Printing device

Abstract

To suppress an image formed on a can body from decreasing in quality owing to curing means for curing the image formed on the can body.SOLUTION: A printing device comprises printing means which is arranged opposite an outer peripheral surface of a can body, and print on an outer peripheral surface of the can body in a rotating state, and curing means which is arranged on an opposite side from an installation side of the printing means across the can body, and cures a print image formed on the outer peripheral surface by the printing means. The printing means uses an inkjet head to print on the outer peripheral surface, and the curing means is arranged on the opposite side from the installation side of the inkjet head across the can body.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a printing device. [Background technology]

[0002] Patent document 1 discloses a printing device having a mandrel wheel, a plurality of rotatable mandrels attached to the mandrel wheel, and an inkjet printing station that forms a printed image by inkjet printing on at least the body portion of the outer surface of a seamless can attached to the mandrel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5891602 Summary of the Invention [Problem to be solved by the invention]

[0004] A printing device that prints on a can body may be provided with a printing unit that prints on the can body and a curing unit that cures the image formed on the can body by the printing unit. The curing means uses light, heat, or the like to harden the image, but this light or heat may act on the printing means, causing a risk of degrading the quality of the formed image. An object of the present invention is to suppress deterioration in the quality of an image formed on a can body caused by a curing means for curing an image formed on the can body. [Means for solving the problem]

[0005] For this purpose, the printing device to which the present invention is applicable is a printing device comprising: a printing means that is arranged at a position opposite the outer peripheral surface of the can body and prints on the outer peripheral surface of the rotating can body; and a curing means that is arranged on the opposite side of the can body from the side on which the printing means is installed and curing the printed image formed on the outer peripheral surface by the printing means.

[0006] Here, the printing means may use an inkjet head to print on the outer circumferential surface, and the curing means may be disposed on the opposite side of the can body to the side where the inkjet head is installed. The printing means may print on the outer peripheral surface of the can body from above, and the curing means may curing the printed image from below the can body. The printing means may form the printed image by printing on the outer peripheral surface using a photocurable ink, and the curing means may cure the printed image by irradiating the outer peripheral surface with light. In addition, the curing means may use light or heat to harden the printed image formed on the outer peripheral surface by the printing means, and may further include a shielding member that blocks the light or heat traveling from the curing means to the printing means. The shielding member may also include a portion for transmitting light or heat from the curing means toward the outer circumferential surface. The portion for passing the electrical wire may be constituted by an opening or a notch formed in the shielding member. In addition, the printing means prints on the outer peripheral surface using photocurable ink, and the curing means turns on a light source and irradiates light onto the outer peripheral surface through the passage portion, and if the can body is not present at a position opposite the passage portion, may turn off the light source or reduce the output of the light source. The shielding member may be provided in plurality, and a gap may be provided between one of the shielding members and another of the shielding members to direct light or heat from the curing means toward the outer circumferential surface. In addition, the printing means prints on the outer peripheral surface using photocurable ink, and the curing means turns on a light source and irradiates light onto the outer peripheral surface through the gap, and if the can body is not present at a position opposite the gap, turns off the light source or reduces the output of the light source. In addition, the can body may be formed in a cylindrical shape and have an axis, and the shielding member may be positioned on the printing means side of an opposing portion of the outer peripheral surface of the can body that faces the hardening means, and may be positioned on the hardening means side of an opposite portion of the outer peripheral surface that is located on the opposite side of the axis from the opposing portion.

[0007] From another perspective, a printing device to which the present invention can be applied is a printing device that includes a printing means that is arranged opposite the outer peripheral surface of a can body and prints on the outer peripheral surface of the rotating can body, a curing means that is arranged opposite the outer peripheral surface of the can body and uses light or heat to curing the printed image formed on the outer peripheral surface by the printing means, and a shielding member that blocks the light or heat directed from the curing means to the printing means.

[0008] Here, the device may further comprise a moving means for moving the shielding member. In addition, at least two positions are set: a shielding position that blocks the light or heat and is located on the movement path of the can body, and an off-path position that is a position off the movement path, and the moving means may move the shielding member from one of the shielding position and the off-path position to the other position, and move the shielding member from the other position to the one position. Effect of the Invention

[0009] According to the present invention, it is possible to suppress deterioration in the quality of the image formed on the can body caused by a curing means that cures the image formed on the can body. [Brief description of the drawings]

[0010] [Figure 1] FIG. [Diagram 2] FIG. 2 is a diagram illustrating an inspection device. [Diagram 3] 13(A) and 13(B) are diagrams showing the structure of a portion where a fourth ink-jet head is provided. [Figure 4]13(A) to 13(C) are diagrams showing other examples of the structure of the portion where the fourth ink-jet head is provided. [Diagram 5] 6(A) to 6(C) are diagrams showing other configuration examples of the shielding member. [Figure 6] 13(A) to 13(C) are diagrams showing other configuration examples. [Figure 7] 13(A) to 13(C) are diagrams showing other configuration examples. [Figure 8] 13(A) and 13(B) are diagrams illustrating other movements of the first and second shielding members. [Figure 9] 13A and 13B are diagrams showing other configuration examples. [Figure 10] 13A and 13B are diagrams showing other configuration examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view of a printing device 500. The printing apparatus 500 is provided with a can body supplying section 510 to which the can bodies 10 are supplied. In this can body supplying section 510, the can bodies 10 are supplied (attached) to a support member 20 that supports the can bodies 10. Specifically, the support member 20 is formed in a cylindrical shape, and the can body 10 is supplied to the support member 20 by inserting the support member 20 into the cylindrical can body 10 .

[0012] Furthermore, the can body supply section 510 is provided with an inspection device 92 . In the inspection device 92, an inspection is performed to check whether the can body 10 is deformed or not. More specifically, the inspection device 92 is provided with a light source 92A, as shown in FIG. 2 (a diagram for explaining the inspection device 92). The light source 92A is provided on one end side of the can body 10, and emits laser light that travels along the outer circumferential surface of the can body 10 and along the axial direction of the can body 10. Furthermore, a light receiving unit 92B that receives the laser light from the light source 92A is provided on the other end side of the can body 10.

[0013] When a part of the can body 10 is deformed as shown by the reference symbol 3A, the laser light is blocked and the laser light is not received by the light receiving section 92B. In this way, the deformation of the can body 10 is detected. In this embodiment, if the inspection device 92 determines that the can body 10 does not satisfy the predetermined conditions (if the can body 10 is determined to be deformed), the discharge mechanism 93 (see Figure 1) discharges the can body 10 outside the printing device 500.

[0014] The discharge mechanism 93 is disposed between the inspection device 92 and the inkjet printing unit 700 (disposed upstream of the inkjet printing unit 700). In this embodiment, the deformed can body 10 is ejected from the printing device 500 before image formation by the inkjet printing unit 700.

[0015] In the discharge mechanism 93, compressed air is supplied to the inside of the support member 20 formed in a cylindrical shape, and the can body 10 moves in the axial direction (the direction perpendicular to the plane of the paper in FIG. 1). Furthermore, the bottom of the can body 10 is sucked by a suction member (not shown). Then, the can body 10 is transported to the outside of the printing apparatus 500 by this suction member, and the can body 10 is discharged to the outside of the printing apparatus 500.

[0016] An inkjet printing unit 700 is provided downstream of the discharge mechanism 93 . The inkjet printing section 700 uses an inkjet printing method to form an image on the can body 10 moving from the upstream side. In addition, in this embodiment, when an image is formed by the inkjet printing section 700, the moving unit 550 moves sequentially from the upstream side of the inkjet printing section 700 toward the inkjet printing section 700 (see arrow 1A). In this embodiment, an image is formed on the can body 10 on the moving unit 550 by the inkjet printing unit 700.

[0017] Here, image formation by the inkjet printing method refers to image formation performed by ejecting ink from the inkjet head 11 and depositing the ink on the can body 10. In forming an image by inkjet printing, a known method can be used, such as a piezo method, a thermal (bubble) method, a continuous method, etc.

[0018] The protective layer forming unit 770 is disposed downstream of the inkjet printing unit 700 . The protective layer forming unit 770 applies a transparent paint onto the image formed by the inkjet printing unit 700, and forms a transparent layer that covers the image. As a result, in this embodiment, a transparent protective layer is formed on the outermost layer of the can body 10.

[0019] Downstream of the protective layer forming section 770, a removing section 780 where the can body 10 is removed from the support member 20 is provided. In this removal section 780, the can body 10 is removed from the support member 20, and the can body 10 is ejected to the outside of the printing apparatus 500. Furthermore, the printing apparatus 500 is provided with a plurality of moving units 550 as an example of a moving body that moves while supporting the can bodies 10.

[0020] In this embodiment, a support member 20 for supporting the can body 10 is attached to the moving unit 550 as indicated by the reference symbol 1X, and the can body 10 moves together with the moving unit 550. In this embodiment, the moving unit 550 supports one can body 10, but the moving unit 550 may support a plurality of can bodies 10. The support member 20 is formed in a cylindrical shape and is provided in a state in which it can rotate in the circumferential direction. In this embodiment, the can body 10 is supported by the support member 20 which can rotate in the circumferential direction, so that the can body 10 is also supported in a state in which it can rotate in the circumferential direction.

[0021] The can body 10 is formed in a cylindrical shape and has an opening 10B at one end. The other end of the can body 10 is closed and has a bottom. The support member 20 is inserted into the can body 10 from the opening 10B. Furthermore, in this embodiment, there is provided a moving mechanism 560 that functions as a moving means for moving the moving unit 550. The moving mechanism 560 is provided with an annular guide member 561 that guides the moving unit 550.

[0022] Each of the moving units 550 is guided by a guide member 561 and moves circularly along a predetermined circular moving path 800 . Accordingly, in this embodiment, the support member 20 provided on the moving unit 550 and the can body 10 supported by this support member 20 also move along a predetermined circular movement path 800.

[0023] The movement path 800 is disposed such that its axis 800C is along the horizontal direction. In other words, the movement path 800 is disposed around the axis 800C along the horizontal direction. Here, the axis 800C extends in a direction perpendicular to the plane of the paper of FIG. In this case, in this embodiment, the support member 20 and the can body 10 make a circular movement about this axial center 800C that extends in a direction perpendicular to the paper surface in the figure.

[0024] The movement path 800 is provided with a first linear portion 810 which is a linear movement path, and a second linear portion 820 which is also a linear movement path. Each of the first linear portion 810 and the second linear portion 820 is disposed so as to extend along the horizontal direction. The first linear portion 810 and the second linear portion 820 are disposed so as to be substantially parallel to each other. Furthermore, in this embodiment, the first linear portion 810 is disposed above the second linear portion 820.

[0025] Furthermore, the first straight portion 810 is provided in an uppermost portion of the circular movement path 800 , and the second straight portion 820 is provided in a lowermost portion of the circular movement path 800 . Furthermore, in this embodiment, an inkjet printing unit 700 is provided above this first linear portion 810 located at the top.

[0026] Furthermore, the movement path 800 is provided with a first curved portion 830 and a second curved portion 840 that have a curvature and are formed to describe a circular arc. The first curved portion 830 connects the right end of the first straight portion 810 and the right end of the second straight portion 820. The first curved portion 830 is formed so as to extend from above toward below. The second curved portion 840 connects the left end of the first straight portion 810 and the left end of the second straight portion 820. The second curved portion 840 is formed so as to extend from the bottom toward the top.

[0027] The inkjet printing unit 700 will now be described. The inkjet printing unit 700 is disposed above the first linear portion 810 and forms an image on the can body 10 located on the first linear portion 810. The inkjet printing unit 700 is provided with a plurality of inkjet heads 11 arranged side by side in the left-right direction in the figure.

[0028] Specifically, the inkjet printing unit 700 is provided with a first inkjet head 11C that ejects cyan ink, a second inkjet head 11M that ejects magenta ink, a third inkjet head 11Y that ejects yellow ink, and a fourth inkjet head 11K that ejects black ink. In the following description, when there is no need to distinguish between the first inkjet head 11C to the fourth inkjet head 11K, they will simply be referred to as "inkjet heads 11."

[0029] In this embodiment, an example is given in which four inkjet heads 11 are provided, but further inkjet heads 11 for ejecting ink of a special color such as a corporate color, and inkjet heads 11 for forming a white layer may be provided. Here, the four inkjet heads 11, the first inkjet head 11C to the fourth inkjet head 11K, form an image on the can body 10 using ultraviolet-curable ink. In other words, the four inkjet heads 11 form images on the can body 10 using photocurable ink that hardens when irradiated with light such as ultraviolet light.

[0030] In this embodiment, the can body 10 moves in a lying state (the can body 10 moves with the axial direction of the can body 10 in a horizontal state), and a part of the outer circumferential surface of the can body 10 faces upward in the vertical direction. In this embodiment, ink is ejected downward from above the outer circumferential surface to form an image on the outer circumferential surface of the can body 10.

[0031] In this embodiment, the moving unit 550 stops below each inkjet head 11, and ink is ejected onto the can body 10 on the moving unit 550, thereby forming an image on the can body 10. Then, in this embodiment, when image formation on the can body 10 is completed, the moving unit 550 moves toward the inkjet head 11 located one downstream, and the inkjet head 11 further forms an image on the can body 10.

[0032] Furthermore, in this embodiment, the four inkjet heads 11 are arranged side by side in the moving direction of the can body 10. Also, each of the four inkjet heads 11 is arranged along a direction perpendicular to (intersecting with) the moving direction of the can body 10. In this embodiment, while the can body 10 passes below the four inkjet heads 11, ink is ejected onto the can body 10 from above, and a printed image is formed on the can body 10.

[0033] More specifically, in this embodiment, the moving unit 550 stops at the installation locations of each of the multiple inkjet heads 11 provided. Then, each inkjet head 11 ejects ink onto the can body 10, forming an image on the can body 10. When each inkjet head 11 forms an image, the can body 10 rotates in the circumferential direction.

[0034] In this embodiment, a driving source (not shown), such as a servo motor, for rotating the can body 10 is provided at each of the stopping points where the moving unit 550 stops. In this embodiment, when each of the moving units 550 reaches the stop position, the moving unit and the drive source are connected, and a rotational drive force is transmitted to the support member 20. This causes the support member 20 to rotate, and accordingly, the can body 10 rotates in the circumferential direction.

[0035] Drive sources are also provided in other locations, such as the inspection device 92 and the protective layer forming section 770, and in these inspection device 92, protective layer forming section 770, etc., the can body 10 is rotated by the drive source. Alternatively, each of the moving units 550 may be provided with a drive source, and the can body 10 may be rotated by the drive source provided in each of the moving units 550.

[0036] Furthermore, although not shown in FIG. 1, in this embodiment, a light irradiation unit 750 (described later) is provided at each of the locations where the four inkjet heads 11 are installed. In this embodiment, the light irradiation unit 750 irradiates the outer peripheral surface of the can body 10 with light having a wavelength in the ultraviolet range (hereinafter, sometimes referred to as "ultraviolet light"), hardening the image formed on the outer peripheral surface of the can body 10.

[0037] Each of the mobile units 550, which is an example of a mobile object, moves at a predetermined moving speed. Moreover, each of the moving units 550 stops at the can body supply section 510, the discharge mechanism 93, each of the inkjet heads 11, the protective layer forming section 770, and the removing section 780, respectively.

[0038] Furthermore, at locations where the inspection device 92, the inkjet heads 11, the protective layer forming section 770, etc. are installed, the can body 10 on the moving unit 550 rotates in the circumferential direction at a predetermined rotation speed. Furthermore, in the printing apparatus 500 of this embodiment, the number of moving units 550 installed is greater than the number of can bodies 10 positioned within the printing apparatus 500. Furthermore, the moving units 550 move around the axial center 800C.

[0039] An electromagnet (not shown) is provided inside an annular guide member 561 that guides the moving unit 550. Furthermore, the moving unit 550 is provided with a permanent magnet (not shown). In this embodiment, a linear mechanism is used to move the moving unit 550. The movement of the moving unit 550 is not limited to a linear mechanism, and may be performed using other known mechanisms. For example, each of the moving units 550 may be provided with a driving source such as a motor, so that each of the moving units 550 moves by itself.

[0040] The printing device 500 of this embodiment is provided with a control unit 900 that controls each part of the printing device 500. The control unit 900 controls the supply of electricity to the electromagnets described above to generate a magnetic field and move each of the moving units 550. The control unit 900 is configured with a program-controlled CPU (Central Processing Unit).

[0041] 1, the moving unit 550 is provided with a base portion 551 that is guided by a guide member 561. A permanent magnet (not shown) is provided on the base portion 551. In this embodiment, a magnetic field generated by an electromagnet provided on the guide member 561 and a permanent magnet provided on the base portion 551 of the moving unit 550 generate a propulsive force in the moving unit 550, causing the moving unit 550 to move along the circular moving path 800.

[0042] Furthermore, the moving unit 550 of this embodiment is provided with a cylindrical support member 20 that supports the can body 10, and a fixing member 553 for fixing the support member 20 to the base portion 551, as shown by the reference symbol 1X. The fixing member 553 is provided in a form that stands up from the base portion 551.

[0043] The support member 20 of this embodiment is formed in a cylindrical shape, and is inserted into the can body 10 through an opening 10B formed in the can body 10 to support the can body 10. The support member 20 is also arranged in a lying state (along the horizontal direction). As a result, in this embodiment, the can body 10 is also arranged in a lying state. In this embodiment, when the can body 10 reaches each inkjet head 11, ink is ejected from each inkjet head 11 onto the can body 10 located below. As a result, an image is formed on the outer peripheral surface of the can body 10.

[0044] In this embodiment, the moving unit 550 stops every time it reaches under each inkjet head 11. In other words, the moving unit 550 stops at each of the predetermined stopping points. In this embodiment, an image is then formed on the outer circumferential surface of the can body 10 held by the moving unit 550 that has stopped at this predetermined stopping point by the inkjet head 11, which is an example of a printing means.

[0045] More specifically, at each installation location of the inkjet head 11, ink is ejected from the inkjet head 11 while the support member 20 (can body 10) rotates in the circumferential direction, and a printed image is formed on the outer peripheral surface of the can body 10. In this embodiment, when the support member 20 rotates 360° after the ink ejection starts, The ejection of the ink stops. As a result, a printed image is formed over the entire outer circumferential surface of the can body 10 in the circumferential direction.

[0046] In this embodiment, the support member 20 shown in Fig. 1 is disposed along a direction perpendicular to the plane of the paper of Fig. 1. In other words, the support member 20 is disposed so as to extend along the horizontal direction. Also, the support member 20 is disposed along a direction perpendicular to (intersecting with) the movement direction of the moving unit 550. However, the supporting member 20 is not limited to this, and may be arranged along the movement direction of the moving unit 550. In this case, the inkjet head 11 is also arranged along the movement direction of the moving unit 550.

[0047] In this embodiment, the inkjet head 11 is positioned above the can body 10, and ink is ejected onto the can body 10 from above. In this case, the effect of gravity acting on the ink droplets ejected from the inkjet head 11 can be reduced compared to when the inkjet head 11 is positioned to the side of or below the can body 10, thereby improving the accuracy of the ink deposition position on the can body 10.

[0048] 3(A) and (B) are diagrams showing the structure of the portion where the fourth ink-jet head 11K is provided. More specifically, Fig. 3(A) is a diagram of the moving unit 550 and the fourth ink-jet head 11K as viewed from the direction indicated by the arrow IIIA in Fig. 1. Fig. 3(B) is a diagram of the can body 10, the fourth ink-jet head 11K, etc. as viewed from the direction indicated by the arrow IIIB in Fig. 3(A). In this embodiment, the configurations at the locations where the first ink-jet head 11C (see FIG. 1) to the third ink-jet head 11Y are installed are also the same as the configuration shown in FIG.

[0049] In this embodiment, the fourth inkjet head 11K, an example of a printing means, is positioned opposite the outer peripheral surface 10A of the can body 10 and ejects ink onto the outer peripheral surface 10A of the rotating can body 10 to perform printing on this outer peripheral surface 10A. The fourth inkjet head 11K is disposed along the axial direction of the can body 10 and above the can body 10, as shown in FIG. 3(A).

[0050] Furthermore, in this embodiment, a light irradiation section 750 as an example of a curing means is provided on the side opposite to the side where the fourth inkjet head 11K is installed across the can body 10. The light irradiation section 750 includes a light source 750A that emits ultraviolet light, and irradiates the ultraviolet light, as an example of light, onto the outer peripheral surface 10A of the can body 10 on which a print image has been formed by the fourth inkjet head 11K. This hardens the print image on the outer peripheral surface 10A. The light irradiation section 750 is disposed below the can body 10 and irradiates ultraviolet light upward, thereby hardening the printed image from below the can body 10.

[0051] In this embodiment, the ultraviolet light emitted from the light irradiating section 750 is blocked by the can body 10, and the ultraviolet light is less likely to reach the fourth inkjet head 11K. In other words, in this embodiment, as shown in FIG. 3(B), the can body 10 is positioned between the light irradiation section 750 and the fourth inkjet head 11K, making it difficult for the ultraviolet light from the light irradiation section 750 to reach the fourth inkjet head 11K. This reduces the likelihood of clogging of the fourth inkjet head 11K, which would otherwise occur if ultraviolet light were to reach the fourth inkjet head 11K.

[0052] Furthermore, in this embodiment, as shown in FIG. 3(B), when the can body 10 is located opposite the light irradiation unit 750, the light irradiation unit 750 turns on the light source 750A and irradiates the outer peripheral surface 10A of the can body 10 with light. More specifically, in this embodiment, a sensor (not shown) is provided to detect the presence of the can body 10 in a position opposite the light irradiation unit 750, and when the can body 10 is detected by this sensor, the light irradiation unit 750 turns on the light source 750A.

[0053] In other words, when the can body 10 is not present in a position facing the light source 750A, the light irradiation section 750 turns off the light source 750A or reduces the output of the light source 750A. More specifically, when the can body 10 is not detected by the sensor, the light irradiation unit 750 turns off the light irradiation unit 750 or reduces the output of the light source 750A. When there is no can body 10 facing the light source 750A, if the light source 750A is turned off or the output of the light source 750A is reduced, the ultraviolet light will not reach the fourth inkjet head 11K.

[0054] [Other configuration examples] 4(A) to 4(C) are diagrams showing other configuration examples of the portion where the fourth inkjet head 11K is provided, where Fig. 4(C) is a diagram of the shielding member 400 as viewed from the direction indicated by the arrow IVC in Fig. 4(A). In this configuration example, a shielding member 400 is provided to shield the light emitted from the light emitting section 750 toward the fourth inkjet head 11K. In this embodiment, the shielding member 400 reduces the ultraviolet light passing through both sides of the can body 10 shown in FIG. 4(B) toward the fourth ink-jet head 11K.

[0055] As shown in FIGS. 4(A) and 4(B), the shielding member 400 is provided between the light emitting section 750 and the fourth inkjet head 11K. 4(B), the shielding member 400 is formed in a plate shape and is disposed beside and along the moving path of the can body 10. The shielding member 400 is disposed between the moving path of the can body 10 and the light irradiation unit 750.

[0056] Here, there is no particular limitation on the shape and material of the shielding member 400. The shielding member 400 is not limited to a plate shape, and may be formed into a sheet shape. The shielding member 400 is made of a metal material or a resin material. In this embodiment, the shielding member 400 further reduces the amount of light traveling from the light emitting section 750 to the fourth inkjet head 11K.

[0057] As shown in Figures 4(A) to (C), the shielding member 400 is provided with a portion 410 (hereinafter referred to as the "light transmitting portion 410") for transmitting light directed from the light irradiating section 750 toward the outer peripheral surface 10A of the can body 10. 4(B), the light transmitting portion 410 is located on a straight line CH connecting the light source 750A and the axis G of the can body 10. In other words, the light transmitting portion 410 is located on the optical path of the ultraviolet light traveling from the light source 750A to the can body 10. Furthermore, in this embodiment, when the light transmitting portion 410 is taken as the starting point, the shielding member 400 is disposed so as to extend toward both the upstream side and the downstream side in the moving direction of the can body 10.

[0058] In this embodiment, the light emitted from the light source 750A of the light irradiation unit 750 passes through the light transmitting portion 410 toward the outer peripheral surface 10A of the can body 10, and is irradiated onto this outer peripheral surface 10A. As a result, the printed image on the outer peripheral surface 10A of the can body 10 is cured, as described above. In this embodiment, the light transmitting portion 410 is configured by an opening (through hole) 411 formed in the shielding member 400, as shown in FIG. 4(C). 4(A) and (C), the opening 411 is formed along the axial direction of the can body 10. In this embodiment, the dimension of the opening 411 in the longitudinal direction is greater than the dimension of the can body 10 in the longitudinal direction.

[0059] Even in the configuration example shown in Figure 4, when a can body 10 is located opposite the light irradiation unit 750, as shown in Figure 4 (B), the light irradiation unit 750 turns on the light source 750A and irradiates light onto the outer peripheral surface 10A of the can body 10 through the light transmission portion 410. More specifically, in this configuration example, a sensor (not shown) is provided to detect the presence of the can body 10 in a position opposite the light irradiation unit 750, and when the can body 10 is detected by this sensor, the light irradiation unit 750 turns on the light source 750A.

[0060] On the other hand, when the can body 10 is not present at a position facing the light transmitting portion 410, the light irradiation section 750 turns off the light source 750A or reduces the output of the light source 750A. More specifically, when the can body 10 is not detected by the sensor, the light irradiation unit 750 turns off the light irradiation unit 750 or reduces the output of the light source 750A. In this embodiment, the light-transmitting portion 410 is configured by the opening 411. However, the light-transmitting portion 410 is not limited to an opening, and may be configured by a notch 412 formed in the shielding member 400, as shown in (C) of FIG. 5 (a diagram showing another example of the configuration of the shielding member 400).

[0061] 6(A) to (C) are diagrams showing other configuration examples. In this configuration example, there are provided a plurality of shielding members 400. Specifically, as shown in Figures 6(B) and (C), a first shielding member 421 and a second shielding member 422 are provided as the shielding members 400. As shown in FIG. 6(B), in the movement direction of the can body 10, the first shielding member 421 and the second shielding member 422 are disposed with their installation positions shifted from each other.

[0062] Specifically, in this embodiment, the first shielding member 421 is disposed upstream of the second shielding member 422 in the movement direction of the can body 10. In addition, in this configuration example, as shown in Figures 6 (B) and (C), a gap 423 is provided between the first shielding member 421 and the second shielding member 422 to direct light from the light irradiation section 750 toward the outer peripheral surface 10A of the can body 10.

[0063] In this embodiment, as shown in Fig. 6(B), this gap 423 is located on a straight line CH connecting the light source 750A and the axis G of the can body 10. In other words, this gap 423 is located on the optical path of the ultraviolet light traveling from the light source 750A to the can body 10. Furthermore, in this embodiment, when gap 423 is taken as the starting point, first shielding member 421 extends toward the upstream side in the movement direction of can body 10, and second shielding member 422 extends toward the downstream side in the movement direction of can body 10.

[0064] In this configuration example as well, when the can body 10 is located opposite the light irradiating unit 750, the light irradiating unit 750 turns on the light source 750A and irradiates the outer circumferential surface 10A of the can body 10 with light through the gap 423. More specifically, as described above, the light irradiation unit 750 turns on the light source 750A when the can body 10 is detected by the sensor. Also, when the can body 10 is not present at the position opposite the gap 423, the light irradiation unit 750 turns off the light source 750A or reduces the output of the light source 750A. As a result, in this configuration example as well, while the can body 10 can be irradiated with ultraviolet light, if the can body 10 is not present at a position opposite the gap 423, the ultraviolet light is less likely to reach the fourth inkjet head 11K.

[0065] 7(A) to (C) are diagrams showing other configuration examples. In this configuration example, similarly to the above, a first shielding member 421 and a second shielding member 422 are provided as the shielding member 400. In this configuration example, as shown in Fig. 7(B), the can body 10 is positioned between the first shielding member 421 and the second shielding member 422. 4 to 6, shielding member 400 was provided on the side of the movement path of can body 10, but in this configuration example, as shown in Fig. 7(B), shielding member 400 is provided on the movement path of can body 10. In other words, in this configuration example, a first shielding member 421 and a second shielding member 422 are provided on the movement path of can body 10, as shown in Fig. 7(B).

[0066] In this configuration example, the portion indicated by reference symbol 10X in FIG. 7(B) is a facing portion 10E of the outer circumferential surface 10A of the can body 10 that faces the light irradiation portion 750. In this embodiment, the portion indicated by the reference symbol 10Y is an opposite side portion 10F of the outer circumferential surface 10A of the can body 10, which is located on the opposite side to the opposing portion 10E with the axis G being sandwiched therebetween. The can body 10 of this embodiment is formed in a cylindrical shape and has an axis G. In this embodiment, an opposite portion 10F is located on the opposite side of the axis G from the facing portion 10E.

[0067] 7(B), in this configuration example, the first shielding member 421 and the second shielding member 422 are disposed closer to the fourth inkjet head 11K than the facing portion 10E. Also, the first shielding member 421 and the second shielding member 422 are disposed closer to the light irradiation unit 750 than the opposite side portion 10F. Furthermore, in this configuration example, as shown in Fig. 7(C), a moving mechanism 600 is provided as an example of a moving means for moving the first shielding member 421 and the second shielding member 422. As shown in Fig. 7(C), this moving mechanism 600 moves the first shielding member 421 and the second shielding member 422 along the axial direction of the can body 10.

[0068] In this embodiment, the installation positions of the first shielding member 421 and the second shielding member 422 are set to a shielding position 610 that is located on the movement path of the can body 10 and blocks light from the light irradiation section 750, as shown in Figure 7 (C). In this embodiment, as shown in FIG. 7(C), an off-path position 620 that is a position off the movement path of the can body 10 is set.

[0069] The movement mechanism 600 moves the first shielding member 421 and the second shielding member 422 from one of the shielding position 610 and the off-path position 620 to the other position. The movement mechanism 600 also moves the first shielding member 421 and the second shielding member 422 from the other position to the one position. More specifically, when the can body 10 is transported to a position facing the light irradiation unit 750, the movement mechanism 600 positions the first shielding member 421 and the second shielding member 422 at an off-path position 620.

[0070] Then, when can body 10 stops at a position facing light irradiation section 750 , movement mechanism 600 moves first shielding member 421 and second shielding member 422 to shielding position 610 . Thereafter, in this embodiment, with the first shielding member 421 and the second shielding member 422 positioned at the shielding position 610, image formation on the can body 10 and irradiation of the can body 10 with ultraviolet light are performed. Thereafter, in this embodiment, the movement mechanism 600 moves the first shielding member 421 and the second shielding member 422 to an off-path position 620. As a result, first shielding member 421 and second shielding member 422 are positioned out of the movement path of can body 10. Thereafter, can body 10 is transported downstream.

[0071] In the configuration example shown in Figure 7, a case is described in which the first shielding member 421 and the second shielding member 422 move in the axial direction of the can body 10 to a position off the movement path of the can body 10. However, the present invention is not limited to this, and the first shielding member 421 and the second shielding member 422 may be moved as shown in FIG. 8 (a diagram showing another movement of the first shielding member 421 and the second shielding member 422).

[0072] In this configuration example shown in FIG. 8, first shielding member 421 and second shielding member 422 are moved in a direction perpendicular to (intersecting with) the axial direction of can body 10. In addition, in this configuration example, as shown by the symbol 8A in Figures 8(A) and (B), the first shielding member 421 and the second shielding member 422 are moved to a location on the side where the light irradiation section 750 is provided and away from the movement path of the can body 10.

[0073] In addition, when moving the first shielding member 421 and the second shielding member 422 in a direction perpendicular to the axial direction of the can body 10, they may be moved toward the side where the fourth inkjet head 11K is provided, as shown by arrow 8B in Figure 8(A). Alternatively, one of the first shielding member 421 and the second shielding member 422 may be moved toward the light irradiation section 750, and the other may be moved toward the fourth inkjet head 11K.

[0074] 9(A) and (B) are diagrams showing other configuration examples, with Fig. 9(B) showing the state when the can body 10 and the like are viewed from the direction indicated by the arrow IXB in Fig. 9(A). In this configuration example, as shown in Fig. 9(B), a plurality of inkjet heads 11 are arranged radially. Also, in this configuration example, as shown in Fig. 9(A), the can body 10 moves along the longitudinal direction of the inkjet heads 11. In this configuration example, the can body 10 moves along the axial direction of the can body 10 in the printing device 500 shown in Fig. 1. Also, in this configuration example, each inkjet head 11 is arranged along the axial direction of the can body 10.

[0075] Furthermore, in this configuration example, as shown in FIG. 9(B), a light irradiation section 750 is provided on the side opposite to the side on which the inkjet heads 11 are installed, with the can body 10 sandwiched therebetween. In this configuration example as well, the light from the light emitting section 750 is blocked by the can body 10, and the amount of ultraviolet light traveling from the light emitting section 750 to the multiple inkjet heads 11 is reduced.

[0076] Also in this configuration example, when the can body 10 is located opposite the light irradiation section 750, the light source 750A of the light irradiation section 750 is turned on, similarly to the above. Furthermore, when the can body 10 is not positioned opposite the light irradiation section 750, the light source 750A of the light irradiation section 750 is turned off or the output of the light source 750A is reduced.

[0077] Furthermore, in this configuration example, in order to avoid interference between the light irradiation unit 750 and the base unit 551 (see FIG. 9(A)), when the can body 10 (moving unit 550) moves downstream from the position facing the light irradiation unit 750, the light irradiation unit 750 is moved to a position indicated by the symbol 9X in FIG. 9(B). Specifically, the light irradiation unit 750 is moved to a position off the movement path of the moving unit 550. Furthermore, in this embodiment, when the light irradiation section 750 is located at a position outside the movement path of the moving unit 550, the light source 750A of the light irradiation section 750 is turned off or the output of the light source 750A is reduced.

[0078] As shown in FIG. 1, the inkjet heads 11 may be arranged at staggered positions in the direction of movement of the can body 10, or as shown in FIG. 9, multiple inkjet heads 11 may be provided at one location. In addition, in FIG. 9, a shielding member 400 is not installed, but similar to the configuration example shown in FIG. 4, a shielding member 400 having a light transmitting portion 410 may be placed between the light irradiation section 750 and the can body 10.

[0079] Also in this configuration example shown in FIG. 9, any of the shielding members 400 shown in FIGS. 5 to 8 may be provided. When installing any of the shielding members 400 shown in Figures 4 to 6, in order to avoid interference between the moving unit 550 and the shielding member 400, the shielding member 400 is moved to a location off the movement path of the moving unit 550 when the moving unit 550 moves downstream, similar to the above-mentioned light irradiation section 750 (light irradiation section 750 indicated by symbol 9X).

[0080] In the configuration example shown in FIG. 9, when the first shielding member 421 and the second shielding member 422 shown in FIGS. 7 and 8 are installed, it is not necessary to move the first shielding member 421 and the second shielding member 422. In this configuration example shown in Figure 9, when the first shielding member 421 and the second shielding member 422 shown in Figures 7 and 8 are installed, the first shielding member 421 and the second shielding member 422 will not be located on the movement path of the can body 10, but will be located to the side of the movement path. In this case, even if first shielding member 421 and second shielding member 422 are not moved, interference between first shielding member 421 and second shielding member 422 and can body 10 can be avoided.

[0081] In the configuration example shown in FIG. 9, a case has been described in which the can body 10 is moved along the axial direction of the can body 10, and a plurality of inkjet heads 11 are arranged along this movement direction. Here, even when multiple inkjet heads are individually provided as shown in FIG. 1, the can body 10 may be moved along the axial direction of the can body 10, and each inkjet head 11 may be arranged along this movement direction.

[0082] 10(A) and (B) are diagrams showing other configuration examples. In this configuration example, similarly to the configuration example shown in FIG. 9, the can body 10 moves along its axial direction, and a plurality of inkjet heads 11 are provided along the axial direction of the can body 10. In this configuration example, as shown in FIG. 10(A), four inkjet heads 11 are arranged radially, and a light irradiation unit 750 is provided beside the four inkjet heads 11.

[0083] More specifically, in this configuration example, a light irradiation unit 750 is provided beside the four inkjet heads 11 and downstream of the four inkjet heads 11 in the rotation direction of the can body 10. The light irradiation section 750 is not limited to being provided on the side opposite the inkjet head 11 across the can body 10, but may be provided next to the inkjet head 11 as in this configuration example. 10(A), the four inkjet heads 11 and the light irradiation unit 750 are all disposed above a horizontal plane H passing through an axis G of the can body 10. In this configuration example, the light irradiation unit 750 is provided to the side of the four inkjet heads 11.

[0084] Furthermore, in this configuration example, a shielding member 400 is provided between the four inkjet heads 11 and the light irradiation unit 750, extending along the axial direction of the can body 10 and extending along the radial direction of the can body 10. In this embodiment as well, the shielding member 400 reduces the amount of ultraviolet light emitted from the light emitting section 750 toward the inkjet head 11 .

[0085] In this specification, the term "ultraviolet light directed from the light emitting section 750 to the inkjet head 11" is not limited to ultraviolet light directed directly from the light emitting section 750 to the inkjet head 11. The "ultraviolet light directed from the light irradiation unit 750 to the inkjet head 11" also includes ultraviolet light reflected by the surface of the can body 10 or by other members other than the can body 10 and directed to the inkjet head 11. In addition, "the shielding member 400 shields ultraviolet light" does not only mean that ultraviolet light traveling directly from the light irradiation unit 750 to the inkjet head 11 is shielded by the shielding member 400. "The shielding member 400 shields ultraviolet light" also includes the shielding member 400 shielding ultraviolet light that is reflected by the surface of the can body 10 or other members and then travels toward the inkjet head 11.

[0086] FIG. 10B is a diagram showing another example of the configuration of the installation portion of one inkjet head 11 when the four inkjet heads 11 are arranged at different positions from one another as in FIG. Specifically, Fig. 10B shows another example of the configuration of the installation portion of the fourth ink-jet head 11K. Note that the configurations of the first ink-jet head 11C to the third ink-jet head 11Y are the same as the configuration shown in Fig. 10B.

[0087] In this configuration example, the light irradiator 750 is provided beside the fourth inkjet head 11K. In other words, the light irradiator 750 is provided downstream of the fourth inkjet head 11K in the rotation direction of the can body 10. Furthermore, in this configuration example as well, a shielding member 400 is provided between the fourth inkjet head 11K and the light irradiation unit 750, extending along the axial direction of the can body 10 and extending along the radial direction of the can body 10. In this embodiment as well, the shielding member 400 reduces the ultraviolet light emitted from the light emitting section 750 toward the fourth inkjet head 11K.

[0088] (others) In the above, an example has been described in which a printed image is formed on the outer peripheral surface 10A of the can body 10 using photocurable ink, and then the printed image is cured by irradiating it with light (ultraviolet light). However, without being limited to this, in each of the configuration examples shown in Figures 3 to 10, a thermosetting ink may be ejected onto the outer peripheral surface 10A of the can body 10 using an inkjet head 11 to form a printed image on this outer peripheral surface 10A. In this case, a heat source is provided instead of the light irradiating unit 750 in each of the configuration examples shown in FIGS.

[0089] In this case, the printed image formed on the outer peripheral surface 10A of the can body 10 is hardened by the heat from the heat source. In this case, the can body 10 positioned between the heat source and the inkjet head 11 and the shielding member 400 positioned between the heat source and the inkjet head 11 reduce the heat flowing from the heat source to the inkjet head 11. This makes it possible to prevent problems such as clogging caused by hardening of the ink in the inkjet head 11 from occurring.

[0090] In the above, the printed image is formed on the can body 10 using the inkjet head 11, but the formation of the printed image is not limited to the inkjet head 11 and may be performed using a printing method using a plate such as a relief printing press. In other words, the printing means for printing on the can body 10 is not limited to printing means that uses an inkjet head printing method, and printing means that uses a plate-type printing method may also be used.

[0091] In this case as well, if a light irradiating unit 750 and a heat source are provided on the opposite side of the can body 10 from the printing means, hardening of the ink in the printing means can be suppressed. Also in this case, if any of the shielding members 400 shown in Figs. 4 to 8 and 10 is provided, the light and heat directed toward the printing means is reduced, and hardening of the ink in the printing means is suppressed. [Explanation of symbols]

[0092] Reference Signs List 10: can body, 10A: outer circumferential surface, 10E: opposing portion, 10F: opposite side portion, 11: inkjet head, 400: shielding member, 410: light transmitting portion, 421: first shielding member, 422: second shielding member, 423: gap, 500: printing device, 600: moving mechanism, 610: shielding position, 620: out-of-path position, 750: light irradiation unit, 750A: light source, G: axis

Claims

[Claim 1] A printing means is disposed at a position facing the outer peripheral surface of the can body and performs printing on the outer peripheral surface of the rotating can body; a curing unit arranged at a position facing the outer peripheral surface of the can body and curing a printed image formed on the outer peripheral surface by the printing unit using light or heat; a shielding member that blocks the light or heat traveling from the curing unit to the printing unit; A moving means for moving the shielding member; Equipped with At least two positions are set, the shielding position for shielding the light or heat being located on the movement path of the can body, and an off-path position being a position off the movement path, the moving means moves the shielding member from one of the shielding position and the off-path position to the other position, and moves the shielding member from the other position to the one position; Printing device.

Images