motion mechanism, a Z-axis linear motion mechanism, an A-axis rotation mechanism, and a B-axis rotation mechanism. The Y-axis linear motion mechanism is mounted on a stand and moves the workpiece in the sub-scanning direction. The Z-axis linear motion mechanism is attached to the Y-axis linear motion mechanism and moves the workpiece vertically. The A-axis rotation mechanism rotates the workpiece around the A-axis. The A-axis extends in the X direction. The fixing jig is attached to the B-axis rotation mechanism. The B-axis rotation mechanism rotates the workpiece around the B-axis. The B-axis extends in the Z-direction. The workpiece drive unit moves the workpiece below the inkjet unit by operating the Y-axis linear motion mechanism, the Z-axis linear motion mechanism, the A-axis rotation mechanism, and the B-axis rotation mechanism. The position and orientation of the workpiece are adjusted by the workpiece drive unit.In addition, the workpiece drive unit has five drive mechanisms: a Y-axis linear motion mechanism, a Z-axis linear motion mechanism, an A-axis rotation mechanism, a B-axis rotation mechanism, and a C-axis rotation mechanism. The C-axis rotation mechanism rotates the workpiece around the C-axis. The C-axis extends in the Z-direction. By increasing the number of drive mechanisms in the workpiece drive unit, the range of adjustment for the workpiece's orientation can be further expanded. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-88110 [Overview of the project] [Problems that the invention aims to solve]

[0004] An inkjet recording device ejects ink from multiple nozzles of an inkjet head onto the surface of a recording medium, thereby recording a pattern on the recording surface of the medium. Examples of recording media include housings (outer shells) of electrical equipment, interior and exterior materials for vehicles and buildings, and furniture. In other words, the recording medium becomes a component that forms various products with a pattern recorded on its recording surface, or a part for various products. In such recording media, the recording surface may have a three-dimensional shape.

[0005] The inventors have investigated a technique for recording patterns on a recording surface having the following three-dimensional shape using an inkjet recording device. This embodiment has a surface shape that is convex or concave in the third coordinate axis direction along the first coordinate axis direction and aligned with the second coordinate axis direction. The second coordinate axis direction is perpendicular to the first coordinate axis direction. The third coordinate axis direction is perpendicular to both the first and second coordinate axis directions.

[0006] The present invention aims to provide an inkjet recording device that can record patterns according to the recording surface of a recording medium. [Means for solving the problem]

[0007] One aspect of the present invention comprises a recording unit for ejecting ink onto the recording surface of a recording medium, a first moving machine for moving the recording unit in a first coordinate axis direction, and a second moving machine for relatively moving the recording medium and the first moving machine in a second coordinate axis direction perpendicular to the first coordinate axis direction, wherein the recording unit includes an inkjet head including a plurality of nozzles for ejecting the ink, a rotating machine for rotating the inkjet head about a rotation axis along the second coordinate axis direction, and a third moving machine for moving the inkjet head in a third coordinate axis direction perpendicular to both the first and second coordinate axis directions, wherein the inkjet head, in a moving state where the recording unit is moving in the first coordinate axis direction by the first moving machine, is ejected from the plurality of nozzles The ink is ejected onto the recording surface, and the rotating machine, when the recording surface has a surface shape that is convex on the first side in the third coordinate axis direction or concave on the second side in the third coordinate axis direction and along the second coordinate axis direction in the first coordinate axis direction, rotates the inkjet head about the rotation axis in the moving state, and aligns the ejection surface of the inkjet head, from which the plurality of nozzles open, with a virtual straight line that passes through the closest opposing position on the recording surface from the reference position on the ejection surface in a vertical direction perpendicular to the ejection surface and is perpendicular to the vertical direction, and the third moving machine, when the recording surface has the surface shape, moves the inkjet head in the third coordinate axis direction in the moving state, and keeps the vertical separation distance between the reference position and the opposing position constant. and the recording unit comprises: a carriage carrying the inkjet head; a support member that supports the carriage; a sub-tank that stores the ink to be supplied to the inkjet head; and a connection flow path that connects the sub-tank and the inkjet head and allows the ink to flow from the sub-tank to the inkjet head, wherein the rotating device and the sub-tank are provided on the support member, the third moving device moves the support member in a third coordinate axis direction that coincides with the vertical direction, the support member rotatably supports the carriage about the rotation shaft, the sub-tank is provided on the support member at a first side in the third coordinate axis direction that is vertically above the inkjet head mounted on the carriage, and the rotating device rotates the carriage about the rotation shaft which is set at a position on the first side in the third coordinate axis direction from the ejection surface of the inkjet head in a state where the ink is ejected from the plurality of nozzles toward the second side in the third coordinate axis direction where the vertical direction is along the third coordinate axis direction and is vertically lower, and on the second side in the third coordinate axis direction from the sub-tank It is an inkjet recording device.

[0008] This inkjet recording device allows the recording unit to be moved along the first coordinate axis while maintaining a constant orientation of the ejection surface relative to the recording surface and a constant distance between the recording surface and the ejection surface. The rotation shaft can be set at a position on the second side in the third coordinate axis direction from the sub-tank. When the inkjet head rotates about the rotation shaft via the carriage, it is assumed that an error Δθ may occur in the actual rotation amount (rotation angle) relative to the target set value. A comparative example is assumed. In the comparative example, the virtual rotation shaft that serves as the center of rotation of the inkjet head is located on the second side in the third coordinate axis direction from the sub-tank. The distance A from the rotation shaft to the reference position is shorter than the distance B from the virtual rotation shaft to the reference position (A<B). When an error of the same Δθ occurs in the rotation amount in the above-described configuration (the former) and the configuration of the comparative example (the latter), the positional deviation amount of the reference position occurring in the former is 2πA×Δθ / 360°, and the positional deviation amount of the reference position occurring in the latter is 2πB×Δθ / 360°. That is, the positional deviation amount of the reference position occurring in the former can be reduced to A / B times that occurring in the latter.

[0011] The connecting channel includes a rotating part that rotates about the rotation axis, an upstream part that connects the sub-tank and the rotating part and through which the ink that has flowed out of the sub-tank flows, and a downstream part that connects the rotating part and the inkjet head and through which the ink that flows into the inkjet head flows, wherein the downstream part is provided along the rotation axis at a position that coincides with the rotation axis, and the rotating part may rotate the downstream part about the rotation axis relative to the upstream part.

[0012] This configuration allows the connecting channel to follow the rotation of the inkjet head around the rotation axis via the carriage. Unlike the connecting channel, a virtual channel is assumed that does not have a rotating part. The virtual channel connects the sub-tank and the inkjet head. In this case, the virtual channel has the following length. This length corresponds to the rotation of the inkjet head around the rotation axis via the carriage. That is, the length of the virtual channel is set to be longer by the length of play required to accommodate this rotation. In the connecting channel, such a length of play can be reduced or omitted.

[0013] The recording unit may include a first recording unit that ejects a first ink as the ink onto the recording surface, and a second recording unit that ejects a second ink as the ink onto the recording surface, wherein the first moving machine moves the first recording unit in the first coordinate axis direction and moves the second recording unit in the first coordinate axis direction.

[0014] This configuration allows the first recording unit and the second recording unit to operate independently. In each of the first and second recording units, the orientation of the ejection surface relative to the recording surface and the distance between the recording surface and the ejection surface can be kept constant while the first and second recording units can be moved in the first coordinate axis direction.

[0015] The first recording unit may eject the first ink of the first color onto the recording surface, and the second recording unit may eject the second ink of a second color different from the first color onto the recording surface.

[0016] With this configuration, patterns can be recorded using the first and second inks. [Effects of the Invention]

[0017] According to the present invention, an inkjet recording apparatus can be obtained that can record a pattern in accordance with the recording surface of a recording medium. 。 [Brief explanation of the drawing]

[0018] [Figure 1] This is a perspective view showing an example of the schematic configuration of an inkjet recording device. It shows the state before the start of the pattern recording operation. [Figure 2] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some parts omitted. The inkjet recording device is shown with the first color recording unit, second color recording unit, third color recording unit, and fourth color recording unit moved to the third end of the first coordinate axis direction. [Figure 3] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some parts omitted. The inkjet recording device shows the state in which the recording unit for the first color is ejecting the first ink onto the first inclined surface of the recording surface. [Figure 4] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some parts omitted. The inkjet recording device shows the state in which the first color recording unit ejects the first ink to the third region in the first coordinate axis direction of the top surface of the recording surface, and the second color recording unit ejects the second ink to the first inclined surface. [Figure 5]This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some details omitted. The inkjet recording device shows the first color recording unit ejecting first ink to the fourth region on the top surface in the direction of the first coordinate axis, the second color recording unit ejecting second ink to the third region on the top surface in the direction of the first coordinate axis, and the third color recording unit ejecting third ink to the first inclined surface. [Figure 6] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some details omitted. The inkjet recording device shows the following states: the first color recording unit ejects the first ink onto the second inclined surface of the recording surface; the second color recording unit ejects the second ink onto the fourth region in the first coordinate axis direction of the top surface; the third color recording unit ejects the third ink onto the third region in the first coordinate axis direction of the top surface; and the fourth color recording unit ejects the fourth ink onto the first inclined surface. [Figure 7] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some details omitted. The inkjet recording device shows the state in which the second color recording unit ejects the second ink onto the second inclined surface, the third color recording unit ejects the third ink onto the fourth region on the top surface in the direction of the first coordinate axis, and the fourth color recording unit ejects the fourth ink onto the third region on the top surface in the direction of the first coordinate axis. [Figure 8] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some details omitted. The inkjet recording device shows the third color recording unit ejecting the third ink onto the second inclined surface, and the fourth color recording unit ejecting the fourth ink onto the fourth side region in the first coordinate axis direction of the top surface. [Figure 9] This is a perspective view showing a schematic example of an inkjet recording device during pattern recording, with some details omitted. The inkjet recording device shows the fourth color recording unit ejecting the fourth ink onto the second inclined surface. [Figure 10]It is a perspective view showing an example of the schematic configuration of an inkjet recording apparatus during a pattern recording operation, with a part omitted. The figure shows a state in which the recording unit for the first color, the recording unit for the second color, the recording unit for the third color, and the recording unit for the fourth color have moved to a moving end on the fourth side in the first coordinate axis direction. [Figure 11] It is a perspective view showing an example of the schematic configuration of an inkjet recording apparatus at the end of a pattern recording operation, with a part omitted. [Figure 12] It is a perspective view showing an example of the schematic configuration of a recording unit during a pattern recording operation on a first inclined surface. The recording unit corresponds to the recording unit for the first color in FIG. 3, the recording unit for the second color in FIG. 4, the recording unit for the third color in FIG. 5, or the recording unit for the fourth color in FIG. 6. The rail and the support base of the second moving device show portions corresponding to the recording unit. [Figure 13] It is a perspective view showing an example of the schematic configuration of a recording unit during a pattern recording operation on a region on the third side in the first coordinate axis direction of a top surface. The recording unit corresponds to the recording unit for the first color in FIG. 4, the recording unit for the second color in FIG. 5, the recording unit for the third color in FIG. 6, or the recording unit for the fourth color in FIG. 7. The rail and the support base of the second moving device show portions corresponding to the recording unit. [Figure 14] It is a perspective view showing an example of the schematic configuration of a recording unit during a pattern recording operation on a region on the fourth side in the first coordinate axis direction of a top surface. The recording unit corresponds to the recording unit for the first color in FIG. 5, the recording unit for the second color in FIG. 6, the recording unit for the third color in FIG. 7, or the recording unit for the fourth color in FIG. 8. The rail and the support base of the second moving device show portions corresponding to the recording unit. [Figure 15] It is a perspective view showing an example of the schematic configuration of a recording unit during a pattern recording operation on a second inclined surface. The recording unit corresponds to the recording unit for the first color in FIG. 6, the recording unit for the second color in FIG. 7, the recording unit for the third color in FIG. 8, or the recording unit for the fourth color in FIG. 9. The rail and the support base of the second moving device show portions corresponding to the recording unit. [Figure 16]This is a partial cross-sectional view showing an example of the schematic configuration of the recording unit during the pattern recording operation on the top surface. The recording unit corresponds to the first color recording unit in Figures 4 and 5, the second color recording unit in Figures 5 and 6, the third color recording unit in Figures 6 and 7, or the fourth color recording unit in Figures 7 and 8. The cutting position corresponds to line II in Figures 13 and 14. The rails and support base of the second moving machine show the parts corresponding to the recording unit. [Figure 17] This is a bottom view showing an example of the schematic configuration of the recording unit. It shows the ejection surface of the inkjet head. [Figure 18] This is a partial cross-sectional front view showing an example of the schematic configuration of the recording unit during the pattern recording operation. The recording unit is shown moving along the recording surface in the first coordinate axis direction. This corresponds to the view of the inkjet recording device from the fifth side in the second coordinate axis direction. This shows a cross-section of the recording unit cut at the position of the inkjet head. [Modes for carrying out the invention]

[0019] Embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the configurations described below, and various configurations can be adopted within the same technical concept. For example, some of the configurations shown below may be omitted or replaced with other configurations. The present invention may include other configurations. The drawings schematically show a given configuration. Each drawing may not correspond accurately to other drawings or to the numerical values ​​described later that specify the configuration in the drawing. Hatching indicates a cross-section. A dashed line is a center line. A dashed line is an imaginary line. A dashed line is a hidden line.

[0020] <Inkjet recording device 10> The inkjet recording device 10 will be described with reference to Figures 1 to 11. In this embodiment, the inkjet recording device 10 is defined by the first coordinate axis direction, the second coordinate axis direction, the third coordinate axis direction, and the vertical direction V. The recording medium 15 is also defined by the first coordinate axis direction, the second coordinate axis direction, and the third coordinate axis direction, based on its state as installed in the inkjet recording device 10 (see Figure 1). The second coordinate axis direction is perpendicular to the first coordinate axis direction. The third coordinate axis direction is perpendicular to both the first and second coordinate axis directions. The third coordinate axis direction is defined as the vertical direction. In this case, the first and second coordinate axis directions are horizontal. One side of the third coordinate axis direction is called the "first side," and the other side of the third coordinate axis direction opposite to the first side is called the "second side." The first side of the third coordinate axis direction is defined as the upper side in the vertical direction, and the second side of the third coordinate axis direction is defined as the lower side in the vertical direction. One side of the first coordinate axis direction is called the "third side," and the other side of the first coordinate axis direction opposite to the third side is called the "fourth side." One side in the direction of the second coordinate axis is called the "fifth side," and the other side in the direction of the second coordinate axis opposite to the fifth side is called the "sixth side." The vertical direction V will be discussed later.

[0021] The inkjet recording device 10 comprises recording units 21, 22, 23, and 24, a first mobile unit 75, and a second mobile unit 85 (see Figure 1). In addition, the inkjet recording device 10 comprises main tanks 101, 102, 103, and 104, and ink channels 106, 107, 108, and 109. The inkjet recording device 10 records a pattern on the recording surface 16 of the recording medium 15 by operating the recording units 21, 22, 23, and 24, the first mobile unit 75, and the second mobile unit 85 (see Figures 2 to 11). In Figures 2 to 11, the intermediate parts of each of the ink channels 106, 107, 108, and 109 are not shown.

[0022] The recording surface 16 has a surface shape that is convex on the first side in the third coordinate axis direction or concave on the second side in the third coordinate axis direction and aligned with the second coordinate axis direction in the first coordinate axis direction. In the embodiment, the recording surface 16 has a surface shape that is convex on the first side in the third coordinate axis direction and aligned with the second coordinate axis direction in the first coordinate axis direction. Furthermore, in the embodiment, this surface shape includes a first inclined surface 17, a top surface 18, and a second inclined surface 19, and the first inclined surface 17, top surface 18, and second inclined surface 19 are connected in this order from the third side to the fourth side in the first coordinate axis direction. The first inclined surface 17 is inclined from the second side to the first side in the third coordinate axis direction as it moves from the third side to the fourth side in the first coordinate axis direction. The first inclined surface 17 is connected to the third side in the first coordinate axis direction of the top surface 18 on the fourth side in the first coordinate axis direction. The top surface 18 is horizontal. The second inclined surface 19 is inclined from the first side to the second side in the third coordinate axis direction as it moves from the third side to the fourth side in the first coordinate axis direction. The second inclined surface 19 is connected to the fourth side of the top surface 18 in the first coordinate axis direction on the third side in the first coordinate axis direction. The recording surface 16 as a whole has a surface shape that is convex on the first side in the third coordinate axis direction and aligned with the second coordinate axis direction. The pattern applied to the recording surface 16 in Figure 11 corresponds to a pattern. The pattern is not shown in Figures 6-10 and Figures 13-16 described later.

[0023] Recording unit 21 ejects the first ink onto the recording surface 16 (see Figures 3-6 and 6-3). Recording unit 22 ejects the second ink onto the recording surface 16 (see Figures 4-7 and 7-4). Recording unit 23 ejects the third ink onto the recording surface 16 (see Figures 5-8 and 8-5). Recording unit 24 ejects the fourth ink onto the recording surface 16 (see Figures 6-9 and 9-6). Recording units 21, 22, 23, and 24 will be described later.

[0024] In this embodiment, the first ink contains a first-color colorant, the second ink contains a second-color colorant, the third ink contains a third-color colorant, and the fourth ink contains a fourth-color colorant. Examples of colorants include pigments and dyes. In this embodiment, the second color is different from the first color, the third color is different from the first and second colors, and the fourth color is different from the first, second, and third colors. An example of a combination of the first, second, third, and fourth colors is a combination of cyan, magenta, yellow, and black. However, cyan, magenta, yellow, and black are examples only. The second color may be the same as the first color, the third color may be the same as the first or second color, and the fourth color may be the same as the first, second, or third color. In other words, the second ink may be the same color as the first ink, the third ink may be the same color as the first or second ink, and the fourth ink may be the same color as the first, second, or third ink. The ink colors of the first, second, third, and fourth inks (first color, second color, third color, and fourth color) are determined appropriately considering various conditions.

[0025] The first mobile unit 75 moves the recording units 21, 22, 23, and 24 in the first coordinate axis direction (see Figures 2-10 and 10-2). The inkjet recording device 10 employs a linear motion mechanism as the first mobile unit 75. An example of a linear motion mechanism that can be used as the first mobile unit 75 is a linear motor actuator. In this embodiment, a linear motor actuator is exemplified as the first mobile unit 75. In this case, the first mobile unit 75 includes a stator 76 and movable elements 81, 82, 83, and 84. The stator 76 is provided along the first coordinate axis direction. The stator 76 is provided on the stand of the inkjet recording device 10. In this embodiment, the illustration of the stand of the inkjet recording device 10 is omitted.

[0026] The movable element 81 moves on the stator 76 from the third side to the fourth side in the first coordinate axis direction by the thrust force acting on the movable element 81 in relation to the stator 76 (see Figures 2-10). The movable element 81 moves on the stator 76 from the fourth side to the third side in the first coordinate axis direction by the thrust force acting on the movable element 81 in relation to the stator 76 (see Figures 10-12). A recording unit 21 is provided on the movable element 81. The first mobile device 75 moves the recording unit 21 in the first coordinate axis direction by moving the movable element 81 in the first coordinate axis direction. That is, the first mobile device 75 moves the recording unit 21 back and forth from the third side to the fourth side in the first coordinate axis direction and from the fourth side to the third side in the first coordinate axis direction.

[0027] The movable element 82 moves on the stator 76 from the third side to the fourth side in the first coordinate axis direction by the thrust force acting on the movable element 82 in relation to the stator 76 (see Figures 2-10). The movable element 82 moves on the stator 76 from the fourth side to the third side in the first coordinate axis direction by the thrust force acting on the movable element 82 in relation to the stator 76 (see Figures 10-12). A recording unit 22 is provided on the movable element 82. The first mobile device 75 moves the recording unit 22 in the first coordinate axis direction by moving the movable element 82 in the first coordinate axis direction. That is, the first mobile device 75 moves the recording unit 22 back and forth from the third side to the fourth side in the first coordinate axis direction and from the fourth side to the third side in the first coordinate axis direction.

[0028] The movable element 83 moves on the stator 76 from the third side to the fourth side in the first coordinate axis direction by the thrust force acting on the movable element 83 in relation to the stator 76 (see Figures 2-10). The movable element 83 moves on the stator 76 from the fourth side to the third side in the first coordinate axis direction by the thrust force acting on the movable element 83 in relation to the stator 76 (see Figures 10-12). A recording unit 23 is provided on the movable element 83. The first mobile device 75 moves the recording unit 23 in the first coordinate axis direction by moving the movable element 83 in the first coordinate axis direction. That is, the first mobile device 75 moves the recording unit 23 back and forth from the third side to the fourth side in the first coordinate axis direction and from the fourth side to the third side in the first coordinate axis direction.

[0029] The movable element 84 moves on the stator 76 from the third side to the fourth side in the first coordinate axis direction by the thrust force acting on the movable element 84 in relation to the stator 76 (see Figures 2-10). The movable element 84 moves on the stator 76 from the fourth side to the third side in the first coordinate axis direction by the thrust force acting on the movable element 84 in relation to the stator 76 (see Figures 10-12). A recording unit 24 is provided on the movable element 84. The first mobile device 75 moves the recording unit 24 in the first coordinate axis direction by moving the movable element 84 in the first coordinate axis direction. That is, the first mobile device 75 moves the recording unit 24 back and forth from the third side to the fourth side in the first coordinate axis direction and from the fourth side to the third side in the first coordinate axis direction.

[0030] Linear motor actuators as linear motion mechanisms are well known. The inkjet recording device 10 can employ a known linear motor actuator as the first mobile unit 75. Therefore, further explanation regarding the structure of the first mobile unit 75 is omitted.

[0031] The second mobile unit 85 moves the recording medium 15 and the first mobile unit 75 relative to each other in the second coordinate axis direction (see Figures 1, 2, 10, and 11). In other words, the second mobile unit 85 moves the recording medium 15 and the recording units 21, 22, 23, and 24 relative to each other in the second coordinate axis direction. In this embodiment, during the recording operation of the handle, this relative movement by the second mobile unit 85 is performed by moving the recording medium 15 from the fifth side to the sixth side in the second coordinate axis direction. That is, during the recording operation of the handle, the second mobile unit 85 moves the recording medium 15 from the fifth side to the sixth side in the second coordinate axis direction. While the recording medium 15 is moving from the fifth side to the sixth side in the second coordinate axis direction, it passes through the following movement path. Along this movement path, the recording units 21, 22, 23, and 24 are moved in the first coordinate axis direction by the first mobile unit 75.

[0032] During the recording operation of the handle, the second mobile unit 85 moves the recording medium 15 from the fifth side to the sixth side in the second coordinate axis direction in accordance with the next first and second main scans. During the first main scan, the first mobile unit 75 moves the recording units 21, 22, 23, and 24 in this order from the third side to the fourth side in the first coordinate axis direction (see Figures 2 to 10). During the second main scan, the first mobile unit 75 moves the recording units 24, 23, 22, and 21 in this order from the fourth side to the third side in the first coordinate axis direction (see Figures 10 to 12). That is, during the recording operation of the handle, the movement of the recording medium 15 by the second mobile unit 85 is performed intermittently in accordance with the arrival of the recording units 21, 22, 23, and 24 at the fourth end of the movement in the first coordinate axis direction during the first main scan (see Figure 10), and the arrival of the recording units 24, 23, 22, and 21 at the third end of the movement in the first coordinate axis direction during the second main scan (see Figure 2).

[0033] The second mobile device 85 moves the recording medium 15 from the fifth side to the sixth side in the second coordinate axis direction by a transport distance T (see Figure 10,2) per move. The transport distance T may be determined according to the dimension of the nozzle region N (see Figure 17, described later) in the second coordinate axis direction. For example, the transport distance T is set to be less than or equal to the dimension of the nozzle region N in the second coordinate axis direction. The nozzle region N will be described later.

[0034] The inkjet recording device 10 employs a linear motion mechanism as the second mobile unit 85. An example of a linear motion mechanism that can be used as the second mobile unit 85 is a combination of a ball screw, a drive unit, and a guide. In this embodiment, the above combination is exemplified as the second mobile unit 85. In this case, the second mobile unit 85 includes a ball screw 86, a drive unit 89, guides 90 and 91, a mounting base 94, and a support base 95 (see Figure 1). The second mobile unit 85 employs linear guides as the guides 90 and 91. However, the guides 90 and 91 may be a combination of a linear shaft and a bush, or they may be a ball spline. An example of a bush is a linear bush. The specifications of the guides 90 and 91 are determined appropriately considering various conditions.

[0035] The screw shaft 87 of the ball screw 86 is rotatably mounted along the second coordinate axis direction. The nut 88 of the ball screw 86 moves in the second coordinate axis direction in accordance with the rotation of the screw shaft 87. A drive unit 89 is connected to the screw shaft 87. A rotating machine such as a motor can be used as the drive unit 89. An example of a drive unit 89 is a servo motor. A servo motor as a drive unit 89 includes an encoder. The drive unit 89 rotates the screw shaft 87. The arc-shaped arrow shown on the outer circumference of the tip of the screw shaft 87 in Figure 1 indicates the direction of rotation of the screw shaft 87. In this embodiment, the drive unit 89 is located on the fifth side in the second coordinate axis direction, and the tip of the screw shaft 87 is located on the sixth side in the second coordinate axis direction. A guide 90 is provided on the third side in the first coordinate axis direction of the ball screw 86. A guide 91 is provided on the fourth side in the first coordinate axis direction of the ball screw 86. In guides 90 and 91, a rail 92 is provided along the second coordinate axis direction, and a block 93 moves along the rail 92 in the second coordinate axis direction. The mounting base 94 is fixed to the block 93 of nuts 88 and guides 90 and 91. The recording medium 15 is placed on the mounting base 94. The mounting base 94 supports the recording medium 15.

[0036] The support base 95 supports the ball screw 86, the drive unit 89, and the guides 90 and 91. Specifically, the support base 95 supports the drive unit 89 on the fifth side in the direction of the second coordinate axis, and rotatably supports the tip of the ball screw 86 on the sixth side in the direction of the second coordinate axis. The support base 95 supports the guide 90 on the third side in the direction of the first coordinate axis, and supports the guide 91 on the fourth side in the direction of the first coordinate axis.

[0037] In the inkjet recording device 10, the drive unit 89 rotates the screw shaft 87 in a predetermined direction, causing the nut 88 to move from the fifth side to the sixth side in the second coordinate axis direction (see Figure 10). In this case, the drive unit 89 rotates the screw shaft 87 by the following amount. This amount of rotation is the amount by which the nut 88 moves from the fifth side to the sixth side in the second coordinate axis direction, and this distance is defined as the transport distance T. The mounting table 94 moves in the same direction and by the same amount (transport distance T) as the nut 88 moves from the fifth side to the sixth side in the second coordinate axis direction. The drive unit 89 rotates the screw shaft 87 in the opposite direction to the aforementioned direction, causing the nut 88 to move from the sixth side to the fifth side in the second coordinate axis direction. In this case, the drive unit 89 rotates the screw shaft 87 by the following amount. For example, this amount of rotation returns the position of the nut 88 in the second coordinate axis direction to Figure 1. The mounting table 94 moves in the same direction and by the same amount as the nut 88 moving from the sixth side to the fifth side in the second coordinate axis direction.

[0038] Guides 90 and 91 guide the movement of the mounting platform 94 from the fifth side to the sixth side in the second coordinate axis direction and from the sixth side to the fifth side in the second coordinate axis direction, as described above. In other words, the mounting platform 94 moves from the fifth side to the sixth side in the second coordinate axis direction and from the sixth side to the fifth side in the second coordinate axis direction while being guided by guides 90 and 91.

[0039] The recording medium 15 is placed on the mounting table 94 with the mounting table 94 moved to the fifth movable end in the second coordinate axis direction (see Figure 1). Consequently, the recording medium 15 is installed in the inkjet recording device 10. The recording medium 15 is removed from the mounting table 94 with the mounting table 94 moved to the sixth movable end in the second coordinate axis direction (see Figure 11). Consequently, the recording medium 15 is recovered from the inkjet recording device 10.

[0040] However, the placement and removal of the recording medium 15 in this manner is illustrative. The recording medium 15 may be removed from the mounting base 94 after the pattern recording operation is completed, with the mounting base 94 moved to the fifth end of the second coordinate axis direction. When the pattern recording operation is performed in the inkjet recording device 10, the second mobile unit 85 may move the recording medium 15 and the first mobile unit 75 relative to each other by moving the recording medium 15 from the sixth to the fifth side of the second coordinate axis direction. For example, after the recording medium 15 is placed on the mounting base 94, the second mobile unit 85 moves the recording medium 15 on the mounting base 94 to the sixth side of the second coordinate axis direction from the first mobile unit 75. After that, the second mobile unit 85 intermittently moves the mounting base 94 by a transport distance T from the sixth to the fifth side of the second coordinate axis direction, as described above.

[0041] In the inkjet recording device 10, the following first, second, and third items are determined appropriately considering various conditions. The first item concerns the position in which the recording medium 15 is placed on the mounting table 94. The second item concerns the position in which the recording medium 15 is removed from the mounting table 94. The third item concerns the orientation in the second coordinate axis direction in which the recording medium 15 is moved.

[0042] The main tank 101 stores the first ink. The ink channel 106 connects the main tank 101 and the recording unit 21. The first ink is supplied from the main tank 101 through the ink channel 106 to the recording unit 21.

[0043] The main tank 102 stores the second ink. The ink channel 107 connects the main tank 102 and the recording unit 22. The second ink is supplied from the main tank 102 through the ink channel 107 to the recording unit 22.

[0044] The main tank 103 stores the third ink. The ink channel 108 connects the main tank 103 and the recording unit 23. The third ink is supplied from the main tank 103 through the ink channel 108 to the recording unit 23.

[0045] The main tank 104 stores the fourth ink. The ink channel 109 connects the main tank 104 and the recording unit 24. The fourth ink is supplied from the main tank 104 through the ink channel 109 to the recording unit 24.

[0046] <Recording Units 21, 22, 23, 24> Recording units 21, 22, 23, and 24 differ in that recording unit 21 ejects the first ink, recording unit 22 ejects the second ink, recording unit 23 ejects the third ink, and recording unit 24 ejects the fourth ink. However, recording units 21, 22, 23, and 24 have the same mechanical structure.

[0047] In this embodiment, when recording units 21, 22, 23, and 24 are not distinguished or are referred to collectively, they are referred to as "recording unit 20". When the first ink, second ink, third ink, and fourth ink are not distinguished or are referred to collectively, they are referred to as "ink". When the main tanks 101, 102, 103, and 104 are not distinguished or are referred to collectively, they are referred to as "main tank 100". When the ink channels 106, 107, 108, and 109 are not distinguished or are referred to collectively, they are referred to as "ink channel 105".

[0048] The descriptions of recording units 21, 22, 23, and 24 will be based on recording unit 20 and refer to Figures 12 to 18, with the exception of some descriptions, and without distinguishing between recording units 21, 22, 23, and 24. In this case, the combinations of recording unit 20, ink, main tank 100, and ink channel 105 are as follows: If recording unit 20 corresponds to recording unit 21, then for this recording unit 20, the ink is the first ink, the main tank 100 is the main tank 101, and the ink channel 105 is the ink channel 106. If recording unit 20 corresponds to recording unit 22, then for this recording unit 20, the ink is the second ink, the main tank 100 is the main tank 102, and the ink channel 105 is the ink channel 107. If recording unit 20 corresponds to recording unit 23, then for this recording unit 20, the ink is the third ink, the main tank 100 is the main tank 103, and the ink channel 105 is the ink channel 108. When recording unit 20 corresponds to recording unit 24, with respect to this recording unit 20, the ink is the fourth ink, the main tank 100 is the main tank 104, and the ink channel 105 is the ink channel 109.

[0049] The recording unit 20 includes an inkjet head 30, a carriage 40, a support 45, a rotating machine 50, a sub-tank 55, a connecting channel 60, and a third moving machine 65 (see Figures 12-16).

[0050] The inkjet head 30 includes multiple nozzles 31 on its ejection surface 32 (see Figures 16 and 17). In Figures 16 and 17, some of the nozzles 31 are denoted with the symbol "31". The ejection surface 32 faces the recording surface 16 in the vertical direction V when in motion (see Figure 18). When in motion, the recording unit 20 moves in the direction of the first coordinate axis by the first moving machine 75 (see Figures 2 to 10 and 10 to 2). The vertical direction V is perpendicular to the ejection surface 32. When the ejection surface 32 is horizontal (see Figures 13 and 14), the vertical direction V coincides with the third coordinate axis (see the two "recording units 20" located on the "top surface 18" in Figure 18). The multiple nozzles 31 open on the ejection surface 32 (see Figures 16 to 18).

[0051] Multiple nozzles 31 are aligned along the second coordinate axis on the discharge surface 32 (see Figures 16 and 17). In this embodiment, the multiple nozzles 31 are arranged in a single row on the discharge surface 32. However, this arrangement of multiple nozzles 31 on the discharge surface 32 is illustrative. The arrangement of multiple nozzles 31 on the discharge surface 32 may be in multiple rows. Suppose that the multiple nozzles 31 are arranged in two rows on the discharge surface 32. In this case, half of the nozzles 31 form the first row of nozzles, and the remaining nozzles 31 form the second row of nozzles. The two rows of nozzles are adjacent on the discharge surface 32 in the following direction. This direction is perpendicular to the second coordinate axis within the discharge surface 32. The two rows of nozzles are offset by a predetermined amount along the second coordinate axis. That is, the multiple nozzles 31 are arranged in a staggered pattern in two rows on the discharge surface 32. The arrangement of the multiple nozzles 31 is determined appropriately considering various conditions.

[0052] The inkjet head 30, in a moving state (see Figures 2-10 and 10-2), ejects ink from multiple nozzles 31 onto the recording surface 16. At this time, the inkjet head 30 ejects ink from the multiple nozzles 31 in a vertical direction V (see Figures 16 and 18). In Figures 16 and 18, the illustration of the ink ejected from the nozzles 31 is omitted. The ink lands on the recording surface 16.

[0053] Assume that in the recording unit 20 shown in Figure 12, the inkjet head 30 ejects ink from multiple nozzles 31. The recording unit 20 in Figure 12 corresponds to the recording unit 20 located on the first inclined surface 17 in Figure 18. In this case, the ink lands on the first inclined surface 17.

[0054] Assume that in the recording unit 20 shown in Figure 13, the inkjet head 30 ejects ink from multiple nozzles 31. The recording unit 20 in Figure 13 corresponds to the recording unit 20 located on the third region in the first coordinate axis direction of the top surface 18 in Figure 18. In this case, the ink lands on the third region in the first coordinate axis direction of the top surface 18.

[0055] Assume that in the recording unit 20 shown in Figure 14, the inkjet head 30 ejects ink from multiple nozzles 31. The recording unit 20 in Figure 14 corresponds to the recording unit 20 located on the fourth region in the first coordinate axis direction of the top surface 18 in Figure 18. In this case, the ink lands on the fourth region in the first coordinate axis direction of the top surface 18.

[0056] Assume that in the recording unit 20 shown in Figure 15, the inkjet head 30 ejects ink from multiple nozzles 31. The recording unit 20 in Figure 15 corresponds to the recording unit 20 located on the second inclined surface 19 in Figure 18. In this case, the ink lands on the second inclined surface 19.

[0057] The inkjet head 30 ejects ink from multiple nozzles 31 on the recording surface 16 in a vertical direction V toward the recording surface 16, recording a pattern on the recording surface 16 (see Figures 12-16, 18). Specifically, the inkjet head 30 of recording unit 21 ejects first ink from multiple nozzles 31 on the recording surface 16 in a vertical direction V toward the recording surface 16, recording a pattern on the recording surface 16 with the first ink. The inkjet head 30 of recording unit 22 ejects second ink from multiple nozzles 31 on the recording surface 16 in a vertical direction V toward the recording surface 16, recording a pattern on the recording surface 16 with the second ink. The inkjet head 30 of recording unit 23 ejects third ink from multiple nozzles 31 on the recording surface 16 in a vertical direction V toward the recording surface 16, recording a pattern on the recording surface 16 with the third ink. The inkjet head 30 of the recording unit 24 ejects a fourth ink from multiple nozzles 31 toward the recording surface 16 in a vertical direction V, thereby recording a pattern on the recording surface 16 with the fourth ink.

[0058] The inkjet head 30 includes a supply port 33 and an internal flow channel 34 (see Figure 16). A connecting flow channel 60 is connected to the supply port 33. Ink flows into the inkjet head 30 from the connecting flow channel 60 through the supply port 33. The internal flow channel 34 connects the supply port 33 to multiple nozzles 31. The ink flowing in from the supply port 33 flows through the internal flow channel 34 and reaches the multiple nozzles 31.

[0059] The internal flow path 34 includes a main flow section 35 and multiple branch flow sections 36. The main flow section 35 is continuous with the supply port 33 and is formed along the second coordinate axis direction. Ink flowing in from the supply port 33 flows through the main flow section 35. The multiple branch flow sections 36 branch off from the main flow section 35 and connect to multiple nozzles 31, respectively. Ink flowing in from the main flow section 35 flows through each of the branch flow sections 36 and reaches each of the multiple nozzles 31, respectively. In Figure 16, one of the multiple branch flow sections 36 is denoted by the symbol "36".

[0060] The carriage 40 mounts the inkjet head 30 (see Figures 12-16). The support 45 supports the carriage 40 on which the inkjet head 30 is mounted. The support 45 supports the carriage 40 so that it can rotate freely around the rotation axis R. The rotation axis R is provided along the second coordinate axis direction. In the recording unit 20, both the carriage 40 and the support 45 have a frame-like structure in which three frames are integrated.

[0061] The recording unit 20 employs a servo motor as the rotating mechanism 50. The servo motor as the rotating mechanism 50 includes an encoder. The rotating mechanism 50 is mounted on the support 45. The rotating mechanism 50 is fixed to the support 45 in the following state (see Figure 16). In this state, the shaft of the servo motor as the rotating mechanism 50 is fixed to the carriage 40. The rotating mechanism 50 rotates the carriage 40 around the rotation axis R (see Figures 12-16, 18). Consequently, the rotating mechanism 50 rotates the inkjet head 30 around the rotation axis R. In Figures 12-15, the arrows in the arcs centered on the rotation axis R indicate the direction of rotation of the inkjet head 30 (carriage 40). In the recording unit 20, the rotation axis R is set to the following position. This position is first in the third coordinate axis direction from the ejection surface 32 of the inkjet head 30 in the following state. In this state, the vertical direction V is aligned with the third coordinate axis direction, and the inkjet head 30 ejects ink toward the second side in the third coordinate axis direction. Furthermore, this position is second to the third coordinate axis direction from the sub-tank 55.

[0062] The sub-tank 55 stores ink (see Figures 12-16). Ink flows out of the main tank 100, through the ink channel 105, and into the sub-tank 55. The sub-tank 55 is mounted on the support 45. The sub-tank 55 is located on the first side in the third coordinate axis direction from the inkjet head 30 mounted on the carriage 40 on the support 45. The recording unit 20 maintains the sub-tank 55 in a constant position regardless of the rotation of the inkjet head 30 (carriage 40).

[0063] The connecting channel 60 connects the sub-tank 55 and the inkjet head 30 (see Figures 12-16). The connecting channel 60 allows ink to flow from the sub-tank 55 to the inkjet head 30. The connecting channel 60 includes a rotating section 61, an upstream section 62, and a downstream section 63. The rotating section 61 rotates about a rotation axis R. An example of the rotating section 61 is a rotating mechanism including a rotating bearing. The upstream section 62 connects the sub-tank 55 and the rotating section 61. Ink that has flowed out of the sub-tank 55 flows through the upstream section 62. The downstream section 63 connects the rotating section 61 and the inkjet head 30. The downstream section 63 is connected to the supply port 33. Ink that flows into the inkjet head 30 flows through the downstream section 63.

[0064] The downstream section 63 is positioned along the rotation axis R at a location that coincides with the rotation axis R (see Figure 16). The rotating section 61 rotates the upstream section 62 and the downstream section 63 relative to each other. That is, the rotating section 61 rotates the downstream section 63 about the rotation axis R relative to the upstream section 62. In the connecting channel 60, the downstream section 63 rotates about the rotation axis R relative to the upstream section 62. In other words, the rotating section 61 rotates the upstream section 62 about the rotation axis R relative to the downstream section 63. In the connecting channel 60, the upstream section 62 rotates about the rotation axis R relative to the downstream section 63.

[0065] A known rotary joint can be used in the connecting channel 60 (see Figures 12-16). When a rotary joint is used in the connecting channel 60, this rotary joint includes a rotating part 61. Furthermore, the rotary joint is provided directly in the supply port 33 (see Figure 16). In this case, this rotary joint includes a rotating part 61 and a downstream part 63, and a pipe as the upstream part 62 is connected to the inflow side of this rotary joint. The rotary joint is a known joint that has already been put into practical use. Therefore, further explanation regarding the rotary joint is omitted.

[0066] The third mobile unit 65 moves the inkjet head 30 in the third coordinate axis direction (see Figures 12-15, 18). That is, the third mobile unit 65 moves the inkjet head 30 from the second side to the first side in the third coordinate axis direction, and moves the inkjet head 30 from the first side to the second side in the third coordinate axis direction. However, in the inkjet recording device 10, the movement of the inkjet head 30 in the third coordinate axis direction by the third mobile unit 65 is performed by moving the support 45 from the second side to the first side in the third coordinate axis direction and from the first side to the second side in the third coordinate axis direction. That is, the third mobile unit 65 is attached to the support 45 and moves the support 45 from the second side to the first side in the third coordinate axis direction and from the first side to the second side in the third coordinate axis direction.

[0067] The inkjet recording device 10 employs a linear motion mechanism as the third mobile unit 65. An example of a linear motion mechanism that can be used as the third mobile unit 65 is a combination of a ball screw, a drive unit, and a guide. In this embodiment, the above combination is exemplified as the third mobile unit 65. In this case, the third mobile unit 65 includes a ball screw 66, a drive unit 69, and a guide 70 (see Figures 12-15). The third mobile unit 65 employs a combination of a linear shaft 71 and a linear bush 72 as the guide 70.

[0068] The screw shaft 67 of the ball screw 66 is rotatably mounted along the third coordinate axis direction. The nut 68 of the ball screw 66 moves along the third coordinate axis direction in accordance with the rotation of the screw shaft 67. The drive unit 69 is connected to the screw shaft 67. A rotating machine such as a motor can be used as the drive unit 69. An example of the drive unit 69 is a servo motor. A servo motor as the drive unit 69 includes an encoder. The drive unit 69 rotates the screw shaft 67. The arc-shaped arrows shown on the outer circumference of the screw shaft 67 in Figures 12-15 indicate the direction of rotation of the screw shaft 67. In the guide 70, a linear shaft 71 is mounted along the third coordinate axis direction. In the guide 70, a linear bush 72 moves along the linear shaft 71 along the third coordinate axis direction. The drive unit 69 is mounted on a mounting fixture 73. The mounting fixture 73 is fixed to the movable element 80. In the third moving unit 65, the nut 68 and the linear bush 72 are fixed to the support fixture 45. Accordingly, the third mobile unit 65 connects to the support 45 and the movable element 80, and the recording unit 20 is attached to the first mobile unit 75.

[0069] The drive unit 69 rotates the screw shaft 67 in a predetermined direction, causing the nut 68 to move from the second side to the first side in the third coordinate axis direction. The support 45 moves in the same direction and by the same amount as the nut 68 moving from the second side to the first side in the third coordinate axis direction. The drive unit 69 rotates the screw shaft 67 in the opposite direction to the aforementioned direction, causing the nut 68 to move from the first side to the second side in the third coordinate axis direction. The support 45 moves in the same direction and by the same amount as the nut 68 moving from the first side to the second side in the third coordinate axis direction. The guide 70 guides this movement of the support 45 in the third coordinate axis direction. In other words, the support 45 moves from the second side to the first side and from the first side to the second side in the third coordinate axis direction, guided by the guide 70. Consequently, the inkjet head 30, carriage 40, rotating machine 50, sub-tank 55, and connecting channel 60 move together with the support 45 from the second side to the first side and from the first side to the second side in the third coordinate axis direction.

[0070] In its moving state (see Figures 2-10 and 10-2), the rotating machine 50 rotates the inkjet head 30 (carriage 40) around the rotation axis R, so that the ejection surface 32 is parallel to the following virtual straight line L (see Figures 12-15, 18). The virtual straight line L passes through the opposing position P2 and is also perpendicular to the vertical direction V. The opposing position P2 is the position of the recording surface 16 closest to the reference position P1 in the vertical direction V (see Figures 16, 17). The reference position P1 may be the center of the nozzle region N of the ejection surface 32 (see Figures 16, 17). Multiple nozzles 31 are provided on the ejection surface 32 in the nozzle region N.

[0071] The nozzle region N can also be described as having the shape of a rectangle with the following four sides: first, second, third, and fourth (see Figure 17). The first and second sides are aligned along the first coordinate axis direction, and the third and fourth sides are aligned along the second coordinate axis direction. The first side is in contact with the fifth side in the second coordinate axis direction of the nozzle 31 that is furthest to the fifth side in the second coordinate axis direction among the multiple nozzles 31 (see "Nozzle 31A" in Figure 17). The second side is in contact with the sixth side in the second coordinate axis direction of the nozzle 31 that is furthest to the sixth side in the second coordinate axis direction among the multiple nozzles 31 (see "Nozzle 31B" in Figure 17). The third side is in contact with the third side in the first coordinate axis direction of the nozzle 31 that is furthest to the third side in the first coordinate axis direction among the multiple nozzles 31. The fourth side is in contact with the fourth side in the first coordinate axis direction of the nozzle 31 that is furthest to the fourth side in the first coordinate axis direction among the multiple nozzles 31.

[0072] In this embodiment, there are nine nozzles 31, all of which have the same shape and are arranged in a single row along the second coordinate axis. The reference position P1 is assumed to be the center of the nozzle region N of the discharge surface 32. In this case, the reference position P1 coincides with the position of the central nozzle 31 among the nine nozzles 31. In this embodiment, the first inclined surface 17 is a plane inclined at a constant angle, the top surface 18 is a horizontal plane, and the second inclined surface 19 is a plane inclined at a constant angle. In this case, when the recording unit 20 is moving along the first inclined surface 17 in the first coordinate axis direction, the following virtual straight line L lies along the first inclined surface 17 (see "recording unit 20" located on "first inclined surface 17" in Figure 18). This virtual straight line L passes through the opposite position P2 of the first inclined surface 17 (see "virtual straight line L" shown as a dashed line along "first inclined surface 17" in Figure 18). When the recording unit 20 is moving along the top surface 18 in the first coordinate axis direction, the following virtual line L follows the top surface 18 (see the two "recording units 20" located on the "top surface 18" in Figure 18). This virtual line L passes through the opposite position P2 on the top surface 18 (see the "virtual line L" shown as a dashed line along the "top surface 18" in Figure 18). When the recording unit 20 is moving along the second inclined surface 19 in the first coordinate axis direction, the following virtual line L follows the second inclined surface 19 (see the "recording unit 20" located on the "second inclined surface 19" in Figure 18). This virtual line L passes through the opposite position P2 on the second inclined surface 19 (see the "virtual line L" shown as a dashed line along the "second inclined surface 19" in Figure 18).

[0073] The third mobile unit 65, in its moving state (see Figures 2-10 and 10-2), moves the inkjet head 30 in the third coordinate axis direction relative to the recording surface 16, and keeps the separation distance D in the vertical direction V between the reference position P1 and the opposing position P2 constant (see Figure 18). The separation distance D may be set to "0 mm < separation distance D ≤ 10 mm". The separation distance D is determined appropriately considering various conditions.

[0074] <Effects of the Embodiment> According to this embodiment, the following effects can be obtained.

[0075] (1) The inkjet recording device 10 records a pattern on the recording surface 16 of the recording medium 15. The recording surface 16 includes a first inclined surface 17, a top surface 18, and a second inclined surface 19, and as a whole has a surface shape that is convex on the first side in the third coordinate axis direction and aligned with the second coordinate axis direction. The inkjet recording device 10 comprises recording units 21, 22, 23, 24, a first mobile device 75, and a second mobile device 85 (see Figure 1).

[0076] Recording unit 21 ejects the first ink onto the recording surface 16 (see Figures 3-6 and 6-3). Recording unit 22 ejects the second ink onto the recording surface 16 (see Figures 4-7 and 7-4). Recording unit 23 ejects the third ink onto the recording surface 16 (see Figures 5-8 and 8-5). Recording unit 24 ejects the fourth ink onto the recording surface 16 (see Figures 6-9 and 9-6). The first mobile unit 75 ejects the first ink onto recording unit 21 ,22,23,24 of respectively The first coordinate axis is moved (see Figures 2-10 and 10-2). The second mobile device 85 moves the recording medium 15 and the first mobile device 75 relative to each other in the second coordinate axis direction (see Figures 1, 2, 10, and 11).

[0077] Recording unit 20, as recording units 21, 22, 23, and 24, includes an inkjet head 30, a rotating machine 50, and a third moving machine 65 (see Figures 12-16). The inkjet head 30 includes a plurality of nozzles 31 (see Figures 16 and 17). The plurality of nozzles 31 eject ink. The rotating machine 50 rotates the inkjet head 30 about a rotation axis R (see Figures 12-16 and 18). The third moving machine 65 moves the inkjet head 30 in the third coordinate axis direction (see Figures 12-15 and 18).

[0078] The inkjet head 30, in a moving state (see Figures 2-10 and 10-2), ejects ink from multiple nozzles 31 onto the recording surface 16 (see Figures 12-16, 18). The rotating machine 50, in a moving state, rotates the inkjet head 30 around the rotation axis R, making the ejection surface 32 parallel to a virtual straight line L (see Figures 12-15, 18). The third moving machine 65, in a moving state, moves the inkjet head 30 along the third coordinate axis, keeping the separation distance D in the vertical direction V between the reference position P1 and the opposing position P2 constant (see Figure 18).

[0079] The inkjet recording device 10 allows the recording units 21, 22, 23, and 24 to be operated independently. Each of the recording units 21, 22, 23, and 24 can be moved along the first coordinate axis while maintaining a constant orientation of the ejection surface 32 relative to the recording surface 16 and a constant distance between the recording surface 16 and the ejection surface 32. The inkjet recording device 10 can record patterns in accordance with the recording surface 16.

[0080] (2) The recording unit 20 includes a carriage 40, a support 45, a sub-tank 55, and a connecting channel 60 (see Figures 12-16). The carriage 40 mounts the inkjet head 30. The support 45 supports the carriage 40. The sub-tank 55 stores the ink supplied to the inkjet head 30. The connecting channel 60 connects the sub-tank 55 and the inkjet head 30, and allows ink to flow from the sub-tank 55 to the inkjet head 30. The rotating machine 50 and the sub-tank 55 are provided on the support 45.

[0081] The third moving mechanism 65 moves the support 45 in the third coordinate axis direction. The support 45 rotatably supports the carriage 40 about the rotation axis R. The sub tank 55 is provided on the first side in the third coordinate axis direction from the inkjet head 30 mounted on the carriage 40 by the support 45. The rotation mechanism 50 rotates the carriage 40 about the rotation axis R set at the following position. This position is on the first side in the third coordinate axis direction from the ejection surface 32 of the inkjet head 30 in the following state, and is on the second side in the third coordinate axis direction from the sub tank 55. In this state, the vertical direction V is along the third coordinate axis direction, and the inkjet head 30 ejects ink from a plurality of nozzles 31 toward the second side in the third coordinate axis direction.

[0082] According to this configuration, the rotation axis R can be set at a position on the second side in the third coordinate axis direction from the sub tank 55. In the rotation of the inkjet head 30 about the rotation axis R via the carriage 40, it is also assumed that an error of "Δθ" occurs in the actual rotation amount (rotation angle) with respect to a target set value. Assume a comparative example. In the comparative example, a virtual rotation axis that is the center of rotation of the inkjet head 30 is located on the second side in the third coordinate axis direction from the sub tank 55. The distance "A" from the rotation axis R to the reference position P1 is shorter than the distance "B" from the virtual rotation axis to the reference position P1 (A < B). When the same error of "Δθ" in the rotation amount occurs in the recording unit 20 and the comparative example, the positional displacement amount of the reference position P1 that occurs in the recording unit 20 is "2πA×Δθ / 360°", and the positional displacement amount of the reference position P1 that occurs in the comparative example is "2πB×Δθ / 360°". That is, the positional displacement amount of the reference position P1 that occurs in the recording unit 20 can be reduced to "A / B" times the positional displacement amount of the reference position P1 that occurs in the comparative example.

[0083] (3) The connecting channel 60 includes a rotating section 61, an upstream section 62, and a downstream section 63 (see Figures 12-16). The rotating section 61 rotates about the rotation axis R. The upstream section 62 connects the sub-tank 55 and the rotating section 61. Ink that has flowed out of the sub-tank 55 flows through the upstream section 62. The downstream section 63 connects the rotating section 61 and the inkjet head 30. Ink that flows into the inkjet head 30 flows through the downstream section 63. The downstream section 63 is provided along the rotation axis R at a position that coincides with the rotation axis R. The rotating section 61 rotates the downstream section 63 about the rotation axis R relative to the upstream section 62.

[0084] This configuration allows the connecting channel 60 to follow the rotation of the inkjet head 30 around the rotation axis R via the carriage 40. Let's consider a virtual channel, unlike the connecting channel 60, which does not have a rotating section 61. The virtual channel connects the sub-tank 55 and the inkjet head 30. In this case, the virtual channel has the following length. This length corresponds to the rotation of the inkjet head 30 around the rotation axis R via the carriage 40. That is, the length of the virtual channel is set to be longer by the length of play required to accommodate this rotation. In the connecting channel 60, this play length can be reduced or omitted.

[0085] <Variation> The embodiment can also be as follows. Some of the modifications shown below can be combined and adopted as appropriate. Below, we will explain the differences from the above, and explain the similarities as appropriate.

[0086] (1) The inkjet recording device 10 includes recording units 21, 22, 23, and 24 as recording units 20 (see Figure 1). The recording units 21, 22, 23, and 24 are arranged in the order of recording unit 21, recording unit 22, recording unit 23, and recording unit 24 from the third to the fourth side in the first coordinate axis direction. However, this arrangement of recording units 21, 22, 23, and 24 in the first coordinate axis direction is illustrative. The arrangement of recording units 21, 22, 23, and 24 in the first coordinate axis direction is determined appropriately considering various conditions. For example, recording unit 22 may be located on the fourth side in the first coordinate axis direction from recording unit 21, or recording units 21 and 22 may not be adjacent in the first coordinate axis direction.

[0087] The number of recording units 20 in an inkjet recording device may be 1 to 3 or 5 or more. The number of recording units 20 in an inkjet recording device is determined appropriately considering various conditions. Suppose some of the recording units 21, 22, 23, and 24 are omitted in the inkjet recording device. In this case, the elements corresponding to the omitted recording units 20 are omitted in the inkjet recording device. For example, if recording units 23 and 24 are omitted, the movable elements 83 and 84, the main tanks 103 and 104, and the ink channels 108 and 109 are omitted. Suppose the inkjet recording device has one or more recording units in addition to the recording units 21, 22, 23, and 24. In this case, the inkjet recording device is provided with movable elements, main tanks, and ink channels corresponding to the additional recording unit.

[0088] (2) The second mobile unit 85 includes a ball screw 86, a drive unit 89, guides 90 and 91, and a mounting base 94 (see Figure 1). The second mobile unit may also be a conveyor. In addition, a linear motor actuator may be used as the linear motion mechanism in the second mobile unit. The specifications of the second mobile unit will be determined as appropriate considering various conditions.

[0089] The second mobile unit 85 moves the recording medium 15 in the second coordinate axis direction (see Figures 1, 2, 10, and 11). The relative movement of the recording medium 15 and the first mobile unit 75 in the second coordinate axis direction by the second mobile unit may also be performed by moving the first mobile unit 75 in the second coordinate axis direction. In this case, during the recording operation of the handle, the second mobile unit intermittently moves the first mobile unit 75 in the second coordinate axis direction in response to the arrival of the recording units 21, 22, 23, and 24 at the fourth moving end in the first coordinate axis direction (see Figure 10) and the arrival of the recording units 24, 23, 22, and 21 at the third moving end in the first coordinate axis direction (see Figure 2). During the recording operation of the handle, the second mobile unit may also move the first mobile unit 75 from the sixth to the fifth side in the second coordinate axis direction, and furthermore, the amount of movement per movement in this movement may be the transport distance T (see Figures 10 and 12), as described above. The direction in which the first moving device 75 is moved along the second coordinate axis during the recording operation of the handle, and the amount of movement per movement, are determined appropriately considering various conditions, as described above.

[0090] (3) The recording unit 20 includes a third mobile unit 65 (see Figures 12-15). The third mobile unit 65 includes a ball screw 66, a drive unit 69, and a guide 70. The third mobile unit 65 employs a combination of a linear shaft 71 and a linear bush 72 as the guide 70. A linear motor actuator may be used as the linear motion mechanism in the third mobile unit. In the third mobile unit, the guide may be a ball spline or a linear guide. Furthermore, in the third mobile unit, a different type of bush than the linear bush 72 may be used for the guide. The specifications of the third mobile unit are determined as appropriate considering various conditions. [Explanation of Symbols]

[0091] 10 Inkjet recording device, 15 Recording medium, 16 Recording surface 17 first inclined surface, 18 top surface, 19 second inclined surface 20, 21, 22, 23, 24 Recording units, 30 Inkjet heads 31, 31A, 31B Nozzles, 32 Discharge surface, 33 Supply port, 34 Internal flow path 35 Main channel, 36 Tributary channel, 40 Carriage, 45 Support 50 Rotating machine, 55 Sub-tank, 60 Connecting channel, 61 Rotating part 62 Upstream section, 63 Downstream section, 65 Third moving mechanism, 66 Ball screw 67 Screw shaft, 68 Nut, 69 Drive mechanism, 70 Guide 71 Linear shaft, 72 Linear bush, 73 Mounting hardware 75 First mobile machine, 76 Stator, 80,81,82,83,84 Mover 85 Second moving mechanism, 86 Ball screw, 87 Screw shaft, 88 Nut 89 Drive unit, 90, 91 Guides, 92 Rails, 93 Blocks 94 Mounting platform, 95 Support platform 100, 101, 102, 103, 104 Main Tanks 105, 106, 107, 108, 109 Ink channels, D Separation distance L: virtual line, N: nozzle region, P1: reference position, P2: opposing position R: Rotation axis, T: Transport distance, V: Vertical direction

Claims

1. A recording unit that ejects ink onto the recording surface of a recording medium, A first moving machine that moves the recording unit in the first coordinate axis direction, The recording medium and the first moving device are further moved relative to each other in a second coordinate axis direction perpendicular to the first coordinate axis direction, and the second moving device is provided. The recording unit is An inkjet head including a plurality of nozzles that eject the aforementioned ink, A rotating machine that rotates the inkjet head about a rotation axis along the second coordinate axis, The inkjet head is moved in a third coordinate axis direction that is orthogonal to both the first coordinate axis direction and the second coordinate axis direction, and includes a third moving device. The inkjet head ejects the ink from the plurality of nozzles onto the recording surface while the recording unit is moving in the first coordinate axis direction by the first moving machine. When the recording surface has a surface shape that is convex on the first side in the third coordinate axis direction or concave on the second side in the third coordinate axis direction and along the second coordinate axis direction in the first coordinate axis direction, the rotating machine rotates the inkjet head about the rotation axis in the moving state, and aligns the ejection surface of the inkjet head from which the plurality of nozzles open with a virtual straight line that passes through the closest opposing position on the recording surface from the reference position on the ejection surface in a vertical direction perpendicular to the ejection surface and is perpendicular to the vertical direction, When the recording surface has the surface shape, the third moving machine moves the inkjet head in the third coordinate axis direction, and keeps the vertical separation distance between the reference position and the opposing position constant. The recording unit is A carriage equipped with the aforementioned inkjet head, A support for the carriage, A sub-tank for storing the ink supplied to the inkjet head, The system includes a connecting channel that connects the sub-tank and the inkjet head, and that flows the ink from the sub-tank to the inkjet head, The rotating machine and the sub-tank are provided on the support, The third moving device moves the support in the third coordinate axis direction which coincides with the vertical direction. The support member supports the carriage so that it can rotate around the rotation axis, The sub-tank is provided on the first side in the third coordinate axis direction, which is vertically above the inkjet head mounted on the carriage by the support, The rotating machine rotates the carriage about a rotation axis set at a position that is first in the direction of the third coordinate axis and second in the direction of the third coordinate axis from the ejection surface of the inkjet head, which ejects the ink from the plurality of nozzles toward a second side in the direction of the third coordinate axis, with the vertical direction aligned with the third coordinate axis and toward the downward in the vertical direction, and toward the second side in the direction of the third coordinate axis from the sub-tank.

2. The aforementioned connecting channel is A rotating part that rotates around the aforementioned rotation axis, The sub-tank and the rotating part are connected, and the ink that has flowed out of the sub-tank flows through the upstream section, The rotating part and the inkjet head are connected, and the downstream part through which the ink flowing into the inkjet head flows is included, The downstream portion is provided along the rotation axis at a position that coincides with the rotation axis, The inkjet recording apparatus according to claim 1, wherein the rotating part rotates the downstream part about the rotation axis relative to the upstream part.

3. As the aforementioned recording unit, A first recording unit that ejects the first ink as the ink onto the recording surface, The recording surface is provided with a second recording unit that ejects a second ink as the ink, The first mobile device is, The first recording unit is moved in the first coordinate axis direction, The inkjet recording apparatus according to claim 1 or claim 2, wherein the second recording unit is moved in the first coordinate axis direction.

4. The first recording unit ejects the first ink of the first color onto the recording surface. The inkjet recording apparatus according to claim 3, wherein the second recording unit ejects a second ink of a second color different from the first color onto the recording surface.

Images