How to adjust the position of the head unit

Abstract

To provide a position adjustment method of a head unit which can highly accurately adjust the position of a second head unit mounted adjacently to a first head unit fixed to a base member in a width direction.SOLUTION: Each position of a second head unit in a width direction and a rotation direction is adjusted while the second head unit is engaged with a tip of a reference pin. More specifically, a width direction adjustment section moves the second head unit in the width direction in a state that a first head unit is fixed to a base member. As a result, a gap between the first head unit and the second head unit is adjusted. A rotation direction adjustment section moves the second head unit in an orthogonal direction at a separation position from the reference pin. As a result, a rotation direction position of the second head unit with respect to the tip of the reference pin is adjusted.SELECTED DRAWING: Figure 7C

Description

Technical Field

[0001] The present invention relates to a method for adjusting the position of a head unit that is detachably attached to a base member and arranged in a predetermined width direction.

Background Art

[0002] <00000​​​​​​​​​​​​​​​​​​​​​​​In the conventional technology described above, multiple module mount assemblies are aligned with each other by the alignment of the clamp assembly. However, in the device described in Patent Document 1, the position of each module mount assembly is adjusted using the biasing force of a spring installed in the clamp assembly. However, this adjustment method has limitations in terms of adjustment accuracy. In addition, external forces acting on the nozzle surface during head cleaning could cause the above adjustment to be misaligned. As a result, the ejection performance, such as ejection direction and ejection position, becomes non-uniform for each nozzle surface, resulting in the problem of not being able to obtain sufficient print quality.

[0005] This invention has been made in view of the above problems, and aims to provide a method for adjusting the position of a head unit that can adjust the position of a second head unit mounted adjacent to a first head unit fixed to a base member in the width direction with high precision. [Means for solving the problem]

[0006] This invention relates to a method for adjusting the position of a second head unit mounted adjacent to a first head unit fixed to a base member in the width direction, comprising: (a) temporarily mounting the second head unit in a mounting area adjacent to the first head unit in the width direction; (b) mounting the base end of a reference pin in a reference pin hole provided in the base member adjacent to the mounting area so that the tip of the reference pin is erected relative to the base member in the direction normal to the base member; (c) attaching an adjustment jig to the base member such that the second head unit is movable in the width direction while engaging with the tip of the reference pin and the second head unit is rotatable about the tip of the reference pin as the center of rotation; and (d) adjusting the position of the first head unit and the second head unit (e) The process of inserting a width direction adjustment part between the head unit and the adjustment jig, and inserting a rotation direction adjustment part between the second head unit and the adjustment jig at a spaced position in the width direction away from the reference pin, is characterized by comprising: (a) With the temporary attachment of the second head unit loosened, the process of adjusting the gap between the first head unit and the second head unit in the width direction by moving the second head unit in the width direction using the width direction adjustment part, and adjusting the rotation direction position of the second head unit relative to the tip of the reference pin by moving the second head unit in an orthogonal direction perpendicular to both the width direction and the normal direction at the spaced position using the rotation direction adjustment part; and (f) After the completion of step (e), the process of fastening the second head unit to the base member to permanently attach it.

[0007] In this configuration, the position of the second head unit in the width direction and rotation direction is adjusted while the second head unit engages with the tip of the reference pin. More specifically, while the first head unit remains fixed to the base member, the width direction adjustment unit moves the second head unit in the width direction. This adjusts the gap between the first head unit and the second head unit. In addition, the rotation direction adjustment unit moves the second head unit in a perpendicular direction at a position away from the reference pin. This adjusts the rotational position of the second head unit relative to the tip of the reference pin. [Effects of the Invention]

[0008] As described above, according to the present invention, the position of the second head unit relative to the first head unit can be adjusted with high precision. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic front view showing an example of a printing system equipped with a head unit to which one embodiment of the head unit position adjustment method according to the present invention has been applied. [Figure 2] This is a perspective view showing the main components of the print bar unit. [Figure 3] This is a perspective view showing the attachment and detachment operation of the head unit to the base member. [Figure 4] This is a perspective view showing an example of a removal and installation jig used when installing or removing a head unit. [Figure 5] This is a flowchart showing one embodiment of the method for adjusting the position of a head unit according to the present invention. [Figure 6] Figure 5 is a perspective view showing the mounting structure of the adjustment jig, width direction adjustment section, rotation direction adjustment section, reference pin, and contact block used in the position adjustment method shown. [Figure 7A] This diagram schematically illustrates the procedure for adjusting the position of the head unit. [Figure 7B] This diagram schematically illustrates the procedure for adjusting the position of the head unit. [Figure 7C] This diagram schematically illustrates the procedure for adjusting the position of the head unit. [Figure 7D] This diagram schematically illustrates the procedure for adjusting the position of the head unit. [Modes for carrying out the invention]

[0010] Figure 1 is a schematic front view showing an example of a printing system equipped with a head unit to which one embodiment of the head unit position adjustment method according to the present invention is applied. In Figure 1 and the following figures, in order to clarify the arrangement of each part of the device, the horizontal direction in which the coating device 2, printing device 3, and drying device 4 that constitute the printing system 1 are arranged is referred to as the "X direction," the horizontal direction from the right side to the left side in Figure 1 is referred to as the "+X direction," and the opposite direction is referred to as the "-X direction." In addition, of the horizontal direction Y perpendicular to the X direction, the front side of the device is referred to as the "+Y direction," and the rear side of the device is referred to as the "-Y direction." Furthermore, the upward and downward directions in the vertical direction Z are referred to as the "+Z direction" and the "-Z direction," respectively.

[0011] This printing system 1 controls each part of the device by the control unit 100, transporting a long, strip-shaped printing medium M from the feed roll 11 to the take-up roll 12 in a roll-to-roll manner, while applying coating, printing, and drying processes to the printing medium M. Specifically, the coating device 2 applies a coating solution to the printing medium M. Then, the printing device 3 applies various inks to the printing medium M using an inkjet method to print an image. Furthermore, the drying device 4 dries the ink adhering to the printing medium M. The material of the printing medium M is a film such as OPP (oriented polypropylene) or PET (polyethylene terephthalate). However, the material of the printing medium M is not limited to film and may be paper or the like. Such a printing medium M is flexible. In the following, of the two sides of the printing medium M, the side on which the image is printed will be appropriately referred to as the front surface M1, and the side opposite to the front surface M1 will be appropriately referred to as the back surface M2.

[0012] The coating apparatus 2 includes a pan 21 for storing liquid primer (coating solution), a gravure roller 22 that is partially immersed in the primer stored in the pan 21, and a transport unit 23 for transporting the printing medium M. The coating apparatus 2 is provided with a coating area where the gravure roller 22 contacts the printing medium M, which is transported by the transport unit 23, from below. The transport unit 23 transports the printing medium M along the coating area with the surface M1 of the printing medium M facing downwards. Meanwhile, the gravure roller 22 supplies primer to the coating area by rotating while holding the primer on its circumferential surface. In this way, the primer supplied by the gravure roller 22 is applied to the surface M1 of the printing medium M in the coating area. Furthermore, in the coating area, the direction of travel of the printing medium M and the direction of rotation of the circumferential surface of the gravure roller 22 are opposite. In other words, the primer is applied to the printing medium M using a so-called reverse kiss method. The transport unit 23 then carries the printing medium M from the coating device 2 to the printing device 3, with the surface M1 of the primer-coated printing medium M facing upwards.

[0013] The printing apparatus 3 comprises a housing 31, a color printing unit 32 located inside the housing 31, a white printing unit 33 located above the color printing unit 32 inside the housing 31, and a transport unit 34 that transports the printing medium M using a plurality of rollers located inside the housing 31.

[0014] The color printing unit 32 has a plurality of (four in this embodiment) print bar units 321 arranged in the direction of travel of the printing medium M above the printing medium M transported by the transport unit 34. Each of the plurality of print bar units 321 has a nozzle that faces the surface M1 of the printing medium M passing below it from above, and ejects color inks of different colors from the nozzles using an inkjet method. Here, color ink means ink other than white, and includes inks such as cyan, magenta, yellow, and black. In this way, the plurality of print bar units 321 of the color printing unit 32 print a color image on the surface M1 of the printing medium M by ejecting color ink from above onto the surface M1 of the printing medium M passing below it.

[0015] Further, the white printing unit 33 has a single printing bar unit 331 disposed above the printing medium M conveyed by the conveying unit 34. The printing bar unit 331 has nozzles facing the surface M1 of the printing medium M passing below it from above, and ejects white ink from the nozzles by an inkjet method. Thus, the printing bar unit 331 of the white printing unit 33 prints a white image on the surface M1 of the printing medium M by ejecting white ink from above onto the surface M1 of the printing medium M passing below it.

[0016] The printing bar units 321 and 331 are composed of a plurality of ink ejection heads that eject ink from the nozzle surfaces by an inkjet method. In the present embodiment, ten ink ejection heads are arranged in the width direction Y of the printing medium M. The detailed configuration of the printing bar units 321 and 331, the adjustment and replacement of each ink ejection head, etc. will be described in detail later.

[0017] Although not shown in FIG. 1, two types of drying units are provided in the housing 31 of the printing apparatus 3. One is a pre-drying unit that dries the color ink adhered to the surface M1 of the printing medium M by the color printing unit 32. The other is an upper drying unit that dries the white ink adhered to the surface M1 of the printing medium M by the white printing unit 33.

[0018] The drying device 4 dries the ink adhering to the surface M1 of the printing medium M conveyed from the printing apparatus 3. The drying device 4 has a housing 41 (drying furnace). In the housing 41, rollers 42, 43, and 46 are arranged on the (+X) direction side, and air turn bars 44 and 45 are arranged on the (-X) direction side. As a result, a substantially S-shaped conveyance path is formed when viewed from the (+Y) direction side, and the printing medium M is conveyed along the conveyance path. The ink adhering to the surface M1 of the printing medium M is dried during this conveyance. Then, the printing medium M that has undergone the drying process is carried out of the drying device 4 and wound around the winding roll 12.

[0019] Figure 2 is a perspective view showing the main part of the print bar unit. In print bar units 321 and 331, ten head units 6 are mounted adjacent to each other in the width direction Y on a base member 5 that extends in the width direction Y. As shown in the enlarged section of the figure, each head unit 6 holds an ink ejection head 61 with a head holder 62 and is fixed with fixing screws 65.

[0020] By the way, in the print bar units 321 and 331 configured as described above, if one of the head units 6 that constitutes it malfunctions and needs to be replaced, the malfunctioning head unit 6 is removed from the row of head units arranged in the width direction Y. Then, a new head unit 6 is installed in the mounting area that has become vacant due to this removal. At this time of installation, it is necessary to adjust the new head unit 6 with high precision. Therefore, in this embodiment, the position of the new head unit 6 is adjusted as follows. For the sake of making it easier to understand the contents of the invention, the head unit 6 that remains fixed to the base member 5 adjacent to the vacant mounting area (reference numeral 51 in Figure 3) will be referred to as head unit 6a, the head unit 6 that is removed will be referred to as head unit 6b, and the head unit 6 that is newly installed in the vacant mounting area will be referred to as head unit 6c.

[0021] Figure 3 is a perspective view showing the operation of attaching and detaching the head unit to the base member, and Figure 4 is a perspective view showing an example of an attachment / detachment jig used when attaching and detaching the head unit. The attachment / detachment jig 10 is a jig for attaching and detaching the head unit 6 to the base member 5 on a head unit basis. As shown in Figure 4, the attachment / detachment jig 10 has a jig body 101 that can be attached to the base member 5. The jig body 101 has a pair of mounting members 103 that are attached to the base member 5 by fastening fittings 102 such as bolts, and a guide member 104 that extends in the sliding direction Z perpendicular to the width direction Y. The mounting members 103 are attached to the base member 5 corresponding to the planned mounting position for attaching the head unit 6 to the base member 5, as shown in Figure 3, for example. With this attachment, the guide member 104 extends downward from the base member 5. A slider 105 capable of supporting the head unit 6 is attached to the guide member 104 so as to be movable in the sliding direction Z. Therefore, by moving the slider 105 upward (+Z) while the head unit 6b(6c) is supported by the slider 105, the head unit 6b(6c) can be easily and accurately positioned at the desired location on the base member 5. Here, if the width of the slider 105 is set to be less than or equal to the width of the head unit 6 in the width direction Y, interference between the slider 105 and the head unit 6 mounted on the base member 5 can be effectively prevented. For example, as shown in Figure 3, the slider 105 supporting the head unit 6b(6c) does not interfere with the head units 6a, 6a adjacent to the head unit 6b(6c) on the base member 5, making it easy to insert the head unit 6b(6c) between the head units 6b, 6c or to remove it from between the head units 6b, 6c.

[0022] Therefore, in this embodiment, when attaching or detaching the head unit, the attachment / detachment jig 10 shown in Figure 4 is used. For example, as shown in Figure 3, the removal of head unit 6b, which is sandwiched between head units 6a and 6a, can be performed smoothly by following the work procedure below. That is, the removal work is • The mounting member 103 of the attachment jig 10 is attached to the base member 5 by fastening fitting 102 at a position corresponding to the head unit 6b. Raise the empty slider 105 to the above position and support the head unit 6b with the slider 105. - Release the fastening fitting 66 from the head unit 6. - The slider 105 and head unit 6 are lowered together to the lowest position (separated position) of the guide member 104 (see Figure 3). Remove head unit 6 from slider 105. It includes.

[0023] On the other hand, the installation of the new head unit 6c into the vacant mounting area 51 on the surface of the base member 5 can be carried out smoothly by performing the following work procedure. That is, the installation work is The mounting member 103 of the attachment jig 10 is attached to the base member 5 by fastening fitting 102 at a position corresponding to the vacant mounting area 51. Lower the empty slider 105 to the lowest position (separated position) of the guide member 104 (see Figure 3). • The head unit 6c is mounted on the slider 105 at the lowest position. - Raise the slider 105 and head unit 6c together to the mounting area 51. After mounting the head unit 6c to the mounting area 51 of the base member 5, the support of the head unit 6c by the slider 105 is released. It includes.

[0024] The head unit 6c is then mounted in the mounting area 51. However, in order to ensure high print quality, it is necessary to precisely adjust the position of the newly mounted head unit 6c so that its relative position to the head unit 6a fixed to the base member 5 is as designed. Therefore, in this embodiment, the head unit position adjustment described below is performed.

[0025] Figure 5 is a flowchart showing one embodiment of the head unit position adjustment method according to the present invention. Figure 6 is a perspective view showing the mounting structure of the adjustment jig, width direction adjustment unit, rotation direction adjustment unit, reference pin, and contact block used in the position adjustment method shown in Figure 5. Figures 7A to 7D are schematic diagrams showing the head unit position adjustment procedure. In this embodiment, the operator adjusts the width direction position of the head unit 6c in the width direction X and the rotation direction position of the head unit 6c in the rotation direction R with the reference pin 71 as the rotation center, following the procedure shown in Figure 5.

[0026] The operator attaches the new head unit 6c to the mounting area 51. Following this temporary attachment, the operator removes the attachment jig 10 from the base member 5 (step S1: corresponding to an example of step (a) of the present invention). For example, as shown in Figure 7A, the head unit 6c is fastened to the base member 5 by the fastening fitting 66. Reference numerals 52 to 54 in the figure represent the reference pin hole, width direction adjustment hole, and rotation direction adjustment hole, respectively. These reference pin hole 52, width direction adjustment hole 53, and rotation direction adjustment hole 54 are pre-provided in the base member 5 adjacent to the mounting area 51. Reference numeral 621 in the figure represents a screw hole for attaching the backing block to the head unit 6c.

[0027] While maintaining the temporary mounting, the operator attaches the parts necessary for position adjustment (=reference pin 71, support block 72, adjustment jig 73, width direction adjustment part 74, rotation direction adjustment part 75) (steps S2 to S4). More specifically, as shown in Figure 7B, the operator attaches the base end of the reference pin 71 to the reference pin hole 52 (Figure 7A) provided in the base member 5 adjacent to the mounting area 51. As a result, as shown in Figures 6 and 7B, the tip 71a of the reference pin 71 is erected on the base member 5 in the direction ND normal to the surface of the base member 5 (corresponding to an example of step (b) of the present invention). The operator then places the support block 72 on the head holder 62 of the head unit 6c, and further inserts the fastening fitting 67 through the through hole (not shown) provided in the support block 72, and screws its tip into the screw hole 621. As a result, the support block 72 is attached to the head unit 6c (step S2).

[0028] Next, the operator attaches the adjustment jig 73 to the base member 5 (step S3: corresponding to an example of step (c) of the present invention). As shown in Figures 6 and 7B, the adjustment jig 73 has a plate member 731 that can be attached to the base member 5. The plate member 731 is wider than the head holder 62 in the width direction Y, and one end 732 and the other end 733 each partially protrude in the (+X) direction, i.e., toward the head unit 6. The one end 732 extends to the outside of the tip 71a of the reference pin 71 (left side in Figure 7B) and is capable of engaging with the tip 71a. The other end 733 extends to a position opposite the widthwise end of the contact block 72. A plunger 734 is attached to the X-direction end of the other end 733 so as to be able to move back and forth in the Y direction. The tip of the plunger 734 faces the contact block 72, and when operated by the operator, the tip of the plunger 734 comes into contact with the contact block 72 and is pressed by a spring (not shown) provided on the plunger 734. In this way, the adjustment jig 73 supports the head unit 6c so that it can move in the width direction X while engaging with the tip 71a of the reference pin 71.

[0029] Furthermore, in the adjustment jig 73, a strip-shaped member 735, which is bent toward the side of the plate member 731 opposite the head unit (the downward side in Figure 7B), is attached to the plate member 731. The strip-shaped member 735 and the plate member 731 are provided with two pairs of through holes aligned in the X direction. Screw members 736 are inserted through the strip-shaped member 735 from the side of the head unit opposite the strip-shaped member 735, and the tips of the screw members 736 are screwed into the head holder 62 of the head unit 6c. A spring 737 is externally fitted to the central part of each screw member 736, providing a biasing force to the strip-shaped member 735 and the plate member 731. As a result, the adjustment jig 73 engages with the tip 71a of the reference pin 71 and supports the head unit 6c so that it can rotate freely in the rotational direction R with the tip 71a of the reference pin 71 as the center of rotation.

[0030] In this manner, by attaching the adjustment jig 73 to the base member 5, the head unit 6c is biased toward the reference pin 71 side (left-hand side in Figure 7B) in the width direction Y, while engaged with the tip 71a of the reference pin 71, and biased clockwise in the rotation direction R in the plane of Figure 7B. Therefore, in this embodiment, as shown in Figure 7C, the head unit 6c can be displaced in the width direction X while resisting the biasing force of the plunger 734 by attaching the width direction adjustment part 74 to the width direction adjustment hole 53, and the head unit 6c can be displaced in the rotation direction R while resisting the biasing force of the spring 737 by attaching the rotation direction adjustment part 75 to the rotation direction adjustment hole 54 (step S4: corresponds to an example of step (d) of the present invention).

[0031] The width direction adjustment section 74 and the rotation direction adjustment section 75 have basically the same configuration, differing only in their orientation when installed in the width direction adjustment hole 53 and the rotation direction adjustment hole 54, respectively. Therefore, the configuration of the width direction adjustment section 74 will be explained here based on Figure 7C, and the configuration of each part of the rotation direction adjustment hole 54 will be omitted, with corresponding reference numerals used.

[0032] The width direction adjustment section 74 has a fixing section 741 that can be attached to a width direction adjustment hole 53 provided in the base member 5 adjacent to the mounting area 51. The fixing section 741 has a mounting portion 741a that can be inserted into and removed from the width direction adjustment hole 53, and an upright portion 741b that is erected from the mounting portion 741a in the direction normal to the surface ND. A groove (not shown) is provided on the outer surface of the mounting portion 741a, and an O-ring 741c made of an elastic material is fitted onto the groove. This O-ring 741c has an outer diameter slightly larger than the inner diameter of the width direction adjustment hole 53. Therefore, when the operator press-fits the mounting portion 741a of the fixing section 741 into the width direction adjustment hole 53, as shown in Figure 7C, the upright portion 741b is positioned between the head units 6a and 6c, and the fixing section is firmly fixed to the base member 5 via the O-ring 741c. The fixing section 741 is also provided with an inclined surface 741d. Then, with the inclined surface 741d facing the head unit 6c, the fixing part 741 is fixed to the base member 5. Here, if the head unit 6c approaches the head unit 6a due to the biasing force of the plunger 734, the work of attaching the width direction adjustment part 74 to the base member 5 becomes troublesome. Therefore, as described above, this problem is resolved by maintaining a temporary attachment. The same applies to the rotation direction adjustment part 75.

[0033] As described above, a coil spring 742 is positioned on the (+ND) end face of a fixed portion 741 fixed to the base member 5, and a movable portion 743 is placed on the (+ND) end face of the coil spring 742. More specifically, as shown in Figure 7C, the movable portion 743 has a shape that integrates a rectangular plate member provided to cover the coil spring 742 from the (+ND) side, and an extended member extending from the head unit 6c side (right side in the figure) of the rectangular plate member toward the fixed portion 741. The rectangular plate member has a through hole formed therein with an inner diameter approximately the same as the inner diameter of the coil spring 742. A screw member 744 is then screwed into the fixed portion 741 from the (+ND) side of the movable portion 743, passing through the through hole and the inside of the coil spring 742. Therefore, when the operator rotates the screw member 744 in the forward direction while resisting the biasing force of the coil spring 742, the movable part 743 moves toward the fixed part 741. At this time, the tip 743a of the extended member of the movable part 743 slides against the inclined surface 741d of the fixed part 741 and moves toward the head holder 62 of the head unit 6c. As a result, the tip 743a is displaced by a distance corresponding to the amount of rotation of the screw member 744, pushing the head unit 6c toward the (+Y) direction. Conversely, when the operator rotates the screw member 744 in the reverse direction, the movable part 743 as a whole moves toward the (+ND) direction due to the biasing force of the coil spring 742, and the tip 743a is displaced toward the (-Y) direction.

[0034] In this embodiment, the fixing portion 741, mounting portion 741a, upright portion 741b, inclined surface 741d, movable portion 743, and tip portion 743a correspond to examples of the "first fixing portion," "first mounting portion," "first upright portion," "first inclined surface," "first movable portion," and "first sliding contact portion" of the present invention, respectively, and the first structure having these functions as a width direction adjustment portion 74.

[0035] On the other hand, with respect to the rotation direction adjustment unit 75, the operator press-fits the mounting portion 751a of the fixed portion 751 of the rotation direction adjustment unit 75 into the rotation direction adjustment hole 54 at a distance from the reference pin 71 in the Y direction, with the inclined surface 751d of the fixed portion 751 facing the head unit 6c. As a result, as shown in Figure 7C, the rotation direction adjustment unit 75 is inserted between the head unit 6c and the plate member 731 of the adjustment jig 73. Then, when the operator rotates the screw member 754 in the forward direction and screws it in while resisting the biasing force of the spring 737, the movable portion 753 moves toward the fixed portion 751. At this time, the tip of the extended member of the movable portion 753 slides against the inclined surface of the fixed portion 751 and moves toward the head holder 62 of the head unit 6c. As a result, the tip is displaced by a distance corresponding to the amount of rotation of the screw member 754, pushing the head unit 6c toward the (+X) direction. As a result, the tip 71a of the reference pin 71 is displaced in the rotational direction R, more specifically in the counterclockwise direction in Figure 7C, with the tip 753a as the center of rotation. Conversely, when the operator rotates the screw member 754 in the reverse direction, the movable part 753 moves as a whole in the (+ND) direction due to the biasing force of the coil spring 752, and the tip 753a is displaced in the (-X) direction.

[0036] In this embodiment, the fixing portion 751, mounting portion 751a, upright portion 751b, inclined surface 751d, movable portion 753, and the tip of the movable portion 753 correspond to examples of the "second fixing portion," "second mounting portion," "second upright portion," "second inclined surface," "second movable portion," and "second sliding contact portion" of the present invention, respectively, and the second structure having these functions as the rotation direction adjustment portion 75.

[0037] Once the width direction adjustment section 74 and the rotation direction adjustment section 75 are installed, the operator loosens the fastening between the base member 5 and the head unit 6c by operating the fastening fitting 66 (step S5). As a result, the head unit 6c is displaced in the (-Y) direction according to the biasing force of the plunger 734 and comes into contact with the movable part 743 of the width direction adjustment section 74. That is, the head unit 6c is sandwiched between the plunger 734 and the width direction adjustment section 74 in the width direction Y. After this, by rotating the screw member 744 of the width direction adjustment section 74, it becomes possible to continuously displace the head unit 6c in the Y direction by a distance corresponding to the amount of rotation.

[0038] Meanwhile, the head unit 6c is also displaced in the X direction and comes into contact with the rotation direction adjustment part 75. That is, the head unit 6c is displaced in the (-X) direction according to the biasing force of the spring 737 and comes into contact with the movable part 753 (Figure 6). At this time, the (-Y) side end of the head unit 6c engages with the tip 71a of the reference pin 71, while a biasing force acting toward the (-X) direction acts on the (+Y) side further away from it. Due to this biasing force, the head unit 6c rotates around the tip 71a of the reference pin 71 as the center of rotation and is locked to the movable part 753 (Figure 6) of the rotation direction adjustment part 75 at a position separated from the reference pin 71 in the (+Y) direction. In this way, the head unit 6c is positioned in the rotation direction R. After this, by rotating the screw member 754 of the rotation direction adjustment part 75, the head unit 6c is displaced in the X direction by a distance corresponding to the amount of rotation, and as a result, the head unit 6c can be continuously displaced in the rotation direction R.

[0039] Returning to Figure 5, we continue the explanation of the adjustment procedure for the head unit 6c. In order to adjust the head unit 6c with high precision, it is necessary to reliably capture even slight displacements of the head unit 6c and adjust the amount of displacement with high resolution. Therefore, in this embodiment, as shown in Figure 7D, the operator attaches the adjustment camera 76 to the base member 5 (step S6). The image captured by the adjustment camera 76, that is, the image of the adjacent region AR (hereinafter referred to as "adjacent image") where the head units 6a and 6c are adjacent to each other with a gap formed between the ink ejection heads 61 of the head units 6a and 6c, is displayed on a display that is not shown. Referring to this adjacent image, the operator operates the screw member 744 of the width direction adjustment unit 74 and / or the screw member 754 of the rotation direction adjustment unit 75. As a result, the position of the head unit 6c, which is the target of adjustment and is mounted adjacent to the head unit 6a in the width direction Y (= position in the width direction Y + rotation position in the rotation direction R), is adjusted with high precision (step S7: corresponding to an example of step (e) of the present invention). Then, once the position adjustment of the head unit 6c is complete, the operator firmly fastens the loosened fastening fitting 66 and permanently attaches the head unit 6c to the base member 5 (step S8: corresponding to an example of step (f) of the present invention).

[0040] Afterward, the operator performs the reverse procedure described above, namely removing the adjustment camera 76 (step S9), removing the width direction adjustment unit 74 and the rotation direction adjustment unit 75 (step S10), removing the adjustment jig 73 (step S11), and removing the reference pin 71 and the contact block 72 (step S12), in that order.

[0041] As described above, in this embodiment, the head unit 6c is moved in the width direction Y by a width direction adjustment part 74 inserted between the head unit 6c to be adjusted and the head unit 6a which remains fixed to the base member 5. This adjusts the gap between the head units 6a and 6c. In other words, the width direction position of the head unit 6c is adjusted in the width direction Y. Furthermore, with the head unit 6c engaged with the tip 71a of the reference pin 71, the head unit 6c is moved in the X direction by a rotation direction adjustment part 75 inserted between the head unit 6c to be adjusted and the adjustment jig 73 attached to the base member 5 at a distance from the reference pin 71 in the Y direction, thereby adjusting the position of the head unit 6c in the rotation direction R, i.e., the rotation direction position. As a result, the position of the head unit 6c relative to the head unit 6a can be adjusted with high precision.

[0042] Furthermore, in this embodiment, the width direction adjustment unit 74 is configured to move the tip 743a of the extension member of the movable unit 743 while sliding it against the inclined surface 741d, as described above. As a result, the following effects can be obtained. As a means of adjusting the gap between the head units 6a and 6c, adjustment members such as pin members or shim members may be used (comparative example). That is, multiple adjustment members with different Y-direction sizes may be prepared in advance, and the position of the head unit 6c may be adjusted by repeatedly inserting and removing the adjustment members. However, in this comparative example, there is a problem that if there is an error in the outer diameter of the adjustment member, it will result in a position adjustment error. Also, high-precision position adjustment is difficult due to manufacturing errors and insertion errors of the adjustment member. In contrast, in this embodiment, as described above, a so-called wedge-shaped part is used in which the tip 743a of the extension member of the movable unit 743 moves continuously while sliding against the inclined surface 741d, so high-precision position adjustment is possible compared to the comparative example. The same applies to the rotation direction adjustment unit 75.

[0043] Furthermore, in the comparative example, each time an adjustment member was replaced, an adjustment pattern was actually printed, and the size of the next adjustment member to be installed was determined based on the print result. In other words, whether or not the relative positional relationship of head unit 6c to head unit 6a was adjusted as designed was not directly measured, but only indirectly. As a result, high-precision adjustment was difficult. In contrast, in this embodiment, the position of head unit 6c is adjusted while referring to adjacent images captured by the adjustment camera 76. In other words, the relative positional relationship is reflected in the adjacent images, and the relative positional relationship is directly measured. Moreover, since the position adjustment is performed continuously based on this, it is possible to adjust the relative positional relationship so that it matches the set value. As a result, high-quality printing becomes possible.

[0044] Furthermore, in this embodiment, prior to adjusting the position of the head unit 6c (step S7), the head unit 6c to be adjusted is temporarily attached to the base member 5 while the reference pin 71, contact block 72, adjustment jig 73, width direction adjustment section 74, and rotation direction adjustment section 75 are attached (steps S2 to S4). This allows for smooth preparation for position adjustment and improves the efficiency of the position adjustment process.

[0045] As described above, in this embodiment, head units 6a and 6c correspond to examples of the "first head unit" and "second head unit" of the present invention, respectively. The X direction corresponds to the "orthogonal direction" of the present invention.

[0046] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, in the above embodiment, the plunger 734 is configured to press the head unit 6c to be adjusted in the (-Y) direction via the contact block 72, but the plunger 734 may be configured to press the head unit 6c directly. [Industrial applicability]

[0047] This invention can be applied to all methods for adjusting the position of head units that are detachably arranged in a predetermined width direction relative to a base member. [Explanation of symbols]

[0048] 5…Base component 6a…(1st) Head Unit 6c…(2nd) Head Unit 51… Mounting area 52…Reference pin hole 53…Width direction adjustment hole 54…Rotation direction adjustment hole 62... Head holder 71…Reference pin 71a... (The tip of the reference pin) 73... Adjustment jig 74…Width direction adjustment section 75...Rotation direction adjustment section 76... Adjustment camera 741...(1st) Fixed part 741a... (1st) Placement site 741b…(1st) Erected part 741d…(1st) Inclined surface 743…(1st) Movable part 743a...Tip (first sliding contact part) 751…(2nd) Fixed part 751a... (Second) Placement site 751b…(2nd) Erected part 751d…(2nd) Slope 753…(2nd) Movable part 753a...Tip (second sliding contact part) ND…Surface normal direction R...Direction of rotation X... orthogonal direction Y...Width direction

Claims

1. A method for adjusting the position of a head unit, which is mounted adjacent to a first head unit fixed to a base member in the width direction, and which is a second head unit. (a) A step of temporarily mounting the second head unit in a mounting area adjacent to the first head unit in the width direction, (b) The step of mounting the base end of the reference pin in a reference pin hole provided in the base member adjacent to the mounting area, thereby erecting the tip of the reference pin in the direction normal to the surface of the base member, (c) A step of attaching an adjustment jig to the base member, which is such that the second head unit is movable in the width direction while engaging with the tip of the reference pin and the second head unit is rotatable about the tip of the reference pin as the center of rotation, (d) Inserting a width direction adjustment unit between the first head unit and the second head unit, and inserting a rotation direction adjustment unit between the second head unit and the adjustment jig at a position spaced apart in the width direction from the reference pin, (e) With the temporary mounting of the second head unit loosened, the gap between the first head unit and the second head unit in the width direction is adjusted by moving the second head unit in the width direction using the width direction adjustment unit, and the rotation direction position of the second head unit relative to the tip of the reference pin is adjusted by moving the second head unit in an orthogonal direction perpendicular to both the width direction and the surface normal direction at the separated position using the rotation direction adjustment unit; (f) After the completion of step (e), the step of fastening the second head unit to the base member and permanently mounting it, A method for adjusting the position of a head unit, characterized by comprising the following features.

2. A method for adjusting the position of a head unit according to claim 1, The aforementioned step (d) is (d-1) A step of preparing a first structure which has, as the width direction adjustment section, a first fixing section having a first mounting section that can be attached to a width direction adjustment hole provided in the base member adjacent to the mounting area and a first erecting section erected in the direction normal to the surface from the first mounting section, and a first movable section which is connected to the first fixing section so as to be movable in the direction normal to the surface while sliding in contact with a first inclined surface of the first erecting section, and the first sliding contact section of the first movable section that slides with the first inclined surface is moved toward the second head unit in accordance with the movement of the first movable section toward the first fixing section in the direction normal to the surface, thereby displacing the second head unit in the width direction. (d-2) The step of mounting the width direction adjustment unit such that the first movable unit is positioned between the first head unit and the second head unit, A method for adjusting the position of the head unit, including the method itself.

3. A method for adjusting the position of a head unit according to claim 2, The aforementioned step (e) is (e-1) A method for adjusting the position of a head unit, comprising the step of adjusting the gap by continuously moving the second head unit in the width direction by moving the first sliding contact portion.

4. A method for adjusting the position of a head unit according to claim 1, The aforementioned step (d) is, (d-3) A step of preparing a second structure which, as the rotation direction adjustment section, has a second fixing section having a second mounting section that can be mounted in a rotation direction adjustment hole provided in the base member adjacent to the mounting area and a second erecting section erected in the direction normal to the surface from the second mounting section, and a second movable section which is connected to the second fixing section so as to be movable in the direction normal to the surface while sliding in contact with the second inclined surface of the second erecting section, and which displaces the second head unit in the rotation direction by moving the second sliding contact section of the second movable section that slides with the second inclined surface toward the second head unit in accordance with the movement of the second movable section toward the second fixing section in the direction normal to the surface, (d-4) The step of mounting the rotation direction adjustment unit such that the second movable unit is positioned between the second head unit and the adjustment jig, A method for adjusting the position of the head unit, including the method itself.

5. A method for adjusting the position of a head unit according to claim 4, The aforementioned step (e) is, (e-2) A method for adjusting the position of a head unit, comprising the step of adjusting the rotational position by continuously moving the second head unit in the orthogonal direction by moving the second movable part.

6. A method for adjusting the position of a head unit according to any one of claims 1 to 5, A method for adjusting the position of a head unit, wherein step (e) is a step of adjusting the gap and the rotational position based on the adjacent images while acquiring adjacent images of the first head unit and the second head unit adjacent to each other with the gap in between.

Images