JP2020082385A - Printed matter, printing plate and production method of printed matter - Google Patents

Abstract

To provide a printed matter with double counterfeit prevention effect by having counterfeit prevention functionality combining fine lines and a hologram, which enables characters or a pattern to be visually recognized from a top face, the characters or the pattern being capable of being recognized as a hologram from the top face but being difficult to visually recognize by irradiating a rear face with light from a light source.SOLUTION: A printed matter comprises: a polarization layer part having a plurality of irregular patterns which are not constant in height or depth on one surface of a first substrate; and a printed part which has fine printing lines formed of at least photochromic ink on one surface of a second substrate. The polarization layer part and the printed part are bonded to each other via an adhesive material layer.SELECTED DRAWING: Figure 3

Description

The present invention is a printed matter that has an uneven pattern and fine lines and displays an image by light interference and diffraction.

It is required that it is difficult to counterfeit a printed matter formed on a part or a front surface of a credit card, an authentication document, securities, bills and the like. As a technique for making it difficult to forge such a printed matter, for example, as shown in Patent Document 1, a hologram, a diffraction grating, or an OVD (Optically Variable Device) such as a multilayer film that causes a color change depending on a viewing angle. There is a medium.

Also, as a fine technique different from holograms and diffraction gratings, there is line drawing formed by a set of lines. This line drawing is used for authenticity judgment centering on banknotes, because it is not possible to form a fine straight line in a conventional copying machine that mainly uses an ink jet that expresses an image by expressing an image with a line of 50 μm or less. This is the method used.

As a method of forming this line drawing, for example, there is a gravure offset printing method. In the gravure offset printing method, printing is performed by transferring ink from a printing plate having recesses filled with ink to a blanket and transferring the ink on the blanket onto a printing substrate.
For example, Patent Document 2 discloses that a gravure offset printing method is used as a method of printing a patterned wiring structure on a frame portion in a method of manufacturing a conductive member for a touch panel having a wiring structure.

Japanese Patent Publication No. 2008-547040 JP, 2011-210148, A

As mentioned above, technological development is being carried out daily for the purpose of designing specifications that are difficult to counterfeit, such as holograms and fine wiring, but with the diversification of manufacturing technology, it is necessary to develop the counterfeit prevention function for each individual printed matter. Is becoming more difficult, and there is a demand for technology that is more difficult to forge and has a high anti-counterfeiting effect.

Therefore, the present invention has been made in view of such a problem, and can be visually recognized as a hologram from the front surface, but by projecting the light of the light source on the back surface, it is difficult to visually recognize characters or patterns from the front. It is an object of the present invention to provide a printed matter which has a forgery prevention function in which fine lines and hologram elements are combined and which is visible, and which has a double anti-counterfeiting effect.

In order to solve the above problems, the first invention of the present invention is
A polarizing layer portion having a plurality of uneven patterns having at least height or depth that is not constant on one surface of the first substrate,
A printed matter comprising a second base material and one printed surface having a fine printed line made of a photochromic ink, which is bonded to one surface of the second base material via an adhesive layer.

The second invention of the present invention is
The printed material is characterized in that the second base material has a fine printed line made of a light-reflective ink on a surface opposite to the fine printed line made of the photochromic ink.

The third invention of the present invention is
The fine printed line made of the photochromic ink is made up of a plurality of lines having a line width of 100 μm or less, and a gap between adjacent lines has a line width of 50 between the two adjacent lines having a narrow line width. It is a printed matter characterized by being less than double.

A fourth invention of the present invention is
The printed matter is characterized in that the fine printed line made of the light-reflective ink is made up of a plurality of lines having a line width of 100 μm or less, and the light-reflective ink of at least one kind of color is used.

The fifth invention of the present invention is
The fine printed line made of the photochromic ink is arranged in a gap portion of the fine printed line made of the light reflective ink when viewed from a direction perpendicular to a printed matter plane. The printed matter according to any one of 1 to 4.

The sixth invention of the present invention is
A polarizing layer portion having a plurality of uneven patterns in which the height or depth is not constant on one surface of the base material, and a printing portion having at least a fine printed line made of a photochromic ink on the other surface of the base material. It is a printed matter characterized by comprising.

The seventh invention of the present invention is
The fine printed line forming the printed portion is a printed matter characterized by being arranged in a predetermined specific wiring pattern in the area of the printed portion.

The eighth invention of the present invention is
The printed matter is characterized in that the shading of the color of the printing section is adjusted by changing the line width of the fine printed line arranged in a unit area.

The ninth invention of the present invention is
The printed matter is characterized by having a plurality of the fine printed lines having a convex structure, and at least a part of the fine printed lines having the convex structure has a multi-layer structure formed by laminating a plurality of inks.

The tenth invention of the present invention is
The printed matter is characterized in that, in the polarizing layer section, at least one image is formed by an uneven pattern having at least one kind of uneven height or depth.

The eleventh invention of the present invention is
It is a printed matter characterized in that it extends in one direction on the plurality of fine printed lines, and the cross section of the fine printed lines has a shape obtained by arbitrarily combining polygonal shapes or curved shapes.

The twelfth invention of the present invention is
A printing plate for intaglio printing, comprising a plurality of linear grooves having a groove width of 100 μm or less on a part of the printing surface of the base material surface, wherein the plurality of linear grooves are adjacent grooves. The printing plate is characterized by having a region in which the groove width is set to 50 times or less the groove width of a groove having a narrow groove width of two adjacent grooves forming the gap.

A thirteenth invention of the present invention is
At least a part of the plurality of linear grooves is a printing plate having a groove width or a groove depth different from those of the other grooves.

The fourteenth invention of the present invention is
A method for producing the printed matter, comprising:
The fine printed lines in the printed matter are printed by at least one or more intaglio plates, and when two or more intaglio plates are used, by aligning and printing each intaglio plate, at least one or more intaglio plates are printed on the same surface. A method for manufacturing a printed matter, which comprises arranging an image.

The fifteenth invention of the present invention is
A method for producing the printed matter, comprising:
Using a plurality of printing plates for intaglio printing having a plurality of linear grooves each having a width of 100 μm or less on a part of the surface of the base material, intaglio printing is sequentially performed on the surface of the base material. By doing this, the ink is transferred to form the printing part,
Manufacturing of a printed product characterized in that a groove formed in one printing plate of the plurality of printing plates has a groove width or a groove depth different from those of grooves formed in another printing plate. Is the way.

According to any one aspect of the printed matter of the present invention, a pattern that can be visually recognized only when light is incident by performing alignment printing using a plurality of uneven patterns, a light-reflective ink, and a light-modifying ink. A print expression such as a pattern can be formed. Further, a double anti-counterfeiting effect can be obtained by pasting or stacking an OVD medium such as a hologram or a diffraction grating on the upper part of the design pattern of this printed matter, and the counterfeiting effect is more difficult and the anti-counterfeiting effect is high. Is obtained.

It is a conceptual diagram explaining the printed matter which concerns on embodiment based on this invention. It is a conceptual diagram explaining the printed matter which concerns on embodiment based on this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a cross-sectional schematic diagram explaining one form of the structure of the printed matter of this invention. It is a conceptual diagram of a printing machine for gravure offset printing. It is a conceptual diagram explaining the example of a printing plate base material.

An embodiment of the present invention will be described below with reference to the drawings.
Here, the drawings are schematic, and the relationship between the thickness and the plane dimension, the thickness ratio of each layer, and the like are different from the actual ones. Further, the embodiments described below exemplify a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is that the material, shape, structure, etc. of the components are as follows. It is not specific to one. The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims described in the claims.

FIG. 3 shows the overall configuration of an embodiment of the printed matter of the present invention.
It should be noted that FIG. 3 is a cross-sectional view taken along the line C of FIG.
As shown in FIG. 3, the printed matter 1 according to the present embodiment has a polarizing layer portion 6 having a fine concavo-convex portion 7 on one surface of a base material 2a and a light reflective fine printing on another surface of another base material 2b. The line 3 and the printing portion 5 including the photo-modified fine printed line 4 are adhered to the other surface of the substrate 2b via the adhesive material 9.
Hereinafter, for convenience, the surface close to the fine concavo-convex portion 7 is referred to as an A surface, and the surface close to the photo-modified fine printed line 4 is referred to as a B surface.

The light-reflective fine printed lines 3 are formed of light-reflective ink and are arranged with a certain gap. The photo-modified fine printed lines 4 are formed of the photo-modified ink and are arranged in the gaps between the patterns of the light-reflective fine printed lines 3 when viewed from the direction perpendicular to the plane of the printed matter 1. As will be described later in detail, when the light is irradiated from the side B side in a direction perpendicular to the printed matter plane as shown in FIG. 2, the light passing through the photo-modified fine printed line 4 is converted into the light-reflecting fine printed line 3. This is because the image discolored by the photo-denatured fine printed lines 4 can be visually recognized by passing through the gap.

It should be noted that the print display that constitutes the printing unit 5 does not necessarily have to be configured such that a clear pattern or the like can be visually recognized in the absence of a light source. The printing pattern of the printing unit 5 according to the present invention may be arranged on at least a part of the base material 2b, and two or more may be arranged on the base material 2b.

The base material 2a, the base material 2b, the fine concavo-convex portion 7, and the adhesive material 9 are all transparent.

The printed matter 1 of the present embodiment has a total thickness of, for example, 5.0 μm or more and 300.0 μm, in which the base materials 2 a and 2 b, the light-reflecting fine printed lines 3, the photo-modified fine printed lines 4, and the fine uneven portions 7 are combined. Thickness. The base material 2b may have a printing portion other than the printing portion 5 according to the present invention. Further, the photo-modified fine printed line 4 according to the present invention may be arranged as a part of the printed portion other than the printed portion 5 according to the present invention.

In the present embodiment, a printed matter 1 including a printed display such as a pattern is configured by combining a plurality of light-reflective fine printed lines 3 and photo-modified fine printed lines 4 and fine uneven portions 7 as shown in FIG. 3, for example. To be done.

The light-reflective fine printed line 3 is formed of a fine printed line having a line width E of 100 μm or less with a gap that cannot be visually recognized. At this time, the light-reflective fine printed lines 3 are formed by combining at least one color from a light-reflective ink (which will be described later in detail), so that the front surface of the printed matter (viewed from the side A in FIG. 3) is formed. The visibility of the fine uneven portion image from the surface) is improved.

Further, the photo-modified fine printed line 4 according to the present invention has a line width which cannot be visually recognized, and the fine line has a line width E of 100 μm or less. At this time, when the light-modified fine printed line 4 is composed of a combination of at least one color from a light-modified ink (which will be described later in detail), the light can be incident from the back surface (B surface side). The image of the photo-modified fine printed line 4 can be visually recognized from the front surface (A surface side).

The polarizing layer portion 6 is a functional layer having an OVD effect, and the fine concavo-convex portion 7 therein includes an OVD medium such as a relief hologram pattern and a diffraction grating pattern.
The OVD medium has, for example, a uniform diffraction grating pattern formed on the surface of the pattern forming layer or at least one diffraction grating pattern.

In the diffraction grating pattern, at least one parameter is different with the spatial frequency and the depth or height of the concavo-convex pattern as parameters, and thus the displayed pattern changes due to the difference in the viewing angle. Therefore, it is possible to display not only a display image that is uniform over the entire surface but also images such as pictures, characters, and symbols by changing these parameters variously.

This diffraction grating pattern has a depth or height that cannot be visually recognized, and the difference between the apex and the low point of the diffraction grating pattern is 1 μm or less.

(Method of forming fine irregularities)
An example of a method of forming the fine irregularities 7 will be described.
The fine concavo-convex portion 7 is formed by using a relief type original plate having a fine concavo-convex pattern produced by an optical imaging method utilizing interference of laser light or electron beam drawing.

From this original plate, a metallic stamper is produced by a method such as electroforming, and a thermoplastic resin, a thermosetting resin, an ionizing radiation curable resin or the like is applied to a flat substrate by using this metal stamper as a mother mold. , A metal stamper is brought into close contact with the resin, and the resin is cured by applying heat or light to duplicate the pattern of the fine concavo-convex portion 7.

(Thermoplastic resin)
As the thermoplastic resin, PET (polyethylene terephthalate), PC (polycarbonate), PS (polystyrene), COC (cyclic olefin copolymer), PMMA (polymethyl methacrylate (polymethyl methacrylate, acrylic resin)), COP (cycloolefin) Polymer), MS (styrene methacrylic acid copolymer), AS (acrylonitrile styrene copolymer), PMMA (polymethyl methacrylate (polymethyl methacrylate, acrylic resin)), PEN (polyethylene naphthalate), PI (polyimide), etc. It is possible to use thermoplastic resins such as.

As the thermosetting resin, it is possible to use phenol resin, melamine resin, epoxy resin, alkyd, and other thermosetting resins well known in the art.
In addition to the above, engineering plastics such as PBT (polybutylene terephthalate), POM (polyoxymethyl), PA (polyamide), PPS (polyphenyl sulfide), and super engineering plastics can be used.

In addition to these, it is possible to use resins such as acrylic, urethane, epoxy, polyester, and thiol that are cured by ionizing radiation.

(Base material)
In the present embodiment, the base material 2a forming the polarizing layer portion 6 has the fine irregularities 7 formed on the upper surface thereof, but it is not necessary to form it on the entire upper surface of the base material. Further, a print other than the print pattern according to the present invention may be formed on the base material 2b.

Here, the base material 2a and the base material 2b shown in FIG. 3 are collectively referred to as the base material 2. The base material 2 is not limited to a sheet-shaped material, and may be hollow or solid, and an arbitrary flat surface or curved surface can be used as a printing surface for forming the printing portion 5.

The substrate 2 is, for example, a glass plate such as soda lime glass, low-alkali borosilicate glass, or non-alkali aluminoborosilicate glass, or polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), polycarbonate. In addition to plastic plates and plastic films made of (PC), processed paper known in the relevant field such as clean paper, coated paper, calendar paper, etc., known in the relevant field such as sodium polyacrylate, polyvinyl alcohol, polyethylene oxide, etc. It is possible to use biocompatible polymers known in the art such as known water-soluble polymers, polylactic acid, polyglycolic acid, and polycaprolactone.

(Adhesive material)
In order to integrally form the printing portion 5 and the polarizing layer portion 6, a method of coating an adhesive material 9 such as vinyl acetate on either the printing portion 5 or the polarizing layer portion 6 and integrally adhering the other layer is possible. is there.

Examples of the adhesive material 9 used for integrally bonding include vinyl acetate, acrylic, urethane-based, rubber-based, and silicon-based adhesive materials. In any case, since it is used at a high temperature, it is desirable that the storage elastic modulus G′ at 100° C. is 1.0×10 ⁴ Pa or more. If the value is lower than this, the resin layer and the base material may be displaced during use.

Transparent particles such as organic particles and inorganic particles having different refractive indexes may be mixed in the adhesive material, and the adhesive material may be a double-sided tape or a single layer. Further, the adhesive material may be processed into a sheet shape in advance, or may be directly applied to a desired member of the base material sheet. The surface adjacent to the adhesive material may be subjected to corona treatment in advance.

As a method for applying the adhesive/adhesive material layer, either extrusion coating, various coating devices such as comma coater, printing method, method using dispenser or spray, or manual coating using a brush or the like Good.

(Light reflective fine printed lines)
In the printed matter 1 shown in FIG. 1, there is no incident light from the B side, and the printed matter 1 is viewed from the A side. In this case, since the light-reflective fine printed line 3 is formed of the reflective ink, it acts as a reflector when visually recognizing the fine uneven portion 7, and a hologram image formed by the diffraction grating pattern of the fine uneven portion 7 is formed. Visibility is improved. At this time, it is difficult to visually recognize the light-modified fine printed lines 4 due to the reflection of the light-reflective fine printed lines 3.

The light-reflective fine printed lines 3 are composed of a plurality of lines, and the plurality of lines are composed of a combination of several line widths so that the line spacing is 100 μm or less.

When the line spacing of the light-reflective fine printed lines 3 is 100 μm or more, the light-modified fine printed lines 4 are likely to be visually recognized even when there is no incident light from the B surface, and the reflective material of the fine irregularities 7 is formed. It does not make sense as.

(Light reflective ink)
As the color-developing pigment of the light-reflective ink forming the light-reflective fine printed lines 3, gold, silver, copper, zinc, aluminum, a pearl pigment alone or a mixture thereof is used in order to have light reflectivity. However, the present invention is not limited to this, and organic pigments/inorganic pigments known in the printing field can be appropriately used.

As the inorganic pigment, other than the above-mentioned metal particles, titanium dioxide, zinc white, other oxides represented by iron black, hydroxide, sulfide, selenide, ferrocyanide, chromate, sulfate, There are carbonates, silicates, phosphates, carbon and the like. Examples of organic pigments include carbon compounds, nitroso-based, nitro-based, azo-based, lake-based, phthalocyanine-based, condensed polycyclic materials and the like.

In contrast to these pigments for the purpose of light reflection, for the purpose of conductivity, metal fine particles, conductive metal oxide fine particles, metal nanowires, metal chlorides, conductive polyaniline, conductive polypropyrole, conductive polythiophene (polyethylenedioxy) A conductive polymer such as thiophene and polystyrene sulfonic acid complex) may be mixed and used.

Light-scattering particles may be mixed in the light-reflecting ink. That is, the light-scattering particles may be contained in any of the inks of different hues that make up the printed matter 1, or may be contained in any of a plurality of laminated layers. As light-scattering particles to be mixed with the light-reflecting ink, spherical particles or irregular particles are used. Further, as the material of the light scattering particles, particles made of inorganic fine particles or organic fine particles are used.

Specific examples include acrylic particles, styrene particles, styrene acrylic particles and cross-linked products thereof, melamine-formalin condensate particles, polyurethane particles, polyester particles, silicon particles, fluorine particles, and epoxy particles thereof. Clay compound particles such as polymer, smectite, kaolinite, talc, silica, titanium oxide, alumina, silica alumina, zirconia, zinc oxide, barium oxide, inorganic oxide particles such as strontium oxide, calcium carbonate, barium carbonate, magnesium carbonate Examples include inorganic fine particles such as barium chloride, barium sulfate, barium nitrate, barium hydroxide, aluminum hydroxide, strontium carbonate, strontium chloride, strontium sulfate, strontium nitrate, strontium hydroxide, and glass particles.

As these transparent particles having a high refractive index, only one kind of particles may be mixed and used, or a plurality of kinds may be mixed and used. The inorganic fine particles or the organic particles may be surface-treated by coating or vapor deposition, and may be used alone or in combination of two or more. That is, the mixed light scattering particles may include at least two light scattering particles having different refractive indexes.

The mixed light-scattering particles may include two or more light-scattering particles having different haze values instead of the light-scattering particles having different refractive indexes. Instead of mixing the light-scattering particles, the ink in the state of forming the light-reflective fine printed lines 3 may include fine voids containing air. For example, a foaming agent is contained in the material of the ink to be printed, and the foaming agent is foamed to form a cavity.

As the solvent in the ink, for example, dodecane or tetradecane is used. Any solvent can be used as the solvent in the ink. For example, in a quick-drying ink, a solvent having a low boiling point (MEK, ethanol, acetone, etc.) that dries at room temperature, water (purified water) for an aqueous ink, and an oil (aliphatic hydrocarbon, which does not evaporate at room temperature for an oil-based ink). Glycol ether, higher alcohols, etc.) can be used. It should be noted that it is preferable to select a material for the blanket 11 that has absorbency for the solvent, depending on the type of the solvent.

The resin material used as the ink material other than the pigment and particles may be a transparent resin, a colored resin, or an opaque resin. That is, for example, polycarbonate resin, acrylic resin, fluorine-based acrylic resin, silicon-based acrylic resin, epoxy acrylate resin, polystyrene resin, acrylonitrile styrene resin, cycloolefin polymer, methyl styrene resin, fluorene resin, PET (polyethylene terephthalate), polypropylene It is possible to use thermoplastic resins such as phenol resin, melamine resin, PEN (polyethylene naphthalate) and PI (polyimide), and general-purpose plastics such as thermosetting resin. As the thermoplastic resin, the above-mentioned materials can be used.
The thermosetting resin can also use the above-mentioned materials.

In the printed matter 1 shown in FIG. 2, when there is incident light 8 from the B side, when the printed matter 1 is viewed from the A side, it is difficult to visually recognize the fine concavo-convex portion 7 by the light from the B side. The photo-modified fine printed lines 4 change color from the gaps between the reflective fine printed lines 3 and can be visually recognized.

(Photo-modified fine printed lines)
The photo-denatured fine printed line 4 is composed of a plurality of lines, and the gap between adjacent lines is 50 times or less than the line width of the narrow line of the two lines forming the gap. Is set. The light-modified fine printed line 4 cannot be visually recognized because it is fine with a single line even if it has a color. Therefore, it is composed of a plurality of lines, and the gap is set to 50 times or less of the line width, so that continuous color is obtained. It becomes visible in the pattern. It should be noted that the lines are not limited to being parallel to each other and may intersect with each other, and the interval is naturally "0" at the intersecting position.

(Photo-modified ink)
The color pigment of the photo-modified ink used for the photo-modified fine printed line 4 is a luminescent rare earth complex such as europium (Eu), terbium (Tb), and neodymium (Nd), or a fluorescent substance, in order to have a color-changing property associated with photoexcitation light emission. Pigments, infrared luminescent pigments and the like may be used alone or as a mixture thereof, and the present invention is not limited thereto, and photochromic organic pigments/inorganic pigments known in the printing field may be appropriately used.

In contrast to these pigments for photochromic properties, metal fine particles, conductive metal oxide fine particles, metal nanowires, metal chlorides, conductive polyaniline, conductive polypropylene, conductive polythiophene (polyethylenedioxy A conductive polymer such as thiophene and polystyrene sulfonic acid complex) may be mixed and used.

The ink used for the light-modified fine printed line 4 may be mixed with light-scattering particles, and these may use one of the contents described above for the light-reflective fine printed line 3 or a combination thereof. ..

As the solvent and resin in the ink used for the light-modified fine printed line 4, it is preferable to select the material having the content described above for the light-reflective fine printed line 3.

The light reflective fine printed lines 3 and the light modified fine printed lines 4 are formed using an intaglio. One intaglio may be arranged on the same plane with a specific wiring pattern, or different intaglios may be aligned and printed to perform a specific wiring pattern. When printing is performed using different intaglio plates, there may or may not be a line interval, but it is preferable to leave a gap of 2 μm or more in order to avoid color mixing.

Hereinafter, in the text, the light-reflecting fine printed lines 3 and the light-modified fine printed lines 4 may be collectively referred to as "plural fine printed lines" or simply "fine printed lines".
A plurality of fine printed lines expressing the printing unit 5 may be arranged in a stack by performing printing by aligning different intaglios on the same plane. At this time, by stacking using the same intaglio, only a specific part may be bulky.

In addition, when the plurality of lines are arranged in parallel along one direction to form the printing unit 5, the light and shade of the color of the print expression forming the photo-denatured fine printed line 4 is the line width of the line arranged per unit area. By changing it, the grayscale representation of the color is adjusted.

Here, conventionally, when printing is expressed by halftone dots, the shade of color is expressed by changing the size of halftone dots. That is, the shade is expressed by changing the occupancy rate (ink area) of the ink per unit area.

On the other hand, according to the present embodiment, it is possible to adjust the shade by changing the line width even if the ink area is the same. For example, instead of arranging the photo-modified fine printed lines 4 having a width of 10 μm at intervals of 10 μm, the ink area (area ratio of 50 in this example) is obtained when the photo-modified fine printed lines 4 having a width of 100 μm are arranged at an interval of 100 μm. %), the color intensity (color difference meter measurement value) becomes dark when visually observed.

As described above, in the present embodiment, it is possible to adjust the shading without changing the ink area. As a result, in the present embodiment, the degree of freedom in adjusting the shade of color is widened, and higher-definition print expression is possible even in fine printing.

When the printing unit 5 is configured by a plurality of fine printed lines, the plurality of fine printed lines can be arranged and expressed by a specific wiring pattern other than parallel straight lines. The specific wiring pattern may be, for example, a pattern in which a plurality of fine printed lines are arranged in a predetermined direction, arranged concentrically, arranged in a lattice, or arranged radially. However, the rule of the wiring pattern is not limited to the above pattern. The present invention is applicable to any wiring pattern such as random arrangement as long as it is a combination of fine printed lines having a line width of 100 μm or less.

Further, the fine printed line of the present embodiment does not have to extend in a straight line shape, and may extend in a curved line such as meandering. In addition, ink may be blurred during printing, but it is sufficient if the line length is 1.5 times or more the line width.

Next, some configuration examples of the printed matter 1 will be shown.
4 to 8 are cross-sectional views in the case where fine printed lines and fine uneven portions are arranged, respectively.
As shown in the sectional view of FIG. 4, fine printed lines may be printed on the front and back of the base material 2 via the adhesive 9 under the fine concavo-convex portion 7, or as shown in FIG. Only the photo-modified fine printed line 4 may be arranged under the uneven portion 7, and in any of the examples, it is possible to obtain a printed matter having a different visible pattern depending on whether light is incident or not.

In FIG. 4, as compared with FIG. 3, the light-reflective fine printed lines 3 and the light-modified fine printed lines 4 are arranged at positions opposite to the front and back of the base material 2b. In FIG. 5, only the photo-modified fine printed line 4 is arranged under the fine uneven portion 7. Further, in FIG. 8, the fine concavo-convex portion 7 is formed on one surface of the base material 2, and the photo-modified fine printed line 4 is arranged on the other surface, and no adhesive material is provided between them.
6 to 8 show a configuration in which the concavo-convex structure portion 7 is formed on the surface of the hologram foil 30 in the polarizing layer portion. Also in this case, the arrangement of the fine printed lines can be the same as the configuration of FIGS.

In the case of the example shown in FIG. 1, for simplification, a visible image by the fine concavo-convex portion when viewed from the A surface when the light source is not turned on to the B surface side is illustrated by a rectangle, and in FIG. In the case of the example shown, the visible image of the photo-modified fine printed line 4 when viewed from the A surface when the light source is turned on to the B surface is illustrated by a circle. These images are examples, and the present invention is not limited to these.

Further, there may be variations in the heights of a plurality of fine printed lines forming one printing unit 5. When the height of one layer of finely printed lines arbitrarily formed in a convex structure is varied, two or more layers of different colors may be laminated and increased for some lines. Examples of the cross-sectional shape include a semicircle, a triangle, a rectangle, and a trapezoid.

In the present invention, all or a part of the plurality of fine printed lines forming the printing unit 5 does not need to have a convex structure. When the fine printed lines are not formed to have a convex structure, for example, the fine printed lines are printed by a relief printing method. You may.

As described above, according to this embodiment, it is possible to form a print expression such as a pattern pattern in which colors are continuously visible by combining fine print lines, and thus it is possible to obtain a high-definition fine print product. Become. The printing substrate 2 is not limited to a sheet shape, and may be a three-dimensional object such as a toy, and the printing section 5 may be formed on the surface of the three-dimensional object.

As described above, the display of the printing unit 5 provided on the printed matter 1 of the present embodiment is arranged with a specific wiring pattern set in advance, so that an OVD and a visual image of a line drawing are displayed depending on the presence or absence of incident light from the back surface light source. It is suitable for producing a printed matter that changes, and it is possible to add design characteristics to a printed matter for advertising, toys, containers and packaging, and the like.
The printing portion 5 having a minute swelling (convex structure) of the ink, which is composed of the fine printing lines as described above, can be formed by printing by intaglio printing by the gravure offset printing method, for example. An example will be described below.

(Printing device)
First, FIG. 9 shows a conceptual diagram of an embodiment of the printing apparatus of the present invention.
The printing device 10 for gravure offset printing includes a printing plate 12 made of an intaglio and a transfer blanket 11.
In FIG. 9, first, in the printing plate 12, a concave portion corresponding to a printing portion to be printed is formed on the transfer surface of the surface of the printing plate base material, the concave portion is filled with the ink 14, and the printing plate 12 is printed by the doctor blade 22. Excess ink on 12 is scraped off. At this time, the printing plate 12 is fixed on the upper surface of the printing plate fixing surface plate 15.

The blanket 11 is then fixed to the surface of the rotatable blanket cylinder 13. The blanket cylinder 13 is rotatably supported by a carriage (not shown), and the carriage is movably supported by a carriage (not shown) on the carriage. Then, the blanket 11 rolls on the printing plate 12 to transfer the ink from the concave portion of the printing surface of the printing plate 12 to the surface (printing surface) of the blanket 11, and further transfer the transferred ink to the base material. The image is transferred onto the surface (print surface) of the printing substrate 2 fixed on the fixing platen 16.

(blanket)
The blanket 11 performs transfer printing by transferring ink as described above. The surface of the blanket 11, that is, the printing surface is generally made of a rubber layer. As the rubber material used for the rubber layer, various materials known as blankets can be used. These rubber materials are selected according to the type of ink and the solvent used for the ink, and those having solvent absorbability such as silicone rubber are suitable. It is possible to form the blanket 11 with the rubber layer alone, but the rubber layer may be provided on the base substrate.

The rubber layer made of a rubber material can be provided by curing the rubber material on the base material or by laminating the rubber material on the film with the base material. Since the base material is attached to the blanket cylinder 13 during printing, it is made of, for example, a flexible film or a thin metal plate.
However, as the base substrate, a polyester film such as polyethylene terephthalate (PET) or a polyimide film is preferable in terms of cost and dimensional stability. Further, a primer layer or an adhesive layer is provided between the base substrate and the rubber layer, if necessary. In addition, a cushion layer is provided below the base substrate, if necessary. A sponge-like material can be used for the cushion layer. The blanket 11 is fixed to the substantially cylindrical blanket cylinder 13 by winding both ends of the blanket 11 in the width direction with attachment devices (not shown).

(Print version)
The printing plate of the present invention will be described. The printing plate 12 shown in FIG. 9 shows an embodiment thereof.
The printing plate 12 will be described in detail later, but for example, a plurality of grooves (recesses) corresponding to the wiring pattern forming the printing unit 5 shown in FIG. 3 are formed in a metal plate such as a copper plate, a nickel plate, or a glass plate, A rub resistant film is formed on the surface by chrome plating or carbon plating.
In addition, the upper skin on which the abrasion-resistant film is formed is coated with diamond-like carbon, a fluorine-based or silicon-based oil repellent, or subjected to a process for improving the surface smoothness by using a method such as vapor deposition or sputtering. Good.

Here, since the printing unit 5 is composed of the plurality of fine printed lines described above, the recess for printing the printing unit 5 is composed of a plurality of linearly extending grooves in the present embodiment. Then, the ink is filled in the concave portion formed by the groove, and unnecessary ink is scraped off by the doctor blade. As the ink 14 to be filled in the concave portion, an ink having a light-reflecting property and a photochromic property, or an ink obtained by adding particles to these inks can be used.
In the present embodiment, the concave portion is filled with ink corresponding to any one of the colorings for each printing plate.

(Printing substrate)
The print base 2 in the present embodiment has a print layer including the print portion 5 formed on one side or both sides thereof by printing. The printed layer does not have to be the entire upper surface of the substrate. Further, a print other than the print design according to the present invention may be formed. The printing substrate 2 is not limited to a sheet-shaped material, and may be hollow or solid, and any flat surface or curved surface can be used as the printing surface for forming the printing portion 5.

Examples of the material of the printing substrate 2 include glass plates such as soda lime glass, low-alkali borosilicate glass, and non-alkali aluminoborosilicate glass, or polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate ( In addition to plastic plates and plastic films made of PMMA), polycarbonate (PC), etc., processed paper known in the relevant field such as clean paper, coated paper, calendar paper, sodium polyacrylate, polyvinyl alcohol, polyethylene oxide, etc. Sheet-like mixture of biocompatible polymers known in the field such as water-soluble polymers, polylactic acid, polyglycolic acid, and polycaprolactone known in the field, and minerals and resins such as limestone. The printing material is used.

(Printing method)
Next, the printing method mentioned in the above description of the printing apparatus will be described in detail.
Here, when the fine printing lines of the printing unit 5 are composed of a plurality of colors, a printing plate is prepared for each color to be printed, and intaglio printing is performed using the printing plates for each color in order. .. The printing plate 12 is prepared for each color to be printed, and when multi-layer coating is performed, the printing plates for the layers are prepared and the intaglio printing is sequentially performed. The depth and width of the groove forming the recess may be changed for each printing plate 12. Further, a part of the plurality of grooves formed in one printing plate may be designed so that the width or depth of part of the grooves is different from the width or depth of the other grooves.

In the following description, one intaglio printing using one printing plate will be described.
The printing plate 12 is dipped in the ink, for example, in an ink reservoir (not shown), and then the doctor blade 22 guides the ink to the recesses of the printing plate 12 and removes the excess ink overflowing from the surface of the printing plate 12. As a result, ink is filled in the recesses of the printing plate 12. At this time, it is desirable that the speed of the doctor blade is arbitrarily set within the range of 5 to 300 mm/s according to the change in the viscosity of the ink due to the shear stress of the doctor blade 22.

Next, in FIG. 9, the printing surface of the blanket 11 continues to the ink 14 filled in the printing plate 12 by the movement of the carriage (not shown) from the right end to the left side and the axial rotation of the blanket cylinder 13. To contact. As a result, the ink 14 is transferred onto the printing surface of the blanket 11. The transfer speed to the blanket 11 can be set to, for example, 50 mm/s. At this time, the printing surface of the blanket 11 is made of an absorbent material capable of absorbing the solvent in the ink 14, so that the ink 14 formed on the printing surface of the blanket 11 is prevented from spreading. After that, the blanket 11 to which the ink 14 has been transferred is moved to the installation position of the printing substrate 2 by the movement of the carriage.

Subsequently, as shown in FIG. 9, the ink transferred onto the blanket 11 is transferred onto the printing surface of the printing substrate 2 by the movement of the carriage and the rotation of the blanket cylinder 13. That is, the rotating blanket is pressed against the printing substrate 2 to transfer the ink. The rotation speed of the printing surface of the blanket 11 is set to a speed synchronized with the moving speed of the carriage.
The transfer speed to the printing substrate 2 can be 100 mm/s, for example. The portion of the ink 14 that remains on the printing surface of the blanket 11 without being transferred is removed by, for example, a cleaning roller (not shown).

In this embodiment, the case where the carriage is moved during transfer is illustrated, but the relative position between the blanket cylinder 13 and the printing plate fixing surface plate 15, the blanket cylinder 13 and the base material fixing surface plate 16 are shown. The printing plate fixing surface plate 15 and the base material fixing surface plate 16 may be moved as long as a change in the relative position with respect to can be realized, and the carriage, the printing plate fixing surface plate 15 and the substrate fixing surface plate You may move three of 16 respectively.

Then, the ink 14 transferred onto the printing substrate 2 is cured. This curing may be performed by various means such as baking, heating, oxidative curing, ionizing radiation curing, and cooling (when using a conductive ink containing a thermoplastic material), depending on the type and composition of the ink used. You can In the case of heating, for example, a flash xenon lamp can be used.
The printed matter 1 is obtained by curing using any one or a combination of one or more of these. Note that the printing apparatus may be provided with a function of drying the solvent absorbed by the blanket 11 when the printing is on standby when the swelling amount of the blanket 11 reaches a predetermined reference value. As the material of the printing surface of the blanket 11, the type of ink used and the type of solvent in the ink, various types other than the above-mentioned examples can be selected.

The blanket 11 is used by being fixed to the cylindrical blanket cylinder 13, but the printing surface shape of the blanket at the time of ink transfer may be a curved surface or a flat surface other than the cylindrical shape. Further, the printing base material 2 may have a curved printing surface, such as a resin molded product, in addition to the sheet shape.

When using a plurality of intaglio printing, it is sufficient to align the plates at the time of printing and repeat the above printing process. The alignment shape may be a circle, a cross, or a radiation shape, and it is possible to use a shape in which the top, bottom, left, and right alignment positions are clearly shown during image recognition by the camera. The alignment is installed outside the area of the printed matter, and it is desirable that there are at least two diagonal points with respect to the printed matter. The alignment accuracy is preferably ±10 μm or more, more preferably 5 μm or more.
If the alignment accuracy deviates from the above range, the lines will overlap and show a color different from the set color, and even if the photo-modified ink emits light due to incident light from the light source, it cannot be seen from the front. May cause problems.
Therefore, by performing alignment and printing, it is possible to print a specific wiring pattern set in advance using a plurality of intaglio plates with high accuracy.

(Processing of printing plates)
The printing plate 12 in this embodiment is formed by cutting the surface of the printing plate base material. The concave portion of the printing plate of the present embodiment is formed by a plurality of linear grooves corresponding to the shape of the printing area of the target printing portion 5 and the wiring pattern for printing.
Conventionally, it is formed by a set of recessed shapes corresponding to dots corresponding to halftone dots, but in the present embodiment, linear grooves corresponding to the fine printed lines forming the printing unit 5 are used to form the printing unit 5. A recess is formed.

In FIG. 10, the printing plate base material 17 includes, for example, a copper plating layer 19, a peeling layer 20, and a copper ballad layer on the surface of a cylindrical body 18 made of aluminum, nickel, and iron in order from the inner diameter side to the outer diameter side. 21 are concentrically stacked.
At the time of forming the grooves, the printing plate base material 17 is rotated about the center of the circle as an axis, and a cutting blade is applied in a radial direction toward the copper ballad layer 21 forming the outer surface to perform cutting to form a linear shape. A plurality of recesses are formed by the grooves.

The cutting depth can be set to 20 μm, for example. The concave portion formed of a groove may extend in the circumferential direction of the printing plate base material 17, or may extend in the spiral direction.
The recessed portion formed by the groove is extended in the circumferential direction by alternately performing the recessed portion formation (cutting movement) by cutting and the relative movement (feeding movement) of the printing plate base material 17 and the cutting blade along the rotation axis. be able to. Further, by performing the cutting movement and the feeding movement simultaneously and continuously, the concave portion can be extended in the spiral direction.
It is also possible to change the width of the recess by changing the cutting depth of the cutting blade toward the axis steplessly or in a plurality of steps. When the fine printed line to be printed extends in a meandering manner, the groove is also formed so as to meander.

The width and depth of the recess are set to values according to the target wiring pattern and the amount (height) of protrusion of each fine printed line formed with ink. As a result, when the ink is transferred onto the printing substrate 2 using this printing plate, the linear ink transferred onto the printing substrate 2 is formed with the intended wiring pattern and ink. It is possible to obtain the printed matter 1 in which the swelling amount (height) of each fine printed line is obtained. As a result, the ink area per unit volume changes, or the width of each fine printed line varies even with the same ink area, so that it is possible to express the shade of the color of the printed matter 1.

In the present embodiment, the recess is formed using a cutting blade. The cutting blade has a single nose portion and two slanting portions sandwiching the single nose portion, and the slanting portion extends non-parallel and non-perpendicular to the cutting direction of the cutting blade. The cutting blade preferably has at least one oblique portion adjacent to the nose portion. The cutting blade used for manufacturing the printing plate 12 in the present embodiment has a single nose portion and two oblique portions that sandwich the single nose portion. The extending directions of the two oblique portions are different from each other with respect to the cutting direction of the cutting blade, and the angle formed by one oblique portion with respect to the cutting direction can be arbitrarily selected.

After such a cutting step, a chromium plating layer (not shown) is formed on the entire surface of the copper ballad layer 21 in order to improve wear resistance. Further, DLC (diamond-like carbon) is formed (not shown) on the chromium plating layer by vapor deposition to improve the surface smoothness. Then, the copper ballad layer 21 is peeled off from the peeling 20 to obtain a flat plate printing plate 12 having a recess as shown in FIG.

The shape of the printing plate recess in the present embodiment may be line-symmetric or asymmetric with respect to the depth direction, or may be a shape in which at least one shape is combined.

In the present embodiment, the printing plate is manufactured using the cutting blade, but it may be manufactured by cutting with a dicing saw, a laser, or a machining center, for example. Further, the printing plate may be manufactured by a multi-step etching method or a multi-step plating method. Further, in the present embodiment, the metal member is used as the plate, but quartz, or a material obtained by transferring resin from quartz or metal may be used as the printing plate.

The thickness of the ink transferred onto the substrate by the printing apparatus including the printing plate 12 according to the present embodiment is 5 μm or less per layer, and the printed matter 1 may be a single layer of ink. In addition, the same processing may be performed again on the ink transferred onto the printing substrate 2, and the same or different ink may be laminated. Further, by using the alignment function, the same or different ink as the ink transferred on the base material may be transferred in a single layer or multiple layers at an arbitrary interval.

By curing or firing the ink transferred onto the substrate by the printing apparatus 10 including the printing plate 12 according to the present embodiment, the printed matter 1 having the printing portion 5 formed on the printing substrate 2 is obtained.

(Other embodiments)
It should be noted that the present invention is not limited to the modes shown in the embodiments, and all modifications, applications and equivalents included in the concept of the present invention defined by the claims are included in the present invention. Therefore, the present invention should not be limitedly interpreted, and can be applied to any other technique belonging to the scope of the idea of the present invention.

For example, in the above-described embodiment, the transfer is performed using the flat plate printing plate, but the transfer is not limited to this, and the transfer may be performed using the cylindrical printing plate. Further, in the embodiment using the cutting blade among the above-described embodiments, the cutting is performed with the cutting blade having the single nose portion, but the cutting may be performed with the irregular-shaped cutting blade having the plurality of nose portions.

Further, for example, in the above-described embodiment, the ink is transferred to the printing substrate 2 via the blanket 11, but the invention is not limited to this, and the ink may be directly transferred from the printing plate to the printing substrate 2. Further, for example, in the above-described embodiment, the print pattern of the ink is formed on the printing base material 2, but the present invention is not limited to this, and the printing pattern is formed on the printing base material 2. After that, the printing base material 2 may be removed and the shape may be maintained only by the printing pattern.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. As Example 1, a printed matter having the configuration shown in FIG. 3 was produced.

(Example 1)
A transparent polyethylene terephthalate (PET) film having a thickness of 25 μm was used as the substrate 2a. On the surface of the base material opposite to the surface in contact with the adhesive material 9, a photo-curable resin (Hypertec UR-108N, manufactured by Nissan Kagaku Co., Ltd.) is applied to form the fine irregularities 7, and a cylindrical original plate is formed. While pressing, ultraviolet rays having a dose of 300 J/cm ² were irradiated from the surface in contact with the adhesive material 9 using a high pressure mercury lamp. As a result, the coating film was cured to transfer the fine concavo-convex shape of the original plate to the base material to form the polarizing layer portion 6 including the fine concavo-convex surface.

Next, a transparent polyethylene terephthalate (PET) film having a thickness of 25 μm was used as the base material 2b. On the surface of the base material 2b that is in contact with the adhesive material 9, a mirror ink having a metallic luster is used as a light-reflective ink, and the image width is 100 μm and the line gap is 20 μm. Formed 3.

On the surface of the base material 2b opposite to the surface on which the light-reflective fine printed lines 3 are formed by the light-reflective ink, light is emitted by the photochromic ink at the vertically downward position of the gap between the lines of the light-reflective ink. A color-changing fine printed line 4 was formed. The photochromic fine printed lines 4 were formed by using an ultraviolet light emitting ink that is excited and emitted by ultraviolet light, and were formed at an equal pitch with a line width of 30 μm and a line gap of 90 μm. As a result, the printing portion 5 having the light-reflective ink and the photochromic ink was formed on the front and back.

The polarizing layer portion 6 and the printed portion 5 produced above were integrally molded via an adhesive material (SK Dyne manufactured by Soken Kagaku Co., Ltd.) to obtain a printed matter 1 having a configuration shown in FIG.

When the printed matter 1 formed in this Example 1 was irradiated with visible light having a wavelength of 380 to 780 nm from the A surface side and visually recognized from the A surface, the hologram by the fine irregularities 7 could be visually recognized. This hologram has good visibility due to retroreflection of light by the light-reflecting ink, while the photochromic ink having different wavelength regions is transparent and difficult to see.

Further, when the printed matter formed in Example 1 is irradiated with ultraviolet light having a wavelength of 315 to 400 nm from the B surface side and visually recognized from the A surface side, the photochromic ink that emits from the gap between the lines of the light reflective ink is generated. I could see it.
At this time, the hologram on the A-side can be visually recognized, but it is difficult to completely visually recognize it because the wavelength of the light is deviated and only the light leaks from the gap between the lines of the light-reflective ink.

As described above, it was confirmed that the present example causes various visual changes in the visually recognized image depending on the presence or absence of light irradiation from the A surface side or the B surface side.

Although the embodiments have been described based on the examples according to the present invention, the present invention is not limited to the above-described examples, and there are various examples within the scope of the technical idea described in the claims. Needless to say.

The printed matter, printing plate, and printing apparatus of the present invention can be used for authenticity determination means and forgery prevention means by utilizing the effects described above, and can be applied to printed matter for advertising, toys, containers and packaging, etc. It is a technology.

1: Printed material 2: Substrate 2a: Substrate 2b: Substrate 3: Light-reflective fine printed line 4: Photo-modified fine printed line 5: Printed part 6: Polarizing layer part 7: Fine uneven part 8: Incident light 9: Adhesive 10: Printing device 11: Blanket 12: Printing plate 13: Blanket cylinder 14: Ink 15: Printing plate fixing surface plate 16: Base material fixing surface plate 17: Printing plate base material 18: Cylindrical body 19: Copper plating Layer 20: Release layer 21: Copper ballad layer 22: Doctor blade 30: Hologram foil A surface: Hologram, diffraction grating or OVD surface B surface: Printing surface C: Cross section

Claims (15)

A polarizing layer portion having a plurality of uneven patterns having at least height or depth that is not constant on one surface of the first substrate,
A printed matter comprising a second base and one surface of which a printed portion having at least a fine printed line made of a photochromic ink is adhered via an adhesive layer. The printed matter according to claim 1, wherein the second base material has a fine printed line made of a light-reflective ink on the surface opposite to the fine printed line made of the photochromic ink. The fine printed line made of the photochromic ink is made up of a plurality of lines having a line width of 100 μm or less, and a gap between adjacent lines has a line width of 50 between the two adjacent lines having a narrow line width. The printed matter according to claim 1 or 2, wherein the printed matter is not more than double. The fine printed line made of the light-reflective ink is composed of a plurality of lines having a line width of 100 μm or less, and is made by using the light-reflective ink of at least one kind of color. Printed matter according to any one. The fine printed line made of the photochromic ink is arranged in a gap portion of the fine printed line made of the light reflective ink when viewed from a direction perpendicular to a printed matter plane. The printed matter according to any one of 1 to 4. A polarizing layer portion having a plurality of uneven patterns in which the height or depth is not constant on one surface of the base material, and a printing portion having at least a fine printed line made of a photochromic ink on the other surface of the base material. A printed matter comprising: The fine printed line forming the printed portion is arranged in a predetermined specific wiring pattern in a region of the printed portion, according to any one of claims 1 to 6. Printed matter. The printed matter according to any one of claims 1 to 7, wherein the shade of the color of the printing portion is adjusted by changing the line width of the fine printed line arranged in a unit area. 9. A plurality of the fine printed lines having a convex structure are provided, and at least a part of the fine printed lines having the convex structure has a multi-layered structure formed by laminating a plurality of inks. Printed matter according to any one. The image formed by the concavo-convex pattern in which at least one kind of height or depth is not constant in the polarizing layer section is at least one image or more, wherein: Printed matter. 11. The plurality of fine printed lines are extended in one direction, and the cross section of the fine printed lines has a shape in which polygons or curved shapes are arbitrarily combined, 11. Printed matter according to any one. A printing plate for intaglio printing, comprising a plurality of linear grooves having a groove width of 100 μm or less on a part of the printing surface of the base material surface, wherein the plurality of linear grooves are adjacent grooves. The printing plate characterized in that the gap between and has a region in which the groove width is set to 50 times or less of the groove width of the narrow groove of the two adjacent grooves forming the gap. The printing plate according to claim 12, wherein at least a part of the plurality of linear grooves has a groove width or a groove depth different from those of the other grooves. It is a manufacturing method of the printed matter in any one of Claims 1-11, Comprising:
The fine printed lines in the printed matter are printed by at least one or more intaglio plates, and when two or more intaglio plates are used, by aligning and printing each intaglio plate, at least one or more intaglio plates are printed on the same surface. A method for producing a printed matter, which comprises arranging an image. It is a manufacturing method of the printed matter in any one of Claims 1-11, Comprising:
Using a plurality of printing plates for intaglio printing having a plurality of linear grooves each having a width of 100 μm or less on a part of the surface of the base material, intaglio printing is sequentially performed on the surface of the base material. By doing this, the ink is transferred to form the printing part,
Manufacturing of a printed product characterized in that a groove formed in one printing plate of the plurality of printing plates has a groove width or a groove depth different from those of grooves formed in another printing plate. Method.