Head unit and method for adjusting head unit

Abstract

To provide a head unit having excellent printing quality, an adjustment method for a head unit, an attaching-detaching tool, and an exchange method.SOLUTION: A head unit includes: an ink discharge head which has a nozzle surface discharging ink; a head holder freely removable from / attachable to a base member while holding the ink discharge head in a holding area; and a posture adjustment mechanism which adjusts a posture of a nozzle surface with respect to a head holder by rotating the ink discharge head with respect to the head holder around a rotary shaft vertical to both a surface normal line of the nozzle surface and an arrangement direction with the head holder unfitted to a base member.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This invention relates to a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction. and The adjustment method of the head unit by the law is related thereto.

Background Art

[0002] There is known a printing apparatus that ejects ink such as aqueous or oily ink from a nozzle surface of an ink ejection head onto a printing medium by an inkjet method to print an image on the upper surface of the printing medium. In this printing apparatus, for example, as described in Patent Document 1, a plurality of fluid ejection modules are arranged in a predetermined direction and mounted on a frame (corresponding to the "base member" of the present invention). More specifically, a module mount assembly (corresponding to the "ink ejection head" of the present invention) is formed by joining a fluid ejection module to a module mount. Thus, a plurality of module mount assemblies are prepared. On the other hand, a plurality of clamp assemblies are attached to the frame, and further, alignment between the clamp assemblies is achieved using an alignment jig. Then, the module mount assemblies are attached to the clamp assemblies one-to-one.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above prior art, a plurality of module mounting assemblies are aligned with each other by the alignment of the clamp assembly. However, it is the alignment of the nozzle surface that directly affects the printing quality, and this point has not been fully considered in the prior art. That is, the fluid ejection module is simply joined to the module mount, and the posture and position of the nozzle surface of the fluid ejection module are not fixed before being mounted on the frame. In addition, since it is difficult to accurately adjust the posture and height of the nozzle surface for each nozzle surface in the state where the frame is mounted, in the apparatus described in Patent Document 1, automatic adjustment is performed using the biasing force of the spring charged in the clamp assembly. However, in this adjustment method, there is a limit to the adjustment accuracy. Also, during head cleaning, an external force may act on the nozzle surface and the above adjustment may be displaced. Due to these reasons, the ejection performance such as the ejection direction and ejection position becomes non-uniform for each nozzle surface, and as a result, there has been a problem that sufficient printing quality cannot be obtained.

[0005] Further, when arranging a plurality of module mounting assemblies side by side in the arrangement direction as in the above prior art, the interval between adjacent module mounting assemblies is narrow. Therefore, in order to replace one of the plurality of module mounting assemblies, it is necessary to selectively remove the module mounting assembly to be replaced and mount a new module mounting assembly at the removed position. However, since the replacement of the module mounting assembly was performed relying on the visual inspection of the operator, it was difficult to accurately mount it at the removal position, which may have an adverse effect on the printing quality. In addition to the deterioration of the printing quality, during the replacement operation, the module mounting assembly being attached and detached may be damaged just because the extraction direction and insertion direction of the module mounting assembly are slightly displaced. For this reason, a high-level operation has been required for the replacement of the module mounting assembly.

[0006] This invention has been made in view of the above problems, and aims to provide a head unit having excellent printing quality and Adjustment method of the head unit the law and to provide it.

Means for Solving the Problem

[0007] A first aspect of the present invention is a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, including an ink ejection head having a nozzle surface for ejecting ink, a head holder that detachably holds the ink ejection head in a holding region with respect to the base member, and a posture adjusting mechanism that adjusts the posture of the nozzle surface with respect to the head holder by rotating the ink ejection head with respect to the head holder about a rotation axis perpendicular to both the normal line of the nozzle surface and the arrangement direction while the head holder is not attached to the base member. and, the head holder has a first holder member provided on one side of the holding area and a second holder member provided on the other side of the holding area in the array direction, and the posture adjustment mechanism is provided so as to be movable forward and backward toward the holding area with respect to the first holder member, and includes a first movable member and a second movable member that project into the holding area and contact the ink ejection head positioned in the holding area, and a third movable member that is provided so as to be movable forward and backward toward the holding area with respect to the second holder member while facing an intermediate portion of the first holder member positioned between the first movable member and the second movable member, and projects into the holding area and contacts the ink ejection head positioned in the holding area, and adjusts the amount of rotation around the rotation axis of the ink ejection head in accordance with an increase in the amount of protrusion of one of the first movable member and the second movable member into the holding area and a decrease in the amount of protrusion of the other into the holding area It is characterized by this.

[0008] A second aspect of the present invention is a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, including an ink ejection head having a nozzle surface for ejecting ink, a head holder that detachably holds the ink ejection head in a holding region with respect to the base member, and a height adjusting mechanism that adjusts the height position of the nozzle surface with respect to the head holder by moving the ink ejection head with respect to the head holder in a height direction parallel to the normal line of the nozzle surface while the head holder is not attached to the base member. and, the head holder has a holder base that is detachable from the base member, and the height adjustment mechanism has a fourth movable member movably attached to the holder base in the height direction and a moving portion that moves the fourth movable member in the height direction, and adjusts the relative position of the nozzle surface with respect to the head holder in the height direction by moving the fourth movable member by the moving portion with one end portion of the fourth movable member in contact with the ink ejection head It is characterized by this.

[0009] A third aspect of the present invention is a method for adjusting a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction. The head unit has the same configuration as the head unit according to the first aspect Before attaching the head unit to the base member, (a) a step of inserting an ink ejection head having a nozzle surface for ejecting ink into the holding region of the head holder, (b1) a step of adjusting the posture of the nozzle surface with respect to the head holder by rotating the ink ejection head inserted into the holding region with respect to the head holder about a rotation axis perpendicular to both the normal line of the nozzle surface and the arrangement direction, and (c) a step of fixing the ink ejection head to the head holder to form the head unit after executing step (b1).

[0010] Moreover, a fourth aspect of the present invention is a method for adjusting a head unit detachably attached to a base member and arranged in a predetermined arrangement direction, comprising: The head unit has the same configuration as the head unit according to the second aspect before attaching the head unit to the base member, (a) inserting an ink ejection head having a nozzle surface for ejecting ink into a holding region of a head holder; and (b2) moving the ink ejection head inserted into the holding region relative to the head holder in a height direction parallel to the surface normal of the nozzle surface to adjust the height position of the nozzle surface relative to the head holder; and (c) after performing step (b2), fixing the ink ejection head to the head holder to form the head unit.

[0011] Furthermore, a fifth aspect of the present invention is a head unit detachably attached to a base member and arranged in a predetermined arrangement direction, comprising: an ink ejection head having a nozzle surface for ejecting ink; a head holder detachably attached to the base member while holding the ink ejection head in a holding region; and a height adjustment mechanism for adjusting the height position of the nozzle surface relative to the head holder by moving the ink ejection head relative to the head holder in a height direction parallel to the surface normal of the nozzle surface with the head holder not attached to the base member. and, the head holder has a holder base that is detachable from the base member, and the height adjustment mechanism has a fifth movable member movably attached to the holder base in the height direction and a suspension member that is suspended along the holder base in a state of being connected to the ink ejection head by contacting the upper surface of the fifth movable member attached to the holder base from above, and adjusts the relative position of the nozzle surface with respect to the head holder in the height direction by displacement of the suspension member in the height direction according to the attachment position of the fifth movable member It is characterized by this.

Advantages of the Invention

[0013] As described above, according to the present invention, in a state where the head unit is not attached to the base member, the posture and height position of the nozzle surface with respect to the head holder in the head unit can be adjusted, and excellent printing quality can be obtained.

[0014] In addition, since the adjusted head unit can be stably attached to and detached from the base member, excellent printing quality can be obtained even when the head unit is attached to the base member.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0016] FIG. 1 is a front view schematically showing an example of a printing system equipped with an embodiment of a head unit according to the present invention. In FIG. 1 and the figures shown below, in order to clarify the arrangement relationship of each part of the apparatus, the horizontal direction in which the coating apparatus 2, the printing apparatus 3, and the drying apparatus 4 constituting the printing system 1 are arranged is defined as the "X direction", the horizontal direction from the right hand side to the left hand side of FIG. 1 is referred to as the "+X direction", and the opposite direction is referred to as the "-X direction". Further, among the horizontal directions Y orthogonal to the X direction, the front side of the apparatus is referred to as the "+Y direction", and the back side of the apparatus 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.

[0017] This printing system 1 controls each part of the apparatus by a control unit 100, and while transporting a long strip-shaped printing medium M from a pay-off roll 11 to a take-up roll 12 in a roll-to-roll manner, performs a coating process, a printing process, and a drying process on the printing medium M. That is, the coating apparatus 2 applies a coating liquid to the printing medium M. Then, the printing apparatus 3 adheres various inks to the printing medium M by an inkjet method to print an image. Further, the drying apparatus 4 dries the ink adhering to the printing medium M. Note that 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 a film, and may be paper or the like. Such a printing medium M has flexibility. Further, hereinafter, among both sides of the printing medium M, the surface on which the image is printed is appropriately referred to as the front surface M1, and the surface on the opposite side of the front surface M1 is referred to as the back surface M2.

[0018] The coating device 2 includes a pan 21 for storing a liquid primer (coating liquid), a gravure roller 22 partially immersed in the primer stored in the pan 21, and a conveyance unit 23 for conveying the printing medium M. In the coating device 2, a coating area is provided where the gravure roller 22 contacts the printing medium M conveyed by the conveyance unit 23 from below. The conveyance unit 23 conveys the printing medium M along the coating area while facing the surface M1 of the printing medium M downward. On the other hand, the gravure roller 22 supplies the 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. Also, in the coating area, the traveling direction of the printing medium M and the rotational direction of the circumferential surface of the gravure roller 22 are opposite. That is, the primer is applied to the printing medium M by the so-called reverse kiss method. Then, the conveyance unit 23 discharges the printing medium M from the coating device 2 to the printing device 3 while facing the surface M1 of the printing medium M to which the primer has been applied upward.

[0019] The printing device 3 includes a housing 31, a color printing unit 32 disposed within the housing 31, a white printing unit 33 disposed above the color printing unit 32 within the housing 31, and a conveyance unit 34 for conveying the printing medium M by a plurality of rollers disposed within the housing 31.

[0020] The color printing unit 32 has a plurality (four in this embodiment) of printing bar units 321 arranged in the traveling direction of the printing medium M above the printing medium M conveyed by the conveyance unit 34. The plurality of printing bar units 321 each have nozzles facing the surface M1 of the printing medium M passing below from above, and eject color inks of different colors from the nozzles by an inkjet method. Here, the color ink means ink other than white, and includes inks such as cyan, magenta, yellow, and black. In this way, the plurality of printing 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 each of them.

[0021] 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 therebelow 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 therebelow.

[0022] The printing bar units 321 and 331 are composed of a plurality of ink ejection heads that eject ink from the nozzle surface by an inkjet method. In the present embodiment, ten ink ejection heads are arranged in the width direction Y of the printing medium M. That is, the width direction Y corresponds to the "array direction" of the present invention. 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.

[0023] 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.

[0024] The drying device 4 dries the ink adhering to the surface M1 of the printing medium M conveyed from the printing device 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.

[0025] FIG. 2 is a perspective view showing the main part of the printing bar unit. In the printing bar units 321 and 331, ten head units 6 are attached adjacent to each other in the arrangement direction Y with respect to a base member 5 extending in the arrangement direction Y. As shown in the partial enlarged view in the figure, each head unit 6 holds an ink ejection head 61 with a head holder 62 and is fixed with a fixing screw 65 after posture adjustment and height adjustment.

[0026] FIG. 3 is a flowchart showing a manufacturing method of the printing bar unit shown in FIG. 2. In manufacturing the printing bar units 321 and 331, an operator executes steps S1 to S5 shown in FIG. 3. Hereinafter, while appropriately explaining the configuration of the head unit 6, the formation of the ink ejection head 61, the manufacturing of the head unit 6, and the attachment of the head unit 6 will be described. First, the head units 6 are prepared by repeatedly executing steps S1 to S3 the number N of times of the attachment of the head units 6 in the printing bar units 321 and 331. In the present embodiment, N = 10 is set to attach ten head units 6 for each printing bar unit, but the value of N is arbitrary.

[0027] FIG. 4 is an exploded perspective view of the head unit. FIG. 5 is a perspective view of the ink ejection head seen from the lower back side. The ink ejection head 61 and the head holder 62 constituting the head unit 6 each have the following structure, and the ink ejection head 61 can be inserted into a holding region 62a of the head holder 62. Here, the printing bar units 321 and 331 are arranged such that a nozzle surface 611c for ejecting ink faces the surface M1 (FIG. 1) of the printing medium M. Therefore, the direction of the surface normal NL (FIG. 5) of the nozzle surface 611c and the direction of the surface normal of the surface M1 do not always coincide with the vertical direction Z. However, for ease of understanding of the invention content, hereinafter, it is assumed that the direction of the surface normal NL substantially coincides with the vertical direction Z, and the direction Z corresponds to the "height direction" of the present invention, and the description will proceed.

[0028] As shown in FIGS. 2 and 4, the ink ejection head 61 has an ink ejection module 611 and a module mount 612. As is well known in the art, the ink ejection module 611 has a function of ejecting ink circulated and supplied through an ink inlet 611a and an ink outlet 611b in the form of droplets downward (-Z) from a nozzle surface 611c. On the other hand, the module mount 612 has a horizontal portion 612a facing the printing medium M and a vertical portion 612b erected upward from an end of the horizontal portion 612a on the (-X) direction side, and has a substantially L-shaped cross-sectional structure. A rectangular opening (not shown) slightly narrower than the nozzle surface 611c is provided in the horizontal portion 612a, and has a frame shape in a plan view from above. Therefore, when the ink ejection module 611 is inserted upward (+Z) through the rectangular opening with the nozzle surface 611c facing downward, the ink ejection module 611 is locked at the frame portion of the horizontal portion 612a while exposing the nozzle surface 611c downward. Then, the ink ejection module 611 is fixed to the module mount 612. In this way, the ink ejection module 611 and the module mount 612 are integrated to form the ink ejection head 61 (step S1).

[0029] In the ink ejection head 61 formed in this way, as shown in FIG. 5, a pair of protruding portions 612c are provided protruding in the (-X) direction on a vertical surface on the (-X) direction side of the vertical portion 612b. These pair of protruding portions 612c extend in the vertical direction Z and are finished in a shape that can be fitted with the head holder 62. Therefore, as shown in FIG. 4, it is possible to stably insert the ink ejection head 61 into the holding region 62a of the head holder 62 from the lower side. Of course, it is also possible to integrate the ink ejection head 61 and the head holder 62 by moving the head holder 62 from the upper side to the ink ejection head 61.

[0030] As shown in Fig. 4, the head holder 62 has a holder base 620 extending in the vertical direction Z, a first holder member 621 extending in the vertical direction Z on the (-Y) direction side of the holder base 620, and a second holder member 622 extending in the vertical direction Z on the (+Y) direction side of the holder base 620. The region surrounded by the holder base 620, the first holder member 621, and the second holder member 622 corresponds to the holding region 62a, and the ink ejection head 61 can be held in the holding region 62a.

[0031] At the lower center of the holder base 620, as shown in Fig. 4, a height adjustment mechanism 63 for adjusting the relative height position, that is, the relative position, of the nozzle surface 611c with respect to the head holder 62 is attached. Further, an attitude adjustment mechanism 64 for adjusting the attitude of the nozzle surface 611c is attached to the first holder member 621 and the second holder member 622.

[0032] The height adjustment mechanism 63 includes a movable member 631 that is movably provided in the vertical direction Z along the side surface on the (+X) direction side of the holder base 620, and a tip round screw 632 that functions as a moving part for moving the movable member 631 in the height direction Z. The movable member 631 corresponds to an example of the "fourth movable member" of the present invention, and its lower end portion 631a is finished in a shape protruding downward. On the other hand, the upper end portion 631b of the movable member 631 is finished in an inclined surface that is inclined in the height direction Z. As shown in the enlarged view in FIG. 8 to be described later, the (+X) direction side (the left side in the figure) is higher than the (-X) direction side (the right side in the figure). Further, the tip round screw 632 is screwed into the holder base 620 from the (-X) direction side. When the operator rotates the tip round screw 632 clockwise, the tip portion of the tip round screw 632 advances in the (+X) direction while sliding on the inclined surface. As a result, the movable member 631 is moved downward (-Z). Conversely, when the operator rotates the tip round screw 632 counterclockwise to retract the tip round screw 632 in the (-X) direction, the movable member 631 can be moved upward (+Z). That is, the position of the movable member 631 in the height direction Z is controlled according to the rotation amount of the tip round screw 632, and the relative height position (relative position) of the nozzle surface 611c with respect to the head holder 62 can be adjusted during the manufacture of the head unit 6 to be described later.

[0033] The attitude adjustment mechanism 64 includes two movable members 641 and 642 attached to the first holder member 621, and one movable member 643 attached to the second holder member 622. These three movable members 641 to 643 basically have the same configuration, and only the mounting positions are different from each other.

[0034] The movable member 641 is composed of a ball 641a made of stainless steel or resin and a screw 641b, which is inserted into a through hole 621a (Fig. 7) that penetrates in the Y direction above the first holder member 621. The ball 641a is arranged to be movable in the arrangement direction Y within the through hole 621a. Also, the screw 641b is provided so as to be able to advance and retreat in the arrangement direction Y while being screwed into a female screw engraved on the inner peripheral surface of the through hole 621a on the (-Y) direction side of the ball 641a. Therefore, when an operator rotates the screw 641b and moves it in the arrangement direction Y, the amount of protrusion (hereinafter referred to as "protrusion amount") from the (+Y) direction side opening of the through hole 621a toward the holding region 62a changes according to the movement. That is, the pushing amount of the ball 641a against the ink ejection head 61 located in the holding region 62a can be adjusted according to the rotation amount of the screw 641b.

[0035] The movable member 642 is composed of a ball 642a and a screw 642b, which are inserted into a through hole 621b (Fig. 7) that penetrates in the Y direction at a position below the movable member 641 (below the first holder member 621). Therefore, when an operator rotates the screw 642b and moves it in the arrangement direction Y, the amount of protrusion from the (+Y) direction side opening of the through hole 621b changes according to the movement. That is, the pushing amount of the ball 642a against the ink ejection head 61 located in the holding region 62a can be adjusted according to the rotation amount of the screw 642b.

[0036] The movable member 643 is composed of a ball 643a (Fig. 7) and a screw 643b, which are inserted into a through hole 621c that penetrates in the Y direction at the central position of the second holder member 622. This "central position" means a position facing the intermediate part of the first holder member 621 located between the movable members 641 and 642. Therefore, when an operator rotates the screw 643b and moves it in the arrangement direction Y, the amount of protrusion from the (-Y) direction side opening of the through hole 621c changes according to the movement. That is, the pushing amount of the ball 643a against the ink ejection head 61 located in the holding region 62a can be adjusted according to the rotation amount of the screw 643b.

[0037] By adjusting the pushing-in amounts to the ink ejection head 61 at three different positions from each other in this way, it is possible to adjust the posture of the nozzle surface 611c with respect to the head holder 62. For example, when increasing the protruding amount to one of the holding regions 62a of the movable members 641 and 642 and decreasing the protruding amount to the other holding region 62a, as shown in FIG. 4, with respect to the head holder 62, the ink ejection head 61 can be rotated about a rotation axis AX parallel to the direction (X direction) perpendicular to both the surface normal NL of the nozzle surface 611c and the arrangement direction Y. Thereby, the posture of the nozzle surface 611c can be accurately adjusted within the YZ plane.

[0038] Also, by increasing the protruding amounts of the movable members 641 and 642 and decreasing the protruding amount of the movable member 643, the ink ejection head 61 moves to the second holder member 622 side (+Y direction side). Conversely, by decreasing the protruding amounts of the movable members 641 and 642 and increasing the protruding amount of the movable member 643, the ink ejection head 61 moves to the first holder member 621 side (-Y direction side). Thereby, the position of the nozzle surface 611c in the arrangement direction Y can be accurately adjusted.

[0039] With respect to the head holder 62 configured in this way, an operator fits the ink ejection head 61 formed in step S1 to manufacture the head unit 6 (step S2). Hereinafter, the manufacture of the head unit 6 will be described with reference to FIGS. 4 to 8.

[0040] FIG. 6 is a flowchart showing the work procedure for manufacturing the head unit. FIG. 7 is a diagram schematically showing the horizontal / rotation adjustment operation performed in the manufacture of the head unit. FIG. 8 is a diagram schematically showing the height adjustment operation performed in the manufacture of the head unit. As shown in FIG. 4, the ink ejection head 61 is inserted into the holding region 62a of the head holder 62 while the pair of protruding portions 612c are brought into sliding contact with the holder members 621 and 622 (step S21). Thereby, the ink ejection head 61 is integrated with the head holder 62 with a certain degree of accuracy. In the thus integrated head unit 6, the positioning accuracy of the nozzle surface 611c with respect to the head holder 62 is not sufficient to ensure the required print quality. Therefore, in the present embodiment, the above positioning accuracy is enhanced by performing a horizontal / rotation adjustment operation (steps S22 to S24) and a height adjustment operation (steps S25 to S27). Hereinafter, the head unit 6 before both adjustment operations are completed is referred to as the "unadjusted head unit 6". Note that the order of the horizontal / rotation adjustment operation and the height adjustment operation for the unadjusted head unit 6 is arbitrary, but in the present embodiment, the horizontal / rotation adjustment operation using the horizontal / rotation adjustment device 7 is performed first.

[0041] Here, prior to the description of the horizontal / rotation adjustment operation, the configuration of the horizontal / rotation adjustment device 7 will be described. As shown in column (a) of FIG. 7, the horizontal / rotation adjustment device 7 includes a device base 71, an imaging unit 72, a projector 73, a light receiver 74, and a horizontal / rotation control unit 75. A side view of the state in which the unadjusted head unit 6 is attached to the horizontal / rotation adjustment device 7 as viewed from the X direction is shown in column (a) of the figure, and a cross-sectional view of the attached unadjusted head unit 6 is shown in column (b) of the figure. As shown in column (a) of the figure, the device base 71 is provided with a holding mechanism (not shown) for holding the head holder 62 of the unadjusted head unit 6 at a predetermined position, and the unadjusted head unit 6 is detachable from the device base 71 with the nozzle surface 611c facing downward. When the unadjusted head unit 6 is attached to the device base 71, the head holder 62 is positioned at the reference position.

[0042] The imaging unit 72, the light projector 73, and the light receiver 74 are arranged below the unadjusted head unit 6 mounted on the apparatus base 71. The imaging unit 72 images the nozzle surface 611c and its periphery, and outputs the signal of the captured image to the horizontal / rotation control unit 75. The horizontal / rotation control unit 75 that receives this signal displays the image on the display (not shown) of the horizontal / rotation control unit 75. Therefore, the operator can confirm the current position of the nozzle surface 611c in the XY plane and the attitude of the nozzle surface 611c by observing the image on the display.

[0043] The light projector 73 irradiates light on the nozzle surface 611c at a constant incident angle (e.g., 45°) in the YZ plane (the plane of the paper in FIG. 7) in response to the lighting command of the horizontal / rotation control unit 75. On the other hand, the light receiver 74 receives the reflected light reflected by the nozzle surface 611c, and outputs information regarding the light reception position to the horizontal / rotation control unit 75. The horizontal / rotation control unit 75 that receives this information calculates the rotation angle θ2 of the nozzle surface 611c with the rotation axis AX parallel to the X direction as the rotation center based on the information regarding the light reception position, and displays the calculated value on the display. Therefore, the operator can accurately grasp the rotation angle θ2 of the nozzle surface 611c by checking the numerical value on the display.

[0044] In order to perform the horizontal / rotation adjustment operation using the above-described horizontal / rotation adjustment device 7, as shown in FIG. 7, the operator mounts the unadjusted head unit 6 on the device base 71 (step S22). Subsequently, when the operator instructs the horizontal / rotation control unit 75 to start the adjustment, the entire image of the nozzle surface 611c and the value of the rotation angle θ2 of the nozzle surface 611c are displayed on the display as described above. Thereby, the operator grasps the current position of the nozzle surface 611c and the rotation angle θ2 of the nozzle surface 611c, and if necessary, advances or retracts all or a part of the image processing elements 641b to 643b in the Y direction to perform horizontal / rotation adjustment (step S23). The specific methods for performing the horizontal position adjustment of the nozzle surface 611c in the arrangement direction Y and the rotation adjustment of the nozzle surface 611c around the rotation axis AX are as described above. When these adjustments are completed (in step S24, “YES”), the unadjusted head unit 6 is removed from the device base 71, and the height adjustment operation is started.

[0045] Next, prior to the description of the height adjustment operation, the configuration of the height adjustment device 8 will be described. As shown in column (a) of FIG. 8, the height adjustment device 8 includes a device base 81, a length measuring device 82, and a height control unit 83. A side view of the height adjustment device 8 with the unadjusted head unit 6 mounted thereon as viewed from the X direction is shown in column (a) of the figure, and a cross-sectional view of the mounted unadjusted head unit 6 is shown in column (b) of the figure. As shown in column (a) of the figure, the device base 81 is provided with a holding mechanism (not shown) for holding the head holder 62 of the unadjusted head unit 6 at a predetermined position, and the unadjusted head unit 6 is detachable from the device base 81 with the nozzle surface 611c facing downward. When the unadjusted head unit 6 is mounted on the device base 81, the head holder 62 is positioned at the reference position.

[0046] The length measuring device 82 is disposed directly below the unadjusted head unit 6 mounted on the apparatus base 81. The length measuring device 82 irradiates light toward the nozzle surface 611c, receives the light reflected by the nozzle surface 611c, measures the distance to the nozzle surface 611c, and outputs information regarding the distance to the height control unit 83. Upon receiving this information, the height control unit 83 calculates the height position of the nozzle surface 611c relative to the head holder 62 in the height direction Z based on the information regarding the distance, and displays the calculated value on the display. Therefore, the operator can accurately grasp the height position of the nozzle surface 611c by checking the numerical value on the display.

[0047] In order to execute the height adjustment operation using the above-described height control unit 83, as shown in FIG. 8, the operator mounts the unadjusted head unit 6 (however, horizontal / rotation adjustment has been completed) on the apparatus base 81 (step S25). Subsequently, when the operator instructs the height control unit 83 to start the adjustment, the height position of the nozzle surface 611c is displayed on the display as described above. Thereby, the operator grasps the current position of the nozzle surface 611c in the height direction Z, and performs height adjustment by advancing and retracting the tip round screw 632 in the X direction as necessary (step S26). Note that the specific method for adjusting the height position of the nozzle surface 611c in the height direction Z is as described above. When both the horizontal / rotation adjustment and the height adjustment are completed (in step S27, “YES”), the ink ejection head 61 is fixed to the lower end portion of the head holder 62 with the fixing screw 65 (FIG. 2) while maintaining the adjusted state (step S28). Thus, the operator removes the head unit 6 that has completed the horizontal / rotation adjustment and the height adjustment from the apparatus base 81, and completes the manufacture of the head unit 6.

[0048] Returning to FIG. 3, the description will be continued. When the production of one head unit 6 is completed by the above-described series of operations, an operator determines whether or not the number of adjusted head units 6 has reached the number N to be mounted on the base member 5 (step S3). Then, while it is determined that the prepared number of head units 6 is not yet reached, the operator repeats steps S1 and S2. On the other hand, when N head units 6 that have completed horizontal / rotation adjustment and height adjustment are aligned, the operator mounts the N head units 6 on the base member 5 to manufacture a printing bar unit (step S4). Hereinafter, the manufacturing procedure of the printing bar unit will be described with reference to FIGS. 9 to 11.

[0049] FIG. 9 is a flowchart showing the manufacturing procedure of the printing bar unit. FIG. 10 is a diagram showing a schematic configuration of an alignment device used when manufacturing the printing bar unit. FIG. 11 is a perspective view showing an embodiment of a detaching and attaching jig for the head unit according to the present invention. FIG. 12 is a perspective view showing an example of attachment of the detaching and attaching jig of FIG. 11 to the base member. As shown in FIG. 10, the alignment device 9 used for manufacturing the printing bar unit includes an alignment base 91, a pair of column parts 92, 92, an imaging part 93, and a display part 94. The pair of column parts 92, 92 are erected from the upper surface of the alignment base 91 while being separated in the arrangement direction Y. The upper end parts of these column parts 92, 92 are capable of detachably holding the base member 5 in a horizontal posture. Further, on the upper surface of the alignment base 91, the imaging part 93 is provided so as to be movable in the arrangement direction Y. The imaging part 93 is attached so as to face the base member 5 from below, and is capable of imaging the nozzle surface 611c of the head unit 6 to be mounted on the base member 5 and the image around it as will be described later. Then, the image acquired by the imaging part 93 is displayed on the display part 94.

[0050] Also, the attaching / detaching jig 10 is a jig for attaching / detaching the head unit 6 to / from the base member 5 in units of the head unit. As shown in FIG. 11, the attaching / detaching jig 10 has a jig main body portion 101 that can be attached to and detached from the base member 5. The jig main body portion 101 has a pair of mounting members 103 that are mounted on the base member 5 by fastening fittings 102 such as bolts, and a guide member 104 that extends in the slide direction Z orthogonal to the arrangement direction Y. As shown in FIG. 12, for example, the mounting member 103 is mounted on the base member 5 corresponding to the planned mounting position of the head unit 6 on the base member 5. By this mounting, the guide member 104 extends below the base member 5. A slider 105 capable of supporting the head unit 6 is movably attached to the guide member 104 in the slide direction Z. Therefore, with the head unit 6a (see FIG. 12) supported by the slider 105, the head unit 6a can be easily and accurately positioned at a desired position on the base member 5 by moving the slider 105 upward (+Z). Here, in the arrangement direction Y, if the width of the slider 105 is set to be equal to or less than the width of the head unit 6, it is possible to effectively prevent the slider 105 from interfering with the head unit 6 mounted on the base member 5. As shown in FIG. 12, for example, the slider 105 supporting the head unit 6a can be inserted between the head units 6b and 6c or taken out from between the head units 6b and 6c without interfering with the head units 6b and 6c adjacent to the head unit 6a on the base member 5.

[0051] In this embodiment, while using the above-described alignment device 9 and the detachable jig 10, an operator mounts N head units 6 one by one on the base member 5 according to the work procedure shown in FIG. 9 to manufacture a printing bar unit (Steps S41 to S48). That is, while arranging the longitudinal direction of the base member 5 parallel to the arrangement direction Y, the base member 5 is attached to the upper ends of a pair of column portions 92, 92 (Step S41). Then, for each head unit 6, the work of attaching the head unit 6 to the base member 5 by the detachable jig 10 is executed (Steps S42 to S47). In this attachment work, the attachment member 103 of the detachable jig 10 is attached to the base member 5 by the fastening fitting 102 corresponding to the planned attachment position of the head unit 6 (Step S42). At this time, as shown in FIG. 11, the guide member 104 extends downward (-Z). Also, the slider 105 has descended to the lowermost end position of the guide member 104 by its own weight and is locked by a stopper (not shown). This slider 105 has a slide portion 106 slidably attached to the guide member 104 in the slide direction Z and a protruding portion 107 protruding from below the slide portion 106 in the (+X) direction. Therefore, when the operator places the head unit 6 on the upper surface of the protruding portion 107, the slider 105 can move upward along the guide member 104 integrally with the head unit 6 while supporting the head unit 6 from below (Step S43). Then, the slider 105 and the head unit 6 are integrally raised to the planned attachment position (Step S44). Thereby, the head holder 62 of the head unit 6 is positioned at the planned attachment position while facing the side surface on the (+X) direction side of the base member 5. At this time, an image including the slider 105 and the head unit 6 supported by the slider 105 is projected on the display unit 94. Therefore, the operator may position the head unit 6 at the planned attachment position while referring to the image, which is suitable for improving workability and positioning accuracy.

[0052] Moreover, in the present embodiment, as described above, in the head unit 6, the height adjustment and the posture adjustment of the nozzle surface 611c with respect to the head holder 62 have been completed. As a result, for any head unit 6, the posture and position of the nozzle surface 611c with respect to the base member 5 are adjusted to be constant. Of course, in addition to the positioning operation of the head unit 6 at the planned mounting position, a fine adjustment operation of the head unit 6 with respect to the base member 5 may be performed to further adjust the posture and position of the nozzle surface 611c. As the adjustment at this time, for example, the inkjet head position adjustment method described in Japanese Patent No. 5968632 can be used.

[0053] When the positioning of the head unit 6 at the planned mounting position is completed, fastening fittings 66 (FIGS. 2 and 4) such as bolts are inserted from below toward the head holder 62 through three through holes 108 (FIG. 11) that penetrate the protruding portion 107 in the vertical direction Z. Then, the fastening fittings 66 are screwed into the head holder 62 and the base member 5 to fix the head unit 6 to the base member 5 (step S45). After that, the attachment / detachment jig 10 is removed from the base member 5 (step S46).

[0054] By these series of mounting operations (steps S42 to S46), one head unit 6 is accurately mounted on the base member 5. Therefore, in the next step S47, it is determined whether or not all of the N head units 6 have been mounted on the base member 5. And while there exists an unmounted head unit 6 (``NO'' in step S47), it returns to step S42 and repeats the said series of mounting operations (steps S42 to S46). On the other hand, when all of the N head units 6 are mounted and the print bar unit is completed, the print bar unit is removed from the alignment device 9 (step S48), and the manufacture of the print bar unit is completed.

[0055] Returning to FIG. 3, the description will be continued. The print bar unit 321 (331) thus manufactured is mounted on the printing unit 32 (33) (step S5).

[0056] As described above, according to the present embodiment, in the uninstalled state where the head unit 6 is not attached to the base member 5, the posture and height position of the nozzle surface 611c with respect to the head holder 62 are adjusted in the head unit 6. That is, before manufacturing the printing bar units 321 and 331, the same adjustment is performed on all of the N head units 6. For this reason, the ejection performance such as the ejection direction and ejection position of the ink becomes uniform among the head units 6 that constitute the printing bar units 321 and 331. Moreover, the movable members 631 and 641 to 643 are brought into contact with the head ejection unit 61 to adjust the height position and posture of the nozzle surface 611c. Therefore, the adjustment is more stable and accurate than the conventional device that uses a spring force. As a result, excellent print quality can be obtained.

[0057] Also, when manufacturing the printing bar units 321 and 331 by attaching N head units 6 to the base member 5, the use of the attachment / detachment jig 10 is not essential, but by using the attachment / detachment jig 10 as in the above embodiment, the manufacturing operation can be performed efficiently and stably, which is preferable.

[0058] As described above, in the embodiment, the tip-round screw 632 corresponds to an example of the "adjusting member" of the present invention. The movable members 641 to 643 respectively correspond to examples of the "first movable member", "second movable member", and "third movable member" of the present invention.

[0059] By the way, the manufacturing of the printing bar units 321 and 331 is executed according to the operation procedure shown in FIG. 9. However, when one of the head units 6 that constitute the printing bar units 321 and 331 fails and needs to be replaced, it is preferable to use the attachment / detachment jig 10 shown in FIG. 11. For example, as shown in FIG. 12, the removal of the head unit 6a sandwiched between the head units 6b and 6c can be smoothly performed by executing the following operation procedures (a) to (e). That is, the removal operation is (a) At the position corresponding to the head unit 6a, attach the mounting member 103 of the attachment / detachment jig 10 to the base member 5 with the fastening metal fitting 102. (b) Raise the empty slider 105 to the above position and support the head unit 6a with the slider 105. (c) Release the fixing of the head unit 6 by the fastening fitting 66. (d) Lower the slider 105 and the head unit 6 integrally to the lowermost end position (separated position) of the guide member 104 (see Fig. 12). (e) Remove the head unit 6 from the slider 105. It includes.

[0060] On the other hand, the mounting of the replacement head unit 6a, for which the above height adjustment and posture adjustment have already been performed, between the head units 6b and 6c of the replacement head unit 6a can be performed by the mounting operation (steps S42 to S46) of the above embodiment. By combining such removal work and mounting work, the replacement of the head unit 6 can be performed smoothly and stably. In this replacement work, the head unit 6a to be removed corresponds to an example of the "first head unit" of the present invention, and the replacement head unit 6a corresponds to an example of the "second head unit" of the present invention. The position sandwiched between the head units 6b and 6c corresponds to an example of the "replacement position" of the present invention.

[0061] Prior to the above replacement work, it is preferable to perform the above adjustment on the replacement head unit 6 in advance. Thereby, the homogeneity of the discharge performance is ensured even between the replaced head unit 6 and the unit 6 that has been used previously, and excellent print quality is maintained as it is.

[0062] Note that the present invention is not limited to the above-described embodiment, and various modifications can be made other than those described above without departing from the spirit thereof. For example, in the above embodiment, both horizontal / rotation adjustment and height adjustment are performed, but it may be configured to perform only at least one of them. Also, in the horizontal / rotation adjustment, only the horizontal adjustment by the movement in the arrangement direction Y or only the rotation adjustment by the rotation around the rotation axis AX may be performed.

[0063] In the above-described embodiment, the height position of the nozzle surface 611c with respect to the head holder 62 is adjusted by advancing and retracting the tip round screw 632 of the height adjustment mechanism 63 in the X direction. However, the configuration of the height adjustment mechanism 63 is not limited to this. For example, as shown in FIGS. 13 to 15, the height adjustment mechanism 63 may be configured by a movable block 633, a contact member 634, a support block 635, and a ball plunger 636 (other embodiments).

[0064] FIG. 13 is a view of the height adjustment mechanism provided in another embodiment of the head unit according to the present invention, as seen from the ink ejection head side. FIG. 14 is a perspective view of the contact member constituting the height adjustment mechanism shown in FIG. 13. FIG. 15 is a view of the height adjustment mechanism shown in FIG. 13, as seen from the head holder side. In FIG. 13, the ink ejection head 61 is omitted from the illustration in order to clearly show the positional relationship of each part of the height adjustment mechanism 63 with respect to the head holder 62. On the other hand, in FIG. 15, the head holder 62 is omitted from the illustration in order to clearly show the positional relationship of each part of the height adjustment mechanism 63 with respect to the ink ejection head 61.

[0065] In this height adjustment mechanism 63, as shown in FIG. 13, the movable block 633 is attached to the holder base 620 from the (+X) direction side to the (-X) direction side. More specifically, two female screw portions 633a and 633b are provided on the movable block 633. Then, two fastening members 637, 637 such as bolts are inserted into through holes (not shown) provided in the holder base 620 from the (-X) direction side, and male screw portions provided at the respective tip ends are screwed into the female screw portions 633a and 633b, whereby the movable block 633 is attached to the holder base 620. Here, the inner diameter of the through hole is set to be slightly larger than the shaft portions of the fastening members 637, 637. For this reason, it is possible to adjust the attachment position of the movable block 633 in the height direction Z by only that difference.

[0066] Thus, the contact member 634 is suspended along the holder base 620 with respect to the movable block 633 attached to the holder base 620. As shown in FIG. 14, this contact member 634 has an extended portion 634a extending in the height direction Z. The lower end 634b of this extended portion 634a can be connected to the ink ejection head 61 (see FIG. 15). On the other hand, at the upper end of the extended portion 634a, a contact portion 634c protrudes in the (-X) direction. The lower end of the contact portion 634c is finished to be tapered downward. Therefore, as shown in FIG. 15, when the contact portion 634c of the contact member 634 contacts the upper surface of the movable block 633 from above, in the holding region 62a, the contact member 634 is suspended along the holder base 620 while the ink ejection head 61 is connected. Therefore, by adjusting the mounting position of the movable block 633 in the height direction Z as described above, the operator can adjust the height position of the ink ejection head 61 with high precision.

[0067] In this way, the contact member 634 functions as the "suspension member" of the present invention. However, if only the ink ejection head 61 is suspended, the ink ejection head 61 may move in the height direction Z due to an external force. Therefore, in order to stabilize the height position of the ink ejection head 61, in the present embodiment, a support block 635 and a ball plunger 636 are arranged directly above the contact member 634. The support block 635 is provided with two female screw portions 635a and 635b. Then, two fastening members 638, 638 such as bolts are inserted into through holes (not shown) provided in the holder base 620 from the (-X) direction side, and male screw portions provided at the respective tip ends are screwed into the female screw portions 635a and 635b, so that the support block 635 is attached to the holder base 620 at a position directly above the contact portion 634c of the contact member 634. A ball plunger 636 is embedded in the support block 635 from the (+Z) direction. The tip end portion of the ball plunger 636 protrudes downward from the lower surface of the support block 635, presses the upper surface of the contact member 634 from above, and restricts the upward movement of the contact member 634. That is, the ball plunger 636 functions as an example of the "restricting member" of the present invention, and sandwiches the contact member 634 in the height direction Z together with the movable block 633 (corresponding to an example of the "fifth movable member" of the present invention). As a result, even if an external force acts on the ink ejection head 61, it is possible to effectively prevent the height position of the ink ejection head 61 from fluctuating. Instead of the ball plunger 636, a tip-round screw or the like may be used.

Industrial Applicability

[0068] The present invention can be applied to a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, a method for adjusting the head unit, a detaching and attaching jig, and an entire replacement method.

Explanation of Reference Numerals

[0069] 5... Base member 6, 6a, 6b, 6c... Head unit 10... (For the head unit) Detaching and attaching jig 61... Ink ejection head 62… Head holder 62a… Holding area 63… Height adjustment mechanism 64… Posture adjustment mechanism 101… Fixture main body part 104… Guide member 105… Slider 321, 331… Printing bar unit 611c… Nozzle surface 620… Holder base 621… First holder member 622… Second holder member 631… (Fourth) movable member 631a… Lower end part (of the fourth movable member) 641… (First) movable member 642… (Second) movable member 643… (Third) movable member 632… Tip round screw (moving part) 633… Movable block (fifth movable member) 634… Contact member (suspension member) 634c… Contact part 636… Ball plunger (restricting member) AX… Rotation axis M… Printing medium NL… Normal line of the (nozzle surface) Y… Arrangement direction Z… Slide direction

Claims

1. A head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, comprising: An ink ejection head having a nozzle surface for ejecting ink; A head holder that detachably holds the ink ejection head in a holding region while being detachably attached to the base member; An attitude adjustment mechanism that rotates the ink ejection head with respect to the head holder about a rotation axis perpendicular to both the surface normal of the nozzle surface and the arrangement direction in a state where the head holder is not attached to the base member, thereby adjusting the attitude of the nozzle surface with respect to the head holder. The head holder has a first holder member provided on one side of the holding region and a second holder member provided on the other side of the holding region in the arrangement direction. The attitude adjustment mechanism includes: A first movable member and a second movable member that are provided so as to be movable forward and backward toward the holding region with respect to the first holder member and project into the holding region to contact the ink ejection head positioned in the holding region; A third movable member that is provided so as to be movable forward and backward toward the holding region with respect to the second holder member while facing an intermediate portion of the first holder member positioned between the first movable member and the second movable member and projects into the holding region to contact the ink ejection head positioned in the holding region. A head unit that adjusts the amount of rotation of the ink ejection head about the rotation axis in accordance with an increase in the protrusion amount of one of the first movable member and the second movable member into the holding region and a decrease in the protrusion amount of the other into the holding region.

2. The head unit according to claim 1, wherein: The attitude adjustment mechanism includes: The ink ejection head is moved toward the second holder member by increasing the protrusion amount of the first movable member and the second movable member into the holding region and decreasing the protrusion amount of the third movable member into the holding region. The ink ejection head is moved toward the first holder member by decreasing the protrusion amount of the first movable member and the second movable member into the holding region and increasing the protrusion amount of the third movable member into the holding region.

3. The head unit according to claim 1 or 2, wherein: A head unit further comprising a height adjustment mechanism for adjusting the height position of the nozzle surface with respect to the head holder by relatively moving the ink ejection head with respect to the head holder in a height direction parallel to the surface normal of the nozzle surface in a state where the head holder is not attached to the base member.

4. The head unit according to claim 3, wherein the head holder has a holder base that is detachable from the base member, the height adjustment mechanism includes a fourth movable member movably attached to the holder base in the height direction, and a moving portion that moves the fourth movable member in the height direction, and by moving the fourth movable member by the moving portion with one end portion of the fourth movable member in contact with the ink ejection head in the height direction, a head unit for adjusting the relative position of the nozzle surface with respect to the head holder in the height direction.

5. A head unit detachably attached to a base member and arranged in a predetermined arrangement direction, an ink ejection head having a nozzle surface for ejecting ink, a head holder that is detachable from the base member while holding the ink ejection head in a holding region, a height adjustment mechanism for adjusting the height position of the nozzle surface with respect to the head holder by moving the ink ejection head with respect to the head holder in a height direction parallel to the surface normal of the nozzle surface in a state where the head holder is not attached to the base member, wherein the head holder has a holder base that is detachable from the base member, the height adjustment mechanism includes a fourth movable member movably attached to the holder base in the height direction, and a moving portion that moves the fourth movable member in the height direction, and by moving the fourth movable member by the moving portion with one end portion of the fourth movable member in contact with the ink ejection head in the height direction, a head unit for adjusting the relative position of the nozzle surface with respect to the head holder in the height direction.

6. The head unit according to claim 4 or 5, wherein the other end portion of the fourth movable member is finished to have an inclined surface that is inclined with respect to the height direction. The moving part is a head unit having an adjusting member that adjusts the position of the fourth movable member in the height direction by moving along a direction orthogonal to the height direction while bringing the tip into sliding contact with the inclined surface.

7. A method for adjusting a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, wherein the head unit has the same configuration as the head unit according to any one of claims 1 to 4, before attaching the head unit to the base member (a) a step of inserting an ink ejection head having a nozzle surface for ejecting ink into a holding region of a head holder; (b1) a step of adjusting the posture of the nozzle surface with respect to the head holder by rotating the ink ejection head inserted into the holding region with respect to the head holder about a rotation axis perpendicular to both the surface normal of the nozzle surface and the arrangement direction; (c) a step of fixing the ink ejection head to the head holder to form the head unit after performing the step (b1); A method for adjusting a head unit, characterized by performing the above steps.

8. A method for adjusting a head unit according to claim 7, before attaching the head unit to the base member (b2) a step of adjusting the height position of the nozzle surface with respect to the head holder by moving the ink ejection head inserted into the holding region with respect to the head holder in a height direction parallel to the surface normal of the nozzle surface; wherein the step (c) is performed after both the step (b1) and the step (b2) are performed.

9. A method for adjusting a head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, wherein the head unit has the same configuration as the head unit according to claim 5 or 6, before attaching the head unit to the base member (a) a step of inserting an ink ejection head having a nozzle surface for ejecting ink into a holding region of a head holder; (b2) a step of adjusting the height position of the nozzle surface with respect to the head holder by moving the ink ejection head inserted into the holding region with respect to the head holder in a height direction parallel to the surface normal of the nozzle surface; (c) a step of fixing the ink ejection head to the head holder to form the head unit after performing the step (b2); A method for adjusting a head unit, characterized by performing

10. The head unit according to claim 3, wherein the head holder has a holder base that is detachable from the base member, the height adjustment mechanism has a fifth movable member that is movably attached to the holder base in the height direction, and a suspension member that is suspended along the holder base while being connected to the ink ejection head by abutting against the upper surface of the fifth movable member attached to the holder base from above. A head unit that adjusts the relative position of the nozzle surface with respect to the head holder in the height direction by displacing the suspension member in the height direction according to the attachment position of the fifth movable member.

11. A head unit that is detachably attached to a base member and arranged in a predetermined arrangement direction, an ink ejection head having a nozzle surface for ejecting ink, a head holder that detachably holds the ink ejection head in a holding region and is detachably attached to the base member, and a height adjustment mechanism that moves the ink ejection head relative to the head holder in a height direction parallel to the surface normal of the nozzle surface with the head holder not attached to the base member, thereby adjusting the height position of the nozzle surface with respect to the head holder. The head holder has a holder base that is detachable from the base member, the height adjustment mechanism has a fifth movable member that is movably attached to the holder base in the height direction, and a suspension member that is suspended along the holder base while being connected to the ink ejection head by abutting against the upper surface of the fifth movable member attached to the holder base from above. A head unit that adjusts the relative position of the nozzle surface with respect to the head holder in the height direction by displacing the suspension member in the height direction according to the attachment position of the fifth movable member.

12. The head unit according to claim 10 or 11, wherein the suspension member has a contact portion that contacts the upper surface of the fifth movable member, and the height adjustment mechanism further has a regulating member that presses the contact portion of the suspension member suspended on the fifth movable member from above to regulate the upward movement of the suspension member.

Images