Printing apparatus

Abstract

To provide a printer that secures improvement of printing processing capacity, while preventing radiation of a diffusion medium of a hardening medium onto a printing head.SOLUTION: A printer includes: a conveyance part for conveying a printing object along a conveyance path; a printing head for performing printing by spraying ink from a nozzle onto a printing object in the process of being conveyed along the conveyance path; a light source for irradiating the printing object with a hardening medium, for example, hardening light, in order to harden the ink sprayed onto the printing object PB; and a shielding body for shielding the nozzle from radiation of diffusion light of the hardening light radiated onto the printing object. The shielding body moves between a shielding position for shielding diffusion light, and a retreat position for not disturbing the conveyance of a printing object by the conveyance part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a printing apparatus that applies decorations such as characters and patterns to a container for beverages, for example, as an object to be printed.

Background Art

[0002] In beverage products filled in containers made of resin materials, from the perspective of environmental protection, label-free is recommended by eliminating labels made of resin material films. In order to achieve label-free, for example, as disclosed in Patent Document 1, it has been considered to apply decorations such as characters and patterns as an alternative to labels by printing on the surface of the container.

[0003] Patent Document 1 uses a photocurable printing ink using a print head as a printing means, and after the ink is printed, the printed ink is cured by irradiating ultraviolet rays, which is an example of a curing medium. Patent Document 1 points out, as a problem in the case of using photocurable printing ink, that the diffused light from the container based on the ultraviolet rays irradiated for ink curing is irradiated to the print head. This is because if the photocurable printing ink remaining on the print head cures and the nozzles of the print head become clogged, there is a risk that the subsequent print quality will deteriorate or printing itself will become impossible. Therefore, Patent Document 1 proposes to surround the container as an object to be printed with a shield enclosure for shielding diffused light having a U-shaped shape in a plan view in order to eliminate nozzle clogging of the print head due to irradiation of ultraviolet rays.

[0004] In Patent Document 1, the container is printed while being placed on a rotary table and conveyed along an arc-shaped locus. The shield enclosure is arranged at a position where the U-shaped opening faces the outside in the radial direction of the rotating body. A rotating body called a star wheel is used to carry the container before printing into the conveying rotary table and to carry out the printed container from the conveying rotary table.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] US2015 / 0059600 A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Here, it is necessary to avoid interference between the star wheel and the container held by the star wheel and the shield enclosure, and in Patent Document 1, the opening of the shield enclosure facing radially outward is widened. However, widening the opening of the shield enclosure widens the pitch between adjacent containers, which reduces the number of containers that can be placed on the conveying rotary table for printing. This hinders the improvement of printing processing capacity. Therefore, the present disclosure aims to provide a printing apparatus that can improve printing performance while preventing irradiation of the print head with a diffusion medium based on the curing medium. [Means for solving the problem]

[0007] The printing apparatus according to this disclosure comprises a transport unit that transports a print target along a transport path, a print head that sprays ink from a nozzle onto the print target as it is transported along the transport path to perform printing, a medium source that irradiates the print target with a curing medium for curing the ink sprayed onto the print target, and a shielding body that blocks the diffusion medium of the curing medium irradiated onto the print target from being irradiated onto the nozzle. The shield moves between a shielding position that can block diffused light and a retracted position that does not interfere with the transport of the printing object by the transport unit. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a printing apparatus that can improve printing performance while preventing irradiation of the print head with a diffusion medium based on the curing medium. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view showing the schematic configuration of a printing apparatus according to the first embodiment of this disclosure. [Figure 2] This is a front view showing the configuration of a printing apparatus according to the first embodiment. [Figure 3] This is a plan view showing the printing procedure of the printing apparatus according to the first embodiment. [Figure 4] This is a plan view showing the configuration of a printing apparatus according to a second embodiment of this disclosure. [Figure 5] These are a partially enlarged plan view (FP) and a partially side view (SV) of the printing apparatus according to the second embodiment. [Figure 6] These are a partially enlarged plan view (FP) and a side view (SV) of a printing apparatus according to the third embodiment of this disclosure. [Figure 7] This is a plan view of a printing apparatus according to a fourth embodiment of the present disclosure. [Figure 8] This is a plan view of a printing apparatus according to a fifth embodiment of the present disclosure. [Figure 9] This is a plan view of a printing apparatus according to the sixth embodiment of the present disclosure. [Figure 10] This is a plan view of a printing apparatus according to a seventh embodiment of the present disclosure. [Figure 11] This figure shows another example of the direction of movement of the shielding in this disclosure. [Modes for carrying out the invention]

[0010] Hereinafter, several preferred embodiments of this disclosure will be described with reference to the attached drawings. These embodiments share the common feature of being printing apparatuses that can improve printing performance while preventing diffuse light irradiation of the print head. This common feature is achieved by having a shielding body, which prevents irradiation of curing light (an example of a curing medium) to the print head, move between a light-shielding position that can block diffuse light based on curing light from the printing material PB and a retracted position that does not interfere with the supply and discharge of the printing material PB. Hereinafter, several embodiments will be described in order with reference to the drawings.

[0011] [First Embodiment: Printing Device 1A: FIGS. 1, 2, and 3] Referring to FIGS. 1 to 3, the printing device 1A according to the first embodiment will be described. The printing device 1A performs printing such as characters and illustrations on the outer surface of a printing object PB that is continuously conveyed, for example, a container for beverages. The printing device 1A performs printing by the printing unit 30 in the process of conveying the printing object PB by a conveying unit 10 that rotates about a revolution axis C1. The conveying unit 10 includes a shielding mechanism 20 that can reciprocate along the radial direction R of the revolving table 11. This radial direction R is parallel to the horizontal direction H. The conveying unit 10 including the shielding mechanism 20 and the printing unit 30 can perform a predetermined operation according to an instruction from the control unit 100. Hereinafter, the configuration of the printing device 1A will be described in the order of the conveying unit 10 and the printing unit 30, and then the operation of the printing device 1A will be mentioned.

[0012] [Conveying Unit 10: FIGS. 1 and 2] In addition to the revolving table 11 rotating in a predetermined direction, for example, clockwise, in order to convey the placed printing object PB along the circumferential direction, the conveying unit 10 has a function of rotating the printing object PB placed on the revolving table 11 about its rotation axis C2. Hereinafter, the rotation of the revolving table 11 about the revolution axis C1 in a predetermined direction is referred to as the revolution of the printing object PB, and the rotation of the printing object PB about the rotation axis C2 is referred to as the rotation of the printing object PB.

[0013] As shown in FIGS. 1 and 2, the conveying unit 10 includes a revolving table 11 that is a rotating body having a circular outer shape in a plan view, and a plurality of rotating tables 13 provided along the circumferential direction in the vicinity of the outer peripheral edge of the revolving table 11. The conveying unit 10 includes a loading wheel 15 that continuously supplies the printing object PB to the revolving table 11, and an unloading wheel 17 that discharges the printing object PB on which printing has been performed on the revolving table 11. During one rotation of the revolving table 11 that has received the printing object PB from the loading wheel 15, printing is performed on the printing object PB placed on and rotating on the rotating table 13. Note that the description of the printing object PB is omitted in FIG. 1.

[0014] [Revolving table 11] The conveying unit 10 includes a revolving electric motor 12 that rotates the revolving table 11 around the revolving axis C1. The revolving electric motor 12 intermittently performs a rotation operation and a stop operation according to an instruction from the control unit 100. This operation will be described later.

[0015] [Rotating table 13] The rotating table 13 is provided at a pitch of equally spaced intervals in the circumferential direction in the vicinity of the outer surface 11C of the revolving table 11 as an example. Further, the rotating table 13 is rotationally driven by a rotating electric motor 14 with the printing object PB placed thereon. This rotational drive is performed to perform printing on the outer surface of the printing object PB. Here, as an example, 20 rotating tables 13 are provided, but this number is merely an example.

[0016] The rotating electric motor 14 is disposed below the revolving table 11, and its output shaft penetrates the revolving table 11 to support the rotating table 13. The rotating electric motor 14 rotationally drives the rotating table 13. The rotating electric motor 14 also intermittently performs a rotation operation and a stop operation according to an instruction from the control unit 100. This operation will be described later.

[0017] The loading wheel 15 is rotationally driven by an electric motor (not shown), receives the printing object PB from the upstream side, and delivers it toward the rotating table 13 of the revolving table 11 located on the downstream side. The loading wheel 15 employs a star wheel as an example, and continuously delivers the printing object PB to the rotating table 13 corresponding to the speed and pitch at which the rotating table 13 revolves by the revolving table 11. The unloading wheel 17 is rotationally driven by an electric motor (not shown), receives the printing object PB from the revolving table 11 located on the upstream side, and delivers the printing object PB toward the downstream side. The unloading wheel 17 employs a star wheel as an example, and continuously receives the printing object PB corresponding to the speed and pitch at which the rotating table 13 revolves by the revolving table 11. In this embodiment, the upstream and downstream are determined according to the direction in which the object to be printed, PB, is transported.

[0018] [Shielding mechanism 20: Figures 1 and 2] As shown in Figures 1 and 2, the shielding mechanism 20 is provided on the orbital table 11 so as to correspond to each of the rotational tables 13. Each shielding mechanism 20 includes a shielding body 21 for the purpose of blocking diffuse light from the object to be printed PB from irradiating the print head 31, and a shielding drive source 23 for reciprocating the shielding body 21 along the radial direction R of the revolving table 11.

[0019] As an example, the shielding body 21 has a U-shape when viewed from above, as shown in Figure 1. For example, it comprises an inner plate 21A perpendicular to the radial direction R, and a pair of side plates 21B, 21B connected to each end of the inner plate 21A and parallel to the radial direction R. The pair of side plates 21B, 21B are parallel to each other, and the ends facing the inner plate 21A are open 21D. The upper end of the shielding body 21 is also open 21E. In this way, the shielding body 21 has a shielding area that covers the horizontal periphery of the printing target PB, excluding the opening 21D.

[0020] The depth dimension of the shielding body 21, that is, the dimension L1 between the opening 21D and the inner plate 21A, is equal to the diameter R of the printable object PB placed on the rotating table 13. PB It is set to be larger than the opening 21D of the shielding body 21 at shielding position P0, so that the object to be printed PB does not protrude, or if it does, only by a small amount. Also, the circumferential dimension C of the shielding body 21, that is, the dimension L2 between the side plates 21B, 21B, is set to the diameter R of the object to be printed PB placed on the rotating table 13. PB This is larger than the gap between the side plates 21B, 21B of the shielding body 21 at shielding position P0 and the object to be printed PB. Therefore, at shielding position P0, the shielding body 21 can accommodate the object to be printed PB in the radial direction R and the circumferential direction C. However, the opening 21D is open. Furthermore, the vertical dimension L3 of the shielding body 21 is set to be at least the same height as the top of the printing object PB in the vertical direction V, which is placed on the rotating table 13. Therefore, at the shielding position P0, the shielding body 21 can accommodate the printing object PB in the vertical direction V as well. However, the opening 21E is open. Also, the above dimension L3 is just an example, and the dimension L3 may be higher or lower than the top of the printing object PB in the vertical direction V.

[0021] The shielding body 21 is not limited in material as long as it can block diffused light from the object PB to be printed, and metal materials, resin materials, etc., can be used. When a resin material is used for the shielding body 21, it is preferable to use a heat-resistant resin material to cope with the temperature of the shielding body 21 rising due to irradiation with curing light. At the shielding position P0, the surface of the shielding body 21 facing the object PB to be printed is preferably black, especially matte black, so as to absorb curing light and suppress reflection. Furthermore, since the surface roughness of the surface facing the object PB to be printed also affects the reflection of curing light, it is desirable to adjust the surface roughness in addition to the color.

[0022] The shielding drive source 23 is positioned inside the shielding body 21, closer to the orbital axis C1. This placement of the shielding drive source 23 is just one example; it can be positioned in other locations, such as above or to the side of the shielding body 21, as long as the shielding body 21 can be moved and does not interfere with other components. The shielding drive source 23 is provided with a drive shaft 24 that moves forward and backward along the radial direction R, and for example, a linear electric motor or a hydraulic piston-cylinder mechanism can be applied. When the shielding drive source 23 is driven and the drive shaft 24 moves forward, the shielding body 21 is in the shielding position P0, and when the shielding drive source 23 is driven and the drive shaft 24 moves backward, the shielding body 21 is in the retracted position P1. As shown in Figure 1, the shielding body 21 is in the retracted position P1 between the discharge wheel 17 and the input wheel 15, but the shielding body 21 is in the shielding position P0 between the input wheel 15 and the discharge wheel 17. In the retracted position P1, the shielding body 21 avoids interference with the printing object PB that is transferred from the input wheel 15 to the orbital table 11, and also avoids interference with the printing object PB that is transferred from the orbital table 11 to the discharge wheel 17. In this way, even with the shielding body 21 in place, the loading and unloading of the printing target PB is ensured.

[0023] [Printed section 30: Figures 1 and 2] Next, the printing unit 30 of the printing device 1A will be described. As shown in Figure 1, the printing unit 30 includes a plurality of print heads 31 provided at predetermined intervals, in this case evenly spaced, from the outer surface 11C of the orbital table 11, and a light source 33 provided corresponding to each print head 31. Each print head 31 is equipped with a nozzle (not shown) for ejecting ink.

[0024] Multiple print heads 31 are arranged at equal intervals along the circumferential direction, and the light sources 33 are also arranged at equal intervals along the circumferential direction. In this circumferential direction, as an example, the print heads 31 and light sources 33 are arranged alternately. As another example, two print heads 31,31 and one light source 33 can be treated as one group, and these groups can be arranged alternately. In this case, ink of a different color is ejected from each of the two print heads 31,31.

[0025] The print head 31 is, for example, an inkjet type head, and in this embodiment, as an example, we propose a case in which three different colors are printed using two index operations. These three colors are, for example, cyan, magenta, and yellow. In other words, in Figure 1, print heads 31A and 31B, print heads 31C and 31D, and print heads 31E and 32F each eject ink of the same color. By increasing the size of the orbital table 11, the number of print heads 31 and light sources 33 can be increased, making it possible to support full-color printing, such as 6-color printing.

[0026] Light source 33 irradiates ultraviolet light to dry and cure the ink applied to the surface of the object PB printed by the print head 31. In Figure 1, light sources 33A, 33B, 33C, 33D, 33E, and 33F are denoted as such, corresponding to the print heads 31A, 31B, 31C, 31D, 31E, and 31F. For example, ink applied by print head 31A is cured by light source 33A, and ink applied by print head 31D is dried and cured by light source 33D. It is preferable to provide a shield or focus the curing light with a lens to prevent the curing light from light source 33 from irradiating adjacent print heads 31. The curing medium in this disclosure is not limited to ultraviolet light as the curing light; other curing media such as electron beams can be applied.

[0027] In this embodiment, the print heads 31A, 31B, 31C, 31D, 31E, 31F and the light sources 33A, 33B, 33C, 33D, 33E, 33F are arranged alternately in groups of two, but this is merely one example. For example, the print heads 31A-31F and the light sources 33A-33F may be arranged alternately one by one, or the print heads 31A-31F and the light sources 33A-33F may be arranged alternately in groups of three or more.

[0028] [Operation of Printer 1A: Figure 3] Next, the operation of the printing device 1A will be explained with reference to Figure 3. [Delivery process ~ Printing process] Printing begins when the print objects PB are transported from the loading wheel 15 to the revolving table 11, and then the print objects PB2 and PB1 are transported in front of the print heads 31A and 31B. In this explanation, the first print object to be transported is referred to as print object PB1, and subsequent print objects are referred to as print objects PB2, PB3, and so on. Until the printing objects PB1, PB2, etc. are transferred from the loading wheel 15 to the revolving table 11, the shielding body 21 of the shielding mechanism 20 remains in the retracted position P1. After the transfer, the shielding body 21 moves to the shielding position P0. In this way, the shielding body 21 moves in conjunction with the transport of the printing objects PB.

[0029] [Printing process] As the orbital table 11 rotates clockwise in the figure, and the print targets PB2 and PB1 are transported to the front of the print heads 31A and 31B, the rotation, or orbit, of the orbital table 11 stops. When the orbit of the orbital table 11 stops, printing on the print targets PB2 and PB1 begins (Figure 3 STEP 1). Printing on the print targets PB2 and PB1 is performed by rotating the respective rotating tables 13, 13 on which the print targets PB2 and PB1 are placed, driven by the rotating electric motor 14, and by spraying ink from the print heads 31A and 31B toward the outer surface of the print targets PB2 and PB1. During this time, the orbital table 11 is stopped. Note that the rotating table 13 may rotate while the orbital table 11 is orbiting.

[0030] After a predetermined period of orbital cessation, the orbital table 11 revolves (rotates) in a predetermined direction by a predetermined angle. As a result, the print targets PB2 and PB1 are transported in front of the light sources 33A and 33B. Then, the next print targets PB4 and PB3 are transported in front of the print heads 31A and 31B, and the orbit of the orbital table 11 stops. When the revolution of the orbital table 11 stops, ultraviolet light is irradiated onto the printing targets PB2 and PB1 by light sources 33A and 33B, and printing is performed on the printing targets PB4 and PB3 by print heads 31A and 31B (Figure 3 STEP 2). During this time, each of the rotating tables 13 on which the printing targets PB1 to PB4 are placed rotates. The rotation of the printing targets PB1 to PB4, the irradiation of ultraviolet light by light sources 33A and 33B, and the spraying of ink from print heads 31A and 31B all occur while the revolution of the orbital table 11 is stopped.

[0031] By repeatedly spraying ink onto the print target PB and irradiating it with ultraviolet light, which is a curing light, the first and second print target PB2 and PB1 supplied will complete printing by the print heads 31E and 31F and irradiation with ultraviolet light by the light sources 33E and 33F, and the printing including the desired decorations, text, etc. will be completed (Figure 3 STEP 7).

[0032] While the above printing process is being carried out, the shielding body 21 is positioned at the shielding position P0, thereby blocking the irradiation of diffuse light from the object PB to be printed onto the print head 31. When ultraviolet light is shone onto the printing target PB2 in front of the light source 33A, the ultraviolet light is shone onto the printing target PB2, but diffused light is generated when it is reflected by the printing target PB2. However, since the printing target PB2 is closed on the inside in the radial direction R and on both sides in the circumferential direction C by the shielding body 21 at the shielding position P0, the diffused light is blocked from being shone onto the adjacent print heads 31A, 31B and other print heads 31. The shielding body 21 has an opening 21D on the outside in the radial direction R and an opening 21E at the upper end in the vertical direction V, and although there is a risk of diffused light leaking out from there, the direction in which the diffused light leaking from openings 21D and 21E travels is considerably different from the direction toward the print heads 31, and if any diffused light is shone onto the print heads 31, it is either none or only a small amount.

[0033] [Export process] The first and second printed objects PB2 and PB1, which have been printed as desired, are transferred from the rotating table 13 of the revolving table 11 to the discharge wheel 17 and then discharged downstream. During this transfer, the shielding body 21 moves from its previous shielding position P0 to the retracted position P1. The movement of the shielding body 21 to the retracted position P1 continues until the printed objects PB are delivered from the loading wheel 15.

[0034] [Effects of Printing Device 1A] Printing device 1A produces the following effects: The printing apparatus 1A is provided with a shielding mechanism 20 corresponding to each of the rotating tables 13 on which the object to be printed PB is placed. The shielding body 21 of the shielding mechanism 20 is in the shielding position P0 during the printing process and the curing light irradiation process, and blocks the diffused light from the object to be printed PB so that it does not irradiate the print head 31. Furthermore, the shielding body 21 of the shielding mechanism 20 is in a retracted position P1 between the transfer of the print target PB to the discharge wheel 17, which is not involved in the irradiation of curing light, and the receipt of the print target PB from the loading wheel 15, thereby avoiding interference with the transfer and receipt of the print target PB. Furthermore, in the shielding body 21, interference with the printed object PB being fed in or out can be avoided without unnecessarily increasing the circumferential dimension L2 C in the opening 21D, so the pitch between adjacent rotating tables 13, 13 can be narrowed. As a result, the number of rotating tables 13 that can be placed on the same-sized orbiting table 11 can be increased, thereby achieving high printing processing capacity.

[0035] [Second Embodiment Printing Apparatus 1B: Figures 4 and 5] Next, the printing apparatus 1B according to the second embodiment will be described with reference to Figures 4 and 5. The printing device 1B moves the shielding body 21 between the shielded position P0 and the retracted position P1 by means of a cam mechanism 40 that converts the rotational force of the revolving table 11 into the linear motion of the shielding body 21. The cam mechanism 40 includes a grooved cam 43 as a driving link provided at a predetermined distance from the surface of the revolving table 11, and a roller 47 as a driven link that travels inside the grooved cam 43.

[0036] The grooved cam 43, positioned at a predetermined distance from the orbital table 11, is connected in the circumferential direction C and its position is fixed relative to the rotation of the orbital table 11. The grooved cam 43 has a cam passage 45 on its inside through which the roller 47 travels, and movement of the shielding body 21 between the shielding position P0 and the retracted position P1 is achieved by changing the distance from the orbital axis C1 to the cam passage 45. Specifically, the distance from the orbital axis C1 is relatively increased at the shielding position P0, while the distance from the orbital axis C1 is relatively decreased at the retracted position P1. The distance from the orbital axis C1 at the shielding position P0 is constant. As an example, the grooved cam 43 receives the roller 47 at a position slightly above the shielding body 21. In the grooved cam 43, the region where the shielding body 21 is at the shielding position P0 is called the shielding region A0, and the region where the shielding body 21 is at the retracted position P1 is called the retracted region A1. The groove cam 43, the roller 47 (described later), and the sliding mechanism 50 can be installed in positions other than those exemplified, provided that each can perform its respective function.

[0037] The rollers 47 are provided corresponding to each of the shielding bodies 21 and travel in the cam passages 45 of the grooved cams 43 as the revolving table 11 revolves. For example, the rollers 47 are positioned in the cam passages 45 while being rotatably supported at the upper end of a support 49 fixed to the inner plate 21A of the shielding body 21. In this way, the rollers 47 traveling in the cam passages 45 are connected to the shielding body 21 via the support 49, so the shielding body 21 moves in accordance with the movement of the rollers 47 from the revolving axis C1, which corresponds to the distance of the cam passages 45 from the revolving axis C1. This movement occurs between the shielding position P0 and the retracted position P1.

[0038] To ensure smooth operation of the cam mechanism 40, the printing device 1B is equipped with a slide mechanism 50. The slide mechanism 50, for example, supports the shielding body 21 from below and enables reciprocating movement in the radial direction R. As shown in Figure 5, the sliding mechanism 50 includes a pair of guide rails 51 fixed to the revolving table 11 with the rotating table 13 in between, and a travel wheel 53 that moves along each of the pair of guide rails 51. Two travel wheels 53 are rotatably provided for each guide rail 51 at the lower end of the shielding body 21.

[0039] [Operation of Printer 1B] The following describes the characteristic operation of printing device 1B relative to printing device 1A. As shown in Figure 5, while the roller 47 attached to the shielding body 21 is traveling within the retraction area A1 of the groove cam 43, the shielding body 21 is in the retracted position P1 so as not to obstruct the loading and unloading of the printing object PB. On the other hand, while the roller 47 attached to the shielding body 21 is traveling within the shielding area A0 of the groove cam 43, the shielding body 21 is in the shielding position P0 to suppress diffused light. The movement of the shielding body 21 between the shielded position P0 and the retracted position P1 is achieved by the operation of the cam mechanism 40 in conjunction with the rotation of the orbital table 11.

[0040] [Effects of Printing Device 1B] In addition to the effects of the printing apparatus 1A according to the first embodiment, the printing apparatus 1B provides the following effects. The printing device 1B does not require a shielding drive source 23 corresponding to each shielding body 21, and it does not need to receive signals from the control unit 100 to control the operation of each shielding drive source 23. Therefore, the number of terminals such as slip rings that transmit control signals to the orbital table 11 can be reduced.

[0041] [Third Embodiment Printing Apparatus 1C: Figure 6] Next, the printing apparatus 1C according to the third embodiment will be described with reference to Figure 6. Printing device 1C, as an alternative to the cam mechanism 40 of printing device 1B, uses a gear mechanism 60 that converts the rotational force of the revolving table 11 into the linear motion of the shielding body 21 to move the shielding body 21 between the shielded position P0 and the retracted position P1. A rack and pinion is used as the gear mechanism 60 of printing device 1C.

[0042] The gear mechanism 60 includes a forward drive rack 61A used to move the shielding body 21 from the retracted position P1 to the shielded position P0, and a reverse drive rack 61B used to move the shielding body 21 from the shielded position P0 to the retracted position P1. The forward drive rack 61A and the reverse drive rack 61B play a similar role to the groove cam 43 in the printing device 1B, and their positions relative to the revolving table 11 are fixed. In other words, the forward drive rack 61A is positioned only within the range necessary to move the shielding body 21 from the retracted position P1 to the shielded position P0, and the reverse drive rack 61B is positioned only within the range necessary to move the shielding body 21 from the shielded position P0 to the retracted position P1. Both the forward drive rack 61A and the reverse drive rack 61B have an arc shape when viewed from above, corresponding to the required range. Although not shown in the diagram, the forward drive rack 61A has teeth formed on the inside in the radial direction R that mesh with the pinion gear 63, and the reverse drive rack 61B has teeth formed on the outside in the radial direction R that mesh with the pinion gear 63. Furthermore, both the forward drive rack 61A and the reverse drive rack 61B are fixed in the same vertical direction V position as the groove cam 43.

[0043] The gear mechanism 60 includes a pinion gear 63 that meshes with the forward drive rack 61A and the reverse drive rack 61B, and a driven rack 65 that meshes with the pinion gear 63 and moves along the radial direction R. The pinion gear 63 and the driven rack 65 are provided corresponding to the respective shielding mechanisms 20.

[0044] The driven rack 65 has a linear shape, with one side fixed to the back surface of the inner plate 21A of the shielding body 21, and is positioned along the radial direction R. Therefore, as the driven rack 65 moves forward or backward in the radial direction, the shielding body 21 also moves forward or backward in the radial direction. The shielding body 21 is supported below it by a sliding mechanism 50 similar to that of the printing device 1B.

[0045] As the shielding body 21 moves from the retracted position P1 to the shielded position P0, the pinion gear 63 engages with both the forward driving rack 61A and the driven rack 65. At this time, as the shielding body 21 moves in the circumferential direction C due to the rotation of the orbital table 11, the pinion gear 63 moves in the circumferential direction C while engaging with the inner teeth of the forward driving rack 61A, and rotates, for example, counterclockwise. As the pinion gear 63 rotates, the driven rack 65, which engages with the pinion gear 63, gradually moves outward in the radial direction R, and when the pinion gear 63 moves from the starting point S1 to the ending point E1 of the forward driving rack 61A, the shielding body 21 reaches the shielded position P0. As the rotation of the orbital table 11 continues, the engagement between the pinion gear 63 and the forward drive rack 61A is disengaged. Thereafter, the relative position between the pinion gear 63 and the driven rack 65 is maintained, and the shielding position P0 of the shielding body 21 is maintained until it reaches the reverse drive rack 61B. The pinion gear 63 is rotatably supported, for example, at the upper end of a support cylinder 64 erected on the surface of the orbital table 11. The support cylinder 64 is fixed in position relative to the orbital table 11 and moves in the circumferential direction C as the orbital table 11 rotates.

[0046] As the shielding body 21 moves from the shielding position P0 to the retracted position P1, the pinion gear 63 engages with both the retracting drive rack 61B and the driven rack 65. At this time, as the shielding body 21 moves in the circumferential direction C due to the rotation of the orbital table 11, the pinion gear 63 moves in the circumferential direction C while engaging with the outer teeth of the retracting drive rack 61B, and rotates, for example, clockwise. Due to this rotation of the pinion gear 63, the driven rack 65 that engages with the pinion gear 63 gradually moves inward in the radial direction R, and when the pinion gear 63 moves from the starting point S1 to the ending point E2 of the retracting drive rack 61B, the shielding body 21 reaches the retracted position P1. As the rotation of the orbital table 11 continues, the engagement between the pinion gear 63 and the retracted drive rack 61B is disengaged. Subsequently, the relative position between the pinion gear 63 and the driven rack 65 is maintained, and the retracted position P1 of the shielding body 21 is maintained until it reaches the forward drive rack 61A.

[0047] [Effects of Printing Device 1C] In addition to the effects of the printing apparatus 1B according to the second embodiment, the printing apparatus 1C can reduce manufacturing costs because the area where the forward drive rack 61A and the reverse drive rack 61B are provided only needs to be a part of the circumferential direction C.

[0048] [Fourth Embodiment Printing Apparatus 1D: Figure 7] Referring to Figure 7, the printing apparatus 1D according to the fourth embodiment will be described. The printing device 1D has the same basic configuration as the printing device 1A, but a single shielding body 21 corresponds to multiple print targets PB. In other words, the printing device 1D accommodates two print targets PB with the shielding body 21. The printing device 1D corresponds to the alternating arrangement of two print heads 31 and two light sources 33, but the number of print targets PB accommodated by the shielding body 21 can be three or more. However, if the number of print targets PB to be accommodated becomes too large, the shielding body 21 needs to be made larger, and the load of moving it between the shielding position P0 and the retracted position P1 increases. Therefore, it is preferable to keep the number of print targets PB accommodated by the shielding body 21 to five or less.

[0049] [Effects of Printer 1D] The printing apparatus 1D can achieve the effects of the printing apparatus 1A according to the first embodiment while reducing the number of mechanical elements such as the shielding body 21 and the shielding drive source 23. The printing apparatus 1D can also be implemented using a cam mechanism 40 as in the second embodiment, or using a gear mechanism 60 as in the third embodiment.

[0050] [Fifth Embodiment Printing Apparatus 1E: Figure 8] The printing apparatus 1E according to the fifth embodiment will be described with reference to Figure 9. The basic configuration of the printing device 1E is the same as that of the printing device 1A, but instead of moving the entire shielding body 21, only the side plates 21B, 21B, i.e., a part of the shielding body 21, is moved between the shielding position P0 and the retracted position P1. In this printing device 1E, the inner plate 21A is a circular shape when viewed from above, connected in the circumferential direction, while the pair of side plates 21B, 21B can pass through slits 22, 22 formed at predetermined positions in the inner plate 21A and move back and forth between the shielding position P0 and the retracted position P1.

[0051] [Effects of Printing Device 1E] The printing apparatus 1D is effective in saving space and efficiently arranging movable parts, as well as reducing driving force by decreasing movable mass, while still achieving the effects of the printing apparatus 1A according to the first embodiment.

[0052] [Sixth Embodiment Printing Apparatus 1F: Figure 9] Referring to Figure 9, the printing apparatus 1F according to the sixth embodiment will be described. Printing apparatus 1F is the same as printing apparatus 1E in that a part of the shielding body 21 moves, but the shape of the shielding body 21 in plan view is different. In other words, the shielding body 21 of printing apparatus 1F is composed of three elements: a movable plate 21F, a movable plate 21G, and a fixed plate 21H. The movable plate 21F, movable plate 21G, and fixed plate 21H all have an arc shape when viewed in plan, and their radii of curvature are set to be larger than the radius of the object to be printed PB. The fixed plate 21H is always fixed in a predetermined position near the rotating table 13 and inside the radial direction R. Also, in the retracted position P1, the movable plate 21F and movable plate 21G are positioned behind the fixed plate 21H and overlapping in the radial direction R. However, in the shielding position P0, the movable plate 21F and movable plate 21G each move forward outside the radial direction R according to an arc-shaped trajectory, and together with the fixed plate 21H, contribute to shielding diffused light.

[0053] [Effects of Printing Device 1F] The shielding body 21 of the printing device 1F has an arc shape when viewed from above, formed by the movable plate 21F, movable plate 21G, and fixed plate 21H at the shielding position P0. This arc shape allows the occupied area, including the movable range, to be smaller compared to a "U" shape. Therefore, the printing device 1F can achieve the effects of the printing device 1A according to the first embodiment while realizing space saving and effective arrangement of movable parts, which are effective in avoiding interference with other equipment, as well as reducing driving force by reducing the movable mass.

[0054] [Seventh Embodiment Printing Apparatus 1G: Figure 10] Referring to Figure 10, the printing apparatus 1G according to the seventh embodiment will be described. The printing apparatus 1G prints on the object PB, which is conveyed in a straight line, while moving the shielding body 21 between the shielding position P0 and the retracted position P1.

[0055] The printing apparatus 1G comprises a transport unit 10 that transports the object to be printed PB along a straight transport path, a printing unit 30 provided on one side of the transport unit 10 in the width direction W, and a shielding mechanism 20 provided on the other side of the transport unit 10 in the width direction W.

[0056] The transport unit 10 in the printing apparatus 1G consists of, for example, a conveyor system, which receives the object to be printed PB from the upstream (U) side and transports the object to be printed PB downstream (L). Printing is performed on the object to be printed PB during the transport process by the transport unit 10. Unlike the object to be printed PB placed on, for example, a rotating table 13, which rotates around its central axis, the object to be printed PB transported by the transport unit 10 maintains its orientation while being transported by the transport unit 10.

[0057] The printing unit 30 in the printing device 1G also includes multiple print heads 31 and multiple light sources 33. However, in the printing unit 30 of the printing device 1G, four print heads 31A, 31B, 31C, and 31D and four light sources 33A, 33B, 33C, and 33D are arranged alternately, one at a time. In other words, the printing unit 30 of the printing device 1G prints on the object PB using four colors of ink, as an example.

[0058] Next, the shielding mechanism 20 in the printing apparatus 1G will be described. The shielding mechanism 20 includes a circulating path 25 that, in plan view, has the shape of a racetrack. The circulating path 25 constitutes a circular track consisting of straight paths 25A, 25B and reverse paths 25C, 25D. The shielding body 21 of the shielding mechanism 20 moves along the circulating path 25 and can also move forward and backward relative to the transport unit 10. The movement of the shielding body 21 can be achieved, for example, by a linear motor. That is, an electromagnetic coil, which is one element of the linear motor, is provided in the circulating path 25, and a permanent magnet, which is the other element of the linear motor, is provided in the shielding body 21. As a result, the shielding body 21 and the circulating path 25 constitute a linear motor, so that the shielding body 21 can be moved in the direction of the circulating path 25, and the shielding body 21 can also be moved forward and backward relative to the transport unit 10 to which the object to be printed PB is transported. This forward and backward movement allows the shielding body 21 to move between a shielding position P0 and a retracted position P1, as will be described below.

[0059] In the printing apparatus 1G, the shielding mechanism 20 has a shielding body 21 positioned at the shielding position P0, except for a portion of the upstream (U) and downstream (L) of the straight path 25A, which is provided opposite the transport unit 10, to shield diffused light. When the object to be printed PB is printed by the print head 31D located at the furthest downstream (L) and irradiated with curing light from the light source 33D, and reaches a predetermined position, the shielding body 21 retracts to the retracted position P1. The shielding body 21, having retracted to the retracted position P1, passes through the straight path 25A, then through the reversing path 25C, the straight path 25B, and the reversing path 25D, remaining at the retracted position P1 until it reaches a predetermined position on the straight path 25A.

[0060] [Effects of Printer 1G] Even in a printing apparatus 1G where the object to be printed PB is transported along a linear transport path, the spacing between the objects to be printed PB placed on the transport section 10 can be narrowed by moving the shielding body 21 between the shielding position P0 and the retracted position P1. Therefore, a high printing capacity can be ensured, similar to printing apparatus 1A. Furthermore, with the printing device 1G, since the object to be printed PB being transported along the linear transport section 10 is not rotated, printing is performed on one side of the object to be printed PB, which is particularly effective for printing on rectangular objects to be printed PB. However, with the printing device 1G, even with round objects to be printed PB, printing is possible within a limited range in the circumferential direction. Furthermore, the printing device 1G can continuously supply and discharge the object PB to be printed without stopping its transport, thus achieving a higher processing capacity than the printing device 1A, which operates the orbital table 11 intermittently.

[0061] In the printing apparatus 1G, the shielding body 21 moves back and forth in the horizontal direction H, but as shown in Figure 11, for example, the shielding body 21 can be configured to move up and down in the vertical direction V. In this case, the print head 31 and the light source 33 can be placed on both of the opposing pair of sides of the object to be printed PB, so that printing can be done on the pair of moving sides of the object to be printed PB.

[0062] [Note] The printing apparatus 1A to 1G according to the first aspect of this disclosure includes a transport unit (10) that transports a print target (PB) along a transport path, a print head (31) that sprays ink from a nozzle onto the print target as it is transported along the transport path to perform printing, and a medium source (33) that irradiates the print target with a curing medium for curing the ink sprayed onto the print target (PB). The device includes a shield (21) for blocking the diffusion medium of the curing medium irradiated onto the printing target (PB) from being irradiated onto the nozzle. The shielding body (21) in this disclosure moves between a shielding position (P0) that can block diffused light and a retracted position (P1) that does not interfere with the transport of the printing object (PB) by the transport unit (10).

[0063] A second aspect of this disclosure is that the shielding body (21) according to the first aspect preferably comprises an opening (21D) on the side facing a fixed print head (31) and a light source (33), and a shielding area that covers the horizontal periphery of the object to be printed (PB) excluding the opening (21D), and moves as the object to be printed (PB) is transported.

[0064] In the third embodiment of this disclosure, the shielding body (21) preferably has a U-shape or arc shape when viewed from above. The shield (21) of the fourth aspect of this disclosure moves between a shielding position (P0) and a retracted position (P1) preferably in the horizontal or vertical direction, in any of the first to third aspects. In any of the first to fourth embodiments of the shielding body (21) in the fifth embodiment of this disclosure, preferably a portion thereof moves between a shielding position (P0) and a retracted position (P1). In a sixth aspect of this disclosure, in any of the first to fifth aspects, preferably, a single shielding body (21) is provided corresponding to a plurality of printable objects (PB).

[0065] The transport unit (10) of the seventh aspect of this disclosure preferably comprises, in any of the first to sixth aspects, a rotary table (11) that transports a plurality of printable objects (PB) along an arc-shaped transport path, and a rotating wheel (15) that rotates and continuously transfers the printable objects (PB) to the rotary table (11). In this case, the shielding body (21) is in a retracted position (P1) that does not obstruct the transfer of printable objects (PB) from the rotating wheel (15) to the rotary table (11). The shielding body (21) according to the eighth aspect of this embodiment preferably moves radially along the rotary table (11) between a shielding position (P0) and a retracted position (P1), using the rotation of the rotary table (11) as the driving source, as in the seventh aspect.

[0066] The transport unit (10) according to the ninth aspect of this disclosure preferably transports a plurality of printable objects (PB) along a linear transport path in any of the first to eighth aspects, and the print head (31) and light source (33) are provided in a predetermined range along the linear transport path. In this configuration, the plurality of shielding bodies (21) move between a shielding position (P0) corresponding to the predetermined range and a retracted position (P1) corresponding to an area outside the predetermined range. The transport unit (10) according to the tenth embodiment of this configuration preferably includes a circulating path that includes a linear transport path through which a plurality of shielding bodies (21) move, as in the ninth embodiment. [Explanation of Symbols]

[0067] 1A,1B,1C,1D,1E,1F,1G Printing device 10 Conveying section 11. Orbital Table 11C External surface 12. Orbital electric motor 13 Rotating Table 14. Electric motor 15 Loading Wheels 17. Transport Wheel 20 Shielding mechanism 21 Shield 21A Inner plate 21B Lateral plate 21D,21E opening 21F,21G Movable plate 21H Fixed plate 22 slits 23 Shielded drive source 24 drive shafts 25 Circulation pathways 25A,25B straight road 25C, 25D Reversing path 30 Printing Department 31, 31A, 31B, 31C, 31D, 31E, 31F Printhead 33,33A,33B,33C,33D,33E,33F Light source 40 Cam mechanism 43 groove cam 45 Cam passage 47 Laura 49 Support 50 Slide mechanism 51 Guide rail 53 Driving Wheels 60 Gear mechanism 61A Forward Drive Rack 61B Reverse drive rack 63 Pinion Gear 64 Support tube 65 Driven Rack 100 Control Unit PB, PB1, PB2, PB3, PB4 Printable items P0 shielding position P1 Evacuation position A0 shielding area A1 Evacuation area C1 Axis of Revolution C2 Rotation axis S1, S2 starting point E1, E2 terminus L downstream U Upstream V Vertical direction H horizontal direction W (width direction) R radial direction C circumferential direction

Claims

1. A transport unit that transports the object to be printed along the transport path, A print head that sprays ink from a nozzle onto the object to be printed while being transported along the aforementioned transport path, A medium source that irradiates the object to be printed with a curing medium for curing the ink sprayed onto the object to be printed, The system includes a shielding body for blocking the diffusion medium of the curing medium, which is irradiated onto the object to be printed, from being irradiated onto the nozzle, The aforementioned shielding body is A shielding position that can block the diffusion medium, It moves between a retracted position that does not obstruct the transport of the object to be printed by the transport unit, The aforementioned transport unit is A rotary table that transports multiple printable objects along the arc-shaped transport path, It comprises a rotating wheel that rotates while continuously transferring the object to be printed to the rotating table, The printing apparatus is such that the shielding body is in the retracted position so as not to obstruct the transfer of the object to be printed from the rotating wheel to the rotating table.

2. A transport unit that transports a printable object along a transport path, A print head that sprays ink from a nozzle onto the object to be printed while being transported along the aforementioned transport path, A medium source that irradiates the object to be printed with a curing medium for curing the ink sprayed onto the object to be printed, The system includes a shielding body for blocking the diffusion medium of the curing medium, which is irradiated onto the object to be printed, from being irradiated onto the nozzle, The aforementioned shielding body is A shielding position that can block the diffusion medium, It moves between a retracted position that does not obstruct the transport of the object to be printed by the transport unit, The transport unit transports a plurality of the objects to be printed along the linear transport path. The print head and the media source are provided within a predetermined range along the linear transport path. Multiple shielding bodies move between the shielding position corresponding to the predetermined range and the retracted position corresponding to the area outside the predetermined range. The transport unit comprises a circulating path including a linear transport path on which a plurality of shielding bodies move, in a printing apparatus.

3. The aforementioned shielding body is An opening on the side facing the print head and the media source, whose position is fixed, It comprises a pair of side plates spaced apart along the transport path, excluding the aforementioned opening, and an inner plate connecting the ends of the pair of side plates that are away from the opening, and a shielding region covering the horizontal periphery of the object to be printed, and The object to be printed moves as it is transported. The printing apparatus according to claim 1 or claim 2.

4. The aforementioned shielding body is When viewed from above, its shape is U-shaped or arc-shaped. A printing apparatus according to any one of claims 1 to 3.

5. The aforementioned shielding body is Moving between the shielding position and the retracted position in the horizontal or vertical direction, A printing apparatus according to any one of claims 1 to 3.

6. The aforementioned shielding body is A part of it moves between the shielding position and the retracted position. A printing apparatus according to any one of claims 1 to 3.

7. A single shielding body, Provided in accordance with multiple print targets, A printing apparatus according to any one of claims 1 to 3.

8. The aforementioned shielding body is The rotation of the rotary table is used as the driving source to move the rotary table radially between the shielded position and the retracted position. The printing apparatus according to claim 1.

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