JP5504825B2 - Indicator - Google Patents

Description

  The present invention relates to a display body excellent in forgery prevention effect.

A pattern constituted by a diffraction grating or a hologram has a directional gloss that cannot be expressed by a normal printing technique, and thus is widely used in security products for decorative purposes and forgery prevention.
The advantage of anti-counterfeiting technology using diffraction grating technology is that it has a visual discrimination function (so-called overt function) that makes it easy to determine authenticity without using discrimination equipment compared to other anti-counterfeiting technologies. In addition, expensive and advanced technology (EB drawing device, nanoimprint technology, etc.) is necessary and others cannot easily manufacture, and the total thickness of the medium equipped with the diffraction grating is thin, and a unique brightness due to diffracted light is produced. It is excellent in design properties.

Recently, however, the ones close to those manufactured by the conventional diffraction grating technology can be duplicated and are often abused.
On the other hand, a high-definition diffraction grating as shown in Patent Document 1 has recently been proposed. This document proposes a two-dimensional diffraction grating having a fineness more than twice that of a normal diffraction grating. This high-definition diffraction grating is manufactured by a process that is much more difficult than a normal hologram manufacturing process, and cannot be obtained without incorporating a nanoimprint technique. And this high-definition diffraction grating is completely different from the conventional diffraction grating, showing black in the front direction (most viewing area), and an angle close to the horizontal direction with respect to the object (deep to the normal direction) It has a feature that diffracted light is emitted at an angle.
Such devices having new optical characteristics are effective as security devices, but recently, it has been desired to provide devices with higher security.

JP 2008-107470 A

  The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a novel display body having a higher anti-counterfeit effect.

In order to achieve the above-described problems, the invention according to claim 1 is a concavo-convex structure in which a plurality of concave portions and / or convex portions arranged two-dimensionally are provided on one main surface of a light transmission layer. A plurality of recesses and / or protrusions in the concavo-convex structure region having a minimum center-to-center distance of 200 nm to 500 nm. In the concavo-convex structure region having a specific periodicity and provided with the plurality of concave portions and / or convex portions, concave portions or convex portions having substantially the same depth or height are continuously formed. The part provided adjacently is provided in a part over a length of 10 μm or more, scatters well in the front direction (perpendicular direction to the display body), and deep angular direction (close to the horizontal of the display body) Direction) with an anisotropic scattering element with less scattering Display the height of the saw narrowing, and deep angular depth of the recess so that the diffracted light to the recursive direction (direction close to horizontal of the display) is emitted and / or projections, characterized in that a non-uniform Is the body.

Still further, the invention according to claim 2, in the display of claim 1, wherein the maximum height of the maximum depth and / or the convex portion of the concave portion is under 750nm or less.

Furthermore, the invention according to claim 3 is the display body according to claim 1 or 2 , wherein the arrangement pattern formed by the plurality of recesses and / or protrusions provided in the uneven structure region is a pattern derived from Benard cell. It is characterized by being.

Furthermore, the invention according to claim 4 is the display body according to any one of claims 1 to 3 , wherein a plurality of the concavo-convex structure regions are provided on one main surface of the light transmission layer. The at least one concavo-convex structure region is characterized in that the center-to-center distance and the arrangement pattern are different from those of the other concavo-convex structure regions.

Furthermore, the invention according to claim 5 is the display body according to any one of claims 1 to 4 , wherein a one-dimensional diffraction grating pattern region is provided on one main surface of the light transmission layer. The distance between the centers of the recesses and / or protrusions in the three-dimensional diffraction grating pattern region is larger than the distance between the centers of the recesses and / or protrusions in the uneven structure region, and the depth of the recesses in the one-dimensional diffraction grating pattern region. The height of the convex part is smaller than the maximum depth of the concave part and / or the maximum height of the convex part of the concavo-convex structure region.

Furthermore, the invention according to claim 6 is the display body according to any one of claims 1 to 5 , wherein a plurality of concavo-convex structure regions are provided on one main surface of the light transmission layer, and at least the concavo-convex structure. The minimum center-to-center distance of the plurality of recesses and / or projections in the concavo-convex structure region other than the structure region is in the range of 200 nm to 500 nm, and the plurality of recesses and / or projections in the region has a specific periodicity. And having a forward tapered concavo-convex structure in which the depth of the plurality of concave portions and / or the height of the convex portions is substantially uniform.

  The display body of the present invention recognizes a white pattern from the front, but when tilted, it emits diffracted light with spectroscopy, has an excellent anti-counterfeit effect, and provides a high security device. Make it possible.

It is a top view which shows schematically the display body which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the display body shown in FIG. FIG. 3 is an enlarged perspective view illustrating an example of a structure that can be employed in a first uneven structure region of the display body illustrated in FIGS. 1 and 2. It is a perspective view which expands and shows an example of the structure employable for the 2nd uneven structure area | region of the display body shown in FIG.1 and FIG.2. It is a perspective view which expands and shows an example of the structure employable for the 3rd uneven structure area | region of the display body shown in FIG.1 and FIG.2. It is a perspective view which expands and shows an example of the structure employable for the 1st uneven structure area | region of the display body shown in FIG.1 and FIG.2. It is a perspective view which expands and shows the other example of the structure employable as the 1st uneven structure area | region of the display body shown in FIG.1 and FIG.2. It is a perspective view which expands and shows the other example of the structure employable as the 1st uneven structure area | region of the display body shown in FIG.1 and FIG.2. It is a top view which shows roughly the example of the arrangement pattern of the recessed part or convex part which can be employ | adopted as a 1st uneven structure area | region. It is a top view which shows roughly the example of the arrangement pattern of the recessed part or convex part which can be employ | adopted as a 1st uneven structure area | region. It is a figure which shows a mode that a 4th uneven structure area | region emits a diffracted light schematically. It is a figure which shows roughly a mode that a 1st uneven structure area | region or a 2nd uneven structure area | region emits a diffracted light. It is a top view which shows roughly an example of the gift certificate formed by supporting the forgery prevention stripe transfer foil on the article. It is sectional drawing along the AA line of the display body 40 of FIG. It is an image figure of the scattering pattern (arrangement pattern) of 12a. 2 is a planar SEM image of the concavo-convex structure 12a of Example 1. FIG. 2 is a tilted SEM image of the concavo-convex structure 12a of Example 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same referential mark is attached | subjected to the component which exhibits the same or similar function, and the overlapping description is abbreviate | omitted. In the present invention, “scattering” and “diffusion” are used interchangeably.

  FIG. 1 is a plan view schematically showing a display body according to one aspect of the present invention. 2 is a cross-sectional view taken along the line II-II of the display shown in FIG.

  The display body 10 includes at least a light transmission layer 11, a reflection layer 13, and an adhesive layer 15. In the example shown in FIG. 2, the light transmission layer 11 side is the front side and the adhesive layer 15 side is the back side. The interface between the light transmission layer 11 and the reflection layer 13 includes uneven structure regions 12a, 12b, 12c, and 12d provided with a plurality of recesses and / or protrusions arranged two-dimensionally, and a flat region 12e. Yes. The adhesive layer 15 is formed on the reflective layer 13.

  For example, the light transmission layer 11 serves as a base of the reflection layer 13. The light transmissive layer 11 protects the concavo-convex structure from dirt and scratches on the surface, thereby achieving the effect of maintaining the visual effect of the display body 10 over a long period of time. Furthermore, the light transmission layer 11 does not expose the concavo-convex structure, thereby making its replication difficult.

  As a constituent material of the light transmission layer 11, for example, a resin having light transmittance can be used. Examples of the resin having optical transparency include polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, nitrocellulose, polyethylene, polypropylene, acrylic styrene copolymer, vinyl chloride, and polymethyl methacrylate. Thermosetting resins such as polyimide, polyamide, polyester urethane, acrylic urethane, epoxy urethane, silicone, epoxy, melamine resin, etc., and various acrylic monomers, epoxy acrylate, urethane acrylate that are UV or electron beam curable Reactive polymers such as oligomers such as polyester acrylate, acrylics and epoxies with acrylic and methacrylic groups, and cellulosic resins are used. Possible it is.

The light transmission layer 11 may have a structure of two or more layers in consideration of surface strength, easiness of forming a concavo-convex structure, and the like. Further, when a metal is used as the constituent material of the reflective layer 13, in order to change the metallic luster color derived therefrom to a different color, a dye or pigment is mixed into the light transmission layer 11, and a specific wavelength is set for the dye or pigment. It is also possible to absorb the light.

  On the other hand, the reflective layer 13 plays a role of increasing the reflectance of the interface provided with the concavo-convex structure. As a constituent material of this reflective layer 13, metal materials, such as aluminum, silver, tin, chromium, nickel, copper, gold | metal | money, and those alloys, can be used, for example. The reflective layer 13 may be made of a material having a refractive index different from that of the constituent material of the light transmission layer 11 such as a dielectric material. The reflective layer 13 is not limited to a single layer, and may be a multilayer. The reflective layer 13 can be formed by using a metal and an oxide such as titanium oxide or zinc sulfide and utilizing a vacuum film forming method. As the vacuum film-forming method, a vacuum deposition method, a sputtering method, or the like can be applied, and the thickness may be controlled to about 1 to 100 nm.

On the other hand, the adhesive layer 15 is provided in order to attach the display body 10 to an article for which anti-counterfeiting measures are desired. This adhesive layer 15 may have a structure of two or more layers in consideration of the adhesive strength between the display body 10 and the article to be counterfeited, the smoothness of the adhesive surface of the article, and the like.
2 shows a configuration in which the display body 10 is observed from the light transmission layer 11 side, but a configuration in which the display body 10 is observed from the reflective layer 13 side can also be employed.

  Next, the concavo-convex structure provided at the interface between the light transmission layer 11 and the reflection layer 13 will be described. The first uneven structure region 12a in the first interface, the second uneven structure region 12b in the second interface, the third uneven structure region 12c in the third interface, and the fourth uneven structure region 12d in the fourth interface are the same as described above. Thus, it has a concave structure and / or a convex structure. More specifically, the first uneven structure region 12a has a scattering and diffraction structure, the second uneven structure region 12b has a light absorption and diffraction structure, and the third uneven structure region 12c has a scattering structure. Further, the fourth uneven structure region 12d has a diffractive structure.

  FIG. 3 is an enlarged view showing an example of a structure that can be adopted as the diffraction structure of the fourth uneven structure region 12d of the display body 10 shown in FIGS. FIG. 4 is an enlarged view showing an example of a structure that can be adopted as the light absorption and diffraction structure of the second uneven structure region 12b of the display body 10 shown in FIGS. FIG. 5 shows an enlarged example of a structure that can be adopted as the scattering structure of the third concavo-convex structure region 12c. FIG. 6 shows an enlarged example of a structure that can be adopted as the scattering and diffraction structure of the first concavo-convex structure region 12a.

  As shown in the figure, the fourth uneven structure region 12d is provided with a relief type diffraction grating in which a plurality of grooves 14d are arranged. The distance between the centers of the grooves 14d is, for example, in the range of 0.5 μm to 2 μm. The depth of the groove 14d is, for example, in the range of 0.1 μm to 1 μm, and typically in the range of 0.1 μm to 0.3 μm.

  The term “diffraction grating” means a structure that generates a diffracted wave when irradiated with illumination light such as natural light. In addition to a normal diffraction grating in which a plurality of grooves 14d are arranged in parallel and at equal intervals, the term “diffraction grating” is recorded on a hologram. The interference fringes made are also included. Further, the groove 14d or a portion sandwiched between the grooves 14d is referred to as a “lattice line”.

  As shown in the figure, the second uneven structure region 12b is provided with a plurality of concave portions or convex portions 14b. These concave portions or convex portions 14b are two-dimensionally arranged with a center distance smaller than the minimum center distance of the groove 14d described above. Each concave portion or convex portion 14b has a forward tapered shape. The depth or height of the recess or protrusion 14b is usually larger than the depth of the groove 14d described above, and is typically in the range of 0.3 μm to 0.5 μm.

As shown in the figure, the third uneven structure region 12c is provided with a plurality of concave portions or convex portions 14c having scattering properties. These concave portions or convex portions 14c are randomly arranged and the sizes are also random. The size of each uneven structure is, for example, in the range of 1 μm to 100 μm, and typically in the range of 1 μm to 10 μm. In addition, in the case of exhibiting anisotropic scattering instead of mere isotropic scattering, the arrangement or shape may be biased in any one of the planar directions (uniaxial or multiaxial).

  As shown in the figure, the first concavo-convex structure region 12a is provided with a plurality of concave portions or convex portions 14a. These concave portions or convex portions 14a are two-dimensionally arranged with a center distance smaller than the minimum center distance of the groove 14d described above. The minimum center-to-center distance between the plurality of recesses and / or protrusions is in the range of 200 nm to 500 nm, and the plurality of recesses and / or protrusions have a specific periodicity within the same uneven structure region, and The depth of the plurality of concave portions and / or the height of the convex portions are not uniform.

  Conventionally, there have been attempts to arrange various uneven structures in the display body to mix white display and diffracted light. However, diffraction structures such as diffraction gratings and holograms can be neatly dispersed with a point light source. Although shining, the diffractive effect is halved with a diffuse light source, and the effect is almost unknown when observed through a diffuser (it is often not even present). Therefore, conventionally, the diffraction grating pattern and the scattering structure pattern are divided into regions, and are often used independently as a part of characters and images, respectively. In addition, there is a technique in which a plurality of diffraction gratings having different spatial frequencies are arranged so that light of a plurality of colors (R, G, B) is emitted at the same angle, and white is displayed at a specific angle, but it is glossy white. This is different from the so-called matte white (so-called paper white). If the region is divided, the scattering structure region (area) is also limited, so it becomes white, and the diffraction structure region (area) is also limited, so that the intensity of the diffracted light is weakened, resulting in a display with poor optical effect. End up. In addition, when a diffractive structure is superimposed on a diffraction grating or a hologram by multiple exposure, the incident light or / and the emitted light are in the scattering angle region in the conventional spatial frequency diffraction grating, and the optical effect due to diffraction is reduced. It becomes scarce.

  In order to prevent the optical effects due to diffraction from becoming poor, the diffractive structure must also prevent incident light and / or emitted light from entering the scattering angle region. However, by giving the scattering structure a certain directionality. It becomes possible to have directivity. In other words, even a scattering structure with a random size of about 1 to 10 μm, such as a lenticular sheet or a sheet in which a plurality of prism lenses are arranged, has a structural directionality (axis) in either direction. In particular, anisotropic scattering (that is, scattering in many directions and scattering in any direction becomes less) can be realized, and reduction of the optical effect due to diffraction can be prevented. Preferably, a portion in which concave portions or convex portions having substantially the same depth or height are continuously provided adjacent to each other is provided in a part thereof over a length of 10 μm or more. The scattering can be anisotropic. In particular, it incorporates an anisotropic scattering element that scatters well in the front direction (perpendicular to the display) and has little scattering in the deep angle direction (close to the horizontal direction of the display), and the deep angle direction (of the display). It is preferable to design so that the diffracted light is emitted in a recursive direction in a direction close to horizontal). Therefore, the distance between the centers of the diffraction grating is preferably in the range of 200 nm to 500 nm, and it is preferable to have an ultrafine structure as compared with the conventional diffraction grating. Further, it is desirable that the diffuser plate has a speckle interference pattern or a Benard cell shape generated due to a surface defect in the drying process at the time of coating so that the scattering property (whiteness) is excellent in the front direction.

In providing these concavo-convex structures at the interface between the light transmitting layer 11 and the reflective layer 13, a nickel original plate is prepared by nickel electroforming or the like, and a fine diffraction grating is formed on a predetermined film using the nickel original plate. Emboss the pattern, emboss the scattering pattern before forming the fine diffraction grating, emboss the predetermined fine diffraction grating pattern again, or speckle interference pattern by diffuser plate or Benard cell shape image and fine diffraction grating pattern An image obtained by combining and is drawn by an EB drawing apparatus and applied by one embossing in a conventional hologram embossing process. When coating an embossed layer on a film only for scattering components derived from Benard cell shape, it is possible to provide a scattering and diffractive structure without going through multiple embossing steps by making the embossed layer a Benard cell shape surface. It becomes.

Here, the speckle interference pattern by the diffusion plate will be described.
The speckle interference pattern by the diffuser is a bright and dark spot pattern that occurs when light with good coherency is scattered or reflected or transmitted by a rough surface. Light scattered by minute irregularities on the rough surface interferes with an irregular phase relationship. It is caused by doing.
Examples of a method for producing a film having such a pattern include the following methods.
That is, first, the coherent light is applied to the diffusion plate, and the resulting speckle pattern is recorded on the photoresist. After that, a conductive film such as nickel is formed on the recording surface by a vapor deposition method, etc. By doing so, an original nickel plate is prepared. Next, an ultraviolet curable resin is poured into the nickel original plate and cured with ultraviolet rays, and then peeled off to produce an anisotropic scattering film, or a heated nickel original plate is pressed against a thermoplastic resin to apply a pattern. What is necessary is just to mold and produce an anisotropic scattering film.

Next, the Benard cell will be described.
If the paint or ink coating is drying rapidly, or if the dispersion of the particles is insufficient, or in the case of a resin mixture with poor compatibility, between the inside of the coating and the surface This is a phenomenon in which the surface state becomes a pattern like a turtle shell or an irregular partition due to thermal convection. Benard cells can be formed by increasing the air volume in the drying path and drying rapidly at a drying temperature of + 30 ° C. or higher of the boiling point of the solvent in the ink. FIG. 15 shows an example of an image diagram of a scattering pattern derived from Benard cell.

  On the other hand, the fifth interface portion is a flat region portion 12e. In the present invention, in some cases, the second concavo-convex structure region 12b, the third concavo-convex structure region 12c, the fourth concavo-convex structure region 12d, and the flat region 12e other than the first concavo-convex structure region 12a are omitted. be able to.

  In short, the display body 10 according to the present invention includes at least the first concavo-convex structure region 12a provided with a plurality of concave portions or convex portions 14a. As described above, the recesses or projections 14a are two-dimensionally arranged with a center distance smaller than the minimum center distance of the grooves 14d forming the diffraction grating. That is, the display body 10 includes a finer structure than the grooves 14d forming the diffraction grating.

  From the display body 10 having such a configuration, it is difficult to accurately analyze the fine structure having the above-described configuration. Even if the fine structure as described above can be analyzed from such a display body 10, it is difficult to forge or imitate the display body including the fine structure. In the case of a diffraction grating, the structure may be copied as interference fringes by an optical duplication method using laser light or the like, but the fine structure of the first concavo-convex structure region 12a cannot be duplicated.

  Further, the display body 10 has a very special visual effect. That is, the fourth concavo-convex structure region 12d generates diffracted light with wavelength dispersion, appears to be color-shifted to seven colors depending on the viewpoint position, and is recognized as a normal interface on which a diffraction grating is formed. On the other hand, in the normal observation region around the normal to the display body, the first concavo-convex structure region 12a and the third concavo-convex structure region 12c are displayed in white, and the second concavo-convex structure region 12b is displayed in black. At first glance, therefore, it is difficult for a person who attempts forgery or imitation to recognize that the previous fine structure exists in the first concavo-convex structure region 12a.

In addition, the expression of the diffracted light at a deep angle is possible not only in the conventional second uneven structure region 12b but also in the first uneven structure region 12a which is a new structure. It becomes possible to express the design from the angle, and the structure is more complicated, making it very difficult for the counterfeit team to guess the structure.

  Therefore, when this display body 10 is used as an anti-counterfeit medium, a high anti-counterfeit effect can be achieved.

The visual effect of the display body 10 will be described in more detail.
First, the visual effect resulting from the uneven structure of the fourth uneven structure region 12d will be described.
When the diffraction grating is illuminated, the diffraction grating emits strong diffracted light in a specific direction with respect to the traveling direction of the illumination light that is incident light.

The most representative diffracted light is first-order diffracted light. The emission angle β of the first-order diffracted light can be calculated from the following equation (1) when the light travels in a plane perpendicular to the grating line of the diffraction grating.
d = λ / (sin α−sin β) (1)
In this equation (1), d represents the grating constant of the diffraction grating, and λ represents the wavelengths of incident light and diffracted light. Α represents the exit angle of 0th-order diffracted light, that is, transmitted light or specularly reflected light. In other words, the absolute value of α is equal to the incident angle of the illumination light, and the incident angle is symmetrical with respect to the Z axis (in the case of a reflective diffraction grating). For α and β, the clockwise direction from the Z axis is the positive direction.

  As is apparent from equation (1), the exit angle β of the first-order diffracted light changes according to the wavelength λ. That is, the diffraction grating has a function as a spectroscope. Accordingly, when the illumination light is white light, the color perceived by the observer changes when the observation angle is changed in a plane perpendicular to the grating line of the diffraction grating.

In addition, the color perceived by the observer under a certain observation condition changes according to the lattice constant d.
For example, it is assumed that the diffraction grating emits first-order diffracted light in the normal direction. That is, the exit angle β of the first-order diffracted light is assumed to be 0 °. If the observer perceives this first-order diffracted light, and the emission angle of the 0th-order diffracted light at this time is αN, equation (1) can be simplified to equation (2) below. .

d = λ / sin αN (2)
As is clear from equation (2), in order for the observer to perceive a specific color, the wavelength λ corresponding to the color, the incident angle | αN | of the illumination light, and the lattice constant d are equal to each other. What is necessary is just to set so that the relationship shown in (2) may be satisfied. For example, white light including all light components having a wavelength in the range of 400 nm to 700 nm is used as illumination light, the incident angle | αN | of the illumination light is set to 45 °, and the spatial frequency (reciprocal of the lattice constant) is used. ) Is distributed in the range of 1000 lines / mm to 1800 lines / mm. In this case, when the diffraction grating is observed from the normal direction, a portion having a spatial frequency of about 1600 lines / mm looks blue and a portion having a spatial frequency of about 1100 lines / mm looks red.

  Note that the diffraction grating is easier to form when the spatial frequency is smaller. Therefore, in a normal display body, the majority of diffraction gratings are diffraction gratings having a spatial frequency of 500 lines / mm to 1600 lines / mm.

  As described above, the color perceived by the observer under a certain observation condition can be controlled by the grating constant d (or spatial frequency) of the diffraction grating. When the observation angle is changed from the previous observation condition, the color perceived by the observer changes.

  In the above description, it is assumed that light travels in a plane perpendicular to the grid lines. When the diffraction grating is rotated around the normal line from this state, the effective value of the grating constant d changes according to the rotation angle with respect to a certain observation direction. As a result, the color perceived by the observer changes. In other words, when a plurality of diffraction gratings having only different grating line orientations are arranged, different colors can be displayed on the diffraction gratings. Further, when the rotation angle becomes sufficiently large, diffracted light cannot be recognized from a certain observation direction, and is recognized in the same manner as when there is no diffraction grating.

  Further, when the depth of the groove 14d constituting the diffraction grating is increased, the diffraction efficiency changes (depending on the wavelength of illumination light, etc.). And if the area ratio of the diffraction grating with respect to the pixel demonstrated later is enlarged, the intensity | strength of diffracted light will become larger.

  Accordingly, in the fourth uneven structure region 12d, when a plurality of pixels in which the concave portions or the convex portions 14d are arranged in a predetermined arrangement pattern are arranged, in a part of those pixels and the other part, When the spatial frequency and / or orientation of the groove 14d is changed, different colors can be displayed on the pixels, and observable conditions can be set. Then, if at least one of the depth of the groove 14d and / or the area ratio of the diffraction grating with respect to the pixel is made different between a part of the pixels constituting the fourth concavo-convex structure region 12d and the other part, The luminance of the pixels can be made different. Therefore, by using these, it is possible to display an image such as a full-color image and a stereoscopic image in the fourth uneven structure region 12d.

  The “image” here means an image that can be observed as a spatial distribution of color and / or luminance. The “image” includes a photograph, a figure, a picture, a character, a symbol, and the like.

Next, the visual effect resulting from the uneven structure of the second uneven structure region 12b will be described.
FIG. 11 is a diagram schematically illustrating how the fourth uneven structure region emits diffracted light. FIG. 12 is a diagram schematically showing how the second uneven structure region 12b emits diffracted light. 11 and 12, 31a and 31b indicate illumination light, 32a and 32b indicate regular reflection light or 0th-order diffracted light, and 33a and 33b indicate first-order diffracted light.

  As described above, the plurality of concave portions or convex portions 14b provided in the second concavo-convex structure region 12b is compared with the minimum center distance of the groove 14d provided in the fourth concavo-convex structure region 12d, that is, the lattice constant of the diffraction grating. Are arranged two-dimensionally with a smaller center-to-center distance. Therefore, even if the concave portions or the convex portions 14b are regularly arranged and the second concavo-convex structure region 12b emits the diffracted light 33b, the observer can obtain the fourth concavo-convex structure having the same wavelength as the diffracted light 33b. The diffracted light 33a from the region 12d is not perceived at the same time. If the difference between the grating constant of the diffraction grating and the distance between the centers of the concave portions or the convex portions 14b is sufficiently large, the observer can compare the diffracted light 33a from the fourth concavo-convex structure region 12d with the first light regardless of the wavelength. The diffracted light 33b from the two concavo-convex structure region 12b is not perceived at the same time. That is, in this case, the observer does not visually recognize the diffracted light 33b from the second uneven structure region 12b within an observation angle range in which the diffracted light 33a from the fourth uneven structure region 12d can be visually recognized.

  Moreover, each recessed part or convex part 14b has a forward taper shape. Therefore, the reflectance of the regular reflection light of the second uneven structure region 12b is small no matter what angle is observed. However, if the aspect ratio (height / minimum center distance) between the minimum center distances and the heights of the plurality of grooves in each of the recesses or projections 14b is less than 0.5, black is insufficient and gray It becomes a close color. On the other hand, when the aspect ratio exceeds 1.5, the blackness is sufficient, but the diffraction efficiency is extremely deteriorated, and the visibility of the diffracted light is lowered, which is not good.

Therefore, for example, when the display 10 is observed from the normal direction, the second uneven structure region 12b looks darker than the fourth uneven structure region 12d. In this case, the second concavo-convex structure region 12b typically appears black. Here, “black” means, for example, all light components having a wavelength in the range of 400 nm to 700 nm when the display 10 is irradiated with light from the normal direction and the intensity of specular reflection light is measured. Means that the reflectance is 10% or less.

  If the emission angle of the first-order diffracted light 33b from the second concavo-convex structure region 12b is larger than −90 °, the observer can appropriately set the angle formed between the normal direction of the display body 10 and the observation direction. The first-order diffracted light 33b from the second uneven structure region 12b can be perceived. Therefore, in this case, it can be visually confirmed that the second uneven structure region 12b is different from a simple black print layer.

When this configuration is adopted, the center-to-center distance of the recesses or protrusions 14b is optimally within a range of 200 nm to 500 nm, for example. This is because, if it is less than 200 nm, diffracted light does not emerge, so it is difficult to differentiate it from simple black printing, and if it exceeds 500 nm, it is difficult to make it black. And it becomes easy to inject | emit diffracted light also to the range of a front direction.
Further, when this configuration is adopted, the distance between the centers of the concave portions or the convex portions 14b may be, for example, in a range of 200 nm to 350 nm. Thus, as is apparent from the above equation (2), the second uneven structure region 12b does not emit diffracted light having a wavelength corresponding to red, but emits diffracted light having a wavelength corresponding to blue. On the other hand, the fourth uneven structure region 12d emits diffracted light having a wavelength corresponding to red. Therefore, in this case, it is easier to confirm that the display body 10 is genuine as compared with the case where the fourth uneven structure region 12d emits diffracted light having a wavelength corresponding to red.

  In the second concavo-convex structure region 12b, when a plurality of pixels in which concave portions or convex portions 14b are arranged in a predetermined arrangement pattern are arranged, a concave portion is formed by a part of the pixels and the other part. Alternatively, if at least one of the shape, depth or height, average center distance, and arrangement pattern of the protrusions 14b is made different, the reflectance of the pixels can be made different as described in detail later. . Therefore, by using this, gradation can be expressed by the second concavo-convex structure region 12b.

  Next, the visual effect resulting from the uneven structure of the third uneven structure region 12c will be described. FIG. 5 is an enlarged perspective view showing an example of a concavo-convex structure that can be employed in the third concavo-convex structure region 12 c of the display body 10. By making a scattering structure with a surface relief as shown in the concave or convex portions 14c, the light is scattered in the front direction and becomes white.

  As a method for producing the scattering structure, (1) surface etching with chemicals, etc., (2) sand blasting method for hitting particles, (3) using a metal plate produced by engraving, electron beam (EB), laser, etc. There is a method of transferring irregularities with heat or ultraviolet rays. Considering reproducibility and accuracy, the uneven transfer system (3) is most preferable. Above all, in the method using an EB drawing apparatus, the density and shape of the concave and / or convex portions formed in a minute region can be arbitrarily controlled, and special scattering properties such as anisotropic scattering can be designed. It is. Since the concavo-convex structure of the second concavo-convex structure region 12b is black, it is preferable that a white expression portion such as the third concavo-convex structure region 12c is disposed as a contrast because the contrast is improved.

Next, the visual effect resulting from the uneven structure of the first uneven structure region 12a will be described.
The effect on the diffracted light in the first concavo-convex structure region 12a acts in the same way as the second concavo-convex structure region 12b, and will be described with reference to FIG.

As described above, the plurality of concave portions or convex portions 14a provided in the first concavo-convex structure region 12a is more compared with the minimum center distance of the groove 14d of the fourth concavo-convex structure region 12d, that is, the lattice constant of the diffraction grating. It is arranged two-dimensionally with a small center distance. Therefore, even if the concave portions or the convex portions 14a are regularly arranged and the first concavo-convex structure region 12a emits the diffracted light 33b, the observer can obtain the fourth concavo-convex structure having the same wavelength as the diffracted light 33b. The diffracted light 33a from the region 12d is not perceived at the same time. If the difference between the grating constant of the diffraction grating and the distance between the centers of the concave portions or the convex portions 14b is sufficiently large, the observer can compare the diffracted light 33a from the fourth concavo-convex structure region 12d with the first light regardless of the wavelength. The diffracted light 33b from the two concavo-convex structure region 12b is not perceived at the same time. That is, in this case, the observer does not visually recognize the diffracted light 33b from the first concavo-convex structure region 12a within the observation angle range in which the diffracted light 33a from the fourth concavo-convex structure region 12d can be visually recognized.

  Moreover, each recessed part or convex part 14a has a scattering structure. Therefore, the first concavo-convex structure region 12a is recognized as a white display even when observed from almost any angle. However, it is preferable to set the maximum height to be higher than that of the conventional diffraction grating because the scattering properties can be obtained by the difference in height between the plurality of heights of the concave portions or the convex portions 14a. On the other hand, if the height of the convex portion exceeds 750 nm, the reflectance is not white, but the reflectance is lowered and grayed, the diffraction efficiency is extremely deteriorated, and the visibility of the diffracted light is lowered, which is not good. In this example, the height of the convex portion is described, but the same can be said for the depth of the concave portion.

  Therefore, for example, when the display body 10 is observed from the normal direction, the first concavo-convex structure region 12a is scattered and recognized as a white display in the same manner as the third concavo-convex structure region 12c.

  If the emission angle of the first-order diffracted light 33b from the first interface portion 12a is larger than −90 °, the observer can set the angle formed by the normal direction of the display body 10 and the observation direction as appropriate. The first-order diffracted light 33b from the one interface portion 12a can be perceived. Therefore, in this case, it can be visually confirmed that the first interface portion 12a is different from a simple scattering structure.

  When this configuration is adopted, the center-to-center distance of the concave portion or convex portion 14a is, for example, in the range of 200 nm to 500 nm. This is because, if it is less than 200 nm, diffracted light is not emitted, so it is difficult to differentiate it from a simple scattering structure, and if it exceeds 500 nm, incident light or emitted light is extremely deteriorated due to the influence of the scattering structure. .

  When this configuration is adopted, the center-to-center distance of the concave portion or the convex portion 14a may be in the range of 200 nm to 350 nm, for example. Thus, as is apparent from the above equation (2), the first uneven structure region 12a does not emit diffracted light having a wavelength corresponding to red, but emits diffracted light having a wavelength corresponding to blue. On the other hand, the fourth uneven structure region 12d emits diffracted light having a wavelength corresponding to red. Therefore, in this case, it is easier to confirm that the display body 10 is genuine as compared with the case where the fourth uneven structure region 12d emits diffracted light having a wavelength corresponding to red.

  In addition, in the 1st uneven structure area | region 12a, when the some of the pixel by which the recessed part or the convex part 14a is arranged by the predetermined | prescribed arrangement pattern is arrange | positioned, it is a recessed part by some of these pixels and other part Alternatively, if at least one of the shape, the average center-to-center distance, and the arrangement pattern of the convex portion 14a is made different, the scattering components (haze) of the pixels can be made different as will be described in detail later. Therefore, by using this, gradation can be displayed in the first concavo-convex structure region 12a.

Further, in the display body 10, the first uneven structure region 12a, the second uneven structure region 12b, the third uneven structure region 12c, and the fourth uneven structure region 12d are in the same plane. Therefore, for example, a convex structure and / or a concave structure corresponding to the first concavo-convex structure region 12a, the second concavo-convex structure region 12b, the third concavo-convex structure region 12c, and the fourth concavo-convex structure region 12d are formed on one original plate. Then, by transferring this convex structure and / or concave structure to the light transmission layer 11, the respective convex structure and / or concave structure can be formed simultaneously. Accordingly, if the convex structure and / or the concave structure is formed with high precision on the original plate, each of the first concavo-convex structure region 12a, the second concavo-convex structure region 12b, the third concavo-convex structure region 12c, and the fourth concavo-convex structure region 12d. There can be no problem of misalignment. In addition, the fine concavo-convex structure and high-precision features enable high-definition image display and can be easily distinguished from those produced by other methods. The fact that genuine products can be manufactured stably with extremely high accuracy makes it easier to distinguish between counterfeit products and counterfeit products.

When the reflective layer is made of a metal material, it is possible to further improve the anti-counterfeit effect by adopting a method of partially removing the metal as described below.
Next, this partial metal removal method will be described.

  The first method is to print water-washing ink with a negative pattern on the substrate, form a metal reflective layer on the entire surface using vapor deposition or sputtering, and then wash the printed portion with water. Thus, the water-washed sea light processing is performed in which a pattern is formed by removing the metal reflective layer thereon.

  The second method is an etching process in which a mask agent is printed as a positive pattern on the metal reflective layer and a pattern is formed by corroding a portion not printed with the mask agent with a corrosive agent.

  The third method is laser processing in which a pattern is formed by selectively destroying the metal reflection layer by applying a strong laser to the portion of the metal reflection layer to be removed.

  On the other hand, FIG. 9, FIG. 10 is a top view which shows roughly the example of the arrangement pattern of the recessed part or convex part which can be employ | adopted as the 1st uneven structure area | region 12a.

  In FIG. 9, the recessed part or the convex part 14a has shown the example arranged in the square lattice form. Such an arrangement is relatively easy by manufacturing using a microfabrication apparatus such as an electron beam drawing apparatus or a stepper, and high-precision control such as the distance between the centers of the concave or convex portions 14b is also relatively easy.

  The concave portions or convex portions 14a in FIG. 9 are regularly arranged. Therefore, when the distance between the centers of the concave portions or the convex portions 14b is set to be relatively long, diffracted light can be emitted from the first concave-convex structure region 12a. In this case, it can be visually confirmed that the first uneven structure region 12a is different from the scattering structure. In addition, when the distance between the centers of the concave portions or the convex portions 14a is set to be relatively short, for example, when set to 200 nm or less, diffracted light is not emitted from the first uneven structure region 12a. In this case, at the time of observation, it is difficult to understand that the first uneven structure region 12a is different from the scattering structure.

  In the example of FIG. 9, the distance between the centers of the recesses or protrusions 14a is made equal in the X direction and the Y direction, but the distance between the centers of the recesses or protrusions 14a is made different between the X direction and the Y direction. May be. That is, the arrangement of the concave portions or the convex portions 14a may form a rectangular lattice.

When the distance between the centers of the concave or convex portions 14a is set to be relatively long in both the X direction and the Y direction, the display body 10 is illuminated from the direction perpendicular to the X direction when the display body 10 is illuminated from the direction perpendicular to the Y direction. The diffracted light can be emitted from the first concavo-convex structure region 12a both when illuminated, and the wavelength of the diffracted light can be made different between the former and the latter. If the distance between the centers of the concave portions or the convex portions 14a is set to be relatively short in both the X direction and the Y direction, the emission of diffracted light from the first interface portion 12b can be prevented regardless of the illumination direction. When the distance between the centers of the recesses or the protrusions 14a is set to be relatively long in one of the X direction and the Y direction, and set to be relatively short on the other side, the display 10 is illuminated from a direction perpendicular to one of the Y direction and the X direction. In this case, diffracted light is emitted from the first concavo-convex structure region 12a, and when the display body 10 is illuminated from a direction perpendicular to the other of the Y direction and the X direction, the diffracted light is emitted from the first concavo-convex structure region 12a. Can be prevented.

  In the example of FIG. 10, the arrangement of the recesses or protrusions 14a forms a triangular lattice. When this structure is employed, as in the case of employing the structure of FIG. 9, diffracted light can be emitted from the first uneven structure region 12a if the distance between the centers of the recesses or protrusions 14a is set relatively long. If the distance between the centers of the concave portions or the convex portions 14a is set to be relatively short, the emission of diffracted light from the first concave-convex structure region 12a can be prevented.

  In addition, when the structure of FIG. 10 is adopted, if the distance between the centers of the recesses or protrusions 14a is appropriately set, for example, when the display body 10 is illuminated from the A direction, the diffracted light is emitted from the first uneven structure region 12a. When the display body 10 is illuminated from the B direction and the C direction, diffracted light can be emitted from the first interface portion 12a. That is, a more complicated visual effect can be obtained.

  As illustrated in FIG. 7 or FIG. 8, various modifications can be made to the arrangement pattern of the concave portions or the convex portions 14 a. Each arrangement pattern has a visual effect unique to it. Therefore, if the first interface portion 12a is configured by a plurality of pixels having different arrangement patterns of the concave portions or the convex portions 14a, a more complicated visual effect can be obtained.

  FIG. 7 or FIG. 8 is an enlarged perspective view showing another example of a structure that can be employed in the first uneven structure region of the display body shown in FIG. 1 and FIG.

The structure shown in FIG. 7 is a modification of the structure shown in FIG. Each of the concave portions or the convex portions 14a shown in FIG. 7 or FIG. 8 has a non-uniform height but periodicity.
In the structure shown in FIG. 7, the concave portion or the convex portion 14a has a quadrangular prism shape. The concave portion or the convex portion 14a may have a prismatic shape other than a quadrangular prism shape such as a triangular prism shape.

  The structure shown in FIG. 8 is a structure having a concave portion and a convex portion. By adopting a structure having a concave portion and a convex portion in this way, a display with a great variety of changes becomes possible. For example, the convex portion has the structure of the first concavo-convex structure region 12a, and the concave portion has the structure of the second concavo-convex structure region 12b. Then, it looks white when observed from the front (vertical direction) of one surface (front surface), and diffracted light can be seen when the display body is tilted. When observing from the front side of the other side (back side), the place that looked white is displayed in black, and diffracted light can be seen when the display body is tilted.

  The display body 10 according to the configuration as described above can be used as, for example, a seal label, a thread, a stripe transfer foil, a spot transfer foil or the like having an anti-counterfeit effect. Since the display body 10 is difficult to forge or imitate, when the display body 10 is supported by an article, it is difficult to forge or imitate. In addition, since the display body 10 has the above-described visual effect, it is easy to determine an article whose authenticity is unknown between a genuine product and a non-genuine product.

  FIG. 13 is a plan view schematically showing an example of a gift certificate in which an anti-counterfeit stripe transfer foil is supported on an article. As an example of an article with a stripe transfer foil, a printed matter 40 is drawn.

The printed matter 40 includes a paper base material 44, and a printed layer 41 is formed on the paper base material 44. Furthermore, the display body 43 is attached to the printed matter 40 as a forgery-preventing stripe transfer foil. The display body 43 includes a region 46c where a one-dimensional relief type diffraction grating is formed, and a plurality of grooves finer than the region 46c. The minimum center distance is 200 nm to 5 nm.
It includes a region 46a and a region 46b where a two-dimensional relief type diffraction grating having a non-uniform height of the uneven structure at 00 nm is formed, and a region 46d which is a mirror surface. The region 46a is formed with a minimum groove center distance of about 300 nm, and the region 46b is formed with a groove minimum center distance of about 400 nm.

  FIG. 14 is a cross-sectional view taken along line AA of the display shown in FIG. The display body 43 is a laminated body in which a surface protective layer / peeling layer 42, a light transmitting embossed layer 49, an aluminum reflective layer 48, an adhesive layer 45, and a paper base material 44 are laminated. In the example shown in FIG. 14, the surface protective layer / peeling layer 42 side is the front side and the paper substrate 44 side is the back side. The interface between the light transmitting embossed layer 49 and the aluminum reflecting layer 48 includes the two-dimensional relief type diffraction grating region 46a, the two-dimensional relief type diffraction grating region 46b, and the mirror surface region 46d.

  The printed matter 40 includes a display body 43. Therefore, when observed in the vicinity of the perpendicular direction of the printed matter 40, the region 46a and the region 46b are scattered and appear white. However, when the printed product 40 is observed in the vicinity of the perpendicular direction, the design composed of the region 46a and the region 46b cannot be confirmed. This is because the unevenness of the region 46a and the region 46b serves as a light scattering layer for light near the perpendicular direction of the printed matter 40, and there is almost no difference between them. Subsequently, when white light is incident from a direction of 60 to 70 degrees with respect to the vertical direction of the printed matter 40 and observed in a direction of 60 to 70 degrees with respect to the vertical direction of the printed matter 40, green light is emitted in the region 46a. In the region 46b, red light is emitted. Therefore, the design composed of the region 46a and the region 46b can be confirmed, and authenticity determination can be performed. Therefore, the forgery prevention effect is very high.

  As described above, it is difficult to forge or imitate the printed material 40. In addition, since the printed matter 40 includes the display body 43, it is easy to discriminate between an authentic product and a non-authentic product if the product is unknown. Moreover, since the printed matter 40 further includes the printed layer 41 in addition to the display body 43, it is easy to compare the appearance of the printed layer 41 with the appearance of the display body. Therefore, compared with the case where the printed matter 40 does not include the print layer 41, it is easier to distinguish an article whose authenticity is unknown from a genuine product to a non-authentic product.

  Hereinafter, the present invention will be described in more detail with reference to examples.

First, a thin film of a coating liquid having the following composition was applied on a biaxially stretched polyester film (PET film) (Toyobo E5100) having a thickness of 12 μm by a gravure method and then dried to obtain a release layer having a thickness of 1 μm.

Acrylic resin (BR60 manufactured by Mitsubishi Rayon) 100 parts by weight polyethylene wax (additive 180 manufactured by Toyo Ink) 5 parts by weight Solvent (methyl ethyl ketone) 1000 parts by weight

  Subsequently, a thin film of ink having the following composition was applied on the release layer at a thickness of 2 μm by the gravure method, dried, and further subjected to aging at 40 ° C. for 3 days to obtain a film having a light transmission layer.

Two-part curable urethane ink (K448, manufactured by Toyo Ink) 100 parts by weight Isocyanate curing agent (UR100B, manufactured by Toyo Ink) 10 parts by weight Solvent (methyl ethyl ketone) 10 parts by weight

Next, an uneven pattern according to the uneven structure as shown in FIG. 6 was drawn with an EB drawing apparatus, and then a nickel original plate was obtained by a nickel electroforming method. Next, the fine unevenness | corrugation relief film was obtained by carrying out the hot-pressure embossing continuously to the light transmissive layer of the laminated | multilayer film obtained at the said process with the roll which affixed this original plate to the heating cylinder roll.
The concavo-convex pattern of the concavo-convex structure region used here had a pitch of 360 nm, the convex portions were cylindrical, and the arrangement pattern based on Benard cells was used as the scattering component.

Next, an aluminum vapor deposition layer having a thickness of 500 mm was laminated as a light reflection layer on the relief surface of the fine unevenness relief film by a vacuum vapor deposition method.
FIG. 16 shows a plan photograph taken with an electron microscope at this time, and FIG. 17 shows a tilt photograph.

  And the thin film of the adhesive agent of the following composition was apply | coated on the light reflection layer so that thickness might be set to about 10 micrometers by microgravure printing.

Polyester resin (Byron 200 manufactured by Toyobo Co., Ltd.) 60 parts by weight epoxy resin (EP1100L made by Japan Epoxy Resin) 40 parts by weight powdered silica (Silo Hovic # 100 manufactured by Fuji Silysia) 10 parts by weight solvent (toluene) 100 parts by weight solvent (methyl ethyl ketone) 100 parts by weight

In this way, after the obtained hologram transfer foil film was thermocompression bonded to a gift certificate paper at 160 ° C. for 10 seconds, the base material PET film was peeled off, and a gift certificate having an anti-counterfeit transfer foil was obtained. .
The anti-counterfeit transfer foil thus produced was a bright display body that was scattered and displayed white from the front, and exhibited a spectrum characteristic of diffracted light when tilted.

DESCRIPTION OF SYMBOLS 10 ... Display body, 11 ... Light transmission layer, 13 ... Reflection layer, 12a ... 1st uneven structure area | region, 12b ... 2nd uneven structure area | region, 12c ... 3rd uneven structure area | region, 12d ... 4th uneven structure area | region, 12e ... Flat region, 14a ... concave or convex, 14b ... concave or convex, 14c ... concave or convex, 14d ... concave or convex, 15 ... adhesive layer, 16a ... convex array, 16b ... concave array, 31a ... illumination Light, 31b ... Illumination light, 32a ... Regular reflection light or 0th order diffracted light, 32b ... Regular reflection light or 0th order diffracted light, 33a ... First order diffracted light, 33b ... First order diffracted light, 40 ... Display body, 41 ... Print layer, 42 ... protective layer / peeling layer, 43 ... transfer foil, 44 ... paper substrate, 45 ... adhesive layer, 46a ... first interface part, 46b ... first interface part, 46c ... fourth interface part, 46d ... flat part, 48 ... reflective layer, 49 ... light transmission layer

Claims (6)

  Provided on one main surface of the light transmission layer is a concavo-convex structure region provided with a plurality of recesses and / or projections arranged two-dimensionally, and a reflective layer covering at least a part of the concavo-convex structure region The plurality of recesses and / or projections in the concavo-convex structure region has a minimum center distance within a range of 200 nm to 500 nm and has a specific periodicity, and the plurality of recesses and / or In the concavo-convex structure region provided with the convex portion, a portion where the concave portion or the convex portion having substantially the same depth or height is provided continuously adjacent to each other has a length of 10 μm or more. Incorporates anisotropic scattering elements that scatter well in the front direction (perpendicular to the display) and less scatter in the deep angular direction (the direction close to the horizontal of the display), and the deep angular direction (display) In a direction close to the horizontal of the body) Display body diffracted light is the height of the depth and / or the convex portion of the concave portion so as to emit, wherein the heterogeneous to.   The display body according to claim 1, wherein the maximum depth of the concave portion and / or the maximum height of the convex portion is 750 nm or less. The eggplant arrangement pattern of a plurality of recesses provided on the concavo-convex structure area and / or the protrusions, the display body according to claim 1 or 2, characterized in that a pattern from Benard Cells. A plurality of the concavo-convex structure regions are provided on one main surface of the light transmission layer, and in at least one of the concavo-convex structure regions, the center-to-center distance and the arrangement pattern are different from those of the other concavo-convex structure regions. display body according to any one of claims 1 to 3, wherein different. One principal surface of the light transmission layer has a one-dimensional diffraction grating pattern region, and the distance between the centers of the concave portions and / or convex portions in the one-dimensional diffraction grating pattern region is the Alternatively, the depth of the concave portion and / or the height of the convex portion of the one-dimensional diffraction grating pattern region is larger than the center-to-center distance of the convex portion, and the maximum depth of the concave portion and / or the maximum of the convex portion of the concave-convex structure region. display body according to any one of claims 1 to 4, characterized in smaller that than the height. One main surface of the light transmission layer is provided with a plurality of concavo-convex structure regions, and a minimum center-to-center distance between the plurality of concave and / or convex portions in the concavo-convex structure region other than the concavo-convex structure region is 200 nm to 500 nm. A forward taper in which the plurality of recesses and / or protrusions in the region have a specific periodicity, and the depths and / or heights of the protrusions are substantially uniform. display body according to any one of claims 1 to 5, characterized in that it has a Jo uneven structure.