Printing apparatus

Abstract

To perform printing with high accuracy in a transverse direction relative to an object to be printed that is transported on a conveyor in a printing device.SOLUTION: A printing device 1 includes: a guide transportation part 20 (example of transportation guide) disposed in a transverse direction D2 intersecting a transportation direction D1 of a conveyor 100 relative to an object to be printed P that is transported on a conveyor 100; and a first printing part 10 for nipping the object to be printed P between the guide transportation part 20 and the first printing part and performing printing on the object to be printed P in the transverse direction D2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a printing device that prints laterally on a printing substrate. [Background technology]

[0002] Conventionally, printing has been performed horizontally on the sides of cardboard boxes, etc. For example, in order to perform printing and other processes on a box production line, a stable transfer device has been proposed that suppresses the shaking of boxes transported on a conveyor by using protrusions that raise the edges of the bottom of the boxes above the plane (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-217788 Summary of the Invention [Problem to be solved by the invention]

[0004] In horizontal printing, even with the protrusions of the stable transfer device described above, it is difficult to stabilize the distance between the substrate and the inkjet head (the so-called head gap) due to unevenness in the bottom surface of the substrate or its placement on the belt conveyor. This makes it difficult to print on the substrate with high precision. In particular, when performing full-color printing using multiple nozzle rows with multiple nozzles arranged vertically and spaced apart in the transport direction, an unstable head gap or wobbling of the substrate can easily result in line misalignment and color unevenness.

[0005] Similarly, in printing methods other than inkjet printing, such as contact printing such as flexographic printing, if the position of the printing object is not stable, it will be impossible to print on the printing object with high precision.

[0006] SUMMARY OF THE INVENTION An object of the present invention is to provide a printing apparatus that can print with high precision in the lateral direction on a printing medium transported on a conveyor. [Means for solving the problem]

[0007] In one embodiment, the printing device includes a transport guide arranged laterally across the conveyor's transport direction relative to the substrate being transported on the conveyor, and a first printing unit that clamps the substrate between the transport guide and the first printing unit and prints on the substrate in the laterally direction. [Effects of the Invention]

[0008] According to this aspect, printing can be performed with high precision in the lateral direction on the printing medium being transported on the conveyor. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing a printing device according to a first embodiment. [Figure 2] FIG. 2 is a front view illustrating printing by a head module according to the first embodiment. [Figure 3] FIG. 10 is a plan view showing a printing device according to a second embodiment. [Figure 4] FIG. 10 is a front view illustrating printing by a head module and a plate cylinder in a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, printing devices according to first and second embodiments of the present invention will be described with reference to the drawings.

[0011] First Embodiment FIG. 1 is a plan view showing a printing device 1 according to the first embodiment.

[0012] FIG. 2 is a front view for explaining printing by the head module 11 in the first embodiment.

[0013] Note that the front-rear, left-right, and up-down directions in Figures 1 and 2 and Figures 3 and 4 of the second embodiment described later are an example for the convenience of explanation, assuming that the conveying direction D1 of the conveyor 100 is the right direction.

[0014] As shown in FIG. 1, the printing apparatus 1 includes a first printing unit 10 and a guide conveying unit 20.

[0015] The first printing unit 10 is disposed at the front side of the conveyor 100, and sandwiches the printing substrate P between itself and the guide transport unit 20, which will be described later. The first printing unit 10 prints on the printing substrate P sandwiched in this manner in a lateral direction D2. This lateral direction D2 is a direction that intersects with the transport direction D1 of the conveyor 100 (to the right in FIG. 1), and is, for example, a horizontal direction. However, the lateral direction D2 is not limited to a horizontal direction, and may be a direction that is inclined up or down relative to the horizontal direction. The printing substrate P is, for example, a box such as cardboard, but is not particularly limited as long as it can be transported on the conveyor 100.

[0016] Here, a system including the printing device 1 and the conveyor 100 can be called a printing system. As an example, the conveyor 100 is a belt conveyor that is arranged as part of a box-making machine. Note that the conveyor 100 may be a conveyor other than a belt conveyor, such as a roller conveyor.

[0017] The first printing unit 10 includes a head module 11 and a printing transport unit 12.

[0018] As shown in FIG. 2, the head module 11 has a plurality of heads 11a (shown by hidden dashed lines because they are located at the rear side of the head module 11, which is not visible in FIG. 2). Each head 11a includes one or more nozzle rows (not shown), in which a plurality of nozzles that eject ink are arranged in the height direction. For example, six heads 11a for each of black, cyan, magenta, and yellow are arranged in a staggered pattern in the height direction at different positions in the left-right direction (transport direction D1). The six heads 11a for each color are arranged at intervals for each color in the transport direction D1. In other words, in the head module 11, a plurality of nozzle rows, in which a plurality of nozzles are arranged in the height direction, are arranged at intervals in the transport direction D1.

[0019] The head module 11 prints text such as "XXX apple" or "Harvest date *month*day" (variable printing for *) in four colors (full color) of black, cyan, magenta, and yellow, or prints a pattern of two apples on the side (front) of the printing substrate P. As shown in Fig. 1, the head module 11 is positioned so as to be spaced apart from the contact surface between the printing transport unit 12 and the printing substrate P in the lateral direction D2 by a head gap G.

[0020] As shown in FIGS. 1 and 2, the print transport unit 12 has pulleys 12a, 12b, and 12c and an endless belt 12d stretched around these pulleys, above and below the head module 11. Also, as shown in FIG. 2, the print transport unit 12 has a motor 12e, a transmission pulley 12f, and a transmission belt 12g. The motor 12e is an example of a print transport drive means (actuator). The transmission pulley 12f is provided coaxially with the upper and lower pulleys 12a. The transmission belt 12g is an endless belt stretched around the drive shaft of the motor 12e and the transmission pulley 12f.

[0021] The printing conveying unit 12 transmits the power of the motor 12e to the upper and lower pulleys 12a, 12a via the transmission belt 12g and the transmission pulley 12f, causing the upper and lower belts 12d, 12d to rotate. The upper and lower belts 12d, 12d then convey the printing substrate P while contacting the printing substrate P.

[0022] The first printing unit 10 is not limited to one having a head module 11 and a printing transport unit 12, but may be, for example, a printing unit that performs contact printing on the printing substrate P (for example, the second printing unit 40 that performs flexographic printing in the second embodiment described below), and the printing method is not particularly limited. Furthermore, the first printing unit 10 is not limited to one having a transport unit such as the printing transport unit 12.

[0023] The guide conveyance unit 20 shown in FIG. 1 is an example of a conveyance guide arranged on the rear side of the conveyor 100 (an example of the horizontal direction D2) with respect to the printing substrate P conveyed on the conveyor 100. The guide conveyance unit 20 has pulleys 21 and 22 and a belt 23. As described above, the guide conveyance unit 20 sandwiches the printing substrate P between itself and the first printing unit 10. Therefore, the guide conveyance unit 20 also functions as a pressing mechanism that presses the printing substrate P toward the first printing unit 10.

[0024] The belt 23 is an endless belt stretched over pulleys 21 and 22, and conveys the printing substrate P while rotating when one of the pulleys 21 and 22 is rotated by driving a guide conveyance drive means (actuator) such as a motor (not shown). Of the pulleys 21 and 22, the upstream pulley 21 in the conveyance direction D1 is preferably positioned farther away from the first printing unit 10 (rearward) than the downstream pulley 22 in the conveyance direction D1. This makes it easier for the guide conveyance unit 20 to receive the printing substrate P between itself and the first printing unit 10, and also ensures that the printing substrate P is securely sandwiched between the downstream pulley 22 in the conveyance direction D1 and the first printing unit 10 (printing conveyance unit 12).

[0025] The transport guide, of which the guide transport unit 20 is an example, may be anything that guides the printing substrate P transported on the conveyor 100 in the transport direction D1, and may be, for example, a member that does not transport the printing substrate P, such as a plate having a guide surface that extends in the vertical and horizontal directions. Furthermore, if a printing unit is arranged opposite the first printing unit 10 in the horizontal direction D2, the transport guide may be, for example, a printing transport unit of this printing unit, or may be a printing unit that is arranged opposite the first printing unit 10 in the horizontal direction D2 and performs contact printing on the printing substrate P.

[0026] In the first embodiment described above, the printing device 1 includes a guide conveyance unit 20, which is an example of a conveyance guide, and a first printing unit 10. The guide conveyance unit 20 is disposed in a lateral direction D2 that intersects with the conveyance direction D1 of the conveyor 100 relative to the printing substrate P being conveyed on the conveyor 100. The first printing unit 10 holds the printing substrate P between itself and the guide conveyance unit 20, and prints on the printing substrate P in the lateral direction D2.

[0027] In this way, by sandwiching the printing substrate P transported on the conveyor 100 between the first printing unit 10 and the guide transport unit 20, even if the bottom surface of the printing substrate P is uneven or the printing substrate P is transported shifted in the lateral direction D2, the printing substrate P can be stabilized and printing can be performed on the printing substrate P at a desired position. Therefore, according to the first embodiment, printing can be performed with high precision in the lateral direction D2 on the printing substrate P transported on the conveyor 100.

[0028] In the first embodiment, the first printing unit 10 has a head module 11 and a print transport unit 12. The head module 11 has a plurality of nozzle rows arranged in the height direction at intervals in the transport direction D1, each row including a plurality of nozzles that are arranged in the height direction and eject ink. The print transport unit 12 transports the printing substrate P that is held between itself and the guide transport unit 20.

[0029] In this way, the nozzle rows (heads 11a) are arranged at intervals in the conveyance direction D1, and misalignment of the ink ejection positions of each color can be prevented, for example, when performing full-color printing. Furthermore, by sandwiching the printing substrate P between the print conveyance unit 12 and the guide conveyance unit 20, the head gap G between the printing substrate P and the head module 11 can be kept constant. Therefore, printing can be performed in the lateral direction D2 on the printing substrate P being conveyed on the conveyor 100 with greater precision.

[0030] Second Embodiment FIG. 3 is a plan view showing a printing device 2 according to the second embodiment.

[0031] FIG. 4 is a front view for explaining printing by the head module 11 and the plate cylinder 41 in the second embodiment.

[0032] As shown in FIG. 3, the printing device 2 includes a first printing unit 10, a guide conveyance unit 20 which is an example of a conveyance guide, and a second printing unit 40.

[0033] The first printing section 10 is similar to the first printing section 10 of the first embodiment described above, except that the printing transport section 12 further includes transmission pulleys 12p and 12q and a transmission belt 12r shown in FIG.

[0034] 4 is provided coaxially with the upper and lower pulleys 12a and 12f. The transmission pulley 12q is provided coaxially with the plate cylinder 41, which will be described later. The transmission belt 12r is an endless belt that is stretched over the transmission pulleys 12p and 12q.

[0035] The printing transport unit 12 in the second embodiment not only transmits the power of the motor 12e to the upper and lower pulleys 12a, 12a, but also rotates the plate cylinder 41 via the transmission pulley 12p, the transmission belt 12r, and the transmission pulley 12q. As a result, the plate cylinder 41 performs contact printing on the printing substrate P while rotating.

[0036] The guide conveying section 20 shown in Figure 3 has pulleys 21, 22 and a belt 23, similar to the guide conveying section 20 shown in Figure 1 of the first embodiment described above, but extends further upstream in the conveying direction D1 than the guide conveying section 20 shown in Figure 1, and faces the second printing section 40 described later.

[0037] In this second embodiment, the conveying guide, of which the guide conveying section 20 is an example, may be anything that guides the printing material P being conveyed on the conveyor 100 in the conveying direction D1, and may be a member that does not convey the printing material P, such as a plate having a guide surface that extends in the vertical and horizontal directions.

[0038] As shown in FIG. 4, the second printing unit 40 is located at the front side of the conveyor 100, the same as the first printing unit 10, but upstream of the first printing unit 10 in the conveying direction D1, and performs contact printing on the printing substrate P, thereby sandwiching the printing substrate P between itself and the guide conveying unit 20. Here, the guide conveying unit 20 that sandwiches the printing substrate P together with the second printing unit 40 and the guide conveying unit 20 that sandwiches the printing substrate P together with the first printing unit 10 may be separate units arranged separately in the conveying direction D1, but it is preferable that they be a single guide conveying unit 20. The second printing unit 40 may also be located downstream of the first printing unit 10 in the conveying direction D1.

[0039] The second printing unit 40 has a plate cylinder 41, an anilox roll 42, and an ink supply unit 43, and performs flexographic printing, which is an example of contact printing. Note that contact printing may be any type of printing that involves contact with the printing substrate P, such as other relief printing methods.

[0040] The plate cylinder 41 is a member made of, for example, resin or rubber, and has raised portions (plates) that become printing portions provided on its outer circumferential surface. In the example of Fig. 6, raised portions are provided in a checkerboard pattern only on the upper and lower parts of the plate cylinder 41. The plate cylinder 41 is disposed so as to face the pulley 21 of the guide conveyance section 20 in the front-rear direction. Therefore, the pulley 21 functions as an impression cylinder facing the plate cylinder 41.

[0041] The anilox roll 42 has a rotation axis (vertical direction) parallel to the rotation axis of the plate cylinder 41 and transfers ink onto the plate cylinder 41 .

[0042] The ink supply unit 43 has a doctor blade that scrapes off excess ink adhering to the surface of the anilox roll 42, a storage unit that stores ink, and the like, and supplies ink to the anilox roll 42.

[0043] Then, the printing cylinder 41 prints a checkerboard pattern on the side (front) of the printing material P, above and below the printing content of the head module 11 (for example, text such as "XX apple" or "harvest date *month *day", or a pattern of two apples).

[0044] In the second embodiment described above, the same effects as those of the first embodiment described above can be obtained, namely, the ability to print with high precision in the lateral direction D2 on the printing substrate P transported on the conveyor 100.

[0045] In addition, in this second embodiment, the printing device 2 further includes a second printing unit 40 located upstream (or downstream) of the first printing unit 10 in the conveying direction D1, and which clamps the substrate P between itself and the guide conveying unit 20 (an example of a conveying guide) by performing contact printing on the substrate P.

[0046] As a result, the printing material P being transported on the conveyor 100 is not only sandwiched between the first printing unit 10 and the guide transport unit 20, but is also sandwiched between the second printing unit 40 and the guide transport unit 20, thereby further stabilizing the printing material P being transported on the conveyor 100. Furthermore, the second printing unit 40 can also perform printing different from the printing of the first printing unit 10 (for example, variable printing) (for example, spot color printing with good color development by flexographic printing, stencil printing, application of inkjet coating agent, etc.).

[0047] In the second embodiment, the single guide conveyance unit 20 sandwiches the printing substrate P between itself and the first printing unit 10, and also sandwiches the printing substrate P between itself and the second printing unit 40.

[0048] This allows the guide conveying section 20 to clamp the printing material P between the first printing section 10 and the second printing section 40, thereby stabilizing the printing material P being transported on the conveyor 100 with a simple configuration.

[0049] The present invention is not limited to the first embodiment described above, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the first embodiment described above. For example, all of the components shown in the first embodiment may be appropriately combined. Naturally, various modifications and applications are possible without departing from the spirit of the invention. The invention as originally claimed in the present application is described below.

[0050] [Appendix 1] A conveying guide is arranged in a lateral direction intersecting the conveying direction of the conveyor with respect to the printing material conveyed on the conveyor; a first printing unit that sandwiches the printing substrate between itself and the conveying guide and prints on the printing substrate in the lateral direction; A printing device comprising:

[0051] [Appendix 2] The first printing unit has a head module in which a plurality of nozzle rows, each including a plurality of nozzles arranged in a height direction and ejecting ink, are arranged at intervals in the transport direction, and a print transport unit that transports the printing medium sandwiched between the print medium and the transport guide. 2. The printing device according to claim 1.

[0052] [Appendix 3] a second printing unit located upstream or downstream in the transport direction of the first printing unit, and performing contact printing on the printing medium to sandwich the printing medium between itself and the transport guide; 3. The printing device according to claim 1 or 2.

[0053] [Appendix 4] The single conveying guide sandwiches the printing material between the first printing unit and the conveying guide, and sandwiches the printing material between the second printing unit and the conveying guide. 4. The printing device according to claim 3. [Explanation of symbols]

[0054] 1,2 Printing device 10 1st printing department 11 Head module 11a Head 12 Printing transport section 12a, 12b, 12c pulleys 12d belt 12e motor 12f Transmission pulley 12g power transmission belt 12p, 12q transmission pulley 12r power transmission belt 20 Guide conveying section (conveying guide) 21,22 Pulley 23 Belt 40 2nd Printing Department 41 Printing cylinder 42 Anix Roll 43 Ink supply unit 100 Conveyor D1 Conveying direction D2 Horizontal G Head Gap P Printing material

Claims

1. A conveying guide is arranged in a lateral direction, which is a horizontal direction intersecting the conveying direction of the conveyor, with respect to the printing material conveyed on the conveyor; a first printing unit that sandwiches the printing substrate between itself and the conveying guide and prints on the printing substrate in the lateral direction; Equipped with the first printing unit has a head module in which a plurality of nozzle rows, each including a plurality of nozzles arranged in a height direction and ejecting ink, are arranged at intervals in the transport direction, and a print transport unit that transports the printing medium sandwiched between the print medium and the transport guide; the print transport unit transports the printing substrate while belts arranged above and below the head module are in contact with the printing substrate; The head module is disposed so as to be spaced apart from the printing material in the lateral direction by a head gap from the contact surface between the belt and the printing material. A printing device characterized by:

2. a second printing unit located upstream or downstream in the transport direction of the first printing unit, and performing contact printing on the printing medium to sandwich the printing medium between itself and the transport guide; 2. The printing device according to claim 1.

3. The single conveying guide sandwiches the printing material between the first printing unit and the conveying guide, and sandwiches the printing material between the second printing unit and the conveying guide.

3. The printing device according to claim 2.

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