JP2022123866A - Printing method, paper cup, and printer - Google Patents

Abstract

To provide a printing method capable of suppressing occurrence of printing failure such as ink omission.SOLUTION: A printing method includes the steps of: rotating a paper cup around a first axis substantially coaxial with an axis of the paper cup, and detecting a step of a joint of the paper cup by a sensor; stopping the rotation around the first axis of the paper cup at a timing of having detected the step in the detection step or a timing after the timing, and setting a position around the first axis of the step; and rotating the paper cup while bringing the outer peripheral surface of the paper cup whose position around the first axis is set in the setting step into contact with an ink image carrier and transferring an ink image onto an outer peripheral surface of the paper cup.SELECTED DRAWING: Figure 8

Description

The present invention relates to a printing method, a paper cup and a printing apparatus.

2. Description of the Related Art Conventionally, there is known a printing method for printing an ink image on the outer peripheral surface of a paper cup, for example (see Patent Document 1, for example). Usually, paper cups have a seam, and the outer peripheral surface of the paper cup has a step at the seam.

JP-A-2-277638

However, in the conventional printing method, if an ink image is printed on the area including the level difference on the outer peripheral surface of the paper cup, there is a possibility that printing defects such as ink missing may occur.

Accordingly, the main object of the present invention is to provide a printing method capable of suppressing the occurrence of printing defects such as missing ink.

The present invention comprises a step of rotating a paper cup around a predetermined axis substantially coaxial with the axis of the paper cup and detecting a step at the seam of the paper cup with a sensor;
forming an ink image on the outer peripheral surface of the paper cup based on the detection result in the detecting step;
To provide a printing method comprising:
The forming step sets the position of the step about the predetermined axis by stopping the rotation of the paper cup about the predetermined axis at the timing when the step is detected in the detecting step or at a timing after the timing. and a step of applying ink for forming the ink image to the outer peripheral surface of the paper cup whose position around the predetermined axis is set in the setting step.
In the setting step, while at least a part of the ink image is formed on the outer peripheral surface in the attaching step, the ink attachment position where the ink is attached to the outer peripheral surface is prevented from reaching the step. The position of the step around the predetermined axis may be set to .
The ink image includes an information transmission display, and in the setting step, at least the ink for forming the information transmission display is deposited on the outer peripheral surface at the ink deposition position, and the step is formed at the ink deposition position. The position of the step around the predetermined axis may be set so as not to impinge on the step.
In the attaching step, the ink image is applied to the outer peripheral surface of the paper cup by rotating the paper cup while bringing the outer peripheral surface of the paper cup, whose position around the predetermined axis is set in the setting step, into contact with the ink image carrier. may be transcribed.
A plurality of the ink images are superimposed and transferred to the outer peripheral surface of the paper cup, and in the setting step, the new ink image is superimposed and transferred on the ink image already transferred to the outer peripheral surface of the paper cup. In this case, the position of the step around the predetermined axis may be set so that the ink image is transferred to a predetermined overlapping position.
In the setting step, the position of the step about the predetermined axis may be set such that the ink image is formed at a predetermined position in the circumferential direction of the outer peripheral surface of the paper cup with the step as a reference. .
The present invention also provides a paper cup having the ink image printed on its outer peripheral surface by the printing method.
The present invention includes a holding member that detachably holds an inner peripheral surface of a paper cup;
a first rotation support member that supports the holding member holding the paper cup so as to be rotatable around a first axis that is substantially coaxial with the axis of the paper cup, and that is rotatable around a second axis;
a drive unit that rotates the holding member around the first axis;
a second rotary support member that is held by the holding member and supports the ink image carrier so as to be in contact with the outer peripheral surface of the paper cup positioned at the first position around the second axis, and that is rotatable around the third axis; ,
a control unit that controls the driving unit;
When the holding member connected to the control unit and holding the paper cup positioned at a second position around the second axis is rotated around the first axis, a step at the seam of the paper cup is detected. a sensor;
with
The control unit controls the driving unit to rotate the holding member holding the paper cup positioned at the second position around the first axis, and based on the detection result of the sensor, the paper A printing device is also provided for forming an ink image on the outer peripheral surface of the cup.

1 is a plan view schematically showing the configuration of a printing apparatus according to a first embodiment of the invention; FIG. 2 is a block diagram schematically showing the functions of the printing device of FIG. 1; FIG. 2 is a cross-sectional view schematically showing the configuration of a printing unit of the printing apparatus of FIG. 1; FIG. 4A and 4B are diagrams for explaining step detection example 1 using a sensor. 5A and 5B are diagrams for explaining step detection example 2 using a sensor. 6A to 6C are diagrams for explaining step detection example 3 using a sensor. 7A to 7C are diagrams for explaining step detection example 4 using a sensor. 2 is a flowchart for explaining the operation of the printing apparatus of FIG. 1; 9A to 9C are diagrams for explaining an example of an ink image transfer operation. 10A to 10C are diagrams for explaining another example of the ink image transfer operation. FIG. 5 is a side view schematically showing the configuration of a printing apparatus according to a second embodiment of the invention; 12 is a block diagram schematically showing the functions of the printing device of FIG. 11; FIG. 12 is a flow chart for explaining the operation of the printing apparatus of FIG. 11; 12A and 12B are diagrams for explaining the operation of the printing apparatus of FIG. 11; FIG. FIG. 10 is a diagram for explaining a sensor of Modification 1; FIG. 11 is a diagram for explaining a sensor of Modification 2;

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description. The embodiments described below represent representative embodiments of the present invention, and the scope of the present invention should not be construed narrowly. Even if this specification describes that the printing method, the paper cup, and the printing device according to the present invention have multiple effects, the printing method, the paper cup, and the printing device according to the present invention have at least one effect. All you have to do is play. The effects described herein are only examples and are not limiting, and other effects may also occur.

Also, the description is given in the following order.
1. Introduction 2. Configuration of the printing apparatus according to the first embodiment of the present invention3. Operation of the printing apparatus according to the first embodiment of the present invention4. 5. Effects of the printing apparatus according to the first embodiment of the present invention, the printing method using the printing apparatus, and the paper cup on which the ink image is printed by the printing method. Configuration of printing apparatus according to second embodiment of the present invention6. Operation of the printing apparatus according to the second embodiment of the present invention7. 8. Effect of the printing apparatus according to the second embodiment of the present invention, the printing method using the printing apparatus, and the paper cup on which the ink image is printed by the printing method. Modification of the present invention

<1. Introduction>
In recent years, the demand for eco-friendly paper cups has been increasing. Paper cups are classified into those that are distributed plain (the former) and those that are distributed with ink images representing characters, colors, patterns, etc. printed thereon (the latter).
For example, if a method (Method 1) is used in which flat paper is molded into a paper cup and an ink image is printed on the outer peripheral surface of the paper cup (curved surface printing) as necessary, the former and the latter are appropriately selected as the use of the paper cup. Because it is possible, there is a low risk of holding inventory even if a large number of paper cups are molded.
On the other hand, for example, in the method (Method 2) of printing an ink image on plain paper for forming paper cups (planar printing) and molding the plain paper into a paper cup shape, the use of paper cups is limited to the latter. There is a high risk of holding inventory when molding paper cups in large quantities.
Therefore, it can be said that method 1 is more suitable than method 2 for paper cups that are intended for mass production.

By the way, conventionally, for example, in a printing method (curved surface printing method) and a printing apparatus (curved surface printing apparatus) for printing an ink image on the outer peripheral surface of a paper cup, an ink image is printed on an area including steps on the outer peripheral surface of the paper cup. As a result, printing defects such as missing ink occurred.
Therefore, after extensive research, the inventor found that if the position of the step on the outer peripheral surface of the paper cup can be controlled in advance, the ink image can be printed so as not to overlap the step.
As a specific method, first, the paper cup is rotated around its axis, and the position of the step on the outer peripheral surface is detected by a sensor targeting a portion of the outer peripheral surface in the circumferential direction. Next, the rotation of the paper cup is stopped at the detection timing of the sensor or at a timing after the detection timing, and the circumferential position of the step of the paper cup is determined. That is, the circumferential position of the step of the paper cup PC can be freely controlled by the rotation angle (including 0°) of the paper cup from the detection timing of the sensor to the rotation stop timing of the paper cup.
Based on the idea as described above, the inventor developed the printing method and printing apparatus according to the present invention as a printing method and printing apparatus that can suppress the occurrence of printing defects such as missing ink.

A first embodiment of the printing apparatus according to the present invention will be described in detail below.
<2. Configuration of print container according to first embodiment of the present invention>
FIG. 1 is a plan view schematically showing the configuration of a printer 1 according to the first embodiment of the invention. FIG. 2 is a block diagram showing an example of functions of the printing apparatus 1. As shown in FIG. FIG. 3 is a cross-sectional view schematically showing the configuration of the printing section of the printer 1. As shown in FIG.

The printing device 1 is a printing device that prints an ink image on the outer peripheral surface of a paper cup PC, and is also called a “curved surface printing device”. More specifically, as shown in FIG. 3, the printing apparatus 1 rotates the outer peripheral surface of the paper cup PC in contact with the ink image carrier 41 that carries the ink image Ii so that the ink image Ii is applied to the outer peripheral surface. It is a printing device that transfers.

1 and 2, the printing apparatus 1 includes a plurality of (for example, 20) holding members 10, first rotary support members 20, first drive units 30, and second rotary support members 40. , a second driving unit 50, a control unit 60, a sensor 70, and the like.

(Holding member)
Each holding member 10 detachably holds the inner peripheral surface of the paper cup PC.

The paper cup PC is, for example, a paper cup in the shape of a hollow truncated cone with a seam J at a predetermined position in the circumferential direction, as can be seen from FIG. 1 and FIG. 3 . There is a step S of the seam J at a predetermined position in the circumferential direction of the outer peripheral surface of the paper cup PC.

As an example, as shown in FIG. 1, the holding member 10 sucks and holds (closely holds) the inner peripheral surface of the paper cup PC by vacuum suction (vacuum chuck). The holding member 10 is, for example, a metal member having the same shape as the paper cup PC (for example, a truncated cone shape) and having the same size as the paper cup PC or slightly smaller than the paper cup PC. Each holding member 10 is also called a "mandrel". Each retaining member 10 is substantially identical.
The holding member 10 has an axis substantially coaxial with the axis of the paper cup PC while holding the inner peripheral surface of the paper cup PC.
The axis of the holding member 10 extends substantially horizontally, for example.

(First rotation support member)
The first rotary support member 20 supports the holding member 10 holding the paper cup PC rotatably around a first axis AX1 (the axis of the holding member 10) substantially coaxial with the axis of the paper cup PC. The first rotary support member 20 is also called a "turret".

The first rotary support member 20 is rotatable, for example, around a second axis AX2 orthogonal to the first axis AX1. More specifically, the first rotary support member 20 is supported by a support base so as to be rotatable around a second axis AX2 (for example, an axis extending in a substantially vertical direction). The first rotary support member 20 is rotationally driven around the second axis AX2 by a drive mechanism 80 (see FIG. 2) including, for example, gears, pulleys, motors, etc., provided on the support frame.

As an example, the first rotation support member 20 is configured so that the plurality of holding members 10 are radially arranged at positions approximately the same distance from the second axis AX2 as a whole, and each holding member 10 is positioned relative to the holding member. It is supported so as to be rotatable around the first axis AX1.

(first drive unit)
The first driving section 30 (see FIG. 2) rotates the holding member 10 around the first axis AX1. The first drive unit 30 is configured including a motor (preferably a servomotor) as an example. The first driving section 30 is controlled by the control section 60 .

The printing device 1 is, for example, a multi-color image printing device using CMYK (C: cyan, M: magenta, Y: yellow, K: black) process colors, and includes a mounting unit for mounting the paper cup PC on the holding member 10, Surface treatment unit for surface treatment of paper cup PC, multiple (eg, 7) printing/drying units (eg, 1st to 7th printing/drying units), image inspection unit, final drying unit, non-defective product extraction unit, and defective product discharge The units are arranged in this order on the same circumference around the second axis AX2 (circumference on which the paper cup PC held by the holding member 10 can face).

Each printing/drying unit includes a printing section that prints the ink image Ii on the paper cup PC and a drying section that dries the ink image Ii printed on the paper cup PC. The printing units of a plurality of (for example, seven) printing/drying units print ink images of different colors on the paper cup PC. The drying section of each printing/drying unit dries the ink image Ii printed on the paper cup PC by the corresponding printing section. Here, the ink image Ii is formed with UV (ultraviolet) curable ink I, for example. Each drying section and final drying unit has, for example, a UV lamp that emits ultraviolet light.
In each printing/drying unit, the printing section is arranged on the upstream side in the rotation direction of the first rotary support member 20, and the drying section is arranged on the downstream side. That is, the printing section and the drying section are alternately arranged on the circumference. Hereinafter, the printing sections of the first to seventh printing/drying units will be referred to as first to seventh printing sections, respectively, and the drying sections of the first to seventh printing/drying units will be referred to as first to seventh drying sections, respectively. The configuration of each printing unit is substantially the same except for the color of the ink image Ii to be printed. The configuration of each drying section is substantially the same.
The printing section and drying section of each printing/drying unit are controlled by the control section 60 .

(control part)
The control section 60 controls the first drive section 30 , the second drive section 50 and the drive mechanism 80 . The controller 60 is connected to the sensor 70 and memory 90 (see FIG. 2). The control unit 60 is implemented by, for example, a CPU, a chipset, or the like.

As shown in FIG. 1, the control unit 60 rotates the first rotary support member 20 by controlling the drive mechanism 80 to move each holding member 10 holding the paper cup PC to the paper cup facing the mounting unit. The mounting position MP, the surface treatment position STP (second position P2) facing the surface treatment unit, the first printing position PP1 (first position P1) facing the first printing section, the first printing position facing the first drying section A drying position DP1, a second printing position PP2 facing the second printing section (first position P1), a second drying position DP2 facing the second drying section, and a third printing position PP3 facing the third printing section (first position P1). 1 position P1), a third drying position DP3 facing the third drying section, a fourth printing position PP4 facing the fourth printing section (first position P1), a fourth drying position DP4 facing the fourth drying section, A fifth printing position PP5 (first position P1) facing the fifth printing section, a fifth drying position DP5 facing the fifth drying section, and a sixth printing position PP6 (first position P1) facing the sixth printing section. , a sixth drying position DP6 facing the sixth drying section, a seventh printing position PP7 facing the seventh printing section (first position P1), a seventh drying position DP7 facing the seventh drying section, and an image inspection unit They can be sequentially positioned at the opposing image inspection position IIP, the final drying position FDP facing the final drying unit, the good product picking position GTP facing the good product picking unit, and the defective product discharging position DDP facing the defective product discharging unit.

In other words, the printing apparatus 1 rotates the first rotation support member 20 so that the holding member 1
Each of a plurality of paper cup PCs (for example, maximum 20) held at 0 can be simultaneously positioned at different positions where various processes are performed, and various processes can be performed on the plurality of paper cup PCs in parallel. can. Therefore, the printing apparatus 1 is extremely productive.

In the printing apparatus 1, the number of holding members 10 supported by the first rotary support member 20 can be increased or decreased. The number can also be increased or decreased.

(Second rotation support member)
As shown in FIG. 3, the second rotary support member 40 is held by the holding member 10 so that the ink image carrier 41 carrying the ink image Ii is held at a first position P1 (printing position, transfer position) around the second axis AX2. , FIG. 3) is supported so as to be in contact with the outer peripheral surface of the paper cup PC. Note that the printing position and the transfer position can also be called "ink adhesion positions" because they are positions where ink is adhered.
The second rotary support member 40 is rotatably supported by the support frame, for example, around a third axis AX3 substantially orthogonal to the second axis AX2.
As an example, the third axis AX3 is substantially parallel to the first axis AX1, which is the axis of the holding member 10 that holds the paper cup PC positioned at the first position P1.

(Second drive unit)
The second drive section 50 (see FIG. 2) rotates the second rotation support member 40 around the third axis AX3. The second driving section 50 is configured including a motor (preferably a servomotor) as an example.

The ink image carrier 41 is provided on the outer peripheral surface of the second rotation support member 40 . The ink image carrier 41 is also called a "blanket". The second rotation support member 40 is made of, for example, a cylindrical or elliptical cylindrical member, and is also called a "blanket sleeve or blanket cylinder".

The ink image carrier 41 is rotatable around the third axis AX3 while being in contact with a flexographic plate 43 attached to the outer peripheral surface of a plate sleeve 42 that is rotatable around an axis substantially parallel to the third axis AX3. there is The plate sleeve 42 is rotationally driven by, for example, a motor (preferably a servomotor). The motor is controlled by the controller 60 . The flexographic plate 43 is made of a photosensitive resin plate (photopolymer plate). The flexographic plate 43 can be applied to the plate sleeve 42 using a dedicated applicator.

The flexographic plate 43 attached to the outer peripheral surface of the plate sleeve 42 is rotatable while contacting the outer peripheral surface of an anilox roller 44 rotatable around an axis substantially parallel to the third axis AX3. The anilox roller 44 scrapes out the ink I supplied to the ink tray 45 . The ink tray 45 is provided with a doctor blade that contacts the outer peripheral surface of the anilox roller 44. The doctor blade scrapes off excess ink I from the outer peripheral surface of the anilox roller 44, and an appropriate amount of ink I is applied to the flexographic plate 43. supplied. The flexographic plate 43 to which the ink I is supplied is exposed by the exposure device and then developed by the development device to form (visualize) the ink image Ii. The anilox roller 44 is rotationally driven by, for example, a motor (preferably a servomotor). The motor is controlled by the controller 60 .

The ink image carrier 41, the plate sleeve 42, the flexographic plate 43, the anilox roller 44, the ink tray 45 and the doctor blade described above constitute a "printing section".

Here, the printing operation by each printing unit will be briefly described.
First, the ink I is supplied to the ink tray 45 from the ink supply section. Next, the ink I in the ink tray 45 is scraped out by the anilox roller 44, and the ink I adjusted to an appropriate amount is supplied to the flexographic plate 43 by the doctor blade. Next, the flexographic plate 43 supplied with the ink I is exposed and developed to form an ink image Ii on the flexographic plate 43 . Next, the ink image Ii formed on the flexographic plate 43 is transferred to the ink image carrier 41, and the ink image Ii transferred to the ink image carrier 41 is transferred to the paper cup PC.

(sensor)
The sensor 70 detects the step S at the seam J of the paper cup PC when the holding member 10 holding the paper cup PC positioned at the second position P2 around the second axis AX2 is rotated around the first axis AX1. . The second position P2 is a position around the second axis AX2 different from the first position P1, which is the printing position, and is, for example, the surface treatment position STP. The sensor 70 targets (detection position) a portion of the outer peripheral surface of the paper cup PC located at the second position P2 in the circumferential direction.

The sensor 70 is, for example, a laser sensor arranged at a position facing the outer peripheral surface of the paper cup PC positioned at the second position P2. The sensor 70 has a laser light source (eg, semiconductor laser) and a light receiving element (eg, photodiode). The detection position (target) of the sensor 70 is the position where the sensor 70 irradiates the laser light (irradiation light IL) on the outer peripheral surface of the paper cup PC.

As in arrangement example 1 shown in FIGS. 4A and 4B, the sensor 70 is positioned at a position that can face the step S of the seam J of the paper cup PC located at the second position P2 (for example, if the irradiation direction of the irradiation light IL is the paper cup (position substantially parallel to the tangential direction of the PC). In this case, the control unit 60 controls the first driving unit 30 to rotate the holding member 10 holding the paper cup PC around the first axis AX1 at a constant angular velocity ω, while laser beams are projected onto the outer peripheral surface of the paper cup PC. Laser light (irradiation light IL) is emitted from a light source, reflected light RL is received by a light receiving element, and a signal (light receiving signal) output from the light receiving element is monitored. As shown in FIG. 4A, when the irradiation light IL is applied to a position other than the step S on the outer peripheral surface of the paper cup PC, most of the light reflected by the outer peripheral surface of the paper cup PC returns to the sensor 70. Therefore, the signal level of the received light signal becomes low level (for example, approximately 0). On the other hand, as shown in FIG. 4B, when the step S is irradiated with the irradiation light IL, most of the irradiation light IL returns to the sensor 70, so the signal level of the received light signal becomes high. Therefore, the control unit 60 sets the timing at which the signal level of the received light signal switches between the low level and the high level as the timing at which the step S is detected (step detection timing). In this case, the detection position (target) of the sensor 70 determines the position of the step S at the step detection timing. This arrangement example 1 is effective when the orientation of the step S of the paper cup PC is the orientation shown in FIGS. 4A and 4B.

For example, when the orientation of the step S of the paper cup PC is opposite to the orientation shown in FIGS. 4A and 4B, it is effective to arrange the sensor 70 as shown in Arrangement Example 2 shown in FIGS. 5A and 5B. be.

Based on the position of the step S of the seam J of the paper cup PC around the first axis AX1, the control unit 60 controls the position of the holding member 10 holding the paper cup PC around the first axis AX1 and/or the second rotational support. It is possible to adjust the position of the member 40 around the third axis AX3.

The sensor 70 may be arranged at a position where the irradiation direction of the irradiation light IL is substantially orthogonal to the tangential direction of the paper cup PC, as in arrangement example 3 shown in FIGS. 6A to 6C.
In this case, the control unit 60 controls the first driving unit 30 to rotate the paper cup PC around the first axis AX1, monitors the output signal (light receiving signal) of the sensor 70, and detects the waveform of the output signal. The timing at which the is disturbed may be used as the step detection timing. Also in this case, the position of the step S at the step detection timing is determined by the detection position (target) of the sensor 70 .

Further, in arrangement example 3, the control unit 60 controls the first driving unit 30 to rotate the paper cup PC around the first axis AX1, and adjusts the time difference between the light emission timing of the laser light source and the light reception timing of the light receiving element. It may be calculated in real time, and the timing at which the time difference changes significantly may be used as the step detection timing.
For example, as shown in FIGS. 6A and 6B, when the irradiation light IL is irradiated from the sensor 70 to a position other than the step S on the outer peripheral surface of the paper cup PC, the distance from the sensor 70 to the outer peripheral surface is substantially constant. Since it is (d), the said time difference is also substantially constant.
For example, as shown in FIG. 6C, when the irradiation light IL is emitted from the sensor 70 onto the step S on the outer peripheral surface of the paper cup PC, the distance from the sensor 70 to the outer peripheral surface is approximately dt (t is the paper cup thickness of the side wall of PC), the time difference is reduced. Therefore, the control unit 60 may set the step detection timing to be the timing at which the time difference is switched between the time when the time difference is substantially constant and the time when the time difference is small. Also in this case, the position of the step S at the step detection timing is determined by the detection position (target) of the sensor 70 .

When the sensor 70 is arranged as in Arrangement Example 3, for example, as shown in FIGS. It is valid.
In this case, for example, as shown in FIG. 7C, when the irradiation light IL is emitted from the sensor 70 onto the step S on the outer peripheral surface of the paper cup PC, the distance from the sensor 70 to the outer peripheral surface is approximately d+t (t is the paper thickness of the side wall of the cup PC), the time difference becomes large. Therefore, the control unit 60 may determine the timing of switching between when the time difference is substantially constant and when it increases as the step detection timing. Also in this case, the position of the step S at the step detection timing is determined by the detection position (target) of the sensor 70 .

<3. Operation of Printing Apparatus According to First Embodiment of Present Invention>
The operation of the printing apparatus 1 according to the first embodiment of the invention will be described with reference to FIGS. 1 and 8 to 10. FIG. The operation of the printing apparatus 1 shown in the flowchart of FIG. 8 is an example of the printing method of the present invention.

The setting of the printing conditions of the printing apparatus 1, the operation setting of each movable part of the printing apparatus 1, and the like can be performed by the operator through the operation of the personal computer.
Here, it is assumed that the ink image Ii is printed on a part of the outer peripheral surface of the paper cup PC in the circumferential direction (for example, within an angle range of 5° to 355°, 10° to 350°, etc.). A flexographic plate 43 corresponding to the ink image Ii to be printed on the paper cup PC is attached to the plate sleeve 42 in advance. It is assumed that the ink tank 45 of the printing unit is supplied with, for example, a UV curable ink as the ink I.

Upon receiving a printing start request from an operator via a personal computer or the like, the control unit 60 performs printing by the printing device 1 prior to printing by the printing device 1 (final printing). This printing is a preparatory printing for making adjustments such as registration and color matching before final printing, and is intended to improve the stability of the ink I. At the time of printing, trial printing is performed on the paper cup PC held by the holding member 10 in each printing section, and various adjustments are made.

In the first step S1, the controller 60 causes the holding member 10 to hold the paper cup PC. Specifically, the paper cup PC is attached by the attachment unit to the holding member 10 positioned at the paper cup attachment position MP, and the inner peripheral surface of the paper cup PC is sucked and held on the outer peripheral surface of the holding member 10 by vacuum suction. .

In the next step S2, the controller 60 positions the paper cup PC at the surface treatment position STP (second position P2). Specifically, the controller 60 controls the drive mechanism 80 to move the holding member 10 holding the paper cup PC from the paper cup mounting position MP to the surface treatment position STP.

In the next step S3, the control unit 60 controls the first driving unit 30 to rotate the paper cup PC around the first axis AX1 at, for example, a constant angular velocity ω to perform surface treatment. The surface treatment is, for example, surface treatment such as water-repellent treatment on the outer peripheral surface of the paper cup PC.

In the next step S4, the controller 60 determines whether or not the sensor 70 has detected the step S of the paper cup PC. If the judgment here is affirmative, the process proceeds to step S5, and if the judgment is negative, the same judgment is made again. That is, it is in a waiting state.

At step S5, the control section 60 stops the rotation of the paper cup PC. Specifically, the control unit 60 stops the rotation of the sensor 70 at the step detection timing of the paper cup PC or at a timing after the step detection timing, and sets the position of the step S around the first axis AX1. In this case, the position of the step S around the first axis AX1 (hereinafter referred to as the “initial angular position”) at the step detection timing is determined by the detection position of the sensor 70 (the laser beam irradiation position on the paper cup PC). The position (angular position) of the step S around the first axis AX1 when the rotation is stopped when the predetermined time ΔT has elapsed from the step detection timing is the initial angular position +ω×ΔT. The control unit 60 can calculate this angular position using a built-in timer (with step detection timing as a trigger).
That is, the control unit 60 can set the position of the step S around the first axis AX1 by the time (including 0) from the detection timing of the step S to the rotation stop timing of the paper cup PC.

At this time, the control unit 60 controls the first position of the step S so that the ink image Ii is formed on the outer peripheral surface of the paper cup PC at a position outside the step S with respect to the paper cup PC positioned at the first position P1. Set the position around the axis AX1.
Specifically, while the ink image Ii is being transferred to the outer peripheral surface of the paper cup PC located at the second position P2 (transfer position), the control unit 60 controls the contact between the ink image Ii and the outer peripheral surface of the paper cup PC. The position of the step S around the first axis AX1 is set so that the step S does not reach the position CP.

Here, as an example, as shown in FIGS. 9A and 10A, the control unit 60 controls the second driving unit 50 in advance to move the paper cup PC to the first position P1 on the ink image carrier 41. The position of the ink image carrier 41 around the third axis AX3 is adjusted so that the first contact position of the ink image Ii is the leading position of the ink image Ii. At this time, as shown in FIGS. 9A and 10A, the step S of the paper cup PC moved from the second position P2 to the first position P1 passes through the contact position CP between the paper cup PC and the ink image carrier 41. If it is at the position (for example, the position immediately after passing the contact position), the step S does not reach the contact position CP until the paper cup PC makes approximately one rotation. That is, if printing is performed after the step S passes through the contact position CP and before it reaches the contact position CP again, the ink image Ii can be formed at a position outside the step S (FIGS. 9B and 9B). 9C, 10B, 10C).

Therefore, the control unit 60 sets the position of the step S around the first axis AX1 so as to satisfy such conditions. For example, in the case of FIGS. 9A and 10A, the control unit 60 sets the angle range of the ink image Ii transferred to the paper cup PC in the circumferential direction of the paper cup PC to .DELTA..phi. The peripheral position may be set to a position rotated by, for example, +5° to (360°-Δφ-5°) around the first axis from the position corresponding to the contact position CP. If there is a step S within this angular range, the ink image Ii can also be formed in a region other than the step S in the circumferential direction of the outer peripheral surface of the paper cup PC (substantially the entire area is also possible). In the above angle range, the direction of rotation (arrow direction) of the paper cup PC in FIGS. "-".

The control unit 60 stores the setting result (set position) of the position of the step S around the first axis AX1 in the memory 90 .

In the next step S6, the control section 60 sets 1 to k.

In the next step S7, the control section 60 moves the paper cup PC to the k-th printing position PPk (for example, k=1 to 7). Specifically, the control unit 60 controls the drive mechanism 80 to move the paper cup PC held by the holding member 10 to the k-th printing position PPk, which is the position facing the k-th printing unit.

In the next step S8, the controller 60 transfers the k-th ink image Iik to the paper cup PC. Specifically, the control unit 60 controls the first driving unit 30 and the kth printing unit to transfer the kth ink image Iik onto the outer peripheral surface of the paper cup PC held by the holding member 10 (for example, 9A-9C, 10A-10C). Thereafter, the control unit 60 controls the first driving unit 30 to rotate the paper cup PC around the first axis while performing exposure by the exposure device and development by the development device. As a result, the k-th ink image Iik is formed at a position outside the step S on the outer peripheral surface of the paper cup PC.

In the next step S9, the controller 60 moves the paper cup PC to the k-th drying position DPk. Specifically, the controller 60 controls the drive mechanism 80 to move the paper cup PC held by the holding member 10 to the k-th drying position DPk, which is a position facing the k-th drying section.

In the next step S10, the controller 60 dries the k-th ink image Iik transferred to the paper cup PC. Specifically, the control unit 60 controls the first driving unit 30 and the k-th drying unit to rotate the paper cup PC held by the holding member 10 around the first axis while rotating the outer peripheral surface of the paper cup PC. dries the k-th ink image Iik transferred to . After drying of the k-th ink image Iik is completed, the control unit 60 stops the rotation of the paper cup PC around the first axis AX1 at the timing when the step S is positioned at the set position.

In the next step S11, the control unit 60 determines whether or not k<K (for example, 7). If the determination here is affirmative, the process proceeds to step S12, and if the determination is negative, the process proceeds to step S13.

At step S12, the controller 60 increments k. After step S12 is executed, the process returns to step S7. That is, the ink image Ii of another color is transferred to the paper cup PC and dried.

In step S13, the control unit 60 causes the image inspection unit to inspect the K-color ink image (the ink image formed by overlapping the first to Kth ink images) formed on the paper cup PC. Specifically, first, the control unit 60 controls the drive mechanism 80 to move the paper cup PC to the image inspection position IIP. Next, the image inspection unit inspects the K color ink image for printing defects such as lack of printing, fading, bleeding, etc., and outputs the inspection result to the control unit 60 . More specifically, the image inspection unit performs pattern matching by comparing a K-color ink image to be inspected with a non-defective product image captured in advance, and detects missing printing, blurring, and bleeding in the K-color ink image. The presence or absence of printing defects such as

At step S14, the control unit 60 determines whether the paper cup PC has passed the inspection. Specifically, the control unit 60 determines that the inspection is passed when the inspection result from the image inspection unit is "no printing defects", and determines that the inspection is unsuccessful when "printing defects are present". If the determination in step S14 is affirmative, the process proceeds to step S15, and if the determination is negative, the process proceeds to step S17.

In step S15, the controller 60 causes the final drying unit to finally dry the paper cup PC. Specifically, first, the controller 60 controls the drive mechanism 80 to move the paper cup PC to the final drying position FDP. Next, the control unit 60 controls the first driving unit 30 and the final drying unit to rotate the paper cup PC around the first axis AX1, thereby finally drying the K color ink image formed on the outer peripheral surface of the paper cup PC. . After step S15 is executed, the process proceeds to step S16.

In step S16, the control section 60 causes the non-defective product take-out unit to take out the paper cup PC as a non-defective product. Specifically, first, the control unit 60 controls the drive mechanism 80 to move the paper cup PC to the non-defective product take-out position GTP. Next, the control unit 60 releases the holding (vacuum suction) of the paper cup PC by the holding member 10 . Next, the robot arm of the non-defective product retrieving unit extracts the paper cup PC from the holding member 10 and sends it to the line for the next process (for example, sorting process, packing process, shipping process, etc.). After step S16 is executed, the flow ends.

In step S17, the controller 60 causes the defective product discharge unit to discharge the paper cup PC as a defective product. Specifically, first, the control unit 60 controls the drive mechanism 80 to move the paper cup PC to the defective product discharge position DDP. Next, the control unit 60 releases the holding (vacuum suction) of the paper cup PC by the holding member 10 . Next, the robot arm of the defective product ejection unit extracts the paper cup PC from the holding member 10 and sends it to the disposal line. After step S17 is executed, the flow ends.

<4. Printing Apparatus According to First Embodiment of the Present Invention, Printing Method Using the Printing Apparatus, and Effect of Paper Cup on which an Ink Image is Printed by the Printing Method>
The printing apparatus 1 according to the first embodiment of the present invention includes a holding member 10 that detachably holds the inner peripheral surface of the paper cup PC, and the holding member 10 that holds the paper cup PC substantially coaxially with the axis of the paper cup PC. A first rotation support member 20 rotatably supported around a first axis AX1 of and rotatable around a second axis, and a first drive unit 30 (drive unit) that rotates the holding member 10 around the first axis AX1 , the ink image carrier 41 is held by the holding member 10 and supported so as to be in contact with the outer peripheral surface of the paper cup PC positioned at the first position P1 around the second axis AX2, and rotatable around the third axis AX3. A second rotation support member 40, a control unit 60 that controls the first driving unit 30, and a holding member that is connected to the control unit 60 and holds the paper cup PC positioned at the second position P2 around the second axis AX2. and a sensor 70 for detecting a step S at a seam J of the paper cup PC when the paper cup PC 10 is rotated around the first axis AX1. The control unit 60 controls the first driving unit 30 to rotate the holding member 10 holding the paper cup PC positioned at the second position P2 around the first axis AX1, and the sensor 70 detects the step S at the timing or After the timing, the rotation is stopped to set the position of the step S around the first axis AX1, the paper cup PC is moved to the first position P1, and the outer peripheral surface of the paper cup PC is moved to the ink image carrier. 41, the paper cup PC is rotated to transfer the ink image Ii to the outer peripheral surface of the paper cup PC.
Thereby, the position of the step S around the first axis AX1 can be set to a desired position (for example, a position where the ink image Ii is not formed).
As a result, according to the printing apparatus 1 according to the first embodiment, it is possible to provide a printing apparatus capable of suppressing the occurrence of printing defects such as missing ink.

The ink image Ii is transferred to a portion of the outer peripheral surface of the paper cup PC in the circumferential direction. It is preferable to set the position of the step S around the first axis AX1 so that the step S does not reach the contact position CP between the image Ii and the outer peripheral surface of the paper cup PC. As a result, the ink image Ii can be formed at a position outside the step S on the outer peripheral surface of the paper cup PC.

According to the paper cup PC having the ink image Ii printed on the outer peripheral surface using the printing device 1, the paper cup PC having the ink image Ii printed at a position outside the step S on the outer peripheral surface of the paper cup PC is provided. can.

According to the paper cup PC on which the ink image Ii is printed on the outer peripheral surface using the printing device 1, the position (for example, desired A paper cup PC can be provided with an ink image Ii printed at position ).

A printing method using the printing apparatus 1 according to the first embodiment of the present invention rotates the paper cup PC around a first axis AX1 (predetermined axis) substantially coaxial with the axis of the paper cup PC, and the sensor 70 detects the paper cup. a step of detecting the step S of the seam J of the PC; a step of setting a position around the first axis AX1; and rotating the paper cup PC while bringing the outer peripheral surface of the paper cup PC, whose position around the first axis AX1 is set in the setting step, into contact with the ink image carrier 41. and transferring the ink image Ii to the outer peripheral surface of the paper cup PC.
Thereby, the position of the step S around the first axis AX1 can be set to a desired position (for example, a position where the ink image Ii is not formed). As a result, according to the printing method, it is possible to suppress the occurrence of printing defects such as missing ink.

The ink image Ii is transferred to a portion of the outer peripheral surface of the paper cup PC in the circumferential direction. It is preferable to set the position of the step S around the first axis AX1 so that the step does not reach the contact position CP where the image carrier 41 and the outer peripheral surface of the paper cup PC contact each other. As a result, the ink image Ii can be formed at a position outside the step S on the outer peripheral surface of the paper cup PC.

According to the paper cup PC on which the ink image Ii is printed on the outer peripheral surface by the above printing method, it is possible to provide the paper cup PC on which the ink image Ii is printed at a position outside the step S on the outer peripheral surface of the paper cup PC.

According to the paper cup PC on which the ink image Ii is printed on the outer peripheral surface by the above printing method, a position (for example, a desired position) corresponding to the set position of the step S around the first axis AX1 on the outer peripheral surface of the paper cup PC can provide a paper cup PC with an ink image Ii printed on it.

<5. Configuration of Printing Apparatus According to Second Embodiment of Present Invention>
A configuration of a printing apparatus 2 (curved surface printing apparatus) according to a second embodiment of the present invention will be described below with reference to FIGS. 11 and 12. FIG.
FIG. 11 is a side view schematically showing the configuration of the printing device 2. As shown in FIG. FIG. 12 is a block diagram schematically showing the functions of the printing device 2. As shown in FIG.

In the printing apparatus 2, as shown in FIG. 11, a first rotation support member 200 (for example, a turret) is supported by a base 210 so as to be rotatable around a substantially horizontal second axis AX2.
A plurality (e.g., eight) of holding members 10 (e.g., mandrels) are arranged on the first rotation support member 200 at equal angular intervals (e.g., 45° intervals) in the circumferential direction of the first rotation support member 200, and Each of the plurality of holding members 10 is supported so as to be rotatable around the first axis AX1.
Each holding member 10 supported by the first rotation support member 200 rotates counterclockwise (in the direction of arrow U) in FIG. ), it is possible to sequentially move to the paper cup mounting position MP, the standby position SP, the printing position PP, the pre-discharge position, and the discharge position DP. Here, as an example, the paper cup mounting position MP is at the 12 o'clock position, the standby position SP is at a position between the 12 o'clock position and the 10 o'clock position, the printing position PP is at the 9 o'clock position, The pre-ejection position is intermediate between the 9 o'clock position and the 6 o'clock position, and the ejection position DP is the 6 o'clock position.

A first sensor 70-1 for detecting the step S of the paper cup PC held by the holding member 10 positioned at the paper cup mounting position MP is arranged near the paper cup mounting position MP. The first sensor 70-1 has the same configuration as the sensor 70 described above. The first sensor 70-1 is connected to the controller 60 (see FIG. 12).
Further, a mounting unit for mounting the paper cup PC on the holding member 10 is arranged near the paper cup mounting position MP. The mounting unit is controlled by the control section 60 .

A second sensor 70-2 is arranged near the standby position SP to detect the step S of the paper cup PC held by the holding member 10 positioned at the standby position SP. The second sensor 70-2 has the same configuration as the sensor 70 described above. The second sensor 70-2 is connected to the controller 60 (see FIG. 12). Note that the second sensor 70-2 is not essential. If the second sensor 70-2 is not provided, for example, the first sensor 70-1 serves as a sensor for detecting the step S of the paper cup PC held by the holding member 10 positioned at the standby position SP. It may be placed near the SP.

A discharge unit for discharging the paper cup PC held by the holding member 10 is provided near the discharge position DP. The discharge unit is controlled by a control section 60 .

The printing unit 400 of the printing apparatus 2 includes an ink unit group 415 including a plurality (eg, eight (eight colors)) of ink units 410 (eg, first to eighth ink units), and an ink image carrier 41 (eg, a blanket). ) is provided in a predetermined region of the outer peripheral surface in the circumferential direction. The eight colors may be composed of, for example, three colors of C (cyan), M (magenta), and Y (yellow), and five special colors each including K (black) and W (white). The eight colors may be composed of eight spot colors each including K (black) and W (white), for example.

The second rotation support member 420 rotates a third axis substantially parallel to the second axis AX2 so that the ink image carrier 41 contacts the outer peripheral surface of the paper cup PC held by the holding member 10 positioned at the printing position PP. It is supported by a frame 430 so as to be rotatable around AX3.

A plurality of ink units 410 are arranged along the circumferential direction of the second rotation support member 420 .
Each ink unit 410 includes a case 413 , and a transfer roller 411 , an anilox roller 412 and an ink tank 413 arranged inside the case 413 .
Each ink unit 410 may have at least one intermediate transfer roller between the transfer roller 411 and the anilox roller 412 .

The case 413 is fixed via a fixing member 414 to the side surface of a disc portion 430a of the mount 430 that is substantially coaxial with the second rotation support member 420 .

The transfer roller 411 is positioned so that the outer peripheral surface (more specifically, a plate described later) contacts the ink image carrier 41 provided on the outer peripheral surface of the second rotation support member 420 . A plate in which a pattern for forming an ink image of a color corresponding to the transfer roller 411 is engraved (engraved) is attached to the outer peripheral surface of the transfer roller 411 .

The anilox roller 412 is positioned so that its outer peripheral surface contacts the outer peripheral surface of the transfer roller 411 and the ink supply portion of the ink tank 413 . The anilox roller 412 is a roller that scrapes out the ink I from the ink supply portion of the ink tank 413 and transfers it onto the plate on the outer peripheral surface of the transfer roller 411 .

The printing device 2 has a third drive section 55 (see FIG. 12) that drives the transfer roller 411 and the anilox roller 412 of each ink unit 410 . The third driving section 55 is controlled by the control section 60 .

The operation of the printing unit 400 will be described below.
First, the control unit 60 controls the third driving unit 55 to rotate the anilox roller 412 of each ink unit 410 in the direction of arrow P and rotate the transfer roller 411 in the direction of arrow Q to transfer ink I in the ink tank 413 . are sequentially transferred to the plates on the outer peripheral surfaces of the anilox roller 412 and the transfer roller 411 . As a result, an ink image of the color assigned to the ink unit 410 is formed on the plate.
Next, the control unit 60 controls the second driving unit 50 and the third driving unit 55 to rotate the second rotation support member 420 in the direction of arrow R, and rotate the transfer rollers 411 of the plurality of ink units 410 in the direction of arrow Q. By sequentially driving, each color ink image (ink image formed on the plate corresponding to the color) constituting the ink image Ii is sequentially transferred to the ink image carrier 41 rotating together with the second rotation support member 420. do.
That is, with respect to the ink image carrier 41 rotating in the direction of the arrow R (the rotation direction of the second rotation support member 420), the ink unit 410 positioned upstream in the rotation direction of the second rotation support member 420 is further downstream. The transfer of the ink image is performed in order of the ink unit 410 on the side.
An ink image Ii (for example, a full-color ink image) is formed on the ink image carrier 41 when the ink images are transferred from all the ink units 410 to the ink image carrier 41 .

<6. Operation of Printing Apparatus According to Second Embodiment of Present Invention>
Operations of the printing apparatus 2 according to the second embodiment of the present invention will be described with reference to FIGS. 11, 13 and 14. FIG. The operation of the printing device 2 shown in the flowchart of FIG. 13 is an example of the printing method of the present invention.

The setting of the printing conditions of the printing device 2, the operation setting of each movable part of the printing device 2, and the like can be performed by the operator through the operation of the personal computer.
Here, it is assumed that the ink image Ii is printed on a part of the outer peripheral surface of the paper cup PC in the circumferential direction (for example, within an angle range of 5° to 355°, 10° to 350°, etc.). A plate corresponding to each color of ink image that will constitute the ink image Ii to be printed on the paper cup PC is attached in advance to the outer peripheral surface of the transfer roller 411 corresponding to the color. The ink tank 413 of each ink unit 410 is supplied with, for example, UV curable ink as the ink I of the color corresponding to the ink unit 410 .

The control unit 60 controls the second driving unit 50 in advance to drive the second rotation support member 420 so that the tip position of the ink image Ii transferred to the ink image carrier 41 is positioned at the contact position CP (printing position PP). 11).
The control unit 60 controls the drive mechanism 80 in advance to position any one of the eight holding members 10 at the paper cup PC mounting position MP.

In the first step S21, the controller 60 causes the holding member 10 to hold the paper cup PC. Specifically, the controller 60 mounts the paper cup PC on the holding member 10 positioned at the paper cup mounting position MP by means of the mounting unit, and the inner circumference of the paper cup PC is attached to the outer peripheral surface of the holding member 10 by vacuum suction. Adsorb and hold the surface.

In the next step S22, the control section 60 controls the first drive section 30 to rotate the paper cup PC around the first axis AX1 at a constant angular velocity ω (constant velocity), for example.

In the next step S23, the controller 60 determines whether or not the first sensor 70-1 has detected the step S of the paper cup PC. If the judgment here is affirmative, the process proceeds to step S24, and if the judgment is negative, the same judgment is made again. That is, it is in a waiting state.

At step S24, the control section 60 stops the rotation of the paper cup PC. Specifically, the control unit 60 stops the rotation of the first sensor 70-1 at the step detection timing of the paper cup PC or at a timing later than the step detection timing, and detects the position of the step S around the first axis AX1. set. In this case, the position of the step S around the first axis AX1 at the step detection timing (hereinafter referred to as the “initial angular position”) is determined by the detection position of the first sensor 70-1 (laser beam irradiation position on the paper cup PC). is determined. The position (angular position) of the step S around the first axis AX1 when the rotation is stopped when the predetermined time ΔT has elapsed from the step detection timing is the initial angular position +ω×ΔT. The control unit 60 can calculate this angular position using a built-in timer (with step detection timing as a trigger).
That is, the control unit 60 can set the position of the step S around the first axis AX1 by the time (including 0) from the detection timing of the step S to the rotation stop timing of the paper cup PC.
The control unit 60 stores the setting result (set position) of the position of the step S around the first axis AX1 in the memory 90 .

In the next step S25, the controller 60 moves the holding member 10 holding the paper cup PC to the standby position SP. Specifically, the control unit 60 controls the drive mechanism 80 to rotate the first rotary support member 200 by 45 degrees, for example, in the direction of arrow U (see FIG. 11), and waits for the holding member 10 holding the paper cup PC. Move to position SP.

In the next step S26, the control unit 60 confirms the position of the step S. Specifically, the control unit 60 changes the position of the step S around the first axis AX1 based on the detection result of the second sensor 70-2 to the position around the first axis AX1 set in step S24 (stored in the memory 90). Check if it matches the saved setting result). If the control unit 60 determines that they match, it proceeds to the next step S27, and if it determines that they do not match, it outputs error information to, for example, an operation panel or the like, and the printer 2 operates. interrupt.

At step S27, the controller 60 moves the holding member 10 holding the paper cup PC to the printing position PP. Specifically, the control unit 60 controls the drive mechanism 80 to rotate the first rotary support member 200 by 45 degrees, for example, in the direction of arrow U (see FIG. 11) to print the holding member 10 holding the paper cup PC. Move to position PP. At this time, the step S of the paper cup PC is at a position where it does not come into contact with the ink image Ii transferred (held) on the ink image carrier 41 (see FIG. 11).

In the next step S28, the controller 60 transfers the ink image Ii to the paper cup PC. Specifically, the control unit 60 controls the first drive unit 30 and the second drive unit 50 to rotate the holding member 10 holding the paper cup PC in the direction of arrow V, and rotate the second rotation support member 420. By rotating in the direction of arrow R, the ink image Ii is transferred to the outer peripheral surface of the paper cup PC. Here, before the ink image Ii is transferred, the step S is located downstream of the contact position CP in the rotational direction (arrow V direction) of the holding member 10 (see FIG. 11). Since the transfer of the ink image Ii ends before the step S reaches the contact position CP, the step S is located upstream of the contact position CP in the rotational direction of the holding member 10 after the transfer of the ink image Ii ( See Figure 14). That is, during the transfer of the ink image Ii, the step S moves along the circumferential direction of the paper cup PC in a range outside the contact position P, so the ink image Ii is transferred to a position outside the step S of the paper cup PC. be done.

In the next step S29, the controller 60 moves the holding member 10 holding the paper cup PC to the discharge position DP. Specifically, first, the control unit 60 controls the drive mechanism 80 to rotate the first rotation support member 200 in the direction of arrow U (see FIG. 11) by, for example, 45 degrees, thereby turning the paper cup PC (first paper The holding member 10 holding the second paper cup PC is positioned at the pre-ejection position before the ejection position DP, and the holding member 10 holding the next paper cup PC (second paper cup) is positioned at the printing position PP. . Next, the control unit 60 prints the ink image Ii on the second paper cup in the same manner as for the first paper cup. When the printing of the ink image Ii on the second paper cup is completed, the control unit 60 controls the drive mechanism 80 to rotate the first rotary support member 200 by 45 degrees, for example, in the direction of the arrow U, thereby printing the first paper cup PC. to the discharge position DP.

In the last step S30, the control section 60 ejects the paper cup PC. Specifically, the control unit 60 controls the ejection unit to release the suction holding (vacuum suction) of the paper cup PC by the holding member 10 and eject the paper cup PC, for example, upside down to the ejection lane. The paper cups PC discharged to the discharge lane are sequentially sent to the drying lane and the inspection lane, for example, while being turned upside down, and only non-defective paper cups are sent to the shipping lane.

<7. Printing Apparatus According to Second Embodiment of the Present Invention, Printing Method Using the Printing Apparatus, and Effect of Paper Cup with Ink Image Printed on Outer Peripheral Surface by the Printing Method>
The printing apparatus 2 according to the second embodiment described above also has the same effects as the printing apparatus 1 according to the first embodiment.
The printing method using the printing apparatus 2 according to the second embodiment described above also has the same effects as the printing method using the printing apparatus 1 according to the first embodiment.
The paper cup PC on which the ink image Ii is printed by the printing method using the printing apparatus 2 according to the second embodiment described above also has the ink image li printed by the printing method using the printing apparatus 1 according to the first embodiment. It has the same effect as the paper cup PC that has been made.

<8. Modified example of the present invention>
The printing apparatus according to the present invention is not limited to the configuration of the printing apparatuses 1 and 2 according to the first and second embodiments, and can be modified as appropriate.

For example, the control unit 60 sets the position of the step S around the first axis AX1 so that the ink image Ii is formed at a predetermined position in the circumferential direction with the step S as a reference on the outer peripheral surface of the paper cup PC. good too. That is, in the setting step in the above printing method, the ink image Ii is transferred to a predetermined position on the outer peripheral surface of the paper cup PC in the circumferential direction with the step S as a reference. You can set the position.
As a result, the positional relationship in the circumferential direction between the step S and the ink image Ii on the outer peripheral surface of the paper cup PC can be changed to a desired positional relationship (for example, the central position of the ink image Ii in the circumferential direction can be changed from the position of the step S in the circumferential direction to the circumferential position). can be set to a positional relationship such as a position that is shifted by approximately 180° from .

For example, when a plurality of ink images Ii are superimposed and formed on the outer peripheral surface of the paper cup PC as in the printing apparatus 1 according to the first embodiment, the control unit 60 already forms the ink images Ii on the outer peripheral surface of the paper cup PC. The position of the step S around the first axis AX1 is set so that the ink image Ii is formed at a predetermined overlapping position when the new ink image Ii is superimposed on the ink image Ii thus formed. good too. That is, in the setting step in the above printing method, when a new ink image Ii is superimposed on the ink image Ii already formed on the outer peripheral surface of the paper cup PC and transferred, the ink image Ii is placed at a predetermined superimposition position. The position of the step S around the first axis AX1 may be set so that the image is transferred to . For example, if the previous ink image Ii is formed at a predetermined position with the step S as a reference, the ink image Ii after being superimposed on the ink image Ii is also formed at a predetermined position with the step S as a reference. , the overlay accuracy (positioning accuracy) can be improved.
As a result, it is possible to improve the overlay accuracy (positioning accuracy) of the ink images Ii and form a high-quality multicolor ink image.
In the printing apparatus 1, for example, all colors can be represented by multiplying halftone dots of four colors (C, M, Y, K). important.

Laser sensors are used as the sensors 70, 70-1, and 70-2 in the printing apparatuses 1 and 2 of the first and second embodiments, but the present invention is not limited to this. Any sensor may be used as long as it has a target (detection position) in a portion of the circumferential direction.
For example, as shown in FIG. 15, a sensor 70A including an imaging unit (such as a camera) having an angle of view θ and an image analysis unit (such as a CPU) may be used. While the paper cup PC is being rotated around the first axis AX1, the sensor 70A monitors and analyzes the image captured by the imaging section by the image analysis section, and when a linear image appears in the captured image, the image is detected. The image is detected as a step S, and a detection signal is output to the control section 60 .

For example, as shown in FIG. 16, a bent portion Ba formed at the tip of a blade B that is rotatable about an axis parallel to the first axis AX1 is placed along the outer circumference of the paper cup PC, and the paper cup PC is folded. is rotated around the first axis AX1, and when the bent portion Ba hits the step S, the blade B rotates to turn on the relay switch, and a detection signal is output to the control unit 60. good. When the bent portion Ba is not in contact with the step S, the blade B is biased by the tension spring SP and the relay switch is turned off.

In the printing apparatus 1 of the first embodiment, the plurality of holding members 10 holding the paper cups PC circulate around the second axis AX2 to perform printing and drying. A single holding member 10 may be configured to perform printing and drying at a predetermined location. In this case, each of the printing section and the drying section may also be single.

In the printing apparatus 2 of the second embodiment, the plurality of holding members 10 holding the paper cups PC are configured to circulate around the second axis AX2 for printing. One holding member 10 may have a configuration in which printing is performed at a predetermined location.

In the printing apparatuses 1 and 2 of the first and second embodiments described above, the holding member 10 is rotated around the first axis AX1 at the constant angular velocity ω when the step S is detected. It doesn't have to be. For example, the position of the step S around the first axis AX1 is measured by using a sensor (such as a gyro sensor) that detects the rotation angle of the holding member 10 rotated around the first axis AX1 from the timing at which the step S is detected. can do.

In the printing apparatus 1 of the first embodiment, the position (second position P2) where the step S of the paper cup PC is detected is the surface treatment position STP. DPk may be used, or a position (for example, a standby position) at which only detection of the step S is performed without performing other processing may be set separately. At least one sensor for detecting the step S is preferably installed at the position where the step S is detected (second position P2). Further, at the surface treatment position STP, the step detection operation may be performed separately from the surface treatment operation. At the drying position DPk, the step detection operation may be performed separately from the drying process.

The printing apparatus 1 of the first embodiment employs a configuration in which drying is performed each time one color is printed on the paper cup PC. A configuration in which drying is performed after drying may be employed.

The printing apparatuses 1 and 2 of the first and second embodiments are multicolor printing apparatuses, but may be monochrome printing apparatuses.

The present invention only needs to be able to form an ink image on the outer peripheral surface of the paper cup PC based on the results of detection by the sensor. It is not limited to the one described in the form.

For example, the present invention can be applied to an inkjet printing method and an inkjet printing apparatus used in the printing method. The inkjet printing apparatus, for example, includes an ink ejection head and an ink supply system that supplies ink to the ink ejection head. The ink supply system includes a plurality of ink tanks corresponding to multiple colors or a single ink tank corresponding to a single color. The ink ejection head is controlled by the controller according to the image data of the ink image. In the inkjet printing apparatus, for example, from an ink ejection head arranged at a position facing the outer peripheral surface of the paper cup PC held by the holding member 10 (a position near the ink adhesion position), the ink is ejected around the first axis AX1 of the step. An ink image can be formed (printed) by ejecting ink onto the outer peripheral surface of the paper cup PC whose position has been set. At this time, it is preferable to rotate the holding member 10 around the first axis AX1 during printing or between printing as necessary to displace the outer peripheral surface of the paper cup PC in the circumferential direction with respect to the ink ejection head. As a result, an ink image can be formed at a desired position and range in the circumferential direction of the outer peripheral surface of the paper cup PC.

In the above-described first and second embodiments, while the paper cup PC is rotated once (from when the step reaches the ink adhering position to when the step returns after one rotation), the ink is applied to the outer peripheral surface of the paper cup PC. An image is formed, but an ink image may be formed on the outer peripheral surface of the paper cup PC while the paper cup PC is rotated a plurality of times. In this case, the ink image may be formed on a part or the entirety of the outer peripheral surface of the paper cup PC in the circumferential direction.

In the printing method and printing apparatus according to the present invention, when an ink image is formed on the outer peripheral surface of the paper cup PC, information transmission indications (for example, quality indications, product names, cautions, etc.) consisting of letters, numbers, symbols, figures, etc. are formed on the ink images. writing, proviso, expiry date, best-before date, etc.), at least the ink for forming the information transmission display is adhered to a portion of the outer peripheral surface of the paper cup PC other than the step. A position around the first axis AX1 may be set. As a result, deterioration of the visibility of the information transmission display can be suppressed. In this case, the position of the step around the first axis AX may be set so that the portion of the ink image other than the information transmission display is formed on the step.

1, 2: printing apparatus, 10: holding member, 20, 200: first rotation support member, 30: first driving section (driving section), 40, 420: second rotation support member, 50: second driving section, 60: control unit, 70, 70-1, 70-2, 70A, 70B: sensor, PC: paper cup, P1: transfer position (first position), P2: position different from transfer position (second position), AX1: first axis (predetermined axis), AX2: second axis, AX3: third axis.

Claims (9)

a step of rotating a paper cup around a predetermined axis substantially coaxial with the axis of the paper cup and detecting a step at the seam of the paper cup with a sensor;
forming an ink image on the outer peripheral surface of the paper cup based on the detection result in the detecting step;
printing methods, including; The forming step includes:
setting the position of the step about the predetermined axis by stopping the rotation of the paper cup about the predetermined axis at the timing when the step is detected in the detecting step or at a timing after the timing;
a step of attaching ink for forming the ink image to the outer peripheral surface of the paper cup whose position around the predetermined axis is set in the setting step;
The printing method of claim 1, comprising: In the setting step, while at least a part of the ink image is formed on the outer peripheral surface in the attaching step, the ink attachment position where the ink is attached to the outer peripheral surface is prevented from reaching the step. 3. The printing method according to claim 2, wherein the position of said step around said predetermined axis is set to . the ink image includes an informational indicia;
In the setting step, at least the predetermined amount of the step is set so that the step does not reach the ink adhesion position while the ink for forming the information transmission display is being adhered to the outer peripheral surface at the ink adhesion position. 4. The printing method according to claim 3, wherein the position around the axis is set. In the attaching step, the ink image is applied to the outer peripheral surface of the paper cup by rotating the paper cup while bringing the outer peripheral surface of the paper cup, whose position around the predetermined axis is set in the setting step, into contact with the ink image carrier. The printing method according to any one of claims 2 to 4, wherein the printing method is transferred. A plurality of the ink images are superimposed and transferred onto the outer peripheral surface of the paper cup,
In the setting step, when the new ink image is superimposed on the ink image already transferred to the outer peripheral surface of the paper cup and transferred, the ink image is transferred to a predetermined superimposition position. 6. The printing method according to claim 5, wherein the position of said step around said predetermined axis is set. 3. In the setting step, the position of the step about the predetermined axis is set so that the ink image is formed at a predetermined position in the circumferential direction of the outer peripheral surface of the paper cup with the step as a reference. 7. The printing method according to any one of 2 to 6. A paper cup having the ink image printed on its outer peripheral surface by the printing method according to any one of claims 1 to 7. a holding member that detachably holds the inner peripheral surface of the paper cup;
a first rotation support member that supports the holding member holding the paper cup so as to be rotatable around a first axis that is substantially coaxial with the axis of the paper cup, and that is rotatable around a second axis;
a drive unit that rotates the holding member around the first axis;
a second rotary support member that is held by the holding member and supports the ink image carrier so as to be in contact with the outer peripheral surface of the paper cup positioned at the first position around the second axis, and that is rotatable around the third axis; ,
a control unit that controls the driving unit;
When the holding member connected to the control unit and holding the paper cup positioned at a second position around the second axis is rotated around the first axis, a step at the seam of the paper cup is detected. a sensor;
with
The control unit controls the driving unit to rotate the holding member holding the paper cup positioned at the second position around the first axis, and based on the detection result of the sensor, the paper A printing device that forms an ink image on the outer peripheral surface of a cup.

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