JP5028643B2 - Laminated body, adhesive label, recording medium, labeled article and discrimination method - Google Patents

Description

  The present invention relates to a discrimination technique for discriminating an article between a genuine product and a non-genuine product.

  It is desired that counterfeiting is difficult for authentication media such as cash cards, credit cards and passports, and securities media such as gift certificates and stock certificates. Therefore, conventionally, a label that is difficult to forge is attached to such a medium in order to prevent the forgery.

  In recent years, the distribution of counterfeit products has been regarded as a problem for articles other than authentication media and securities media. Therefore, the opportunity to apply the above-described anti-counterfeiting technology for authentication media and securities media to such articles is increasing.

The forgery prevention technology can be classified into an overt technology and a covert technology.
The overt technique is an anti-counterfeiting technique that allows a general user to easily recognize application to an article and easily determine whether it is authentic. In a typical overt technique, a diffractive structure such as a hologram or a multilayer interference film such as Optically Variable Ink (OVI) is used.

  The covert technique is an anti-counterfeiting technique aimed at making it possible for only a specific user who knows the application of the covert technique to an article to make an authenticity determination because it is difficult for a general user to apply to the article. Typical covert techniques use fluorescent printing or line moire.

  Patent Document 1 describes another covert technique. In this covert technology, a label including an absorption type polarizing layer and a birefringent layer is used. The birefringent layer covers the front surface of the absorptive polarizing layer and includes, for example, two portions having different slow axis directions. When this label is observed without passing through a polarizing film, it is difficult to distinguish a region corresponding to one part of the birefringent layer and a region corresponding to the other part. When viewed through a polarizing film, one of these regions appears darker than the other region. Using the visible image formed by the bright part and the dark part, the authenticity of the article to which this label is attached is confirmed.

As described above, the covert technique described in Patent Document 1 uses a label including an absorption-type polarizing layer. Therefore, this label has a problem that it is dark when observed without passing through a polarizing film. In addition, this label has a problem that it is difficult to see the visualized latent image unless the observation angle is optimized.
Special table 2001-525080 gazette

  An object of the present invention is to form a latent image in a bright area and widen the range of observation angles at which the visualized latent image can be visually recognized.

  According to the first aspect of the present invention, the scattering-type polarizing layer, the first portion facing a part of the front surface of the polarizing layer, the other portion of the front surface of the polarizing layer, and the first portion being delayed. There is provided a discriminating laminate comprising a birefringent layer including a second portion having different phase axis directions.

  According to the 2nd side surface of this invention, the adhesive label characterized by having comprised the laminated body which concerns on a 1st side surface, and the adhesion layer supported by the back surface of the said laminated body is provided.

  According to a third aspect of the present invention, there is provided a paper, a pressure-sensitive adhesive layer supported on one main surface of the paper, and a lamination according to the first side surface embedded in the paper so that a back surface faces the pressure-sensitive adhesive layer. An adhesive label characterized by comprising a body is provided.

  According to a fourth aspect of the present invention, there is provided a recording medium comprising paper and a laminate according to the first side surface embedded in the paper.

  According to a fifth aspect of the present invention, there is provided a label comprising: an article whose authenticity is to be confirmed; and a laminate according to the first side surface supported by the article whose authenticity is to be confirmed. Articles are provided.

  According to a sixth aspect of the present invention, there is provided a method for discriminating an article whose authenticity is unknown between a genuine article and a non-authentic article, wherein the authentic article is a labeled article according to the fifth aspect, If the unknown article does not include a light-scattering region that holds a latent image that is visualized by observing through a polarizer, it is determined that the unknown authentic article is non-authentic. A method is provided that includes:

  According to a seventh aspect of the present invention, there is provided a method for discriminating an article whose authenticity is unknown between an authentic product and a non-authentic product, the authentic product including an article whose authenticity is to be confirmed and the authentic product And a laminate according to the first side surface supported by the article to be confirmed, wherein the laminate further includes a reflective layer facing the back surface of the polarizing layer, and the authenticity is If the unknown article is visualized by observing through the polarizing layer and does not hold a latent image in which the positions of the bright part and the dark part are switched by changing the observation angle in the visualized state, the authenticity is obtained. A method is provided that includes determining that the unknown article is non-genuine.

  According to the present invention, it is possible to form a latent image in a bright area and widen the range of observation angles at which the visualized latent image can be visually recognized.

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

  FIG. 1 is a plan view schematically showing a layered product for identification according to one embodiment of the present invention. 2 is a cross-sectional view taken along the line II-II of the laminate shown in FIG. 3 and 4 are perspective views schematically showing the scattering-type polarizing layer included in the laminate of FIG.

  As shown in FIG. 2, the identification laminate 10 includes a scattering polarizing layer 11, a birefringent layer 12, a light absorption / reflection layer 13, and an overcoat layer 14.

  Here, the term “polarizing layer” means a layer functioning as a linear polarizer unless otherwise specified. The term “polarizer” includes “linear polarizer”, “elliptical polarizer”, and “circular polarizer”, and does not include the concept of shape.

The scattering-type polarizing layer 11 is a layer in which the magnitude of light scattering changes when the plane of polarization of linearly polarized light (vibration plane of the electric field vector) as incident light is rotated. As shown in FIG. 3, when the transmission axis _AT of the scattering polarizing layer 11 and the polarization plane of the linearly polarized light L _LP as incident light are parallel, the scattering polarizing layer 11 is ideally linearly polarized. Transmits L _LP without scattering. When the angle formed by the polarization plane of the linearly polarized light L _LP with respect to the transmission axis _AT is increased, the light component scattered by the scattering-type polarizing layer 11 increases. As shown in FIG. 4, when the polarization plane of the linearly polarized light L _LP and the transmission axis _AT are orthogonal, the scattering type polarization layer 11 scatters the most light component.

  Various structures can be adopted for the scattering-type polarizing layer 11 as described below.

  For example, the scattering-type polarizing layer 11 may include a birefringent first layer having an uneven surface as a scattering surface, and a second layer in contact with the uneven surface. For example, when the first layer is a uniaxial crystal having an optical axis substantially parallel to the in-plane direction and the second layer is optically isotropic, the refractive index of the second layer is the ordinary ray refraction of the first layer. If the rate is substantially equal, the scattering-type polarizing layer 11 transmits ordinary light with almost no scattering, and scatters extraordinary light.

  A birefringent material such as calcite can be used as the material for the first layer. As the material of the second layer, for example, a resin such as polymethyl methacrylate can be used.

  When the above structure is adopted for the scattering-type polarizing layer 11, the second layer may be optically anisotropic. For example, when the second layer is a uniaxial crystal, the first layer and the second layer are arranged so that their optical axes are parallel. Then, the ordinary light refractive indexes of the first layer and the second layer are made substantially the same, and the extraordinary light refractive indexes of the first layer and the second layer are made different. The scattering-type polarizing layer 11 employing this structure transmits ordinary light with little scattering, and scatters extraordinary light.

  The scattering polarizing layer 11 may have a multilayer structure including three or more layers. For example, the scattering polarizing layer 11 may have a structure in which a birefringent first layer whose both surfaces are uneven surfaces is sandwiched between a pair of second layers.

  The scattering-type polarizing layer 11 may have a structure in which transparent particles are dispersed in a transparent matrix. For example, when the transparent matrix is a uniaxial crystal and the transparent particles are optically isotropic, if the refractive index of the transparent particles is approximately equal to the ordinary ray refractive index of the transparent matrix, the scattering type polarizing layer 11 is an ordinary ray. Is transmitted with almost no scattering, and extraordinary rays are scattered.

  As the transparent matrix, for example, a uniaxially stretched polymer layer can be used. As the material of the polymer layer, for example, polyethylene, polyethylene terephthalate, polyethylene naphthalate, polypropylene, polycarbonate, polystyrene, polyvinyl chloride, polyvinyl alcohol, and a mixture containing one or more thereof can be used. As a material for the transparent particles, for example, an organic substance such as a crosslinked polystyrene, a divinylbenzene crosslinked product, or a methyl methacrylate crosslinked product can be used. Alternatively, inorganic materials such as silica and alumina may be used as the material for the transparent particles.

  When the above structure is adopted for the scattering polarizing layer 11, the transparent particles may be optically anisotropic. For example, uniaxial crystals are used as the transparent particles, and the optical axes of the transparent particles are substantially parallel to each other. In this case, as a material for the transparent particles, for example, a liquid crystal material exhibiting a nematic phase or a smectic phase in the operating temperature range of the laminate 10, typically a polymer liquid crystal material can be used. The optical axes of the transparent particles can be made substantially parallel to each other, for example, by stretching the scattering polarizing layer 11. Further, when the transparent particles are optically anisotropic, the transparent matrix may be optically isotropic.

  The birefringent layer 12 faces the front surface of the scattering-type polarizing layer 11. The scattering polarizing layer 11 and the birefringent layer 12 are in contact with each other in this example, but they are not necessarily in contact with each other. Any layer may be interposed between the two. For example, an easy-adhesion layer or an alignment film for liquid crystal may be interposed between the scattering-type polarizing layer 11 and the birefringent layer 12 to increase their adhesion.

  The birefringent layer 12 includes a first portion 12a and a second portion 12b that are adjacent to each other in the in-plane direction.

  The first portion 12a has substantially uniform optical characteristics in the plane. Similarly, the second portion 12b also has substantially uniform optical characteristics within the plane. The first portion 12a and the second portion 12b are different in the direction of the slow axis.

For example, the first portion 12a and the second portion 12b are arranged so that their slow axes are orthogonal. In this case, each of the first portion 12a and the second portion 12b may be a quarter-wave plate. When this structure is adopted, the scattering polarizing layer 11 and the birefringent layer 12 are such that the transmission axis _AT of the scattering polarizing layer 11 is the slow axis of the first portion 12a and the slow axis of the second portion 12b. It arrange | positions so that it may become diagonal with respect to each. For example, the angle formed by the transmission axis _AT of the scattering-type polarizing layer 11 with respect to each of the slow axis of the first portion 12a and the slow axis of the second portion 12b is about 45 °.

Alternatively, the first portion 12a and the second portion 12b may be arranged such that their slow axes form an angle of 45 °. In this case, each of the first portion 12a and the second portion 12b may be a half-wave plate. When this structure is adopted, the angle formed by the transmission axis _AT of the scattering polarizing layer 11 with respect to each of the slow axis of the first portion 12a and the slow axis of the second portion 12b is arbitrary.

  In addition, the laminated body 10 is usually designed in consideration of light having a wavelength in the range of 400 nm to 700 nm among visible light. Therefore, a quarter-wave plate is usually used that provides a retardation of λ / 4 at at least one wavelength λ within the above range. In general, a half-wave plate that provides a retardation of λ / 2 at at least one wavelength λ within the above range is used.

  The front surface of the stacked body 10 includes an area AA1 corresponding to the first portion 12a and an area AA2 corresponding to the second portion 12b. Each of the areas AA1 and AA2 forms a latent image that is difficult to distinguish from each other. That is, when the front surface of the laminate 10 is directly observed without using a polarizer, it is difficult to find the difference between the area AA1 and the area AA2. When the front surface of the laminated body 10 is observed through the polarizer, a difference in brightness occurs between the area AA1 and the area AA2. Thereby, the latent image is visualized.

  The birefringent layer 12 may be in direct contact with the front surface of the scattering-type polarizing layer 11. Alternatively, an optically isotropic transparent layer may be interposed between the birefringent layer 12 and the scattering-type polarizing layer 11.

  As each of the 1st part 12a and the 2nd part 12b, a birefringent stretched film can be used, for example. As this stretched film, for example, a uniaxially or biaxially stretched polyolefin film and polyester film can be used.

  A liquid crystal material may be used as the material of the first portion 12a and the second portion 12b. As this liquid crystal material, for example, a liquid crystal material that is solid in the use temperature range of the laminate 10 and exhibits a nematic phase or a smectic phase, typically a polymer liquid crystal material, can be used. In this case, for example, by forming an alignment film including a plurality of portions having different alignment directions, forming a thin film pattern made of a low molecular weight liquid crystal material on the alignment film, and causing polymerization of the liquid crystal material The birefringent layer 12 including the first portion 12a and the second portion 12b can be obtained. An alignment film including a plurality of portions having different alignment directions can be formed using, for example, an optical alignment technique.

  The light absorption / reflection layer 13 is a light absorption layer or a reflection layer. The light absorption / reflection layer 13 faces the back surface of the scattering-type polarizing layer 11. The light absorption / reflection layer 13 may face the entire back surface of the scattering-type polarizing layer 11 or may face only a part thereof. Further, the light absorption / reflection layer 13 may be omitted.

  The light absorption / reflection layer 13 may be in direct contact with the back surface of the scattering polarizing layer 11. Alternatively, a transparent layer may be interposed between the light absorption / reflection layer 13 and the scattering polarizing layer 11.

  When the light absorption / reflection layer 13 is a light absorption layer, this light absorption layer can be obtained, for example, by applying an ink containing a pigment and / or a dye and a resin to the back surface of the scattering polarizing layer 11. Or this light absorption layer is obtained by apply | coating the previous ink on a base material. In this case, the light absorption layer can be attached to the back surface of the scattering-type polarizing layer 11 together with the base material.

  The light absorbing layer may be black or another color. The light absorption layer may include a plurality of portions having different colors and arranged in the in-plane direction.

  When the light absorption layer is black, when the latent image is not visualized, the colors of the regions AA1 and AA2 are white due to the light scattering of the scattering polarizing layer 11. When the latent image is visualized, one of the areas AA1 and AA2 changes to black. If the light absorption layer is black, the contrast ratio of these regions is maximized when the latent image is visualized.

  When a light absorbing layer that absorbs only a part of visible light and reflects another part is used, when the latent image is not visualized, the colors of the regions AA1 and AA2 are the light scattering of the scattering-type polarizing layer 11. This is a color generated by mixing the white color caused by the color and the color caused by the reflection of the light absorption layer. When the latent image is visualized, one of the areas AA1 and AA2 has a weak color due to the reflection of the light absorption layer, and the other has a change to a color due to the reflection of the light absorption layer.

  When the light absorption / reflection layer 13 is a reflection layer, this reflection layer is obtained by depositing a metal or an alloy on the back surface of the scattering-type polarizing layer 11 by, for example, vacuum evaporation or sputtering. Alternatively, the reflective layer can be obtained by depositing a metal or alloy on the substrate by the same method as described above. In this case, the reflective layer can be attached to the back surface of the scattering-type polarizing layer 11 together with the base material.

  When the light absorption / reflection layer 13 is a reflection layer, when the latent image is not visualized, the colors of the regions AA1 and AA2 are white due to the light scattering of the scattering type polarizing layer 11, or the scattering type. It is white due to light scattering of the polarizing layer 11 and reflection of the reflecting layer. When the latent image is visualized, a difference in luminance is generated between the areas AA1 and AA2.

  The overcoat layer 14 covers the front surface of the scattering-type polarizing layer 11 and the birefringent layer 12. The overcoat layer 14 is an optically isotropic transparent layer, typically a transparent resin layer. When the first portion 12a and the second portion 12b form an uneven surface, the overcoat layer 14 flattens the uneven surface. This makes it difficult to understand the boundary between the first portion 12a and the second portion 12b. The overcoat layer 14 may be omitted.

  The overcoat layer 14 is obtained, for example, by applying a transparent printing ink to the birefringent layer 12. For the application of the printing ink, for example, a coating method such as gravure and microgravure can be used.

Next, the visualization of the latent image will be described.
5 and 6 are diagrams schematically illustrating an example of a method for visualizing the latent image held by the stacked body illustrated in FIG. 1. FIG. 5 illustrates a state in which the area AA1 reflects light. FIG. 6 illustrates a state where the area AA2 reflects light.

The laminated body 10 shown in FIG.5 and FIG.6 contains the reflection layer as the light absorption / reflection layer 13, and contains the half-wave plate as the 1st part 12a and the 2nd part 12b. The angle formed by the slow axis of the first portion 12a and the transmission axis _AT of the scattering polarizing layer 11 is 45 °, and the slow axis of the second portion 12b and the slow axis of the first portion 12a form. The angle is 45 °.

  In the method shown in FIGS. 5 and 6, the front surface of the laminate 10 is observed through the verification tool 200 while irradiating the front surface of the laminate 10 with natural light. Here, as an example, an absorptive polarizing layer such as a polarizing layer in which a stretched polyvinyl alcohol layer is impregnated with iodine is used as the verification tool 200. Further, in this method, the laminated body 10, the light source 300, and the observer 400 are arranged so that the observer 400 can observe the reflected light when the laminated body 10 specularly reflects light from the light source 300.

As shown in FIG. 5, in the portion corresponding to the area AA1, natural light L _N from the light source 300 enters the first portion 12a. The first portion 12a transmits this natural light _LN .

The natural light L _N emitted from the first portion 12 a is incident on the scattering polarizing layer 11. Scattering type polarizing layer 11, of the natural light L _N, the plane of polarization parallel to the linearly polarized light transmission axis A _T (or less, S of polarized light) passes through without substantially scattering L _PS. Of the natural light L _N , linearly polarized light (hereinafter referred to as P-polarized light) L _PP whose polarization plane is perpendicular to the transmission axis _AT will be described later.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering-type polarizing layer 11 transmits this S-polarized light _LPS with almost no scattering.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is incident on the first portion 12a. The first portion 12a converts the S-polarized light _LPS into the P-polarized light _LPP .

The P-polarized light L _PP emitted from the first portion 12 a is incident on the absorption-type polarizing layer 200. If the transmission axis A _T absorption type polarizing layer 200 as shown in FIG. 4 'transmission axis A _T of the scattering type polarizing layer 11' is parallel to the absorption-type polarizing layer 200 absorbs the P polarized light L _PP. Therefore, the light component (hereinafter referred to as non-scattered light) transmitted without scattering by the scattering-type polarizing layer 11 does not reach the observer 400.

The scattering-type polarizing layer 11 scatters the P-polarized light L _PP forward and backward from the natural light L _N from the light source 300 transmitted through the first portion 12a. Here, for simplification, it is assumed that the scattering-type polarizing layer 11 scatters the P-polarized light L _PP without converting it into partially polarized light.

The P-polarized light L _PP backscattered by the scattering-type polarizing layer 11 is incident again on the first portion 12a. On the other hand, the P-polarized light L _PP scattered forward by the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering type polarization layer 11 scatters P-polarized light L _PP forward and backward. In this way, the P-polarized light L _PP having low directivity is incident on the first portion 12a. The first portion 12a converts P-polarized light L _PP into S-polarized light L _PS .

The S-polarized light L _PS emitted from the first portion 12 a is incident on the absorption-type polarizing layer 200. Absorptive polarizing layer 200 is transmitted through the S-polarized light L _PS. However, since this S-polarized light _LPS is scattered light, only a part of the light components reach the observer 400 and the remaining light components do not reach the observer 400.

In the portion corresponding to the area AA2, as shown in FIG. 6, the natural light L _N from the light source 300 is incident on the second portion 12b. The second portion 12b transmits this natural light _LN .

The natural light L _N emitted from the second portion 12 b is incident on the scattering polarizing layer 11. Scattering type polarizing layer 11, of the natural light L _N, transmitted almost without scattering the S-polarized light L _PS. Of the natural light L _N , the P-polarized light L _PP will be described later.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering-type polarizing layer 11 transmits this S-polarized light _LPS with almost no scattering.

S-polarized light L _PS with a scattering type polarizing layer 11 emitted is incident on the second portion 12b. The second portion 12b is transmitted without converting the S-polarized light L _PS to P-polarized light L _PP.

The S-polarized light L _PS emitted from the second portion 12 b is incident on the absorption polarizing layer 200. Absorptive polarizing layer 200 is transmitted through the S-polarized light L _PS. Therefore, the light component transmitted without scattering by the scattering-type polarizing layer 11 reaches the observer 400.

The scattering-type polarizing layer 11 scatters the P-polarized light L _PP forward and backward from the natural light L _N from the light source 300 transmitted through the second portion 12b. The P-polarized light L _PP backscattered by the scattering-type polarizing layer 11 is incident again on the second portion 12b. On the other hand, the P-polarized light L _PP scattered forward by the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering type polarization layer 11 scatters P-polarized light L _PP forward and backward. In this way, the P-polarized light L _PP having low directivity is incident on the second portion 12b. The second portion 12b transmits P-polarized light L _PP without converting it into S-polarized light L _PS .

The P-polarized light L _PP emitted from the second portion 12 b is incident on the absorption polarizing layer 200. Since the absorption polarization layer 200 absorbs the P-polarized light L _PP , the P-polarized light L _PP does not reach the observer 400.

  Thus, the area AA1 emits only low-intensity scattered light toward the observer 400 without emitting high-intensity non-scattered light. On the other hand, the area AA2 emits high-intensity non-scattered light toward the observer 400 and does not emit low-intensity scattered light. Therefore, the viewer 400 perceives the areas AA1 and AA2 as dark parts and bright parts, respectively. As described above, the latent image can be visualized.

  In the method described with reference to FIGS. 5 and 6, the laminated body 10, the light source 300, and the observer 400 observe the reflected light when the laminated body 10 specularly reflects the light from the light source 300. Arranged as possible. When only the observation angle is changed in this state, the positions of the bright part and the dark part are switched. That is, the area AA1 changes from a dark part to a bright part, and the area AA2 changes from a bright part to a dark part. This will be described below.

  If only the observation angle is sufficiently changed from the state described with reference to FIGS. 5 and 6, the high-intensity non-scattered light emitted from the area AA <b> 2 cannot reach the observer 400. Since the area AA2 does not emit low-intensity scattered light, the brightness of the area AA2 becomes almost zero.

  On the other hand, the area AA1 does not emit high-intensity non-scattered light, and emits only low-intensity scattered light. For this reason, in the area AA1, there is almost no change in luminance associated with changing the observation angle.

  Therefore, in this case, the observer 400 perceives the areas AA1 and AA2 as dark parts and bright parts, respectively. For this reason, when the observation angle is changed, the positions of the bright part and the dark part are switched.

Even when the angle formed by the transmission axis A _T ′ of the absorbing polarizing layer 200 with respect to the transmission axis A _T of the scattering polarizing layer 11 is changed, the positions of the bright part and the dark part are switched. For example, when the transmission axis A _T ′ is perpendicular to the transmission axis A _T , the positions of the bright part and the dark part are opposite to those described with reference to FIGS.

Further, when a light absorption layer is used as the light absorption / reflection layer 13 instead of the reflection layer, none of the areas AA1 and AA2 emits high intensity non-scattered light. Therefore, when parallel to the transmission axis A _T of the transmission axis A _T 'scattering type polarizing layer 11 of the absorption-type polarizing layer 200, the viewer 400 perceives the regions AA1 and AA2 as a light portion and a dark portion, respectively . Then, when the vertical transmission axes A _T 'absorptive polarizing layer 200 with respect to the transmission axis A _T of the scattering type polarizing layer 11, the viewer 400 perceives the regions AA1 and AA2 respectively as shadow and highlight portions .

  As described above, the light applied to the stacked body 10 for visualizing the latent image need not be linearly polarized light. Therefore, it is not necessary to position the polarizing layer 200 in the vicinity of the stacked body 10. Therefore, this technique makes it easier to visualize the latent image as compared with the case where the laminated body 10 must be irradiated with linearly polarized light in order to visualize the latent image.

  Further, in this method, since the latent image is visualized using scattered light, the range of observation angles at which the visualized latent image can be visually recognized is wide. That is, when the structure described with reference to FIGS. 1 and 2 is employed, a latent image having excellent visibility can be formed when visualized.

  In the method described with reference to FIGS. 5 and 6, natural light is used as light applied to the stacked body 10 in order to visualize the latent image, but linearly polarized light may be used instead. For example, the polarizing layer 200 may be positioned in the vicinity of the stacked body 10 and linearly polarized light transmitted through the polarizing layer 200 may be irradiated onto the stacked body 10.

  In the method described with reference to FIGS. 5 and 6, the polarizing layer is used as the verification tool 200. However, the verification tool 200 may not be a polarizing layer. For example, a polarizing prism may be used. Moreover, the verification tool 200 does not need to be a linear polarizer, and may be an elliptical polarizer.

  In the above description, the polarizer is used as the verification tool 200 for visualizing the latent image. However, the latent image can be visualized without using the polarizer. This will be described below.

  FIG. 7 is a diagram schematically illustrating another example of a method for visualizing the latent image held by the stacked body illustrated in FIG. 1.

In this method, a transparent body 200 ′ such as a transparent plate is used as a verification tool. Specifically, the natural light L _N emitted from the light source 300 is irradiated onto the laminated body 10, and the light reflected by the laminated body 10 is incident on the transparent body 200 ′. Here, as an example, the reflected light from the area AA1 is linearly polarized light (hereinafter referred to as S wave) L _S whose polarization plane is perpendicular to the main surface of the transparent body 200 ′, and the reflected light from the area AA2 is polarized light. It is assumed that the plane is linearly polarized light (hereinafter referred to as P wave) L _P perpendicular to the plane of polarization of the S wave L _S.

The incident angle θ of the S wave L _S and the P wave L _P with respect to the transparent body 200 ′ is made substantially equal to the Brewster angle. For example, when a glass plate having a refractive index of about 1.5 is used as the transparent body 200 ′, the incident angle is set to about 56 °.

In this way, most of the light reflected by the transparent body 200 ′ becomes the S wave L _S. That is, the reflected light from the area AA1 among the reflected light from the stacked body 10 reaches the observer 400, but the reflected light from the area AA2 hardly reaches. Therefore, the viewer 400 perceives the areas AA1 and AA2 as a bright part and a dark part, respectively. As described above, the latent image can be visualized.

  In the arrangement shown in FIG. 7, when the laminated body 10 is rotated by 90 ° around the normal line, the regions AA1 and AA2 appear as dark portions and bright portions, respectively. Similarly to the case described with reference to FIGS. 5 and 6, when only the observation angle is changed from the state shown in FIG. 7, the positions of the bright part and the dark part are switched.

  A light absorption layer can be provided on the back side of the transparent body 200 ′. Employing this configuration improves the contrast ratio of the visible image.

  The transparent body 200 'is typically a transparent plate, but may not be a transparent plate as long as it has a smooth surface. The transparent body 200 ′ may be used only for the visualization, or may be used for other purposes such as a display cover plate mounted on a portable device. Good.

  8 and 9 are diagrams schematically showing still another example of a method for visualizing the latent image held by the stacked body shown in FIG. FIG. 8 illustrates a state in which the area AA1 reflects light. FIG. 9 illustrates a state in which the area AA2 reflects light.

The laminated body 10 shown in FIGS. 8 and 9 includes a reflection layer as the light absorption / reflection layer 13, and includes a quarter-wave plate as the first portion 12a and the second portion 12b. The angle formed by the slow axis of the first portion 12a and the transmission axis _AT of the scattering-type polarizing layer 11 is 45 °, and the slow axis of the second portion 12b and the slow axis of the first portion 12a are orthogonal to each other. I am letting.

  In the method shown in FIGS. 8 and 9, the front surface of the stacked body 10 is observed through the verification tool 200 while irradiating the front surface of the stacked body 10 with natural light. Here, as an example, as the verification tool 200, a laminated body of an absorption-type polarizing layer 201 and a quarter-wave plate 202 is used, and these are polarized between the quarter-wave plate 202 and the observer 400. It arrange | positions so that the layer 201 may intervene. Further, in this method, the laminated body 10, the light source 300, and the observer 400 are arranged so that the observer 400 can observe the reflected light when the laminated body 10 specularly reflects light from the light source 300.

As shown in FIG. 8, in the portion corresponding to the area AA1, the natural light L _N from the light source 300 is incident on the first portion 12a. The first portion 12a transmits this natural light _LN .

The natural light L _N emitted from the first portion 12 a is incident on the scattering polarizing layer 11. Scattering type polarizing layer 11, of the natural light L _N, the polarization plane is transmitted almost without scattering linearly polarized light parallel (S polarized light) L _PS to the transmission axis A _T. Of the natural light L _N , linearly polarized light (P-polarized light) L _PP whose polarization plane is perpendicular to the transmission axis _AT will be described later.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering-type polarizing layer 11 transmits this S-polarized light _LPS with almost no scattering.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is incident on the first portion 12a. The first portion 12a converts the S-polarized light _LPS into left-handed circularly polarized light _LC .

Left circularly polarized light L _LC emitted from the first portion 12a is incident on the quarter-wave plate 202. As shown in FIG. 8, when the fast axis of the first portion 12a and the slow axis of the quarter-wave plate 202 are parallel, the quarter-wave plate 202 converts the left circularly polarized light _LLC to S-polarized light. Convert to L _PS .

The S-polarized light L _PS emitted from the quarter-wave plate 202 is incident on the absorption-type polarizing layer 201. If the transmission axis A _T absorption type polarizing layer 201 as shown in FIG. 8 'transmission axis A _T of the scattering type polarizing layer 11' is parallel to the absorption-type polarizing layer 201 is transmitted through the P-polarized light L _PP. Therefore, the light component (non-scattered light) transmitted without scattering by the scattering type polarizing layer 11 reaches the observer 400.

The scattering-type polarizing layer 11 scatters the P-polarized light L _PP forward and backward from the natural light L _N from the light source 300 transmitted through the first portion 12a. The P-polarized light L _PP backscattered by the scattering-type polarizing layer 11 is incident again on the first portion 12a. On the other hand, the P-polarized light L _PP scattered forward by the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering type polarization layer 11 scatters P-polarized light L _PP forward and backward. In this way, the P-polarized light L _PP having low directivity is incident on the first portion 12a. The first portion 12a converts P-polarized light L _PP into right-circularly polarized light L _RC .

The right circularly polarized light L _RC emitted from the first portion 12 a is incident on the quarter-wave plate 202. Quarter-wave plate 202 converts right circularly polarized light L _RC into P polarized light L _PP .

The P-polarized light L _PP emitted from the quarter-wave plate 202 is incident on the absorption-type polarizing layer 201. The absorptive polarizing layer 201 absorbs the P-polarized light L _PP . Therefore, the light scattered by the scattering-type polarizing layer 11 does not reach the observer 400.

In the portion corresponding to the area AA2, as shown in FIG. 9, the natural light L _N from the light source 300 is incident on the second portion 12b. The second portion 12b transmits this natural light _LN .

The natural light L _N emitted from the second portion 12 b is incident on the scattering polarizing layer 11. Scattering type polarizing layer 11, of the natural light L _N, transmitted almost without scattering the S-polarized light L _PS. Of the natural light L _N , the P-polarized light L _PP will be described later.

The S-polarized light L _PS emitted from the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering-type polarizing layer 11 transmits this S-polarized light _LPS with almost no scattering.

S-polarized light L _PS with a scattering type polarizing layer 11 emitted is incident on the second portion 12b. The second portion 12b converts the S-polarized light _LPS into the right circularly polarized light _LRC .

The right circularly polarized light L _RC emitted from the second portion 12 b is incident on the quarter-wave plate 202. Since the fast axis of the quarter-wave plate 202 and the fast axis of the second portion 12b are parallel, the quarter-wave plate 202 converts the right circularly polarized light L _RC into P polarized light L _PP . .

The P-polarized light L _PP emitted from the quarter-wave plate 202 is incident on the absorption-type polarizing layer 201. The absorptive polarizing layer 200 absorbs P-polarized L _PP . Therefore, the light component transmitted without scattering by the scattering type polarizing layer 11 does not reach the observer 400.

The scattering-type polarizing layer 11 scatters the P-polarized light L _PP forward and backward from the natural light L _N from the light source 300 transmitted through the second portion 12b. The P-polarized light L _PP backscattered by the scattering-type polarizing layer 11 is incident again on the second portion 12b. On the other hand, the P-polarized light L _PP scattered forward by the scattering-type polarizing layer 11 is reflected by the light absorption / reflection layer 13 and enters the scattering-type polarizing layer 11 again. The scattering type polarization layer 11 scatters P-polarized light L _PP forward and backward. In this way, the P-polarized light L _PP having low directivity is incident on the second portion 12b. The second portion 12b converts P-polarized light L _PP into left-circularly polarized light L _LC .

Left circularly polarized light L _LC emitted from the second portion 12b enters the quarter-wave plate 202. Quarter-wave plate 202 converts left circularly polarized light L _LC into S polarized light L _PS .

The S-polarized light L _PS emitted from the quarter-wave plate 202 is incident on the absorption-type polarizing layer 201. Absorptive polarizing layer 201 is transmitted through the S-polarized light L _PS. However, since this S-polarized light _LPS is scattered light, only a part of the light components reach the observer 400 and the remaining light components do not reach the observer 400.

  Thus, the area AA1 emits high-intensity non-scattered light toward the observer 400 and does not emit low-intensity scattered light. On the other hand, the area AA2 does not emit high-intensity non-scattered light toward the observer 400, and emits only low-intensity scattered light. Therefore, the viewer 400 perceives the areas AA1 and AA2 as a bright part and a dark part, respectively. As described above, the latent image can be visualized.

  In the method described with reference to FIGS. 8 and 9, the laminated body 10, the light source 300, and the observer 400 observe the reflected light when the laminated body 10 specularly reflects the light from the light source 300. Arranged as possible. When only the observation angle is changed in this state, the positions of the bright part and the dark part are switched as in the method described with reference to FIGS. That is, the area AA1 changes from a bright part to a dark part, and the area AA2 changes from a dark part to a bright part.

  Further, when a light absorption layer is used as the light absorption / reflection layer 13 instead of the reflection layer, none of the areas AA1 and AA2 emits high intensity non-scattered light. Therefore, when the same arrangement as in FIGS. 8 and 9 is adopted, the observer 400 perceives the areas AA1 and AA2 as dark parts and bright parts, respectively.

Furthermore, in the method described with reference to FIGS. 8 and 9, when only the transmission axis A _T ′ of the polarizing layer 201 is rotated by 90 °, the positions of the bright part and the dark part are switched. However, in the method described with reference to FIGS. 8 and 9, unlike the method described with reference to FIGS. 5 and 6, the transmission axis A _T by rotating the verification tool 200 'is the transmission axis A _T Even if the angle formed with respect to is changed, the positions of the bright part and the dark part are not interchanged.

  As described above, the light applied to the stacked body 10 for visualizing the latent image need not be linearly polarized light. Therefore, it is not necessary to position the verification tool 200 in the vicinity of the stacked body 10. Therefore, this technique makes it easier to visualize the latent image as compared with the case where the laminated body 10 must be irradiated with linearly polarized light in order to visualize the latent image.

  Further, in this method, since the latent image is visualized using scattered light, the range of observation angles at which the visualized latent image can be visually recognized is wide. That is, when the structure described with reference to FIGS. 1 and 2 is employed, a latent image having excellent visibility can be formed when visualized.

  In the method described with reference to FIGS. 8 and 9, natural light is used as light applied to the laminated body 10 in order to visualize the latent image. However, circularly polarized light or linearly polarized light may be used instead. Good. For example, the verification tool 200 may be positioned in the vicinity of the stacked body 10, and circularly polarized light transmitted by the verification tool 200 may be irradiated to the stacked body 10.

  In the method described with reference to FIGS. 8 and 9, a circularly polarizing plate is used as the verification tool 200. However, the verification tool 200 may not be a circularly polarizing plate. For example, a combination of a polarizing prism and a quarter wave plate may be used. Moreover, the verification tool 200 does not need to be a circular polarizer, and may be an elliptical polarizer.

  As described above, when the structure described with reference to FIGS. 5 and 6 is adopted for the laminate 10, a linear polarizer can be used as the verification tool 200. That is, the verification tool 200 having a simple structure can be used.

  Also, in many situations, the light that surrounds us is natural light. However, in some situations, the light surrounding us is partially polarized. This partial polarization is in most cases the sum of natural light and linearly polarized light. Under such circumstances, when the laminate 10 adopting the structure described with reference to FIGS. 5 and 6 is observed without using the verification tool 200, the discrimination between the area AA1 and the area AA2 is possible. May be possible. On the other hand, the laminated body 10 adopting the structure described with reference to FIG. 8 and FIG. 9 can be observed without using the verification tool 200 under such a situation, even if the area AA1 and the area AA2 are observed. It is never possible to distinguish between That is, when the structure described with reference to FIGS. 8 and 9 is adopted for the laminated body 10, it is possible to discriminate between the area AA1 and the area AA2 when the laminated body 10 is observed without using the verification tool 200. It becomes difficult.

  Since the laminate 10 described above includes the scattering-type polarizing layer 11, when the front surface of the laminate 10 is directly observed without using the verification tool 200, the front surface of the laminate 10 does not depend on the observation angle. Looks bright. Therefore, a highly visible print pattern can be formed on the front surface of the laminate 10.

  FIG. 10 is a plan view schematically showing a modification of the laminate shown in FIG. FIG. 11 is a cross-sectional view taken along line XI-XI of the stacked body shown in FIG.

  The laminate 10 shown in FIGS. 10 and 11 is the same as the laminate 10 described with reference to FIGS. 1 and 2 except that the laminate 10 further includes a printed pattern 15 formed on the overcoat layer 14. It has a structure. Thus, the printing pattern 15 can be formed on the overcoat layer 14.

  The print pattern 15 may be interposed between the overcoat layer 14 and the birefringent layer 12. Alternatively, the print pattern 15 may be interposed between the birefringent layer 12 and the scattering-type polarizing layer 11.

  The laminate 10 described above is supported directly or indirectly on an article whose authenticity is to be confirmed. And when discriminating an article whose authenticity is unknown between a genuine product and a non-authentic product such as a counterfeit product, the laminate 10 can be used as described below.

  As described above, the stacked body 10 includes the scattering-type polarizing layer 11. Therefore, the article on which the laminate 10 is supported has a light scattering region. Therefore, when an article whose authenticity is unknown does not have a light scattering region, it can be determined that the article is non-authentic.

  In addition, the stacked body 10 has a latent image that is visualized by being observed through the verification tool 200. That is, at least a partial region of the article supporting the laminated body 10 has a latent image that is visualized by being observed through the verification tool 200. Therefore, if an article with unknown authenticity does not have such a latent image, it can be determined that the article is non-authentic.

  The latent image is formed on the scattering polarizing layer 11. Therefore, even if an article of unknown authenticity includes a light scattering area and an area having a latent image, it is determined that the article is non-authentic if the areas are not identical. can do.

  If an article of unknown authenticity holds the previous latent image, the shape and / or size of the visualized latent image may be compared with that of the authentic product. If the shape and / or size of the visualized latent image is different from that of the genuine product, it can be determined that the article is non-genuine.

  When the light absorption / reflection layer 13 is a reflection layer, the following method can also be used. As described above, when the light absorption / reflection layer 13 is a reflection layer, the positions of the bright part and the dark part are switched by changing the observation angle. Therefore, an article that does not have a latent image that causes such a change can be determined to be non-genuine.

  When a light absorption layer that absorbs only a part of visible light and reflects another part is used as the light absorption / reflection layer 13, as described above, when the latent image is not visualized, the regions AA1 and AA2 The color is a color generated by mixing the white color resulting from the light scattering of the scattering-type polarizing layer 11 and the color resulting from the reflection of the light absorption layer. When the latent image is visualized, one of the areas AA1 and AA2 has a weak color due to the reflection of the light absorption layer, and the other has a change to a color due to the reflection of the light absorption layer. Thus, if an article of unknown authenticity retains the previous latent image, the unvisualized latent image and / or the color of the visualized latent image may be compared to that of the authentic product. If the latent image that has not been visualized and / or the color of the visualized latent image is different from that of the genuine product, the article can be determined to be non-genuine.

  For the determination of an article, only one of the above-described methods may be used, or a plurality of methods may be used in combination. This technique may be combined with other determination techniques. Increasing the number of methods used to determine an article decreases the probability of erroneously determining a non-authentic product as a genuine product.

The laminate 10 can be used in various forms as described below.
FIG. 12 is a cross-sectional view schematically showing an example of an adhesive label including the laminate shown in FIGS. 1 and 2. The pressure-sensitive adhesive label 20 includes a laminate 10 and a pressure-sensitive adhesive layer 21 provided on the back surface thereof. For example, the adhesive label 20 is attached to an article whose authenticity is to be confirmed, or is attached to another article such as a tag to be attached to the article. If it carries out like this, the authenticity of goods can be confirmed by the method mentioned above.

  The adhesive label 20 may be brittle. Such an adhesive label 20 is obtained, for example, by forming a cutout and / or a perforation in the laminate 10. When the pressure-sensitive adhesive label 20 is brittle, the laminate 10 is easily broken when the pressure-sensitive adhesive label attached to an article whose authenticity is to be confirmed is peeled off. Therefore, it becomes difficult to replace the adhesive label 20.

  FIG. 13 is a cross-sectional view schematically showing an example of a recording medium including the laminate shown in FIGS. 1 and 2. The recording medium 30 includes a paper 31 and a laminated body 10 embedded therein. An opening is provided in a portion of the paper 31 that covers the front surface of the laminate 10. Thereby, the visibility of the visualized latent image is enhanced. If the latent image can be visualized, the paper 31 does not have to be provided with the previous opening.

  The recording medium 30 can be used as a sheet for an authentication medium such as a cash card, a credit card and a passport, or a securities medium such as a gift certificate and a stock certificate, for example. Alternatively, the recording medium 30 can be used as a part of an adhesive label described later. Alternatively, the recording medium 30 can be used as a tag or a part thereof to be attached to an article whose authenticity is to be confirmed. Alternatively, the recording medium 30 can be used as a package or a part thereof for containing an article whose authenticity is to be confirmed.

  The recording medium 30 is obtained, for example, by sandwiching the laminate 10 between fiber layers during papermaking. The recording medium 30 obtained by such a method is difficult to forge.

  14 is a cross-sectional view schematically showing an example of an adhesive label including the recording medium of FIG. The adhesive label 40 includes a recording medium 30 and an adhesive layer 41 provided on the back surface thereof. For example, the adhesive label 40 is attached to an article whose authenticity is to be confirmed, or is attached to another article such as a base material of a tag to be attached to the article.

  FIG. 15 is a cross-sectional view schematically showing an example of a labeled article including the laminate shown in FIGS. 1 and 2. This labeled article 100 includes an article 101 and a laminate 10.

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

  The laminate 10 is supported by the article 101. For example, the laminate 10 is attached to the article 101. In this case, for example, the laminate 10 can be supported by the article 101 by attaching the adhesive label 20 shown in FIG. 10 or the adhesive label 40 shown in FIG. 12 to the article 101.

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

  The laminate 10 may be supported by the article 101 by attaching a tag including the laminate 10 to the article 101. If it is difficult for a general user to replace the tag on the article 101, the laminate 10 is sufficiently useful for confirming the authenticity of the article 101.

Examples of the present invention will be described below.
A polyethylene terephthalate film in which crosslinked polystyrene fine particles having a diameter of 2 μm were dispersed as transparent particles was prepared. The film was then uniaxially stretched. In this way, a scattering type polarizing layer having a thickness of 50 μm was obtained. The transparent particles contained in this scattering type polarizing layer were optically isotropic. In this scattering type polarizing layer, the ordinary ray refractive index of the transparent matrix made of polyethylene terephthalate was equal to the refractive index of the transparent particles.

Next, Daiichi Ink Manufacturing Co., Ltd. photo-alignment agent IA-01 was apply | coated to the thickness of 0.1 micrometer on the front surface of the scattering type polarizing layer by the gravure coating method. Next, the entire surface of this coating film was exposed with an illuminance of 1 J / cm ² using linearly polarized light having a wavelength of 365 nm. The linearly polarized light was irradiated so that its polarization plane forms an angle of 45 ° with respect to the transmission axis of the scattering-type polarizing layer. Thereafter, the previous coating film was pattern-exposed with an illuminance of ² J / cm ² using linearly polarized light having a wavelength of 365 nm. A photomask was used for this pattern exposure, and linearly polarized light was irradiated so that the plane of polarization was parallel to the transmission axis of the scattering-type polarizing layer. As described above, an alignment film including two portions having different alignment directions was obtained.

Next, UV curable liquid crystal UCL-008 (manufactured by Dainippon Ink Co., Ltd.) was printed on the alignment film by a gravure coating method. After heating at 65 ° C. for 60 seconds, this coating film was exposed to ultraviolet light at an illuminance of 0.5 J / cm ^{2 in} a nitrogen atmosphere to cure the coating film. As a result, a birefringent layer including first and second portions whose slow axis directions differ by 45 ° was obtained. The thickness of the birefringent layer was 1.5 μm, and the difference between the ordinary light refractive index and the extraordinary light refractive index in each of the first and second portions was 0.18. That is, each of the first and second portions is a half-wave plate that transmits a pair of linearly polarized light having a wavelength λ of 540 nm and gives a phase difference of λ / 2 to the linearly polarized light.

  Thereafter, an adhesive layer having a thickness of 30 μm containing a black dye and an acrylic adhesive was formed on the back surface of the scattering-type polarizing layer. Further, a color shift ink containing a pearl pigment was printed on the birefringent layer. An adhesive label was obtained as described above.

  Next, this adhesive label was affixed on the base material. And while irradiating natural light to an adhesive label, the front surface of the adhesive label was observed first, without using an absorption type polarizing film. As a result, the first part and the second part of the birefringent layer could not be distinguished. Next, the front surface of the pressure-sensitive adhesive label was observed through the absorption polarizing film while irradiating the pressure-sensitive adhesive label with natural light. As a result, the region corresponding to the first portion and the region corresponding to the second portion of the birefringent layer could be viewed as a dark portion and a bright portion, respectively. That is, the latent image could be visualized.

The top view which shows roughly the laminated body for identification which concerns on 1 aspect of this invention. Sectional drawing along the II-II line of the laminated body shown in FIG. The perspective view which shows schematically the scattering type polarizing layer which the laminated body of FIG. 1 contains. The perspective view which shows schematically the scattering type polarizing layer which the laminated body of FIG. 1 contains. The figure which shows schematically an example of the method of visualizing the latent image which the laminated body shown in FIG. 1 hold | maintains. The figure which shows schematically an example of the method of visualizing the latent image which the laminated body shown in FIG. 1 hold | maintains. The figure which shows schematically the other example of the method of visualizing the latent image which the laminated body shown in FIG. 1 hold | maintains. The figure which shows schematically the further another example of the method of visualizing the latent image which the laminated body shown in FIG. 1 hold | maintains. The figure which shows schematically the further another example of the method of visualizing the latent image which the laminated body shown in FIG. 1 hold | maintains. The top view which shows roughly the modification of the laminated body shown in FIG. Sectional drawing along the XI-XI line of the laminated body shown in FIG. Sectional drawing which shows schematically an example of the adhesive label containing the laminated body shown in FIG.1 and FIG.2. FIG. 3 is a cross-sectional view schematically showing an example of a recording medium including the laminate shown in FIGS. 1 and 2. Sectional drawing which shows schematically an example of the adhesive label containing the recording medium of FIG. Sectional drawing which shows roughly an example of the labeled article containing the laminated body shown in FIG.1 and FIG.2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Laminate for identification, 11 ... Scattering-type polarizing layer, 12 ... Birefringent layer, 12a ... 1st part, 12b ... 2nd part, 13 ... Light absorption / reflection layer, 14 ... Overcoat layer, 15 ... Printing Pattern: 20 ... Adhesive label, 21 ... Adhesive layer, 30 ... Recording medium, 31 ... Paper, 40 ... Adhesive label, 41 ... Adhesive layer, 100 ... Article with label, 101 ... Article, 200 ... Verification tool, 200 '... Transparent , 201 ... absorptive polarizing layer, 202 ... quarter wavelength plate, 300 ... light source, 400 ... observer, AA1 ... region, AA2 ... region, A _T ... transmission axis, A _T '... transmission axis, L _LC ... Left circularly polarized light, L _LP ... Linearly polarized light, L _N ... Natural light, L _P ... P wave, L _PP ... Linearly polarized light, L _PS ... Linearly polarized light, L _RC ... Right circularly polarized light, L _S ... S wave.

Claims (10)

  A scattering-type polarizing layer, a first portion facing a part of the front surface of the polarizing layer, and a second portion facing the other part of the front surface of the polarizing layer and having a slow axis direction different from that of the first portion And a birefringent layer containing the first and second portions, each of which is a half-wave plate. The laminate according to claim 1, further comprising a light absorption layer facing the back surface of the polarizing layer. The laminate according to claim 1, further comprising a reflective layer facing the back surface of the polarizing layer. An adhesive label comprising: the laminate according to any one of claims 1 to 3 ; and an adhesive layer supported on a back surface of the laminate. The adhesive label according to claim 4 , wherein the laminate is provided with a notch and / or a perforation. The laminate according to any one of claims 1 to 3 , wherein the laminate is embedded in the paper, an adhesive layer supported on one main surface of the paper, and a back surface facing the adhesive layer. An adhesive label characterized by comprising: A recording medium comprising paper and the laminate according to any one of claims 1 to 3 embedded in the paper. A labeled article comprising: an article whose authenticity is to be confirmed; and a laminate according to any one of claims 1 to 3 supported by the article whose authenticity is to be confirmed. . A method for discriminating an article whose authenticity is unknown between a genuine product and a non-genuine product,
The genuine product is a labeled article according to claim 8 ,
An article of unknown authenticity is non-authentic if the article of unknown authenticity does not include a light-scattering region that holds a latent image that is visualized by viewing through a polarizer. The method characterized by including judging. A method for discriminating an article whose authenticity is unknown between a genuine product and a non-genuine product,
The authentic product is a composite article comprising an article whose authenticity is to be confirmed and the laminate according to claim 3 supported by the article whose authenticity is to be confirmed.
When the article whose authenticity is unknown is visualized by observing through the polarizing layer and does not hold a latent image in which the positions of the bright part and the dark part are switched by changing the observation angle in the visualized state. And determining that the article with unknown authenticity is a non-authentic item.

Images