JP5347234B2 - Diffraction image display and labeled article - Google Patents

Description

  The present invention relates to a diffraction image display and an article with a label.

  The diffraction image display body includes a diffraction grating. The display color of the diffraction grating is a structural color that changes according to the illumination direction and / or the observation direction. That is, the diffraction grating causes a color shift. Such features cannot be reproduced with normal printing techniques. Therefore, as described in Patent Document 1, the diffraction image display is mainly used for the purpose of preventing forgery of articles.

For this purpose, it is necessary that it is difficult to forge the diffraction image display. However, with the development of technology, the difficulty of forming a diffraction grating is decreasing. Therefore, a higher false image prevention effect is desired for the diffraction image display body.
JP-A-10-153702

  An object of the present invention is to achieve a higher anti-counterfeit effect by a false image prevention technique using a diffraction image display.

According to a first aspect of the present invention, when viewed from the second direction perpendicular to and the display surface to identify the information that is retained when viewed from a first direction oblique to the table示面In a direction parallel to the line of intersection between the plane including the first and second directions and the display surface so that the identification of the information is more difficult or impossible compared with the case where the information is observed from the first direction. A first diffraction grating pattern having an extended shape; adjacent to the first diffraction grating pattern in a direction parallel to the display surface; spaced apart from the first diffraction pattern; In order to make it difficult to notice when observing from the second direction that the grating lines have different orientations and / or spatial frequencies and the first diffraction pattern retains information, No. 1 mixed with 1 grating pattern Diffraction image display, characterized in that a diffraction grating pattern.

  According to the second aspect of the present invention, there is provided a labeled article comprising the diffraction image display according to the first aspect and an article supporting the diffraction image display.

  According to the present invention, it is possible to achieve a higher anti-counterfeit effect by using a fake image prevention technique using a diffractive image display.

  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. 1 is a plan view schematically showing a diffraction image display according to one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II of the diffraction image display body shown in FIG. 1 and 2, the X direction is a direction parallel to the display surface, the Y direction is parallel to the display surface and perpendicular to the X direction, and the Z direction is orthogonal to the X direction and the Y direction. Direction.

  As shown in FIG. 2, the diffractive image display body 10 includes a base material 11, a diffraction grating forming layer 12, and a reflective layer 13.

  The base material 11 is a resin layer such as a resin film or a resin sheet, for example. As a material of this resin layer, for example, polyethylene terephthalate, polyethylene, polypropylene, heat resistant vinyl chloride, or polycarbonate can be used. The substrate 11 may have a single layer structure or a multilayer structure. The base material 11 can be omitted, for example, when the diffraction image display body 10 is used as a part of a transfer foil described later.

  The diffraction grating forming layer 12 is formed on the substrate 11. A concave structure and / or a convex structure is provided on the surface of the diffraction grating forming layer 12. This concave structure and / or convex structure forms a relief type diffraction grating pattern 12a. An image displayed by the diffraction grating pattern 12a will be described later.

  As a material of the diffraction grating formation layer 12, for example, a thermoplastic resin, a thermosetting resin, or a photocurable resin can be used. As the thermoplastic resin, for example, an acrylic resin, an epoxy resin, a cellulose resin, or a vinyl resin can be used. As a thermosetting resin, a urethane resin, a melamine resin, or a phenol resin can be used, for example. As the photocurable resin, for example, an epoxy acrylic resin, an epoxy methacrylic resin, a urethane acrylate resin, or a urethane methacrylate resin can be used. These resins may be used alone or in combination. The diffraction grating forming layer 12 may have a single layer structure or a multilayer structure.

  The diffraction grating forming layer 12 can be formed, for example, by transfer using a plate as described below.

  First, a master plate having a concave structure and / or a convex structure on the surface is manufactured. The master plate is manufactured by, for example, a method using optical photographing or a method using electron beam drawing.

  Next, a press plate is manufactured using the master plate manufactured by the method described above. The press plate is manufactured, for example, by forming a nickel layer on the surface of the master plate on which the concave structure and / or the convex structure are provided using an electroplating method.

Thereafter, the diffraction grating forming layer 12 is formed using this press plate.
When a thermoplastic resin is used as the material for the diffraction grating forming layer 12, first, a thermoplastic resin layer is formed on the substrate 11. Next, a press plate is pressed against the thermoplastic resin layer, and the thermoplastic resin layer is heated. Thereby, the concave structure and / or convex structure provided in the press plate are transferred to the thermoplastic resin layer. Thereafter, the press plate is removed from the thermoplastic resin layer. As described above, the diffraction grating forming layer 12 is obtained.

  When a thermosetting resin is used as the material of the diffraction grating forming layer 12, first, the substrate 11 and the press plate are overlapped with an uncured thermosetting resin layer interposed therebetween. Next, in this state, the thermosetting resin layer is heated and cured. Thereafter, the press plate is removed from the thermosetting resin layer. As described above, the diffraction grating forming layer 12 is obtained.

  When using a photocurable resin as the material of the diffraction grating forming layer 12, first, the substrate 11 and the press plate are overlapped with an uncured photocurable resin layer interposed therebetween. Next, in this state, the photocurable resin layer is irradiated with energy rays such as ultraviolet rays or electron beams to be cured. Thereafter, the press plate is removed from the photocurable resin layer. As described above, the diffraction grating forming layer 12 is obtained.

  The reflective layer 13 is formed on the diffraction grating forming layer 12. The reflective layer 13 is a layer having light reflectivity, and makes it easier to visually recognize the structural color expressed by the diffraction grating forming layer 12.

  As the reflective layer 13, for example, a metal reflective layer can be used. As a material of the metal reflective layer, for example, a metal such as aluminum, tin, chromium, nickel, copper and gold, or an alloy thereof can be used.

  In addition to light reflectivity, the reflective layer 13 may further have light transmissivity. As such a reflective layer 13, for example, a high refractive index layer having a larger refractive index than the portion of the diffraction grating forming layer 12 that is in contact with the reflective layer 13 can be used. As a material for the high refractive index layer, for example, zinc sulfide or titanium dioxide can be used.

  The reflective layer 13 may have a single layer structure or a multilayer structure. The reflective layer 13 can be formed by, for example, a vapor deposition method such as a vacuum evaporation method or a sputtering method.

  The reflective layer 13 may be omitted. Alternatively, the reflective layer 13 may be patterned. The patterned reflective layer 13 can be formed using, for example, etching or laser light irradiation.

Next, an image displayed by the diffraction grating pattern 12a will be described with reference to FIGS.
FIG. 3 is a perspective view of the diffraction image display body shown in FIGS. 1 and 2.

  In the diffraction image display 10, the diffraction grating pattern 12 a can identify information held by the diffraction grating pattern 12 a when observed from a first direction oblique to the display surface and is perpendicular to the display surface. Intersection line between the plane including the first and second directions and the display surface so that identification of the previous information is more difficult or impossible when observed from the second direction than when observed from the first direction It has a shape extending in a direction parallel to.

  In the example shown in FIGS. 1 and 3, the diffraction grating pattern 12 a holds character information “ABCDE” and has a shape extending in the Y direction. The information held by the diffraction grating pattern 12a, when viewed from the Z direction, is difficult or impossible to identify as shown in FIG. 1, is perpendicular to the X direction, and is on the display surface. On the other hand, when observed from a certain oblique direction, identification is easy as shown in FIG.

  In general, the diffraction image display is observed from the front. Therefore, a person who does not know that the diffraction grating pattern 12a holds character information or the like does not mean that the diffraction grating pattern 12a holds character information or the like even when the diffraction image display body 10 is observed. It is hard to notice. If a false image of the diffraction image display 10 is attempted without noticing this, it is highly possible that the character information and the like held by the diffraction grating pattern 12a cannot be accurately reproduced. It is easy to discriminate between counterfeit products and genuine products whose character information or the like cannot be accurately reproduced. Therefore, according to this aspect, a higher forgery prevention effect can be achieved.

  The information held in the diffraction grating pattern 12a may not be character information. For example, the diffraction grating pattern 12a may hold graphic information such as barcodes and marks and video information such as photographs. Alternatively, the diffraction grating pattern 12a may hold a combination thereof.

  For example, the grating lines of the diffraction grating pattern 12a intersect the intersection line between the plane including the first and second directions and the display surface. In this case, typically, the grating lines of the diffraction grating pattern 12a are substantially orthogonal to the previous intersection line. The term “grating line” means a groove constituting the diffraction grating. In this case, if the spatial frequency of the grating lines constituting the diffraction grating pattern 12a is appropriately set, for example, when the diffraction image display body 10 is illuminated from the first direction and observed from the second direction, diffraction is performed. The observer can perceive the diffracted light from the grating pattern 12a.

  In this diffraction image display body 10, when the diffraction image display body 10 is illuminated from the first direction, the diffraction grating pattern 12a holds information as the diffraction grating pattern 12a emits first-order diffracted light at a wider angle. Becomes difficult to notice. The grating constant of the diffraction grating is equal to the value obtained by dividing the sine of the diffraction angle by the wavelength, and is the reciprocal of the spatial frequency of the grating line. When the spatial frequency of the grating line is in the range of about 1600 lines / mm to about 3000 lines / mm, for example, about 2000 lines / mm, it is extremely difficult to notice that the diffraction grating pattern 12a holds information. can do.

  Further, in this diffraction image display body 10, the shape of the diffraction grating pattern 12a when the diffraction image display body 10 is observed from the second direction and the shape of the image to be perceived by the observer, that is, the diffraction image display from the first direction. The greater the difference from the shape of the diffraction grating pattern 12a when the body 10 is observed, the more difficult it is to notice that the diffraction grating pattern 12a holds information. The diffraction grating pattern 12a when the diffraction image display body 10 is observed from the second direction is, for example, an image that is to be perceived by the observer parallel to the intersection line between the plane including the first and second directions and the display surface. It is a shape that extends five times or more in the direction, here the Y direction.

  However, if this ratio is excessively increased, it is difficult to identify information held by the diffraction grating pattern 12a when the diffraction image display body 10 is observed from the second direction. Therefore, this ratio is, for example, 20 times or less.

The diffraction image display body 10 can be variously modified.
FIG. 4 is a plan view schematically showing a modification of the diffraction image display body shown in FIGS. FIG. 5 is a perspective view of the diffraction image display shown in FIG.

  The diffraction image display 10 shown in FIG. 4 has the same structure as the diffraction image display described with reference to FIGS. 1 and 2 except that it further includes a diffraction grating pattern 12b in addition to the diffraction grating pattern 12a. have.

  The diffraction grating pattern 12b is adjacent to the diffraction grating pattern 12a in a direction parallel to the display surface. For example, the diffraction grating pattern 12b is configured by a concave structure and / or a convex structure provided on the surface of the diffraction grating forming layer 12 on the reflective layer 13 side. The diffraction grating pattern 12b differs from the diffraction grating pattern 12a in the orientation of the grating lines and / or the spatial frequency.

  When the diffraction grating patterns 12a and 12b are arranged so as to be adjacent to each other, it is possible to make it more difficult to notice that the diffraction grating pattern 12a holds information when the diffraction image display body 10 is observed from the second direction. . That is, the diffraction grating pattern 12b can serve as a dummy pattern that hinders identification of previous information. Therefore, when this configuration is adopted, a higher forgery prevention effect can be achieved.

  Further, since the diffraction grating patterns 12a and 12b have different grating line orientations and / or spatial frequencies, the diffraction grating pattern 12b is visible when the diffraction image display 10 is observed from the first direction as shown in FIG. Or it looks a different color from the diffraction grating pattern 12a. That is, the diffraction grating pattern 12b does not make it impossible to identify information held by the diffraction grating pattern 12a.

  In the diffraction grating pattern 12a and the diffraction grating pattern 12b, for example, the spatial frequency of the grating lines is different by 8 lines / mm or more. Thus, when the diffraction image display body 10 is observed from the first direction, the information held by the diffraction grating pattern 12a can be easily identified.

  As shown in FIG. 4, the diffraction grating pattern 12a and the diffraction grating pattern 12b may be mixed in one region. This makes it more difficult to notice that the diffraction grating pattern 12a holds information when the diffraction image display body 10 is observed from the second direction, compared to the case where they are arranged in different regions. Can do.

  It is advantageous that the image to be displayed on the diffraction image display 10 is composed of a plurality of pixels arranged two-dimensionally. This will be described below.

  FIG. 6 is a plan view schematically showing an example of a diffraction image display body having a pixel structure in which a plurality of pixels are arranged in a matrix.

  The diffraction image display body 10 has a pixel structure in which 12 pixels are arranged in a matrix. The pixel PXa has the same structure, the pixel PXb has the same structure, and the pixel Xc has the same structure. The pixel PXa has the same structure as the portion corresponding to the diffraction grating pattern 12a of the diffraction image display body 10 shown in FIG. The pixel PXb has the same structure as the portion corresponding to the diffraction grating pattern 12b of the diffraction image display body 10 shown in FIG. The pixel PXc has the same structure as the portion of the diffraction image display body 10 shown in FIG. 4 where the diffraction grating patterns 12a and 12b are not provided.

  As described above, in the diffraction image display body 10 shown in FIG. 6, an image is formed by arranging three types of pixels PXa to PXc. If the visual effects of each of these pixels PXa to PXc are known, it is easy to predict the image obtained by rearranging them. Therefore, the structure to be adopted for each pixel can be easily determined from the digital image data. Therefore, when the pixel structure is adopted for the diffraction image display body 10, the design of the diffraction image display body 10 becomes easy.

  The diffraction image display 10 shown in FIG. 6 employs a pixel structure in which three types of pixels are arranged in a matrix, but two or more types of pixels are arranged in a matrix. A pixel structure may be adopted. If the number of types of pixels is increased, a more complicated image can be displayed.

  The diffraction image display body 10 shown in FIG. 6 employs an image structure in which 12 pixels are arranged in a matrix, but the number of pixels included in the pixel structure may be two or more. However, when the number of pixels is increased, a higher-definition image can be displayed.

  The diffraction image display body 10 described with reference to FIGS. 1 to 6 can be used in various forms. Here, the use of the diffraction image display body 10 will be described by taking the diffraction image display body 10 shown in FIGS. 1 and 2 as an example.

  FIG. 7 is a cross-sectional view schematically showing an example of an adhesive label including the diffraction image display body shown in FIGS. 1 and 2. The adhesive label 20 includes a diffraction image display body 10 and an adhesive layer 21 provided on the back surface thereof. The adhesive label 20 is attached to, for example, an article to be confirmed as an authentic product, or attached to another article such as a tag to be attached to such an article. In this way, for example, by observing the image displayed by the diffraction image display 10, it can be confirmed that the article is genuine.

  The adhesive label 20 may be brittle. Such an adhesive label 20 is obtained, for example, by forming notches and / or perforations in the diffraction image display body 10. When the pressure-sensitive adhesive label 20 is brittle, for example, when the pressure-sensitive adhesive label 20 attached to an article to be confirmed to be genuine is peeled off, the diffraction image display body 10 is easily destroyed. Therefore, it becomes difficult to replace the adhesive label 20.

  The adhesive label 20 may be supported on release paper. That is, the adhesive layer 21 may be covered with release paper. This facilitates handling of the adhesive label 20.

  FIG. 8 is a cross-sectional view schematically showing an example of a transfer foil including the diffraction image display body shown in FIGS. 1 and 2. The transfer foil 30 includes a base material 31, a peel protection layer 32, the diffraction image display body 10, and an adhesive layer 33. The diffraction image display 10 does not include the base material 11 shown in FIG. 2 but includes a diffraction grating forming layer 12 and a reflective layer 13.

  The base material 31 serves as a base for forming the peeling protection layer 32, the diffraction image display body 10, and the adhesive layer 33. As the material of the base material 31, for example, the materials exemplified for the base material 11 shown in FIG. 2 can be used.

  The peeling protective layer 32 is interposed between the base material 31 and the diffraction grating forming layer 12. The peeling protective layer 32 plays a role of preventing the diffraction grating forming layer 12 from being damaged when the substrate 31 is peeled from the diffraction image display body 10. Examples of the material of the peeling protection layer 32 include thermoplastic resins such as chlorinated rubber resins, vinyl chloride, vinyl acetate copolymers, acrylic resins, cellulose resins, styrene resins, and chlorinated polypropylene resins, or the like. A paint containing a mixture obtained by adding a release aid such as silicone oil can be used.

  When this transfer foil 30 is used, for example, it is affixed to an article to be confirmed as an authentic product, or affixed to another article such as a tag to be attached to such an article, and then a diffraction image. The base material 31 is peeled from the display body 10. Thereby, the diffraction image display body 10 is supported by the previous article. In this way, for example, by observing the image displayed by the diffraction image display 10, it can be confirmed that the article is genuine.

  The adhesive layer 33 may be covered with release paper. This facilitates handling of the transfer foil 30.

  FIG. 9 is a cross-sectional view schematically showing an example of a recording medium including the diffraction image display shown in FIGS. The recording medium 40 includes paper 41 and a diffraction image display body 10 embedded therein. An opening is provided in a portion of the paper 41 that covers the front surface of the diffraction image display 10. Thereby, the visibility of the image which the diffraction image display body 10 displays is improved. Note that the opening of the paper 41 does not have to be provided as long as this image is visible.

  The recording medium 40 can be used as a sheet for an authentication medium such as a cash card, a credit card and a passport, or a securities medium such as a gift certificate and a stock certificate, for example. Alternatively, the recording medium 40 can be used as a part of an adhesive label described later. Alternatively, the recording medium 40 can be used as a tag to be attached to an article to be confirmed to be genuine or a part thereof. Alternatively, the recording medium 40 can be used as a package or a part thereof that contains an article to be confirmed to be genuine.

  The recording medium 40 is obtained, for example, by sandwiching the diffraction image display body 10 between fiber layers during papermaking. The recording medium 40 obtained by such a method is difficult to forge.

  FIG. 10 is a cross-sectional view schematically showing an example of an adhesive label including the recording medium of FIG. The adhesive label 50 includes a recording medium 40 and an adhesive layer 51 provided on the back surface thereof. The adhesive label 50 is attached to, for example, an article to be confirmed as an authentic product, or attached to another article such as a tag base material to be attached to such an article.

  FIG. 11 is a plan view schematically showing an example of a labeled article including the diffraction image display shown in FIGS. 1 and 2. The labeled article 100 includes an article 101 and a diffraction image display body 10.

  The article 101 is an article to be confirmed to be a genuine product. The article 101 is, for example, an authentication medium such as a cash card, a credit card, and a passport, or a securities medium such as a gift certificate and a stock certificate. The article 101 may be an article other than the authentication medium and the securities medium. For example, the article 101 may be a craft or a work of art. Alternatively, the article 101 may be a packaged product including a package and contents contained therein.

  The diffraction image display body 10 is supported by the article 101. For example, the diffraction image display body 10 is attached to the article 101. In this case, for example, the diffraction image display 10 is supported on the article 101 by attaching the adhesive label 20 shown in FIG. 7 or the adhesive label 50 shown in FIG. 10 to the article 101 or using the transfer foil 30 shown in FIG. Can be made.

The diffraction image display 10 may be supported on the article 101 by other methods.
For example, when the article 101 includes paper, the diffraction image display body 10 may be embedded in the paper. In this case, the labeled article 100 is obtained, for example, by sandwiching the diffractive image display body 10 between fiber layers during papermaking and then performing printing or the like on a paper surface as necessary. In order to facilitate visualization of the latent image, an opening may be provided in a portion of the paper covering the front surface of the diffraction image display body 10. Moreover, there is no restriction | limiting in particular in the shape of the diffraction image display body 10 embedded in paper. For example, the thread-like diffraction image display 10 may be embedded in paper.

The diffraction image display body 10 may be supported by the article 101 by attaching a tag including the diffraction image display body 10 to the article 101. If it is difficult for a general user to replace the tag on the article 101, the diffraction image display 10 is sufficiently useful for confirming the authenticity of the article 101.
The invention described in the original claims is appended below.
[1] A first diffraction grating pattern is provided, and the first diffraction grating pattern can identify information held by the first diffraction grating pattern when observed from a first direction oblique to the display surface; The first and second directions are more difficult or impossible to identify the information when observed from a second direction perpendicular to the display surface than when observed from the first direction. A diffraction image display body characterized by having a shape extending in a direction parallel to a line of intersection between a plane including the display surface and the display surface.
[2] The diffraction image display object according to item 1, which has a pixel structure in which a plurality of pixels each including a diffraction grating are arranged in a matrix.
[3] The image processing apparatus further includes a second diffraction grating pattern adjacent to the first diffraction grating pattern in a direction parallel to the display surface, and the first and second diffraction grating patterns have a grating line orientation and / or a spatial frequency. Item 3. The diffraction image display body according to Item 1 or 2, wherein the second diffraction grating pattern is a dummy pattern that prevents identification of the information when observed from the second direction.
[4] A labeled article comprising the diffraction image display body according to any one of items 1 to 3 and an article supporting the diffraction image display article.

The top view which shows roughly the diffraction image display body which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the diffraction image display body shown in FIG. The perspective view of the diffraction image display body shown in FIG.1 and FIG.2. The top view which shows roughly the modification of the diffraction image display body shown in FIG.1 and FIG.2. The perspective view of the diffraction image display body shown in FIG. The top view which shows roughly an example of the diffraction image display body which has the pixel structure which arranges a some pixel in matrix form. Sectional drawing which shows schematically an example of the adhesive label containing the diffraction image display body shown in FIG.1 and FIG.2. Sectional drawing which shows roughly an example of the transfer foil containing the diffraction image display body shown in FIG.1 and FIG.2. FIG. 3 is a cross-sectional view schematically illustrating an example of a recording medium including the diffraction image display body illustrated in FIGS. 1 and 2. Sectional drawing which shows schematically an example of the adhesive label containing the recording medium of FIG. The top view which shows roughly an example of the labeled article containing the diffraction image display body shown in FIG.1 and FIG.2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Diffraction image display body, 11 ... Base material, 12 ... Diffraction grating formation layer, 12a ... Diffraction grating pattern, 12b ... Diffraction grating pattern, 13 ... Reflection layer, 20 ... Adhesive label, 21 ... Adhesive layer, 30 ... Recording medium 31 ... paper, 40 ... adhesive label, 41 ... adhesive layer, 100 ... article with label, 101 ... article.

Claims (3)

Table示面the identification of the information when viewed from a second direction perpendicular to and the display surface to identify the information that is retained when viewed from a first direction oblique to the first A first shape extending in a direction parallel to a line of intersection between the plane including the first and second directions and the display surface so as to be more difficult or impossible than when observed from the direction . 1 diffraction grating pattern,
Adjacent to the first diffraction grating pattern in a direction parallel to the display surface and spaced apart from the first diffraction pattern, the first diffraction grating pattern is different in the orientation and / or spatial frequency of the grating line, A second diffraction grating pattern mixed with the first diffraction grating pattern in the same region, so that it is difficult to notice when the first diffraction pattern holds information from the second direction;
Diffraction image display characterized by comprising a.   2. The diffractive image display body according to claim 1, having a pixel structure in which a plurality of pixels each including a diffraction grating are arranged in a matrix. A labeled article comprising the diffraction image display body according to claim 1 and an article supporting the diffraction image display article.

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