JP2009037112A - Display body and labeled article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of attaining the effect of higher forgery prevention. <P>SOLUTION: The display body 10 has a plurality of interface sections IF1 and IF2 each of which includes a plurality of recessed parts or projection parts. In each of the plurality of interface sections IF1 and IF2, the plurality of recessed parts or projecting parts are arranged regularly at a center distance that is larger than one half of the minimum wavelength of visible light but smaller than the minimum wavelength. The arrangement direction of the plurality of recessed parts or projecting parts is mutually different, between one part of the plurality of interface sections IF1 and the other part of interface sections IF2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display technique that provides, for example, an anti-counterfeit effect.

  Generally, securities such as gift certificates and checks, cards such as credit cards, cash cards and ID cards, and certificates such as passports and licenses must be printed with ordinary printed materials to prevent counterfeiting. The display body which has a different visual effect is affixed. In recent years, the distribution of counterfeit goods has become a social problem for articles other than these. Therefore, the opportunity to apply the same forgery prevention technology to such articles is increasing.

  As a display body having a visual effect different from that of a normal printed material, a display body including a diffraction grating in which a plurality of grooves are arranged is known. For example, the display body can display an image that changes according to the observation condition, or can display a stereoscopic image. Further, the spectral color according to the explanation displayed by the diffraction grating cannot be expressed by ordinary printing technology. Therefore, a display body including a diffraction grating is widely used for articles that require anti-counterfeiting measures.

  In this display, a relief type diffraction grating is generally used. The relief type diffraction grating is usually obtained by duplicating from an original plate manufactured using photolithography. For example, in Patent Documents 1 and 2, in order to form a diffraction grating, a flat substrate coated with a photosensitive resist on one main surface is placed on an XY stage, and the stage is controlled under computer control. It is described that the photosensitive resist is subjected to pattern exposure by irradiating the photosensitive resist with an electron beam while being moved. Non-Patent Document 1 describes that a diffraction grating is formed using two-beam interference. As can be seen from the above, it is difficult to manufacture the original plate used for manufacturing the display body including the relief type diffraction grating. Therefore, it is difficult to manufacture the display body including the relief type diffraction grating. .

However, as a result of the use of display bodies that include relief-type diffraction gratings in many articles that require anti-counterfeiting measures, this technology has become widely recognized, and along with this, the occurrence of counterfeit products tends to increase. is there. Therefore, it has become difficult to achieve a sufficient anti-counterfeit effect using a display body including a relief type diffraction grating.
JP-A-2-72320 US Pat. No. 5,058,992 Junpei Takiuchi, "Holography", Maruzen Co., Ltd.

  An object of the present invention is to make it possible to achieve a higher anti-counterfeit effect.

  According to the first aspect of the present invention, it comprises a plurality of interface portions each including a plurality of recesses or projections, and in each of the plurality of interface portions, the plurality of recesses or projections have the shortest wavelength of visible light. It is regularly arranged at a center-to-center distance that is longer than ½ and less than the shortest wavelength, and the arrangement direction of the plurality of recesses or projections is different between a part of the plurality of interface parts and the other part. A display body is provided.

  According to the second aspect of the present invention, there is provided a labeled article characterized by comprising the display according to the first aspect and an article that supports the display.

  According to the present invention, it is possible to achieve a higher anti-counterfeit effect.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that, throughout all the drawings, the same reference numerals are given to components that exhibit the same or similar functions, and redundant descriptions are omitted.

  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 a laminated body of a light transmission layer 11 and a reflection layer 13. In the example shown in FIG. 2, the light transmission layer 11 side is the front side, and the reflection layer 13 side is the back side. The interface between the light transmission layer 11 and the reflective layer 13 includes a first interface part IF1, a second interface part IF2, and a third interface part IF3. As will be described later, the interface portions IF1 and IF2 are provided with a concave structure and / or a convex structure. Hereinafter, portions of the display body 10 corresponding to the interface portions IF1 to IF3 are referred to as display portions DA1 to DA3, respectively.

  As a material of the light transmission layer 11, for example, a resin having light transmission properties such as polycarbonate and polyester can be used. For example, when a thermoplastic resin or a photocurable resin is used, the light transmission layer 11 having a concave structure and / or a convex structure on one main surface can be easily formed by transfer using an original plate.

  In FIG. 2, as an example, the light transmissive layer 11 configured by a laminate of the light transmissive substrate 111 and the light transmissive resin layer 112 is depicted. The light transmissive substrate 111 is a film or sheet that can be handled by itself. The light transmissive resin layer 112 is a layer formed on the light transmissive substrate 111. The light transmissive layer 11 shown in FIG. 2 is obtained, for example, by applying a thermoplastic resin or a photocurable resin on the light transmissive substrate 111 and curing the resin while pressing the original plate against the coating film.

  As the reflective layer 13, for example, a metal layer made of a metal material such as aluminum, silver, gold, and alloys thereof can be used. Alternatively, a dielectric layer having a refractive index different from that of the light transmissive member 11 may be used as the reflective layer 13. 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 11 needs to be different from the refractive index of the light transmission layer 11. The reflective layer 13 can be formed by, for example, a vapor deposition method such as a vacuum evaporation method or a sputtering method.

  One of the light transmission layer 11 and the reflection layer 13 can be omitted. However, when the display body 10 includes both the light transmission layer 11 and the reflection layer 13, the interface 10 is less likely to be damaged than when only one of them is included, and the display body 10 is visually recognized. An image with better properties can be displayed.

The display body 10 may further include other layers such as an adhesive layer and a protective layer.
For example, the adhesive layer is provided so as to cover the reflective layer 13. When the display body 10 includes both the light transmission layer 11 and the reflection layer 13, the shape of the surface of the reflection layer 13 is usually almost equal to the shape of the interface between the light transmission layer 11 and the reflection layer 13. When the adhesive layer is provided, it is possible to prevent the surface of the reflective layer 13 from being exposed. Therefore, it is possible to make it difficult to duplicate the concave structure and / or the convex structure of the previous interface.

  When the light transmission layer 11 side is the back side and the reflection layer 13 side is the front side, the adhesive layer is formed on the light transmission layer 11. In this case, not the interface between the light transmission layer 11 and the reflection layer 13, but the interface between the reflection layer 13 and the outside includes the interface portions IF1 to IF3.

  The protective layer is provided on the front side with respect to the laminated body of the light transmission layer 11 and the reflection layer 13. For example, when the light transmissive layer 11 side is the back side and the reflective layer 13 side is the front side, a protective layer is attached to the reflective layer 13 via an adhesive layer or the like as necessary. In addition to being able to suppress damage, replication for the purpose of counterfeiting the concave structure and / or convex structure of the surface can be made difficult.

Next, the interface portions IF1 to IF3 will be described.
FIG. 3 is a perspective view showing an example of a structure that can be employed in the first interface portion of the display body shown in FIGS. 1 and 2. FIG. 4 is a plan view of the structure shown in FIG. FIG. 5 is a perspective view illustrating an example of a structure that can be employed in the second interface portion of the display body illustrated in FIGS. 1 and 2. 6 is a plan view of the structure shown in FIG. 3 and 5 show the interface portions IF1 and IF2 as viewed from the transparent layer 11 side.

  Each of the interface portions IF1 and IF2 is provided with a plurality of convex portions PR. These convex portions PR are regularly arranged with a small center distance. In the example shown in FIGS. 3 and 4, the protrusions PR are arranged in a lattice shape in the x direction and the y direction that are substantially orthogonal to each other. In the example shown in FIGS. 5 and 6, the protrusions PR are arranged in a lattice pattern in the x ′ direction and the y ′ direction substantially orthogonal to each other. That is, in each of the interface portions IF1 and IF2, the convex portions PR are arranged in a square lattice pattern.

  The x direction and the x ′ direction intersect each other, for example, at an angle of about 45 °. That is, the arrangement direction of the protrusions PR is different between the interface part IF1 and the interface part IF2.

  In each of the interface parts IF1 and IF2, each convex part PR typically has a tapered shape. Some of the convex portions PR may not have a tapered shape.

  The tapered shape is, for example, a spindle shape, a cone shape such as a cone and a pyramid, or a truncated cone shape such as a truncated cone and a truncated pyramid. The side surface of the convex part PR may be composed only of an inclined surface or may be stepped. The taper shape helps to reduce the reflectivity of the interface portions IF1 and IF2. In addition, the taper shape facilitates the removal of the light transmission layer 11 from the original plate and contributes to the improvement of productivity.

  In each of the interface portions IF1 and IF2, the distance between the centers of the convex portions PR is shorter than the shortest wavelength of visible light. For example, the center-to-center distance of the convex part PR is less than about 400 nm. Further, in each of the interface portions IF1 and IF2, the distance between the centers of the convex portions PR is longer than ½ of the shortest wavelength of visible light. For example, the center-to-center distance of the convex part PR is longer than about 200 nm. And in each of interface part IF1 and IF2, the average height of convex part PR exists in the range of 300 to 450 nm, for example.

In each of the interface parts IF1 and IF2, the convex part PR forms a diffraction grating. The interface portion IF1 and the interface portion IF2 are different in the arrangement direction of the protrusions PR, that is, the orientation of the diffraction grating. For example, the arrangement direction of the projections PR in the interface part IF1 and the arrangement direction of the projections PR in the interface part IF2 form an angle of about 45 °. Note that the diffraction grating formed by the convex portions PR functions in substantially the same manner as a diffraction grating in which grooves (that is, grating lines) are arranged as indicated by broken lines.
The interface part IF3 is, for example, a flat surface. The interface part IF3 can be omitted.

Next, the visual effect which interface part IF1 and IF2 has is demonstrated.
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 emission angle β of m-order diffracted light (m = 0, ± 1, ± 2,...) can be calculated from the following equation when light travels in a plane perpendicular to the grating line of the diffraction grating. .
d = mλ / (sin α−sin β)
In this equation, d represents the grating constant of the diffraction grating, m represents the diffraction order, 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 in the case of a reflective diffraction grating, the incident direction of the illumination light and the emission direction of the regular reflection light are the method of the interface where the diffraction grating is provided. Symmetric with respect to the line.

  When the diffraction grating is a reflection type, the angle α is 0 ° or more and less than 90 °. In addition, when illumination light is irradiated to the interface provided with the diffraction grating from an oblique direction, and the angle in the normal direction, that is, two angle ranges having a boundary value of 0 °, the angle β is determined as follows. A positive value is obtained when the exit direction and the exit direction of the specularly reflected light are within the same angular range, and a negative value when the exit direction of the diffracted light and the incident direction of the illumination light are within the same angular range. Hereinafter, an angle range including the emission direction of the specularly reflected light is referred to as a “positive angle range”, and an angle range including the incident direction of the illumination light is referred to as a “negative angle range”.

  When the diffraction grating is observed from the normal direction, the diffracted light contributing to the display is only diffracted light having an exit angle β of 0 °. Therefore, in this case, if the lattice constant d is larger than the wavelength λ, there exists a wavelength λ and an incident angle α that satisfy the above equation. That is, in this case, the observer can observe diffracted light having a wavelength λ that satisfies the above equation.

  On the other hand, when the lattice constant d is smaller than the wavelength λ, there is no incident angle α that satisfies the above equation. Therefore, in this case, the observer cannot observe the diffracted light.

  As is apparent from this description, the interface portions IF1 and IF2 do not emit diffracted light in the normal direction, unlike a normal diffraction grating. Therefore, when viewed from the normal direction, the display units DA1 and DA2 do not display the spectral color due to diffraction.

  The diffraction grating provided at the interface portions IF1 and IF2 is different from the normal diffraction grating in the following points.

  FIG. 7 is a diagram schematically showing how the diffraction grating emits the first-order diffracted light. FIG. 8 is a diagram schematically showing how the other diffraction gratings emit the first-order diffracted light. 7 and 8, IF indicates the interface on which the diffraction grating is formed, NL indicates the normal line of the interface IF, IL indicates illumination light, RL indicates specularly reflected light or zero-order diffracted light, and DL indicates 1st order diffracted light is shown.

  As is clear from the above equation, when the grating constant d of the diffraction grating is larger than the shortest wavelength of visible light, for example, larger than about 400 nm, the illumination light IL is irradiated obliquely with respect to the interface IF. Then, as shown in FIG. 7, the diffraction grating emits the first-order diffracted light DL at an emission angle β within a positive angle range.

  On the other hand, when the grating constant d of the diffraction grating is greater than ½ of the shortest wavelength of visible light and less than this shortest wavelength, for example, greater than about 200 nm and less than about 400 nm, it is oblique to the interface IF. When the illumination light IL is irradiated from the direction, the diffraction grating emits the first-order diffracted light DL at an emission angle β within a negative angle range as shown in FIG. For example, considering the case where the angle α is 80 ° and the grating constant d is 300 nm, the diffraction grating emits first-order diffracted light having a wavelength λ of 540 nm at an emission angle β of about −25 °.

  In general, when observing an article, particularly when observing a light-absorbing article having a small light reflection ability and light scattering ability, the article and the light source are relative to the observer's eye so that regular reflection light can be perceived. Align. Therefore, when the configuration described with reference to FIG. 7 is adopted for the interface portions IF1 and IF2, the observer perceives diffracted light with a relatively high probability even if the observer does not know the fact. On the other hand, when the configuration described with reference to FIG. 8 is adopted for the interface portions IF1 and IF2, an observer who does not know the situation cannot perceive diffracted light in many cases. Therefore, it is difficult for the display 10 to realize that the display units DA1 and DA2 can display interference light.

  Further, in the structure shown in FIGS. 3 and 5, the convex part PR has a tapered shape. When such a structure is adopted, if the distance between the centers of the projections PR is shorter than the shortest wavelength of visible light, the region near the interfaces IF1 and IF2 is continuous in the thickness direction of the display body 10. Can be regarded as having a changed refractive index. For this reason, the reflectance of regular reflection light at the interface portions IF1 and IF2 is small regardless of the angle at which the observation is performed. As described above, the interface portions IF1 and IF2 do not emit diffracted light in the normal direction.

  Therefore, for example, when the display body 10 is observed from the normal direction, the display parts DA1 and DA2 appear dark. Typically, the display parts DA1 and DA2 appear dark gray or black. Here, “dark gray” means, for example, all light 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. It means that the reflectance of the component is about 25% or less. “Black” means, for example, the reflectivity of 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 10% or less. Therefore, the display parts DA1 and DA2 look like dark gray or black print layers, for example.

Next, an image displayed by the display body 10 will be described.
FIG. 9 is a diagram schematically showing a state in which the display body shown in FIGS. 1 and 2 is observed from the normal direction. FIG. 10 is a diagram schematically illustrating an example of a state in which the display body illustrated in FIGS. 1 and 2 is observed from an oblique direction. FIG. 11 is a diagram schematically illustrating another example of a state in which the display body illustrated in FIGS. 1 and 2 is observed from an oblique direction. 9 to 11, LS indicates a light source, and OS indicates an observer.

  As shown in FIG. 9, when the display body 10 is irradiated with illumination light IL from a substantially normal direction and the display body 10 is observed from a substantially normal direction, the interface portions IF1 and IF2 have low reflectivity and low scattering. Therefore, the display units DA1 and DA2 display colors with low brightness and saturation such as dark gray or black. On the other hand, since the interface part IF3 has a higher reflectance than the interface parts IF1 and IF2, the display part DA3 looks brighter than the display parts DA1 and DA2.

  As shown in FIG. 10, when the display body 10 is irradiated with illumination light IL from a direction perpendicular to the x direction and oblique to the y direction, and the display body 10 is observed from a direction within a negative angle range, As is apparent from the description made with reference to FIG. 8, the interface IF1 emits the first-order diffracted light DL toward the observer OS. Therefore, the display unit DA1 displays the spectral color due to diffraction. In addition, the arrangement direction of the projections PR in the interface part IF2 and the arrangement direction of the projections PR in the interface part IF1 form an angle of about 45 °. Under the observation conditions shown in FIG. 10, the effective grating constant of the diffraction grating provided at the interface portion IF2 is about 1.4 times the effective lattice constant of the diffraction grating provided at the interface portion IF1. Accordingly, the display unit DA2 does not display the spectral color due to diffraction, or displays the spectral color due to diffraction having a spectrum different from that of the display unit DA1. Here, since the angle formed by the arrangement direction of the projections PR in the interface IF2 and the arrangement direction of the projections PR in the interface IF1 is about 45 °, the display unit DA2 does not display the spectral color due to diffraction, Or even if the spectral color by diffraction is displayed, the brightness is very low.

  As shown in FIG. 11, when the display body 10 is irradiated with illumination light IL from a substantially normal direction, and the display body 10 is observed from a direction perpendicular to the x direction and oblique to the y direction, the interface IF1 Since the effective grating constant of the diffraction grating provided in is smaller than the shortest wavelength of visible light, the interface portion IF1 does not emit diffracted light toward the observer. Therefore, the display unit DA1 looks dark without displaying the interference light. If the effective grating constant of the diffraction grating provided at the interface IF2 is larger than the shortest wavelength of visible light, the interface IF2 can emit the first-order diffracted light toward the observer. Therefore, the display unit DA2 may display interference light.

  Note that when only the orientation of the display body 10 is changed from the state shown in FIG. 10, the display colors of the display units DA1 and DA2 change. For example, when the display body 10 is rotated by 45 ° around the normal line, the display unit DA2 displays the spectral color due to diffraction, and the display unit DA1 does not display the spectral color due to diffraction or has a spectrum different from that of the display unit DA2. Displays spectral colors due to different diffraction. Here, since the angle formed by the arrangement direction of the projections PR in the interface IF2 and the arrangement direction of the projections PR in the interface IF1 is about 45 °, the display unit DA1 does not display the spectral color due to diffraction, Or even if the spectral color by diffraction is displayed, the brightness is very low.

  Further, when only the orientation of the display body 10 is changed from the state shown in FIG. 11, the display colors of the display parts DA1 and DA2 change. For example, when the display body 10 is rotated by 45 ° around the normal line, the display unit DA2 may appear dark without displaying the interference light, and the display unit DA1 may display the interference light.

  As described above, the image displayed on the display body 10 changes variously according to the observation conditions. Images that produce such changes are impossible or extremely difficult to reproduce using other techniques. In particular, as can be seen from the fact that the display color changes only between the spectral color due to diffraction and the silver or gold metallic luster, for example, in a normal reflection type diffraction grating, the display color can be separated by diffraction using other techniques. It is impossible or extremely difficult to change between color and dark gray or black. This diversity is useful for displaying various images such as photographs, figures, pictures, characters and symbols with high design.

  In addition, the interface portions IF1 and IF2 of the display body 10 are provided with convex portions PR that are extremely fine and have a complicated shape. It is difficult to accurately analyze such a fine structure from the completed display body 10. For example, even if the previous fine structure can be analyzed from the completed display body 10, it is difficult to forge or imitate the display body including the fine structure. In the case of a normal 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 interface portions IF1 and IF2 cannot be duplicated.

  And as above-mentioned, the spectral color by the diffraction which display part DA1 and DA2 displays cannot be seen unless it observes on special conditions. That is, it is difficult for a person who attempts counterfeiting or imitation to recognize that the previous microstructure exists in the interface portions IF1 and IF2.

  Therefore, when this display body 10 is used as a label for preventing forgery, a high forgery preventing effect can be realized.

  In addition, the original plate for forming the light transmission layer 11 can be manufactured by the following method, for example.

  First, the resist layer is exposed with a pattern corresponding to the convex portion PR or the concave portion RC by electron beam drawing or laser beam drawing, and thereafter, development and cleaning of the resist layer are sequentially performed. By appropriately setting the power of the electron beam or laser beam, it is possible to obtain a resist layer provided with tapered convex portions or concave portions. Next, a metal stamper is obtained as an original plate for forming the light transmission layer 11 by, for example, electroforming.

  Alternatively, a resist layer is formed on a hard substrate such as a silicon substrate or a glass substrate. Next, pattern exposure, development and washing of the resist layer are sequentially performed to obtain a resist pattern. Next, the previous hard substrate is subjected to etching using the resist pattern as a mask. When isotropic etching is performed as this etching, a hard substrate provided with tapered convex portions or concave portions can be obtained by appropriately setting the etching conditions. This hard substrate may be used as a stamper, or a metal stamper may be produced from this hard substrate and used.

Various modifications can be made to the display body 10.
FIG. 12 is a perspective view showing another example of a structure that can be employed in the first and / or second interface portion of the display body shown in FIGS. 1 and 2. FIG. 13 is a plan view of the structure shown in FIG. In FIG. 12, the interface part IF1 or IF2 viewed from the transparent layer 11 side is depicted.

  In the interface part IF1 / IF2 shown in FIG. 12 and FIG. The angle formed by the x ″ direction and the y ″ direction is, for example, about 60 °. That is, the convex parts PR are arranged in a triangular lattice shape. When such a structure is adopted for the interface part IF1 or IF2, the above-described image change can be made more complicated.

  14 (a) and 14 (b) are perspective views showing still other examples of structures that can be employed in the first and second interface portions of the display body shown in FIGS. 1 and 2, respectively.

  The interface part IF1 shown in FIG. 14A has a longer center-to-center distance of the convex part PR than the interface part IF2 shown in FIG. Therefore, for example, the diffracted light emitted from the interface portion IF1 in the direction perpendicular to the x direction at the exit angle β and the diffracted light emitted from the interface portion IF2 in the direction perpendicular to the x ′ direction at the same exit angle β. Have different wavelengths. Therefore, it is possible to cause a more complicated image change and to obtain a better anti-counterfeit effect, and to improve the design.

In the display body 10 described above, a concave portion may be provided instead of the convex portion PR.
FIG. 15 is a perspective view showing still another example of a structure that can be employed in the first and / or second interface portion of the display body shown in FIGS. 1 and 2. In FIG. 15, the interface part IF1 or IF2 viewed from the transparent layer 11 side is depicted.

  The interface part IF1 / IF2 shown in FIG. 15 is provided with a plurality of recesses RC. These concave portions RC are arranged in the same manner as described with respect to the convex portion PR. Each recess RC typically has a tapered shape. The tapered shape is, for example, a spindle shape, a cone shape such as a cone and a pyramid, or a truncated cone shape such as a truncated cone and a truncated pyramid. The side wall of the recess RC may be composed only of an inclined surface or may be stepped. Even when such a structure is adopted for the interface part IF1 and / or IF2, the same effect as described above can be obtained.

  In at least one of the interface parts IF1 and IF2, a part or all of the convex part PR or the concave part RC may not have a tapered shape. However, when the ratio of the convex part PR or the concave part RC that does not have a tapered shape increases, the reflectance of the interface part IF1 or IF2 increases. Therefore, the visibility of the spectral color due to diffraction displayed by the display unit DA1 or DA2 is reduced.

  Further, in at least one of the interface portions IF1 and IF2, the convex portion PR or the concave portion RC may be a ridge or a groove. That is, the convex part PR or the concave part RC may form a diffraction grating similar to a normal diffraction grating except that the grating constant is less than the shortest wavelength of visible light. However, from the viewpoint of reflectivity, it is advantageous that the convex part PR or the concave part RC has the structure described with reference to FIGS. 3 to 6 and FIGS. 12 to 15.

  Various configurations can be employed for the interface IF3. For example, concave portions and / or convex portions may be irregularly arranged at the interface portion IF3 to provide a light scattering function. Alternatively, a diffraction grating and / or a hologram may be formed by providing a plurality of grooves in the interface part IF3.

FIG. 16 is a cross-sectional view schematically showing a modification of the display body shown in FIGS. 1 and 2.
In the display body 10, a plurality of grooves are provided in the interface part IF3. These grooves form, for example, a diffraction grating. The grating constant of this diffraction grating is not less than the shortest wavelength of visible light. The display body 10 shown in FIG. 16 is the same as the display body 10 described with reference to FIGS. 1 and 2 except that this structure is adopted.

  The grating constant of the diffraction grating formed at the interface part IF3 is, for example, in the range of 0.5 to 2 μm. In addition, the depth of the grooves constituting the diffraction grating is, for example, in the range of 0.1 to 1 μm.

  When the structure shown in FIG. 16 is adopted, for example, when observed from a substantially normal direction or from an oblique direction, the spectral color due to diffraction can be displayed on the display unit DA3. That is, a rainbow image can be displayed on the display unit DA3. Therefore, it is possible to cause a more complicated image change, and it is difficult to realize that the display units DA1 and DA2 can display the spectral color due to diffraction. That is, it becomes possible to obtain a better anti-counterfeit effect and improve the design.

  In addition to the interface portions IF1 and IF2, the display body 10 described above further includes both the interface portion IF3 described with reference to FIGS. 1 and 2 and the interface portion IF3 described with reference to FIG. Also good. Moreover, although the display body 10 mentioned above contains only interface part IF1 and IF2 as an interface part in which the convex part was provided, you may further include the other interface part in which the convex part PR was provided.

A latent image may be formed on the display units DA1 and DA2.
FIG. 17 is a diagram schematically illustrating a state in which a display body according to another modification is observed from the normal direction. FIG. 18 is a diagram schematically illustrating an example of a state in which the display body illustrated in FIG. 17 is observed from an oblique direction.

  In the display body 10 shown in FIGS. 17 and 18, the interface portions IF1 and IF2 described with reference to FIG. 2 are adjacent to each other. Therefore, the display units DA1 and DA2 form a latent image by making their reflectance and scattering function substantially equal and making them impossible or difficult to distinguish from each other when viewed from a substantially normal direction. can do. In the example shown in FIGS. 17 and 18, the display parts DA1 and DA2 constitute a rectangular area, and among these rectangular areas, the display part DA1 corresponds to the part drawn in white in FIG. The display portion DA2 corresponds to a portion adjacent to the display portion DA2.

  When the latent images are formed by the display units DA1 and DA2, the images displayed by the display units DA1 and DA2 vary greatly depending on the observation conditions. Therefore, when this configuration is adopted, it is easy to confirm the change of the image.

  The light transmission layer 11 may be optically isotropic or may have birefringence. In the latter case, when the display body 10 is observed through the polarizer, the image displayed on the display body 10 changes in brightness according to the angle formed by the transmission axis of the polarizer and the optical axis of the light transmission layer 11. Arise. That is, more complicated image changes can be caused.

  The display body 10 described above can be used, for example, as a forgery prevention or identification label. Since the display body 10 is difficult to counterfeit or imitate, when the label is supported on an article, it is also difficult to counterfeit or imitate the genuine article with the label. Moreover, since this label has the visual effect mentioned above, it is also easy to discriminate between an authentic product and a non-authentic product if it is unknown whether the product is genuine.

  FIG. 19 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. 20 is a cross-sectional view of the labeled article shown in FIG. 19 taken along the line XX-XX.

  19 and 20 show a printed matter 100 as an example of a labeled article. The printed material 100 is an IC (integrated circuit) card and includes a base material 20. The base material 20 is made of plastic, for example. A concave portion is provided on one main surface of the substrate 20, and the IC chip 30 is fitted into the concave portion. Electrodes are provided on the surface of the IC chip 30, and information can be written to the IC and / or information recorded on the IC via these electrodes. A printed layer 40 is formed on the substrate 20. The display body 10 mentioned above is being fixed to the surface in which the printing layer 40 of the base material 20 was formed through the adhesion layer, for example. For example, the display body 10 is prepared as an adhesive sticker or a transfer foil, and is fixed to the base material 20 by being attached to the printing layer 40.

  The printed material 100 includes a display body 10. Therefore, forgery or imitation of the printed material 100 is difficult. In addition, since the printed matter 100 includes the display body 10, it is easy to discriminate between a genuine product and a non-authentic product for an article whose authenticity is unknown. Moreover, since the printed material 100 further includes the IC chip 30 and the printed layer 40 in addition to the display body 10, it is possible to adopt a forgery prevention measure using them.

  In FIG. 19 and FIG. 20, an IC 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 another card such as a magnetic card, a wireless card, and an ID (identification) card. Alternatively, the printed matter including the display body 10 may be securities such as gift certificates and stock certificates. Alternatively, the printed matter 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 100 shown in FIG.19 and FIG.20, although the display body 10 is affixed on the base material 20, 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.

The 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. The perspective view which shows an example of the structure employable as the 1st interface part of the display body shown in FIG.1 and FIG.2. FIG. 4 is a plan view of the structure shown in FIG. 3. The perspective view which shows an example of the structure employable as the 2nd interface part of the display body shown in FIG.1 and FIG.2. FIG. 6 is a plan view of the structure shown in FIG. 5. The figure which shows a mode that a diffraction grating inject | emits 1st-order diffracted light schematically. The figure which shows a mode that another diffraction grating inject | emits 1st-order diffracted light. The figure which shows a mode that the display body shown in FIG.1 and FIG.2 is observed from the normal line direction. The figure which shows schematically an example of a mode that the display body shown in FIG.1 and FIG.2 is observed from the diagonal direction. The figure which shows schematically the other example of a mode that the display body shown in FIG.1 and FIG.2 is observed from the diagonal direction. The perspective view which shows the other example of the structure employable as the 1st and / or 2nd interface part of the display body shown in FIG.1 and FIG.2. The top view of the structure shown in FIG. (A) And (b) is a perspective view which shows the further another example of the structure employable for the 1st and 2nd interface part of the display body shown in FIG.1 and FIG.2, respectively. The perspective view which shows the further another example of the structure employable as the 1st and / or 2nd interface part of the display body shown in FIG.1 and FIG.2. Sectional drawing which shows schematically the modification of the display body shown in FIG.1 and FIG.2. The figure which shows a mode that the display body which concerns on another modification is observed from the normal line direction. The figure which shows schematically an example of a mode that the display body shown in FIG. 17 is observed from the diagonal direction. The top view which shows roughly an example of the labeled article formed by making an anti-counterfeiting or identification label supported by the article. Sectional drawing along the XX-XX line of the labeled article shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Display body, 11 ... Light transmissive layer, 13 ... Reflective layer, 20 ... Base material, 30 ... IC chip, 40 ... Print layer, 100 ... Printed matter, 111 ... Light transmissive base material, 112 ... Light transmissive resin layer DA1 ... display unit, DA2 ... display unit, DA3 ... display unit, DL ... first-order diffracted light, IF ... interface, IF1 ... interface, IF2 ... interface, IF3 ... interface, IL ... illumination light, LS ... light source NL ... normal line, OS ... observer, PR ... convex part, RC ... concave part, RL ... regularly reflected light.

Claims (12)

  First and second interface portions each including a plurality of recesses or projections are provided, and in each of the first and second interface portions, the plurality of recesses or projections are ½ of the shortest wavelength of visible light. A display body, which is regularly arranged with a center-to-center distance that is longer and less than the shortest wavelength, and the first and second interface portions have different arrangement directions of the plurality of concave portions or convex portions.   Among the display bodies, the first display unit corresponding to the first interface unit and the second display unit corresponding to the second interface unit give the viewer the same color sensation when viewed from the front. The display body according to claim 1.   The first and second interface portions are separated from each other, and the first and second display portions display images that can be distinguished from each other when viewed from the front. Display body described in 1.   The display body according to claim 2, wherein the first and second display units are adjacent to each other and display a latent image that is impossible or difficult to distinguish from each other when viewed from the front. .   In each of the first and second interface portions, the plurality of recesses or projections are arranged in a square lattice shape, and the arrangement direction is 45 ° different between the first interface portion and the second interface portion. The display body according to any one of claims 2 to 4, wherein the display body is characterized.   6. The display body according to claim 2, wherein the first and second interface portions have different distances between centers of the plurality of concave portions or convex portions.   7. The apparatus according to claim 1, further comprising a third interface portion adjacent to the first and second interface portions in an in-plane direction, wherein the third interface portion is a flat surface. Display body of description.   And a third interface portion adjacent to the first and second interface portions in an in-plane direction. The third interface portion includes a plurality of grooves and a lattice constant equal to or greater than the shortest wavelength. The display body according to claim 1, further comprising a diffraction grating.   The apparatus further includes third and fourth interface portions adjacent to the first and second interface portions in an in-plane direction, the third interface portion is a flat surface, and a plurality of grooves are arranged in the fourth interface portion. The display body according to any one of claims 1 to 6, further comprising a diffraction grating having a lattice constant equal to or longer than the shortest wavelength.   The one main surface includes a light transmissive layer including the plurality of interface portions, and the light transmissive layer has birefringence. The display body.   The at least part of the plurality of recesses or projections in each of the part of the plurality of interface parts and the other part has a tapered shape. The display body according to any one of the above.   A labeled article comprising the display body according to any one of claims 1 to 11 and an article that supports the display body.

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