JP5515244B2 - Display and labeled goods - Google Patents

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 shining in rainbow colors expressed by the diffraction grating cannot be expressed by a normal printing technique. 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 formed with a plurality of grooves 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.

  In the manufacture of a relief type diffraction grating, a metal stamper is usually produced by a method such as electroforming using the original plate thus obtained.

  Next, using this metal stamper as a matrix, a relief type diffraction grating is duplicated. That is, first, a thermoplastic resin or a photocurable resin is applied on a transparent substrate made of, for example, polycarbonate or polyester. Next, a metal stamper is brought into close contact with the coating film, and heat or light is applied to the resin layer in this state. After the resin is cured, the metal stamper is peeled from the cured resin to obtain a relief type diffraction grating.

  Generally, this relief type diffraction grating is transparent. Therefore, usually, a reflective layer is formed on a resin layer provided with a relief structure by depositing a metal such as aluminum or a dielectric in a single layer or multiple layers by vapor deposition.

  Then, the display body obtained in this way is affixed on the base material which consists of paper or a plastic film through an adhesive layer or an adhesion layer, for example. As described above, a printed matter with anti-counterfeit measures is obtained.

  As is apparent from the above description, it is difficult to manufacture the original plate used for manufacturing the display body including the relief type diffraction grating. Further, the transfer of the relief structure from the metal stamper to the resin layer must be performed with high accuracy. That is, high technology is required for manufacturing a display body including a relief type diffraction grating.

However, as a result of the use of display bodies including 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. For this reason, it has become difficult to achieve a sufficient anti-counterfeit effect using a display body that is characterized only by exhibiting rainbow light by diffracted light.
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, one or a plurality of first element regions each including a diffractive structure composed of a plurality of recesses or projections arranged at a center-to-center distance of 500 nm or less, forming a gap, Each includes a diffractive structure composed of a plurality of recesses or protrusions arranged at a center-to-center distance of 500 nm or less, and each includes one or more second element regions filling at least part of the gap. One or a plurality of first interface portions, and each of the first element region and the second element region includes a square having a side length of 3 μm and a short side having a length of 300 μm. Each of the first element region and the second element region is arranged in a checkered pattern, or arranged adjacent to each other, and arranged in the first element region The distance between the centers of the plurality of recesses or projections and the second The difference between the center distances of the plurality of recesses or projections arranged in the element region is within a range of 30 nm to 300 nm, and when illuminated with white light from the first direction , the one or more first The first element display unit corresponding to one element region emits the first diffracted light in the second direction, and the second element display unit corresponding to the one or more second element regions is the first diffracted light. When the second diffracted light having different wavelengths is emitted in the second direction, illuminated with the white light from the first direction and observed with the naked eye from the second direction, the first element display unit is the one Alternatively, it is impossible to distinguish from a portion other than the first element display portion of the first display portion corresponding to the plurality of first interface portions, and the second element display portion is the first display portion of the first display portion. Identification from parts other than the two-element display part is impossible, and the first display part is the first element. Display body and displaying the color mixture which can be identified by the naked eye from either the display color of the display color and the second element display section of the display portion 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. In addition, the same referential mark is attached | subjected to the component which exhibits the same or similar function through all the drawings, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a plan view schematically showing a display body according to one aspect of the present invention. FIG. 2 is an enlarged plan view showing a part of the display body shown in FIG. FIG. 3 is a cross-sectional view taken along line III-III of the display shown in FIG. In FIG. 2, a portion of the display body 10 surrounded by a broken line in FIG. 1 is drawn.

  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. 3, 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 reflection layer 13 includes interface portions IF1 and IF2. The interface IF1 includes element regions IF1a and IF1b. Hereinafter, portions of the display body 10 corresponding to the interface portions IF1 and IF2 are referred to as display portions DA1 and DA2, respectively. Further, portions of the display body 10 corresponding to the element regions IF1a and IF1b are referred to as element display portions DA1a and DA1b, respectively.

  As a material of the light transmission layer 11, for example, when a thermoplastic resin or a photocurable resin is used, the light transmission layer 11 is provided with a convex structure and / or a concave structure on one main surface by transfer using an original plate. Can be easily formed.

  In FIG. 3, as an example, the light transmissive layer 11 formed of 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. As a material of the light transmissive substrate 111, for example, a resin having light transmissive properties such as polycarbonate and polyester can be used.

  The light transmissive resin layer 112 is a layer formed on the light transmissive substrate 111. The light transmissive layer 11 shown in FIG. 3 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. The light transmissive substrate 111 can be omitted.

  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 transmission layer 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. The refractive index of the dielectric layer included in the dielectric multilayer film that is in contact with the light transmission layer 11 is preferably 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 can further include other layers such as an adhesive layer, an adhesive layer, and a resin layer. For example, the adhesive layer or the adhesive layer is provided so as to cover the reflective layer 13. When the display body 10 includes both the light transmissive layer 11 and the reflective layer 13, the shape of the surface of the reflective layer 13 is usually almost equal to the shape of the interface between the light transmissive layer 11 and the reflective layer 13. When the adhesive layer or 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 convex structure and / or the concave 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 or 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 and IF2.

  The resin 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 transmission layer 11 side is the back side and the reflection layer 13 side is the front side, if the reflection layer 13 is covered with a resin layer, damage to the reflection layer 13 can be suppressed, and the convex structure of the surface And / or replication for the purpose of forging the concave structure can be made difficult.

Next, the element regions IF1a and IF1b and the interface part IF2 will be described.
In the interface part IF1, a plurality of element regions IF1a and a plurality of element regions IF1b are two-dimensionally arranged. The element region IF1a forms a gap between them, and the element region IF1b fills these gaps. In this example, the element regions IF1a and IF1b are arranged in a checkered pattern.

  Here, the element regions IF1a and IF1b are arranged uniformly over the entire interface portion IF1. That is, the element regions IF1a and IF1b are arranged so that the ratio of the element region IF1a to the unit area and the ratio of the element region IF1b to the unit area are equal at any position. Instead, the element regions IF1a and IF1b may be arranged such that the ratio of the element region IF1a to the unit area and the ratio of the element region IF1b to the unit area differ depending on the position. For example, the element regions IF1a and IF1b may be arranged so as to form a plurality of regions having different ratios. In this case, images that can be distinguished from each other can be displayed in these regions under conditions where diffracted light can be observed. Or you may employ | adopt the structure which a previous ratio changes gradually toward a different position from a certain position. In this way, gradation can be generated in the color mixture displayed by the display unit DA1.

  The interface IF1 may be configured by one element region IF1a and a plurality of element regions IF1b. For example, the interface IF1 may be configured by a mesh-shaped element region IF1a and a plurality of element regions IF1b filling the mesh.

  Similarly, the interface part IF1 may be configured by a plurality of element regions IF1a and one element region IF1b. For example, the interface IF1 may be configured by a mesh-shaped element region IF1b and a plurality of element regions IF1a filling the mesh.

  The interface IF1 may be configured by one element region IF1a and one element region IF1b. For example, the interface portion IF1 may have a comb shape, and may be configured by element regions IF1a and IF1b arranged such that one comb tooth is alternately adjacent to the other comb tooth in the width direction.

  In each of the element regions IF1a and IF1b, a plurality of convex portions or concave portions are arranged at a short center distance. In each of the element regions IF1a and IF1b, the convex portion or the concave portion has a diffracted light emission function like a diffraction grating.

  The element region IF1a and the element region IF1b emit diffracted light having different wavelengths in the second direction when illuminated with white light from the first direction. However, since the convex portions or the concave portions are arranged at a small center distance in each of the element regions IF1a and IF1b, the display portion DA1 is dark gray or dark when viewed from the front as described in detail later. Looks like a black print layer. Under specific observation conditions, the display unit DA1 is derived from an additive color mixture of a color corresponding to the diffracted light emitted from the element display unit DA1a and a color corresponding to the diffracted light emitted from the element display unit DA1b. Display the mixed color. For example, white, cyan, magenta, yellow, or the like is displayed as a mixed color by two or more additive mixed colors of single colors such as blue, green, and red.

  Each element region included in the interface part IF1 will be described in more detail.

  FIG. 4 is a perspective view showing an example of a structure that can be employed in the element region of the display body shown in FIGS. 1 to 3. FIG. 5 is a plan view of the structure shown in FIG. In FIG. 4, the element region IF1b viewed from the light transmission layer 11 side is depicted. 4 and 5, the x and y directions are perpendicular to each other and perpendicular to the Z direction, and the z direction is a direction parallel to the Z direction.

  In the element region IF1b shown in FIGS. 4 and 5, a plurality of convex portions PR are arranged. In this example, the protrusions PR are arranged in a lattice pattern in the x and y directions orthogonal to each other. The convex parts PR may be arranged in a lattice shape in two directions that intersect diagonally. Moreover, in this example, although the convex part PR is arrange | positioned, you may arrange | position a taper-shaped recessed part instead.

  In the element region IF1b, each projection PR has a tapered shape, that is, a tapered shape. The tapered shape is, for example, a semi-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 tapered shape is useful for reducing the light reflectance of the interface part IF1. 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. Some of the convex portions PR may not have a tapered shape.

  In the element region IF1b, the convex part PR forms a diffraction grating. 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 in a lattice shape corresponding to the arrangement of the convex portions PR.

  In the element region IF1a, the plurality of protrusions PR are arranged in substantially the same manner as the protrusions PR of the element region IF1b. Also in the element region IF1a, the convex part PR forms a diffraction grating.

  In the element region IF1a, like the element region IF1b, each convex part PR has a tapered shape, that is, a tapered shape. The convex part PR provided in the element region IF1a may be similar to the convex part PR provided in the element region IF1b or may not be similar.

  In this example, the convex portions PR are provided in both of the element regions IF1a and IF1b. However, all of the convex portions PR may be replaced with concave portions. Alternatively, only the convex portion PR of the element region IF1a may be replaced with a concave portion, or only the convex portion PR of the element region IF1b may be replaced with a concave portion.

  When the convex part PR has a tapered shape, the reflectance of the display part DA1 can be reduced as compared with the case where the convex part PR has a columnar shape. This effect can also be obtained when a tapered concave portion is provided instead of the tapered convex portion PR.

  The element regions IF1a and IF1b are designed to emit diffracted light of different wavelengths in the same direction when they are illuminated with white light from a certain direction. Typically, the element regions IF1a and IF1b have different distances between the centers of the convex portions PR.

  The interface part IF2 is adjacent to the interface part IF1. The interface part IF2 is a flat surface, for example. Alternatively, the interface portion IF2 is provided with a relief structure different from the element regions IF1a and IF1b. In the latter case, the interface IF2 may be provided with, for example, a plurality of convex portions and / or concave portions that impart light scattering properties, and may be provided with a plurality of grooves that impart a function as a diffraction grating. The interface part IF2 may be omitted.

Next, the optical characteristics of the element regions IF1a and IF1b will be described.
As described above, the convex portion PR functions as a diffraction grating in each of the element regions IF1a and IF1b. 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 specularly reflected 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 clear from this description, unlike the normal diffraction grating, the element regions IF1a and IF1b do not emit diffracted light in the normal direction, or the diffracted light emitted by the element regions IF1a and IF1b in the normal direction is Only those with low visibility.

  The diffraction gratings provided in the element regions IF1a and IF1b are further different from the normal diffraction gratings in the following points.

  FIG. 6 is a diagram schematically showing how a certain diffraction grating emits first-order diffracted light. FIG. 7 is a diagram schematically showing how the other diffraction gratings emit the first-order diffracted light. FIG. 8 is a perspective view showing a part of the interface including the element region shown in FIG.

  6 and 7, IF indicates an interface on which a diffraction grating is formed, and NL indicates a normal line of the interface IF. IL represents white illumination light composed of light of a plurality of wavelengths, RL represents regular reflection light or 0th-order diffracted light, DLr, DLg, and DLb are red obtained by spectrally dividing the white illumination light IL, Green and blue first-order diffracted lights are shown. In FIG. 8, d1 and d2 indicate distances between the centers of the convex portions PR in the element regions IF1a and IF1b, respectively.

  In FIG. 6, a diffraction grating having a lattice constant larger than the shortest wavelength of visible light, for example, about 400 nm, is provided at the interface IF. On the other hand, in FIG. 7, a diffraction grating having a lattice constant smaller than the shortest wavelength of visible light is provided at the interface IF.

  As apparent from the above equation, when the grating constant d of the diffraction grating is larger than the shortest wavelength of visible light, when the illumination light IL is irradiated from an oblique direction to the interface IF, as shown in FIG. The diffraction grating emits the first-order diffracted beams DLr, DLg, and DLb at the emission angles βr, βg, and βb within the positive angle range, respectively. Although not shown, at this time, the diffraction grating similarly emits the first-order diffracted light with respect to light of other wavelengths.

  On the other hand, when the grating constant d of the diffraction grating is larger than ½ of the shortest wavelength of visible light and less than this shortest wavelength, the illumination light IL is irradiated from an oblique direction to the interface IF as shown in FIG. As described above, the diffraction grating emits the first-order diffracted beams DLr, DLg, and DLb at the emission angles βr, βg, and βb within the negative angle range, respectively. For example, considering the case where the angle α is 50 ° and the grating constant d is 330 nm, the diffraction grating diffracts light having a wavelength λ of 540 nm (green) in the white illumination light IL, and converts the first-order diffracted light DLg. Injection is performed at an injection angle βg of about −60 °.

  As is clear from this description, the element regions IF1a and IF1b emit diffracted light only in the negative angle range without emitting diffracted light in the positive angle range, or in the positive angle range. The diffracted light that exits the beam is only low in visibility, and emits diffracted light with high visibility in the negative angle range. That is, unlike the ordinary diffraction grating, the diffraction grating provided in the element regions IF1a and IF1b emits diffracted light with high visibility only in the negative angle range.

  Moreover, in this display body 10, the convex part PR has a taper shape. When such a structure is employed, if the distance between the centers of the protrusions PR is sufficiently short, the region in the vicinity of the interface IF1 can be regarded as having a refractive index that continuously changes in the Z direction. . For this reason, the reflectance for the specularly reflected light of the element regions IF1a and IF1b is small no matter which angle is observed. As described above, the element regions IF1a and IF1b substantially do not emit diffracted light in the normal direction.

  Therefore, the display 10 displays different images depending on the observation conditions, as will be described below.

  FIG. 9 is a diagram schematically showing a state in which the display body shown in FIGS. 1 to 3 is observed under certain conditions. FIG. 10 is a diagram schematically showing a state in which the display body shown in FIGS. 1 to 3 is observed under other conditions.

  FIG. 9 illustrates a state in which the front surface of the display body 10 is illuminated from the direction within the negative angle range and the display body 10 is observed from the direction within the positive angle range. FIG. 10 illustrates a state in which the front surface of the display body 10 is illuminated from a direction within the negative angle range and the display body 10 is observed from a direction within the negative angle range. 9 and 10, only the display unit DA1 of the display body 10 is illustrated.

  As described above, the element regions IF1a and IF1b do not emit diffracted light with high visibility within a positive angle range. The element regions IF1a and IF1b have a small reflectance with respect to regular reflection light. Therefore, under the viewing conditions shown in FIG. 9, the element display units DA1a and DA1b do not emit light with high visibility toward the observer OB. Therefore, the display part DA1 looks like a dark gray or black print layer. Also, when the observation direction is parallel to the normal direction, the display unit DA1 looks like a dark gray or black print layer.

  Thus, under the conditions shown in FIG. 9, the display section DA1 looks like a dark gray or black print layer. The display portion DA2 looks like a mirror surface when the interface portion IF2 is a flat surface, looks white when the interface portion IF2 has light scattering properties, and has a diffraction grating and a hologram at the interface portion IF2. When a diffractive structure such as is provided, the spectral color resulting from the diffractive structure is displayed. Therefore, to the observer OB, the display unit DA1 looks like a dark gray or black print layer provided on a mirror surface, a light scattering surface, or a diffraction grating or hologram.

  Here, “dark gray” means, for example, all light having a wavelength in the range of 400 nm to 700 nm when the display unit DA1 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 reflectance of all light components having a wavelength in the range of 400 nm to 700 nm when the display unit DA1 is irradiated with light from the normal direction and the intensity of specular reflection light is measured. Means 10% or less.

  Under the conditions shown in FIG. 10, for example, any of the diffracted lights DLr, DLg, and DLb emitted from the element display unit DA1a and any of the diffracted lights DLr, DLg, and DLb emitted from the element display unit DA1b are observed. Proceed towards the OB. The diffracted light traveling from the element display portion DA1a toward the observer OB and the diffracted light traveling from the element display portion DA1b toward the observer OB have different wavelengths. For example, the element display unit DA1a emits blue diffracted light toward the observer OB, and the element display unit DA1b emits red diffracted light toward the observer OB.

  The element display parts DA1a and DA1b cannot be distinguished from each other when observed with the naked eye. In addition, the element display portions DA1a and DA1b have a small reflectance for regular reflection light. Accordingly, the display unit DA1 displays a color mixture derived from the diffracted light from the element display unit DA1a and the diffracted light from the element display unit DA1b. For example, when the element display units DA1a and DA1b emit blue and red diffracted light toward the observer OB, the display color varies slightly depending on the intensity ratio, but the display unit DA1 is purple ( Magenta).

  As described above, under the conditions shown in FIG. 10, the display unit DA1 displays a color mixture derived from diffracted light. Note that, under the observation conditions shown in FIG. 10, the display portion DA2 looks like a mirror surface when the interface portion IF2 is a flat surface, and white when the interface portion IF2 has light scattering properties. When the interface IF2 is provided with a diffraction structure such as a diffraction grating and a hologram, it looks like a mirror surface.

  By the way, 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 placed on the observer's eyes so that regular reflection light can be perceived. Position them relative to each other. Therefore, an observer who does not know that the above-described structure is adopted for the display unit DA1 is highly likely to observe the display body 10 under the conditions described with reference to FIG. As described above, under the observation conditions, the element display portions DA1a and DA1b do not emit diffracted light with high visibility toward the observer OB, and therefore the display portion DA1 is a dark gray or black printed layer. Looks like. Therefore, it is difficult for the display 10 to realize that the element display portions DA1a and DA1b can emit diffracted light.

When viewed from a direction within a positive angle range or a substantially normal direction, it looks like a dark gray or black print layer, and when viewed from a direction within a negative angle range, a color mixture derived from diffracted light is displayed. This feature is impossible or difficult to reproduce with other configurations. In addition, high technical skill is required for manufacturing the display body 10, particularly for forming the relief structure of the element regions IF1a and IF1b. That is, even if it is realized that the element display portions DA1a and DA1b can emit diffracted light, the optical characteristics cannot be reproduced by a counterfeit product having a structure different from that of the display body 10, and It is extremely difficult to manufacture a counterfeit product having the same structure as the display body 10.
Therefore, when this display body 10 is used, a high forgery prevention effect can be achieved.

  In the display body 10, in each element region included in the interface portion IF1, the distance between the centers of the convex portions PR or the concave portions is 500 nm or less, typically 450 nm or less, and according to an example, 400 nm or less. . In each element region, the distance between the centers of the projections PR or the depressions is, for example, 200 nm or more, and typically 300 nm or more.

  If the distance between the centers of the convex part PR or the concave part is sufficiently small, each element region does not emit the first-order diffracted light in the Z direction, or the first-order diffracted light emitted from each element region in the Z direction has a low visibility. Of light only. Therefore, when the distance between the centers of the convex portions PR or the concave portions is reduced, the brightness and the saturation are lowered, and black with higher color purity can be displayed on the display portion DA1. On the other hand, when the distance between the centers of the convex portions PR or the concave portions is increased, the luminance slightly increases, and the display portion DA1 appears dark gray. If the distance between the centers of the convex portions PR or the concave portions is excessively small, each element region does not emit the first-order diffracted light, or the first-order diffracted light emitted from each element region is only light having a wavelength with low visibility. Become.

  When the distance between the centers of the convex portions PR or the concave portions is made different between a certain element region included in the interface portion IF1 and another element region, the difference in the distance between the centers is, for example, within a range of 30 nm to 300 nm. And When the difference in the distance between the centers is small, these element regions emit diffracted light having substantially the same wavelength. Therefore, it is difficult to distinguish the color mixture displayed by the display unit DA1 from the single color displayed by each of the element regions. When the difference between the center distances is excessively large, the wavelength of the diffracted light emitted from any of the element regions deviates from the wavelength range of visible light. Therefore, it may be impossible to display the mixed color on the display unit DA1.

  As an example, it is assumed that the element regions IF1a and IF1b have the same orientation direction of the convex portions PR and different distances between the centers of the convex portions PR. In the element region IF1a, the protrusions PR are arranged at a center distance within a range of 300 nm to 360 nm, and in the element region, the protrusions PR are arranged at a center distance within a range of 390 nm to 450 nm.

  In the interface part IF1, the ratio of the area of the element region IF1a to the sum of the area of the element region IF1a and the area of the element region IF1b is, for example, in the range of 0.1 to 0.9, typically 0.3 to Within the range of 0.7. When this ratio is small or large, it is difficult to distinguish the color mixture displayed by the display unit DA1 from the single color displayed by the element display unit DA1a or DA1b with the naked eye.

  In the display body 10, when the convex portion PR is increased or the concave portion is deepened while the distance between the centers is constant, the display portion DA1 displays black with higher color purity. On the other hand, when the convex part PR is lowered or the concave part is deepened while the center-to-center distance is kept constant, the luminance increases and the display color of the display part DA1 changes to dark gray.

  It is desirable that the height of the convex part PR or the depth of the concave part be ½ or more of the center-to-center distance. For example, when the center-to-center distance of the convex part PR or the concave part is 400 nm, if the height of the convex part PR or the depth of the concave part is 200 nm or more, the display part DA1 can display dark gray. And if the height of the convex part PR or the depth of the concave part is 400 nm or more, the display part DA1 can display black with high color purity.

  In addition, when the ratio of the height of the convex part PR or the depth of the concave part with respect to the center-to-center distance is increased, black having high color purity can be displayed on the display part DA1, and more precise manufacturing technology is required. It becomes. That is, a higher anti-counterfeit effect can be achieved.

  As described above, in each of the element regions IF1a and IF1b, the convex portions or the concave portions are typically arranged at a center-to-center distance within a range of about 0.3 μm to about 0.5 μm. In order for each of the element regions IF1a and IF1b to function as a diffraction grating, it is desirable that approximately 10 or more protrusions or recesses per direction are arranged in each of the element regions IF1a and IF1b. Therefore, each of the element regions IF1a and IF1b has a shape including a square having a side length of 3 μm, for example.

  Further, when each of the element regions IF1a and IF1b is large, for example, when they have a size larger than the general resolution of the human eye, the element display part DA1a and the element display part DA1b look different colors, The display unit DA1 does not display mixed colors. Accordingly, each element region has, for example, a shape enclosed in a rectangle having a short side of 300 μm.

  The interface IF1 has the same structure as described above for the element regions IF1a and IF1b, and when diffracted light having a wavelength different from that of the element regions IF1a and IF1b when illuminated with white light from the first direction is second. It may further include one or more element regions that emit in the direction. In this case, in the element regions IF1a and IF1b and the additional element region, the element region IF1b fills only a part of the gap formed between the element regions IF1a and the additional element region fills the rest of the gap. To place. Then, when illuminated with white light from the first direction and observed with the naked eye from the second direction, each element display unit corresponding to the additional element region cannot be identified from the other element display units of the display unit DA1. The display unit DA1 designs the interface unit IF1 so as to display a mixed color that can be identified with the naked eye from the display colors of the element display units included in the display unit DA1.

  In the case where the interface portion IF1 is configured by three types of element regions including the element regions IF1a and IF1b, and the orientation directions of the convex portions PR are equal and the center-to-center distances of the convex portions PR are different between the element regions, for example, The following configuration is adopted. That is, in the element region IF1a, the projections PR are arranged at a center distance within a range of 300 nm to 330 nm, and at the element region IF1b, the projections PR are arranged at a center distance within a range of 360 nm to 390 nm. Then, the convex portions PR are arranged at a center-to-center distance within a range of 420 nm to 450 nm. For example, when such a configuration is adopted, diffracted light of blue, green, and red is emitted in the same direction to the element region IF1a, the element region IF1b, and the additional element region, respectively, and white is displayed on the display unit DA1. Can do.

  The feature of displaying dark gray or black under the conditions described with reference to FIG. 9 and displaying white under the conditions described with reference to FIG. 10 is very special. Such a feature cannot be reproduced only by using a normal diffraction grating or functional ink. Therefore, when a configuration for displaying white as a mixed color is adopted, a higher forgery prevention effect can be achieved.

  When the display unit DA1 is composed of three types of element display units, for example, the following arrangement can be adopted for these element display units.

  FIG. 11 is a plan view schematically showing an example of the arrangement of the element display units. FIG. 11 shows an example of the arrangement of the element display units DA1a to DA1c that can be adopted when the display unit DA1 is composed of three types of element display units DA1a to DA1c.

  In the arrangement of FIG. 11, each element display section DA1a is adjacent to two element display sections DA1b and two element display sections DA1c. Each element display section DA1b is adjacent to two element display sections DA1c and two element display sections DA1a. Each element display section DA1c is adjacent to two element display sections DA1a and two element display sections DA1b. Therefore, when this arrangement is adopted, it is difficult for some of the element display portions DA1a to DA1c to be distinguished from other portions.

  It is desirable to display information such as characters, symbols, and patterns on the display unit DA1. By displaying such information, the gaze effect of the user can be improved, and design properties can be imparted to the display body 10 and the labeled article having the display body 10.

  The display body 10 described above can be used, for example, by being attached to a printed material or an article via an adhesive or the like as a forgery prevention label. As described above, the display body 10 is impossible or difficult to counterfeit and imitate. Therefore, a labeled article formed by supporting the label on the article is also impossible or difficult to counterfeit and imitate.

  FIG. 12 is a plan view schematically showing an example of a labeled article. FIG. 13 is a cross-sectional view taken along line XIII-XIII of the labeled article shown in FIG.

  12 and 13 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 described above is fixed to the surface of the base material 20 on which the printed layer 40 is formed, for example, via an adhesive layer 50. 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 the display body 10 described above. Therefore, forgery and imitation of the printed material 100 is impossible or difficult. 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 FIGS. 12 and 13, 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 material 100 shown in FIG.12 and FIG.13, 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 invention described in the original claims is appended below.
[1] One or a plurality of first element regions each including a diffractive structure composed of a plurality of recesses or projections arranged at a center-to-center distance of 500 nm or less, forming a gap, and a center-to-center distance of 500 nm or less One or a plurality of first elements each including a diffractive structure composed of a plurality of concave portions or convex portions arranged in a row, and each including one or a plurality of second element regions filling at least a part of the gap. The first element display unit corresponding to the one or more first element regions emits first diffracted light in the second direction when the interface unit is provided and illuminated with white light from the first direction, The second element display unit corresponding to one or a plurality of second element regions emits second diffracted light having a wavelength different from that of the first diffracted light in the second direction, and is illuminated with the white light from the first direction. Then, when observed with the naked eye from the second direction, the first element display unit is The first display unit corresponding to one or a plurality of first interface portions cannot be identified from a portion other than the first element display unit, and the second element display unit is not connected to the first display unit. Of these, it is impossible to distinguish from parts other than the second element display part, and the first display part is visually recognized from both the display color of the first element display part and the display color of the second element display part. A display body characterized by displaying a mixed color that can be identified by the above.
[2] In at least one of the one or more first interface parts, the one or more first element regions are a plurality of first elements arranged uniformly over the entire first interface part. Item 1 is a single element region, wherein the one or more second element regions are a plurality of second element regions arranged uniformly over the entire first interface portion. Display body of description.
[3] In at least one of the one or more first interface portions, the one or more first element regions and the one or more second element regions occupy a unit area. Item 3. The display according to Item 1 or 2, wherein the area ratio is different depending on the position.
[4] In the one or more first element regions, the plurality of recesses or protrusions are arranged at a center-to-center distance within a range of 300 nm to 360 nm, and in the one or more second element regions, the plurality of the plurality of recesses or protrusions are arranged. Item 4. The display body according to any one of items 1 to 3, wherein the concave portions or the convex portions are arranged at a center-to-center distance within a range of 390 nm to 450 nm.
[5] The one or more second element regions fill only part of the gap, and each of the one or more first interface portions includes a plurality of arrays arranged at a center-to-center distance of 500 nm or less. When each includes a diffractive structure consisting of a concave portion or a convex portion, and further includes one or a plurality of third element regions filling the other part of the gap, and when illuminated with the white light from the first direction The third element display unit corresponding to the one or more third element regions emits third diffracted light having a wavelength different from that of the first and second diffracted light in the second direction, and the first direction When the third element display unit is illuminated with the white light and observed with the naked eye from the second direction, the third element display unit is indistinguishable from a part other than the third element display unit in the first display unit. Yes, the first display unit has a display color of the first element display unit and a display of the second element display unit. Display body according to any one of claim 1 to 3, characterized in that to display the color mixture which can be identified by the naked eye from either the display color of the third element display section.
[6] In the one or more first element regions, the plurality of recesses or projections are arranged at a center-to-center distance within a range of 300 nm to 330 nm, and in the one or more second element regions, the plurality of the plurality of recesses or protrusions are arranged. The recesses or projections are arranged at a center distance within a range of 360 nm to 390 nm, and the plurality of recesses or protrusions are arranged at a center distance within a range of 420 nm to 450 nm in the one or more third element regions. Item 6. The display body according to Item 5, wherein
[7] One main surface includes the light transmission layer including the one or more first interface portions, and a reflective layer covering at least a part of the one or more first interface portions. Item 7. The display according to any one of Items 1 to 6, wherein
[8] It further includes a second interface portion adjacent to at least one of the one or more first interface portions and having optical characteristics different from the first interface portion, and the first display portion can be used when the eye is observed with the naked eye. Item 8. The display body according to any one of Items 1 to 7, wherein an image that can be identified from a second display unit corresponding to the second interface unit is displayed.
[9] A labeled article comprising the display according to any one of items 1 to 8 and an article supporting the display.

The top view which shows schematically the display body which concerns on 1 aspect of this invention. The top view which expands and shows a part of display body shown in FIG. Sectional drawing along the III-III line of the display body shown in FIG. FIG. 4 is a perspective view illustrating an example of a structure that can be employed in an element region of the display body illustrated in FIGS. 1 to 3. The top view of the structure shown in FIG. The figure which shows a mode that a certain 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 perspective view which shows a part of interface part containing the element area | region shown in FIG. The figure which shows a mode that the display body shown in FIG. 1 thru | or FIG. 3 is observed on a certain condition. The figure which shows a mode that the display body shown in FIG. 1 thru | or FIG. 3 is observed on other conditions. The top view which shows an example of arrangement | positioning of an element display part roughly. The top view which shows an example of a labeled article schematically. Sectional drawing along the XIII-XIII line of the labeled article shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Display body, 11 ... Light transmission layer, 13 ... Reflection layer, 20 ... Base material, 30 ... IC chip, 40 ... Printing layer, 50 ... Adhesion layer, 100 ... Printed matter, 111 ... Light transmission base material, 112 ... Light transmissive resin layer, DA1 ... display section, DA1a ... element display section, DA1b ... element display section, DA1c ... element display section, DA2 ... display section, DLb ... diffracted light, DLg ... diffracted light, DLr ... diffracted light, IF ... interface part, IF1 ... interface part, IF1a ... element area, IF1b ... element area, IF2 ... interface part, IF3 ... interface part, IL ... illumination light, LS ... light source, NL ... normal, OB ... observer, PR ... Convex part, RL ... Regular reflection light.

Claims (8)

Each includes a diffractive structure composed of a plurality of concave portions or convex portions arranged at a center distance of 500 nm or less, and one or a plurality of first element regions forming a gap, and arranged at a center distance of 500 nm or less. One or a plurality of first interface portions each including a diffractive structure composed of a plurality of concave portions or convex portions, each including one or a plurality of second element regions filling at least a part of the gap. Prepared,
Each of the first element region and the second element region includes a square having a side length of 3 μm and a short side having a length of 300 μm.
Each of the first element region and the second element region is arranged in a checkered pattern, or adjacent to each other,
The difference between the center distances of the plurality of recesses or projections arranged in the first element region and the center distance of the plurality of recesses or projections arranged in the second element region is 30 nm to 300 nm. Is in range,
When illuminated with white light from the first direction, the first element display unit corresponding to the one or more first element regions emits first diffracted light in the second direction, and the one or more first elements are displayed. The second element display unit corresponding to the two element region emits second diffracted light having a wavelength different from that of the first diffracted light in the second direction,
When the first element display unit is illuminated with the white light from the first direction and observed with the naked eye from the second direction, the first element display unit is a first display unit corresponding to the one or more first interface units. Identification from a part other than the first element display part is impossible, and the second element display part is impossible to identify from a part other than the second element display part in the first display part, The first display unit displays a mixed color that can be identified with the naked eye from both the display color of the first element display unit and the display color of the second element display unit.   In at least one of the one or more first interface portions, the one or more first element regions are a plurality of first element regions arranged uniformly over the entire first interface portion. The one or more second element regions are a plurality of second element regions arranged uniformly over the entire first interface portion. Display body.   The ratio of the first element region to the unit area of the one or more first element regions and the one or more second element regions in at least one of the one or more first interface portions. The display body according to claim 1, wherein the display bodies are arranged so as to be different depending on positions.   The plurality of recesses or projections in the one or more first element regions are arranged at a center-to-center distance within a range of 300 nm to 360 nm, and the plurality of recesses or projections in the one or more second element regions. The display unit according to any one of claims 1 to 3, wherein the portions are arranged at a center-to-center distance within a range of 390 nm to 450 nm. The one or more second element regions fill only a part of the gap,
Each of the one or more first interface portions includes a diffractive structure composed of a plurality of concave portions or convex portions arranged at a center-to-center distance of 500 nm or less, and fills the other part of the gap 1 One or more third element regions,
When illuminated with the white light from the first direction, the third element display unit corresponding to the one or more third element regions has a third diffracted light having a wavelength different from that of the first and second diffracted lights. In the second direction,
When the white light is illuminated from the first direction and observed with the naked eye from the second direction, the third element display unit is identified from a portion of the first display unit other than the third element display unit. The first display unit can be identified with the naked eye from any of the display color of the first element display unit, the display color of the second element display unit, and the display color of the third element display unit. The display body according to claim 1, wherein a color mixture that can be displayed is displayed.   The plurality of recesses or projections in the one or more first element regions are arranged at a center-to-center distance within a range of 300 nm to 330 nm, and the plurality of recesses or projections in the one or more second element regions. The portions are arranged at a center-to-center distance within a range of 360 nm to 390 nm, and the plurality of recesses or projections are arranged at a center-to-center distance within a range of 420 nm to 450 nm in the one or more third element regions. The display body according to claim 5.   One main surface includes the light transmission layer including the one or more first interface portions, and a reflection layer covering at least a part of the one or more first interface portions. The display body according to any one of claims 1 to 6. A labeled article comprising the display body according to any one of claims 1 to 7 and an article that supports the display body.

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