JP4848852B2 - Light diffraction structure - Google Patents

Description

The present invention relates to a light diffractive structure, and more particularly, to a light diffractive structure capable of obtaining a gentle gradation.

Holograms, diffraction gratings, and the like can express special decorative images and three-dimensional images, and are therefore used for printed materials with improved design. Further, since advanced technology is required for production, it is used as a means for preventing forgery.
Fields used to enhance design properties include high-priced product packaging materials, pamphlets, POPs, book covers, etc., and fields used as anti-counterfeiting means include, for example, credit cards, ID cards, etc. Cards, gift vouchers such as gift certificates, checks, bills, stock certificates, admission tickets, and various certificates.
In addition, as a method of attaching these holograms and diffraction gratings to an object, there are a method of attaching by thermal transfer and a method of attaching as a label.
The thermal transfer method is used for a long time and is often used for the aforementioned cards and cash vouchers that have a flat application surface. The label method is used when the object to be applied does not have a flat surface. The

A “display having a diffraction grating pattern” has been provided as a diffraction grating used to enhance the above-described designability (see, for example, Patent Document 1).
The technique introduced in Patent Document 1 is for producing a display body in a display formed by disposing a plurality of cells made of minute diffraction gratings (gratings) on the surface of a planar substrate. Based on the first original data, the diffracted light intensity of each diffraction grating cell at the time of reproduction is suppressed by appropriately changing the ratio of the line width and the grating interval of the diffraction grating constituting each diffraction grating cell. It is said that.

JP-A-7-84110

The technique disclosed in Patent Document 1 can easily realize gradation expression even when a binary device such as an electron beam exposure apparatus is used, and has a good moldability even in a replication process, and performs simpler replication. It is said that the object is to provide a display having a diffraction grating pattern that can be applied, and does not provide an optical diffraction structure that smoothly expresses gradation.
Accordingly, an object of the present invention is to provide an optical diffraction structure capable of obtaining a gentle gradation as a means for solving the above-described problems.

In order to solve the above-mentioned problem, the first aspect of the light diffraction structure of the present invention is composed of a symbol component having a different grating pitch, with a set of symbol components formed at the same grating pitch as a unit region. In an optical diffraction structure in which a plurality of unit regions are arranged side by side without overlapping each other and a pattern is formed , one of the adjacent unit regions at an arbitrary position of the pattern is A, and a lattice pitch constituting A is adjacent to A When the other one of the unit regions is B, and the lattice pitch constituting B is b, a lattice between the lattice pitch a and the lattice pitch b is provided in each partial region near at least the boundary of A and B. It is characterized in that a pitch symbol component is incorporated .

In the second aspect, a set of symbol components formed at the same lattice angle is used as a unit region, and a plurality of unit regions configured with symbol components having different lattice angles are arranged without overlapping each other. In the light diffractive structure in which A is formed , one of the adjacent unit regions in any place of the pattern is A, the lattice angle constituting A is a, the other one of the adjacent unit regions is B, and B is configured When the lattice angle to be performed is b, a symbol component having a lattice angle intermediate between the lattice angle a and the lattice angle b is incorporated in each partial region near at least the boundary of A and B. To do.

In the third aspect, a set of symbol components formed with the same lattice density is used as a unit region, and a plurality of unit regions configured with symbol components having different lattice densities are arranged without overlapping each other. In the light diffraction structure in which is formed,
When one of the adjacent unit regions in any place of the symbol is A, the lattice density constituting A is a, the other one of the adjacent unit regions is B, and the lattice density constituting B is b In addition, a symbol component having a lattice density intermediate between the lattice density a and the lattice density b is incorporated in each partial region at least near the boundary of A and B.

Further, in the fourth aspect, the pattern component incorporated in each partial region at least near the boundary of the light diffraction structure of any one of the first to third aspects has the shading described in another claim. It is characterized by being replaced with an approximate symbol component and incorporated .

Further, in the fifth aspect, in the optical diffraction structure of any one of the first to fourth aspects, the symbol component incorporated in each partial region close to the boundary of the adjacent unit regions is an error diffusion method. It is formed based on this.

Unlike the case where the grating angle, the grating pitch, and the grating density are continuously changed, the light diffraction structure of the present invention provides a gradation in which light flows, and a conventional stepped boundary is generated. This makes it difficult to observe the unnaturalness.
As a result, the design is enhanced and the analysis becomes difficult. As a result, the copy is difficult and can be used in the field of anti-counterfeiting means.

Hereinafter, the optical diffraction structure of the present invention will be described with reference to the drawings.
1 is a diagram for explaining an example of a light diffraction structure of the present invention, FIG. 2 is a diagram for explaining an example of a conventional light diffraction structure, and FIG. 3 is a diagram of an example of the light diffraction structure of the present invention. FIG. 4 is a diagram for explaining another example of the light diffraction structure of the present invention, and FIG. 5 is a diagram for explaining another example of the light diffraction structure of the present invention. .

As the hologram, a relief hologram of a three-dimensional image expressed by interference fringes due to interference of light between the object light and the reference light, and a diffraction grating based on a two-dimensional image are often used.
As means for improving design and for preventing counterfeiting, there are many rainbow holograms and color holograms that are white light reproduction holograms, and synthetic holograms that are produced by combining these holograms with characters, figures, symbols, etc. used.

The use form of the hologram is roughly classified into a case where it is used in a state where it is transferred onto a substrate and a case where it is used after being labeled on a state where it is formed on the substrate.
When the hologram is used in a transferred state, a release layer is formed on a heat-resistant base film, and, for example, a thermosetting resin layer is formed thereon, and the thermosetting resin layer is formed. An uneven structure is formed, a reflective layer is formed, a heat-sensitive adhesive layer is formed thereon to form a transfer film, and an extremely thin hologram layer including the adhesive layer is formed by a heated metal mold or the like. It is used by transferring onto printed matter such as paper.
When using the hologram in a label state, a thermosetting resin layer is formed on the base film, an uneven structure is formed on the thermosetting resin layer, and a reflective layer is formed on the uneven structure, An adhesive layer is formed on the surface, the adhesive surface is covered with release paper, the base film is punched into a predetermined size together with the release paper to form a label, and the release paper is peeled off and attached to the object. use.

The reflection layer of the hologram is provided to give reflectivity to the uneven surface of the hologram forming layer.
The reflective layer includes an opaque reflective layer and a transparent reflective layer, but when used as a means for enhancing the design effect, an opaque reflective layer made of metal such as aluminum or nickel is formed.
As a method for forming the reflective layer, there are a vacuum vapor deposition method, a sputtering method, an ion plating method, and the like, which are properly used depending on the purpose.
In addition, as a means for forming a release layer, a thermosetting resin layer, an adhesive layer, an adhesive layer, etc., a general coating method such as gravure coating, die coating, knife coating, roll coating, etc., and a printing method such as silk screen Select from and use.

With reference to FIG. 1, an example of the light diffraction structure of the present invention will be described.
As shown in the figure, the light diffraction structure 1 is composed of a pattern 11 drawn by a diffraction grating and a rectangular background 12.
The pattern 11 depicted by the diffraction grating is composed of wine glass and wine poured into the wine glass.
The wine portion is depicted darker toward the right side along the glass, and is a smooth gradation expression portion by a diffraction grating.

An example of a conventional light diffraction structure will be described with reference to FIG.
FIG. 2A shows a part 111 of the pattern by the diffraction grating of FIG. 1 expressed by a conventional drawing means. In FIG. a, the brightness is changed in three stages from the left side. As a technique for changing the brightness, a technique of changing the grating angle while fixing the grating density and grating pitch of the diffraction grating is used.
In FIG. a, a part 111 of a pattern formed by a diffraction grating is divided into three regions, which are a region having a “grid angle of 10 °”, a region of “a lattice angle of 20 °”, and a region of “a lattice angle of 30 °” from the left side. .
In each region, the symbol component 1111 is configured so that the lattice angle “α” shown in FIG.
As a result, the boundary between the region where the lattice angle “α” is 10 ° and the region where the lattice angle “α” is 20 °, and the boundary between the region where the lattice angle “α” is 20 ° and the region where the lattice angle “α” is 30 °. In this case, a discontinuous state occurs due to a difference in concentration.

An example of the light diffraction structure of the present invention will be described with reference to FIG.
In FIG. 3b, as described in FIG. 2, the pattern by the diffraction grating is expressed by the difference in the grating angle, and the symbol component of the grating angle not included in any of the symbol components is fitted. And replace it.
Here, one of the “lattice angles not included in any of them” is a symbol component 1111b (see FIG. B2) having a lattice angle of 15 ° between the lattice angle of 10 ° and the lattice angle of 20 ° shown in FIG. The other one is a symbol component 1112b (see FIG. B3) having a lattice angle of 25 ° between the lattice angle of 20 ° and the lattice angle of 30 ° shown in FIG.
In FIG. b, when the number of “regions” divided in the lateral direction is increased and, for example, a region having a lattice angle of 40 ° and a lattice angle of 50 ° is formed, the lattice angle of 35 ° Add a pattern component with a grid angle of 45 ° and scatter and fit.
Such a method is a technique generally used as an error diffusion method.

Here, the error diffusion method will be described.
When expressing the shade of an image by a printing machine or printer, the image is decomposed and expressed by small dots called halftone dots.
Since it is difficult to add shading to the halftone dots themselves, the halftone dot spacing is fixed and the halftone dot size is changed, or the halftone dot size is constant and the density (interval) is changed to express the shading of the image. To do. This is called the dither method.
In other words, the dither method is a method of expressing the shade of the intermediate color with a dot pattern generated randomly. The dither method is one of area gradation methods that compensate for the shortage of the number of colors and smoothly express the color gradation.
There are several dithering methods, but the most common is the error diffusion method.
The error diffusion method is one of the methods to express an image smoothly. In the error diffusion method, the smoothness is adjusted by equalizing pixels (pixels) constituting a digital image to intermediate colors (tones) between colors. .

With reference to FIG. 4, another example of the light diffraction structure of the present invention will be described.
The c diagram of FIG. 4 expresses the pattern by the diffraction grating described in FIG. 2 by the difference in the grating density, and inserts the symbol component of the grating density not included in any of the symbol components, It is a replacement.
Here, one of the “lattice densities not included in any of them” is a symbol component 1111c (see FIG. C2) having a lattice density of 70%, which is intermediate between the lattice density of 60% and the lattice density of 80% shown in FIG. The other is a symbol component 1112c (see FIG. C3) having a lattice density of 90%, which is intermediate between the lattice density of 80% and the lattice density of 100%, as shown in FIG.
In FIG. c, when the number of “regions” divided in the lateral direction is increased, for example, when regions having a lattice density of 20% and a lattice density of 40% are formed, the lattice density of 30% Add 50% density design components and scatter and fit.

With reference to FIG. 5, another example of the light diffraction structure of the present invention will be described.
The d diagram of FIG. 5 expresses the pattern by the diffraction grating described in FIG. 2 by the difference in the grating pitch, and inserts the symbol component of the grating pitch not included in any part of the symbol component, It is a replacement.
Here, one of the “lattice pitches not included in any of them” is a symbol component 1111d having a lattice pitch of 0.8 μm between the lattice pitch of 0.6 μm and the lattice pitch of 1.0 μm (see FIG. D2). The other is a symbol component 1112d (see FIG. D3) having a lattice pitch of 1.2 μm, which is intermediate between the lattice pitch of 1.0 μm and the lattice pitch of 1.4 μm.
In FIG. c, when the number of “regions” divided in the horizontal direction is increased, for example, when a region having a lattice pitch of 20% and a lattice pitch of 40% is formed, the lattice pitch of 30% Add a pattern component with a pitch of 50% and scatter and fit.

Although not shown, for example, an area having a grating pitch of 1.0 μm in an “area” having a grating pitch of 0.6 μm, a grating pitch of 1.0 μm, and a grating pitch of 1.4 μm shown in FIG. It can be replaced with a “region” having a lattice density of 80% or a “region” having a lattice angle of 20 °.
Then, the symbol component 1111d and the symbol component 1112d having the above-described lattice pitch can be fitted into the “region” and used.
Further, for example, a region having a lattice density of 60% in the “region” having a lattice density of 60%, a lattice density of 80%, and a lattice density of 100% shown in FIG. Alternatively, it can be replaced with a “region” having a lattice pitch of 0.6 μm.
The symbol component 1111c or the symbol component 1112c having the above-described lattice density can be fitted into the “region” and used.

  As described above, in order to add gradation to the pattern formed by the diffraction grating constituting the optical diffraction structure, random shades are randomly generated within the shade range of the pattern, and the entire gradation is included. It is possible to express the gradation smoothly by being scattered.

In the field of special printed matter, it is used by attaching it to packaging materials, brochures, POPs, book covers, etc. for expensive products.
In addition, as an anti-counterfeiting field, for example, it is used by sticking to cards such as credit cards and ID cards, gift certificates, checks, bills, stock certificates, admission tickets, and various certificates.

It is a figure for demonstrating an example of the light diffraction structure of this invention. It is a figure for demonstrating an example of the conventional light diffraction structure. It is a figure for demonstrating an example of the light diffraction structure of this invention. It is a figure for demonstrating other examples of the optical diffraction structure of this invention. It is a figure for demonstrating other examples of the optical diffraction structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light diffractive structure 11 Design 12 Background 111, 111b Part of the pattern which expressed light and shade by the difference in a grid angle 111c Part of the pattern which expressed light and shade by the difference in lattice density 111d The pattern which expressed light and shade by the difference in lattice pitch Part 1111, 1111 b, 1111 c, 1111 d Symbol component of light area 1112, 1112 b, 1112 c, 1112 d Symbol component of dark area

Claims (5)

In an optical diffraction structure in which a set of symbol components formed with the same grating pitch is used as a unit region, and a plurality of the unit regions configured with symbol components having different grating pitches are arranged without overlapping each other . ,
When one of the adjacent unit regions at any place of the symbol is A, the lattice pitch constituting A is a, the other one of the adjacent unit regions is B, and the lattice pitch constituting B is b A light diffractive structure characterized in that a pattern component having a lattice pitch intermediate between the lattice pitch a and the lattice pitch b is incorporated in each partial region close to the boundary between A and B. In a light diffractive structure in which a set of symbol components formed with the same grating angle is used as a unit region, and a plurality of the unit regions configured with symbol components having different grating angles are arranged without overlapping each other . ,
When one of the adjacent unit regions in any place of the symbol is A, the lattice angle constituting A is a, the other one of the adjacent unit regions is B, and the lattice angle constituting B is b A light diffractive structure characterized in that a pattern component having a lattice angle intermediate between the lattice angle a and the lattice angle b is incorporated in each partial region near at least the boundary of A and B. In an optical diffraction structure in which a set of design components formed with the same lattice density is used as a unit region, and a plurality of the unit regions configured with design components having different lattice densities are arranged side by side without overlapping each other . ,
When one of the adjacent unit regions in any place of the symbol is A, the lattice density constituting A is a, the other one of the adjacent unit regions is B, and the lattice density constituting B is b A light diffractive structure characterized in that a pattern component having a lattice density intermediate between the lattice density a and the lattice density b is incorporated in each partial region close to the boundary between A and B. The symbol component incorporated in each partial region at least near the boundary of the light diffraction structure according to any one of claims 1 to 3 is replaced with a symbol component having an approximate shade according to another claim. An optical diffraction structure characterized by being incorporated . In the light diffraction structure in any one of Claims 1-4,
A light diffractive structure characterized in that a symbol component incorporated in each partial region close to a boundary between adjacent unit regions is formed based on an error diffusion method.

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