JP2010231002A - Display body and article with label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display body having an excellent forgery prevention effect with respect to the problem that although advanced techniques are required to manufacture diffraction structure, forgery of a display body containing the diffractive structure is becoming possible with the improvement in recent years in the analysis technique of fine structure and spread of fine processing technology, and distinctiveness of visual effects provided by the diffractive structure is decreasing with the spread of the display body containing the diffraction structure. <P>SOLUTION: The display body 10 includes a rugged structure region 12 having recessed parts 12b or projecting parts 12a or both thereof one-dimensionally or two-dimensionally arrayed on one principal surface of a light transmitting layer, and a reflection layer supported on the one principal surface to cover at least a part of the rugged structure region 12. The center-to-center distance of the plurality of recessed parts 12b or projecting parts 12a or both thereof ranges from 200 nm to 500 nm, and the reflectance is controlled by the thickness of the reflection layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a forgery prevention technique. For example, the present invention relates to a display body or a labeled article that has been subjected to forgery prevention technology.

It is desirable that authentication items such as cash cards, credit cards and passports, and securities such as gift certificates and stock certificates are difficult to counterfeit. Therefore, conventionally, in order to prevent the counterfeiting, such an article has been attached with a label that is difficult to counterfeit or counterfeit and can be easily distinguished from a counterfeit or counterfeit product.
In recent years, the distribution of counterfeit products has been regarded as a problem for items other than certified items and securities. Therefore, the opportunity to apply the above-described anti-counterfeiting technology with respect to certified articles and securities is increasing.

  For such purposes, an OVD (Optical Variable Device) that generates a color change (color shift) according to an observation angle or the like has been used. Examples of the OVD include a multilayer film, a hologram, and a diffraction grating.

  The multilayer film has a structure in which multiple layers of ceramics and metals having different optical characteristics are laminated. In the multilayer film, by appropriately designing the optical thickness of each layer, interference that strengthens light of a certain wavelength can be generated, and interference that weakens light of another wavelength can be generated. Since the optical path length between the interfaces changes according to the observation angle, when the observation angle is changed, the wavelength of light that causes constructive interference and the wavelength of light that causes destructive interference change. Based on such a principle, the multilayer film causes a color shift corresponding to the observation angle.

  A diffractive structure such as a hologram and a diffraction grating is composed of, for example, a fine concavo-convex pattern or a layer provided with a striped refractive index distribution. When illuminated with white light, the diffractive structure emits diffracted light at different angles depending on the wavelength. The diffractive structure causes a color shift because of this spectral action or the like.

  Thus, OVD, especially diffractive structures, have a characteristic visual effect. When the diffractive structure is used, a complicated image such as a stereoscopic image or a special decorative image shining in rainbow can be displayed. In addition, as explained below, diffractive structures require advanced techniques for their manufacture.

Holograms can be classified into, for example, volume holograms and relief holograms.

  In the production of a volume hologram, interference fringes are recorded three-dimensionally on a layer made of a recording material such as a photosensitive resin. As the volume hologram, a Lippmann hologram is generally used.

  In manufacturing a relief hologram, first, an original plate including a resin layer having a fine concavo-convex pattern on its surface is produced by an optical imaging method using interference of laser light or electron beam drawing. Next, a metal stamper is produced from this original plate by electroforming or the like. Thereafter, a thermoplastic resin, a photocurable resin, or the like is applied onto a flat surface of a base material made of polyethylene terephthalate (PET) or the like, and the above-mentioned metal stamper is brought into close contact therewith. In this state, heat or light is applied to cure the resin, and the metallic stamper is peeled from the resin layer to obtain a relief hologram.

  For example, the diffraction grating is manufactured by the same method as described for the manufacture of the relief hologram.

  Patent Document 1 describes a display body that displays a stereoscopic image using a diffraction grating. Patent Document 2 describes a display body that employs a pixel structure. When the incident angle of the illumination light to the diffraction grating is fixed and the diffraction grating is illuminated with white light, the color displayed by the diffraction grating is the grating constant of the diffraction grating, that is, the space of the grating lines constituting the diffraction grating. It is determined by the frequency, the angle formed by the observation direction with respect to the normal line of the diffraction grating, and the angle formed by the lattice line with respect to a plane parallel to the observation direction and the normal line of the diffraction grating. Therefore, when the display body is composed of a plurality of pixels, the structure to be adopted for the diffraction grating of each pixel can be specified from the color of the image to be displayed. Employing such a pixel structure facilitates the design of the display body.

  As described above, the diffractive structure can provide a characteristic visual effect and requires advanced techniques for its manufacture. For this reason, a display body including a diffractive structure may be supported on the above-described article in anticipation of an anti-counterfeit effect. In addition, as described above, the diffractive structure may provide a characteristic visual effect, and thus may be used for general printed materials such as decorative materials, picture books, and catalogs.

US Pat. No. 5,058,992 JP-A-6-82612

As described above, a diffractive structure requires a high level of technology for its manufacture, but with the recent improvement of fine structure analysis technology and the spread of fine processing technology, it is becoming possible to forge a display body including the diffractive structure. . That is, the forgery prevention effect of the display body including the diffractive structure is decreasing.
In addition, with the widespread use of display bodies including a diffractive structure, the peculiarity of visual effects provided by the diffractive structure is decreasing.

  An object of the present invention is to realize a display body that is difficult to forge and can provide a special visual effect.

As means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that a plurality of concave or convex portions or one-dimensionally arranged at least partly on one main surface of the light transmission layer, or It includes a concavo-convex structure region including both of them, and is provided with a reflective layer supported on the one main surface and covering at least a part of the concavo-convex structure region,
A distance between centers of the plurality of concave portions and / or convex portions is in a range of 200 nm to 500 nm, and a thickness of at least a part of the reflective layer is 130 nm to 500 nm. .

  Further, the invention according to claim 2 is the display body according to claim 1, further comprising a flat region 14 having no structure, together with the uneven structure 12, on one main surface of the light transmission layer. is there.

  According to a third aspect of the present invention, the depth or height of the plurality of concave portions 12b or convex portions 12a is ½ or more of the center-to-center distance on one main surface of the light transmission layer. The display body according to claim 1, wherein:

  The invention according to claim 4 is the display body according to any one of claims 1 to 3, wherein a thickness of at least a part of the reflective layer is different from that of other reflective layers. .

  The invention according to claim 5 is provided with the concavo-convex structure region 12 on one main surface of the light transmission layer 11, supported by the one main surface, and covering at least a part of the concavo-convex structure region 12. The display body according to any one of claims 1 to 4, further comprising: a reflective layer 13 that is supported; and a resin layer that is supported by the one main surface and covers at least the uneven structure region 12. It is.

  The invention according to claim 6 is a labeled article comprising the display body according to any one of claims 1 to 5 and an article supporting the display body.

The present invention can express blackness that cannot be seen in conventional holograms and diffraction gratings when viewed from the front, which is easy to see, and can be combined with conventional holograms and diffraction gratings to prevent counterfeiting and design. It is intended to provide a display body and an article using the display body that can easily determine the authenticity by displaying a pattern, a character, a symbol, etc. when observed with a large tilt from the front. .
In addition, a display body presents information, such as a character, a picture, a design, etc. by a change in light intensity, and can be confirmed by visual observation or machine reading.

  According to the first aspect of the present invention, a concavo-convex structure including a plurality of concave portions 12b and / or convex portions 12a arranged in one or two dimensions on at least a part of one main surface of the light transmission layer. A plurality of concave portions 12b and / or convex portions 12a, or a distance between the centers of the plurality of concave portions 12b and / or convex portions 12a. Is within the range of 200 nm to 500 nm, the surface area of the concave portion 12b or the convex portion 12a can be increased, thereby increasing the light absorption and expressing black to gray that could not be expressed by a conventional hologram or diffraction grating. The thickness of at least a part of the reflective layer can be 130 nm or more and 500 nm or less, and uniform properties can be obtained without precise thickness control of the reflective layer. It is possible to exhibit. “Black to gray” means that the reflectance is 50% or less for all light components having a wavelength in the range of 400 nm to 700 nm.

The outline of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory perspective view of the concavo-convex structure 12. FIG. 2 is a cross-sectional view of the concavo-convex structure 12 along the line AA ′ shown in FIG. 1, and FIG. 3 is an explanatory diagram when the display body 10 is observed.
By covering at least a part of the concavo-convex structure region 12 including one or two-dimensionally arranged recesses 12b and / or protrusions 12a on one main surface of the light transmission layer 11, the reflective layer 13 The surface area of the reflective layer 13 can be increased, thereby increasing light absorption.
When observed from the front (VW1), the regular reflection light LR1 of the illumination light LI from the light source LS becomes small, and black or gray can be expressed. Further, by setting the center-to-center distance of the concavo-convex structure 12 to 200 nm to 500 nm, diffracted light LD1 due to the concavo-convex structure 12 is not generated in the front direction of the display body, but diffracted light is generated at a large angle with respect to the front direction. Therefore, it is possible to display a pattern, a character, a symbol, and the like by diffracted light only when observed with a large tilt from the front (VW2).

Next, FIG. 4 shows changes in reflectance and transmittance of the uneven structure depending on the thickness of the reflective layer 13.
FIG. 4 is a perspective view of FIG. 1 and a saddle-shaped recess 12b (height H400 nm, center-to-center distance P300 nm) and saddle-shaped recess 12b (height H400 nm, center-to-center distance P400 nm), flat as shown in FIG. It is obtained by performing normal incidence reflectivity and transmittance simulations at a light wavelength of 532 nm with respect to a reflective layer made of aluminum (Al), each of which is provided in a square lattice shape, by the FDTD (finite difference time domain) method. Data are shown.

From this simulation result, when the thickness of the reflective layer Al is not less than 150 nm and not more than 500 nm, there is no change due to the Al thickness of the concavo-convex structure and no change due to the Al thickness of the flat portion.
In this range, it is possible to show stable performance without accurately controlling the thickness of Al. Even if the uneven thickness 13b of the reflective layer shown in FIG. 2 occurs, the observer cannot distinguish the difference, so that it does not become a defect. Moreover, the said display body can be produced in the film form suitable for mass production by setting it as 500 nm or less.

  According to the second aspect of the present invention, the flat region 14 is provided along with the concavo-convex structure 12 on one main surface of the light transmission layer 11, so that the black and gray of the concavo-convex structure region 12 and the flat region 14 are provided. By arranging the specular reflections, it is possible to express with high contrast.

  According to the third aspect of the present invention, the depth or height of the concave portion 12b or the convex portion 12a of the concavo-convex structure region 12 is set to 1/2 or more of the center-to-center distance, thereby increasing light absorption. , Can express darker black.

  According to the third aspect of the present invention, the depth or height of the concave portion 12b or the convex portion 12a of the concavo-convex structure region 12 is set to 1/2 or more of the center-to-center distance, thereby increasing light absorption. , Can express darker black.

  According to the invention described in claim 4, by making the thickness of at least a part of the reflective layer different from the thickness of the other part of the reflective layer, both thicknesses of the reflective layer are 130 nm to 500 nm. In this case, the difference in the thickness of the reflective layer can be hidden from the observer, and the thickness of the reflective layer is not caused by the shape of the concavo-convex structure by making one thickness of the reflective layer 130 nm or less. The difference due to the cause can be clearly shown to the observer.

  According to the invention described in claim 5, the light-transmitting layer 11 includes the concavo-convex structure region 12 on one main surface, is supported by the one main surface, and covers at least a part of the concavo-convex structure region 12. The concavo-convex structure region 12 can be protected by sequentially including the reflective layer 13 to be formed and the resin layer supported on the one main surface and covering at least the concavo-convex structure region.

  According to the invention described in claim 6, by providing the article with the display body, a labeled article having a high effect of preventing forgery can be provided.

The perspective view for explanation of concavo-convex structure 12 of the present invention. Sectional drawing of the uneven structure along the A-A 'line | wire shown in FIG. Effect explanatory drawing when observing the display body 10 of this invention. The graph which shows an example of the relationship between the thickness of the reflection layer 13 of the display body 10 of this invention, and a reflectance / transmittance. The top view which shows roughly the display body which concerns on the 1st aspect of this invention. The top view which shows roughly the display body which concerns on the 2nd aspect of this invention. Sectional drawing of the uneven structure 12 along the B-B 'line | wire shown in FIG. The graph which shows the thickness of the reflection layer 13 which has coat | covered the uneven structure 12 along the B-B 'line shown in FIG. The top view which shows roughly an example of the labeled article formed by making the article support the label for forgery prevention or the identification according to the third aspect of the present invention. Sectional drawing which shows an example of an adhesive label roughly. The perspective view which shows schematically the example of the structure employable as the uneven structure 12. FIG. The perspective view which shows schematically the example of the structure employable as the uneven structure 12. FIG. The perspective view which shows schematically the example of the structure employable as the uneven structure 12. FIG. The perspective view which shows schematically the example of the structure employable as the uneven structure 12. FIG. The perspective view which shows roughly the modification of a display body.

  Hereinafter, specific embodiments of a display body and an article using the display body according to the present invention will be described with reference to the drawings.

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.
FIG. 5 is a plan view schematically showing the display 10 according to the first aspect of the present invention. DP1 is a region constituted by the bowl-shaped recess 12b (height H400 nm, center distance P300 nm), and DP2 is a region constituted by the bowl-shaped recess 12b (height H400 nm, center-center distance P400 nm). DP3 is a flat region. Further, the display body 10 is entirely coated with 150 nm of Al as the reflective layer 13.
As the reflective layer 13, for example, a metal material such as aluminum, silver, gold, and alloys thereof, or a metal layer made of metal ink can be used. Alternatively, as the reflective layer 13, a dielectric layer having a refractive index different from that of light transmission may be used. Alternatively, as the reflective layer 13, a laminate of dielectric layers having different refractive indexes between adjacent ones, that is, a dielectric multilayer film may be used. However, the refractive index of the dielectric layer included in the dielectric multilayer film that is in contact with the light transmission layer needs to be different from the refractive index of the light transmission layer.
When the table 10 of the present invention is observed in the regular reflection direction (VW1) with the illumination light LI angle from the light source LS being 30 degrees as in FIG. 4, the reflected light from DP1 and DP2 is weak (from FIG. 4). , It is difficult to identify the difference. Further, since the reflected light from DP3 serving as a mirror surface has a high reflectance with respect to DP1 and DP2, an image with high contrast is displayed.
Next, when observed with a large tilt from the front (observation angle 70 degrees VW2), blue diffracted light LD1 (wavelength 432 nm) can be observed from DP1, and yellow diffracted light LD1 (wavelength 576 nm) can be observed from DP2. DP1 and DP2 can be identified. Further, the flat area of DP3 becomes dark. By having the above-mentioned special visual effect, it becomes possible to enhance the forgery prevention effect and to easily perform the deliberation judgment of the display body.

FIG. 6 is a plan view schematically showing the display body 10 according to the second aspect of the present invention. FIG. 7 is a cross-sectional view taken along the line BB ′ of the display body shown in FIG. 6, and FIG. 8 shows the thickness distribution of the reflective layer (Al) on the line BB ′ of the display body shown in FIG. It is a figure.
The display body of FIG. 6 is composed of DP1, DP2, and DP3 as in the first mode. However, as shown in FIGS. 7 and 8, the thickness of Al coated as the reflective layer is continuously changed from 50 nm to 200 nm.
In DP2a, the thickness of the reflective layer Al continuously changes from 50 nm to 130 nm. Therefore, the reflectance changes continuously as shown in FIG. 4, so that black or gray gradation can be expressed. However, since there is no difference in the concavo-convex structure 12, no difference appears in the analysis of the concavo-convex structure 12. Further, in DP2b, the thickness of the reflective layer Al changes from 150 nm to 200 nm, but there is no change in the reflectance in DP2b, and a uniform reflectance can be exhibited.
Further, DP3, which is a flat region, has almost the same reflectance regardless of the difference in the thickness of Al, so it is difficult to recognize the difference in the thickness of the reflector 13 only by visually observing the display body 10. It is possible to increase the anti-counterfeit effect.

  FIG. 10 is a plan view schematically showing an example of a labeled article in which an anti-counterfeiting or identification label is supported on the article.

  FIG. 10 shows a printed matter as an example of the labeled article. The printed material is an ID (identification) card and includes a printed material main body 20.

  The printed material main body 20 includes a base material 210. The base 210 is made of plastic, for example. A printed layer 220 is formed on the substrate 210. The display body 10 described above is fixed to the surface of the substrate 210 on which the printed layer 220 is formed, for example, via the adhesive layer 30. The display body 10 is fixed to the base material 210 by being pasted through, for example, the adhesive layer 30 or the adhesive layer 50.

  This printed matter includes the display body 10. Therefore, counterfeiting or imitation of this printed matter is difficult. In addition, since the printed matter includes the display body 10, it is easy to discriminate between an authentic product and a non-authentic product for an article whose authenticity is unknown. In addition, since the printed matter 20 further includes a printed layer 220 in addition to the display body 10, a forgery prevention measure using the printed layer 220 can be employed.

  In FIG. 10, an ID card is illustrated as a printed material including the display body 10, but the printed material including the display body 10 is not limited thereto. For example, the printed matter including the display body 10 may be other cards such as a magnetic card, a wireless card, and an IC (integrated circuit) card. Alternatively, the printed matter 20 including the display body 10 may be securities such as gift certificates and stock certificates. Alternatively, the printed matter 20 including the display body 10 may be a tag to be attached to an article to be confirmed as a genuine product. Alternatively, the printed matter including the display body 10 may be a package body that contains an article to be confirmed to be genuine or a part thereof.

  Moreover, in the printed matter 20 shown in FIG. 10, although the display body 10 is affixed on the base material 40, the display body 10 can be supported on a base material by another method. For example, when paper is used as the base material, the display body 10 may be rolled into the paper and the paper may be opened at a position corresponding to the display body 10. Alternatively, when a light-transmitting material is used as the base material, the display body 10 may be embedded therein, or the display body 10 may be fixed to the back surface of the base material, that is, the surface opposite to the display surface. .

  Moreover, the labeled article may not be a printed material. That is, the display body 10 may be supported on an article that does not include a printed layer. For example, the display body 10 may be supported by a luxury product such as a work of art.

  The display body 10 may be used for purposes other than forgery prevention. For example, the display body 10 can be used as a toy, a learning material, or a decoration.

For the production of these labeled articles, for example, an adhesive label or a transfer foil can be used.

FIG. 9 is a cross-sectional view schematically showing an example of an adhesive label.
This adhesive label includes the display body 10 and the adhesive layer 30 described above. The adhesive layer 30 is supported by the display body 10 on the back side of the display surface. That is, the adhesive layer 30 covers the back surface of the display surface of the display body 10. The pressure-sensitive adhesive label may further include a release paper that releasably covers the pressure-sensitive adhesive layer 30.

  The display body 10 described above can be variously modified. For example, the previous display body 10 includes only two display sections DP1 and DP2 as a display section including the concavo-convex structure 12 composed of the two-dimensionally arranged bowl-shaped recesses 12b. Three or more such display units may be included. Further, a diffraction grating arranged one-dimensionally as the concavo-convex structure 12 may be used.

  Moreover, although the example where the recessed part 12b is the bowl-shaped recessed part 12b was demonstrated here, the shape of these uneven structures is not restricted to the bowl-shaped recessed part 12b.

FIG. 11 to FIG. 14 are perspective views schematically showing examples of structures that can be adopted for the concavo-convex structure 12.
The concavo-convex structure 12 may have a columnar shape, a truncated cone shape, a cone shape, a combination shape of a cone and a column, a hemisphere, a semi-ellipsoid, or a shape obtained by deforming them.

  Further, the light transmission layer 11 may be provided with a convex portion 12a instead of the concave portion 12b.

FIG. 15 is a perspective view schematically showing a modification of the display body.
FIG. 15 shows a state in which a part of the display body 10 is observed.

  The display body 10 is the same as the display body 10 described above, except that the concavo-convex structure 12 is provided with a convex portion 12a instead of the concave portion 12b. Thus, also when the convex part 12a is provided instead of the concave part 12b, the above-described effects can be obtained.

DESCRIPTION OF SYMBOLS 10 ... Display body, 11 ... Light transmission layer, 12 ... Uneven structure, 13 ... Reflection layer, 14 ... Flat area | region,
20 ... printed matter body, 30 ... adhesive layer, 40 ... base material, 50 ... adhesive layer, 130 ... release protective layer,
210 ... base material, 220 ... print layer, DP1 ... display unit, DP2 ... display unit, DP3 ... display unit,
LD1 ... diffracted light, LR1 ... reflected light, LS ... light source, LI ... illumination light, VW1 ... observer,
VW2 ... Observer

Claims (6)

At least part of one main surface of the light transmission layer is provided with a concavo-convex structure region including a plurality of concave or convex portions or both arranged one-dimensionally or two-dimensionally, supported by the one main surface, A reflective layer covering at least a part of the uneven structure region;
The display body, wherein a distance between centers of the plurality of concave portions and / or convex portions is in a range of 200 nm to 500 nm, and a thickness of at least a part of the reflective layer is 130 nm to 500 nm. The display body according to claim 1, wherein a flat region having no structure is formed together with the uneven structure region on one main surface of the light transmission layer. 3. The depth or height of a concave portion or a convex portion of the concavo-convex structure region on one principal surface of the light transmission layer is ½ or more of the center-to-center distance. The display body. The display body according to claim 1, wherein a thickness of at least a part of the reflective layer is different from a thickness of another part of the reflective layer. Provided with the concavo-convex structure region on one main surface of the light transmission layer,
A reflective layer supported on the one main surface and covering at least a part of the concavo-convex structure region;
A resin layer supported on the one main surface and covering at least the uneven structure region;
The display body according to claim 1, wherein the display body is sequentially provided. An article with a label comprising the display body according to any one of claims 1 to 5 and an article that supports the display body.

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